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Kamal O, Haghshomar M, Yang J, Lalani T, Bijan B, Yaghmai V, Mendiratta-Lala M, Hong CW, Fowler KJ, Sirlin CB, Kambadakone A, Lee J, Borhani AA, Fung A. CT/MRI technical pitfalls for diagnosis and treatment response assessment using LI-RADS and how to optimize. Abdom Radiol (NY) 2025; 50:2022-2037. [PMID: 39433603 DOI: 10.1007/s00261-024-04632-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2024] [Revised: 10/02/2024] [Accepted: 10/04/2024] [Indexed: 10/23/2024]
Abstract
Hepatocellular carcinoma (HCC), the most common primary liver cancer, is a significant global health burden. Accurate imaging is crucial for diagnosis and treatment response assessment, often eliminating the need for biopsy. The Liver Imaging Reporting and Data System (LI-RADS) standardizes the interpretation and reporting of liver imaging for diagnosis and treatment response assessment, categorizing observations using defined categories that are based on the probability of malignancy or post-treatment tumor viability. Optimized imaging protocols are essential for accurate visualization and characterization of liver findings by LI-RADS. Common technical pitfalls, such as suboptimal postcontrast phase timing, and MRI-specific challenges like subtraction misregistration artifacts, can significantly reduce image quality and diagnostic accuracy. The use of hepatobiliary contrast agents introduces additional challenges including arterial phase degradation and suboptimal uptake in advanced cirrhosis. This review provides radiologists with comprehensive insights into the technical aspects of liver imaging for LI-RADS. We discuss common pitfalls encountered in routine clinical practice and offer practical solutions to optimize imaging techniques. We also highlight technical advances in liver imaging, including multi-arterial MR acquisition and compressed sensing. By understanding and addressing these technical aspects, radiologists can improve accuracy and confidence in the diagnosis and treatment response assessment for hepatocellular carcinoma.
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Affiliation(s)
- Omar Kamal
- Oregon Health and Science University, Portland, OR, USA.
| | - Maryam Haghshomar
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Jessica Yang
- Royal Prince Alfred and Concord Hospitals, Sydney, NSW, Australia
| | - Tasneem Lalani
- University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Bijan Bijan
- University of California Davis Medical Center, Sacramento, CA, USA
| | | | | | | | | | | | | | - James Lee
- University of Kentucky, Lexington, KY, USA
| | - Amir A Borhani
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Alice Fung
- Oregon Health and Science University, Portland, OR, USA
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Tan XZ, Chen X, Liu P. Potential Influence of Inconsistent Arterial Phase Imaging on Macrotrabecular-massive Hepatocellular Carcinoma Prediction. Radiology 2024; 310:e232349. [PMID: 38226884 DOI: 10.1148/radiol.232349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Affiliation(s)
- Xian-Zheng Tan
- Department of Radiology, Hunan Provincial People's Hospital, the First Affiliated Hospital of Hunan Normal University, Changsha 410005, China
| | - Xiang Chen
- Department of Radiology, Hunan Provincial People's Hospital, the First Affiliated Hospital of Hunan Normal University, Changsha 410005, China
| | - Peng Liu
- Department of Radiology, Hunan Provincial People's Hospital, the First Affiliated Hospital of Hunan Normal University, Changsha 410005, China
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Tan XZ, Liu P, Xiang H. The Influence of Single Arterial Phase Imaging on Prediction of Microvascular Invasion of Hepatocellular Carcinoma. Radiology 2023; 309:e231141. [PMID: 37962505 DOI: 10.1148/radiol.231141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Affiliation(s)
- Xian-Zheng Tan
- Department of Radiology, Hunan Provincial People's Hospital, the First Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Peng Liu
- Department of Radiology, Hunan Provincial People's Hospital, the First Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Hua Xiang
- Department of Interventional Radiology, Hunan Provincial People's Hospital, the First Affiliated Hospital of Hunan Normal University, No. 61 Jiefang West Road, Changsha 410005, Hunan, China
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Ye H. Effect of Patient Factors on Portal Vein and Hepatic Contrast Enhancement at Computed Tomography Scan With Protocol Combining Fixed Injection Duration and Patients’ Body Weight Tailored Dose of Contrast Material. Cureus 2022; 14:e29283. [PMID: 36147863 PMCID: PMC9482779 DOI: 10.7759/cureus.29283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2022] [Indexed: 12/02/2022] Open
Abstract
Introduction Fixed injection duration with patients’ body weight tailored dose of contrast material was recommended as the practical scan protocol in multiphasic contrast-enhanced abdominal computed tomography (CT). This study evaluated the effect of the demographic variables on portal vein and hepatic contrast enhancement in hepatic arterial phase (HAP), aiming to reduce the patient-to-patient variability and optimize the HAP images. Methods This retrospective analysis included 87 patients who underwent abdominal enhancement multiphase CT from April to June 2022. All the patients were examined using protocol combining fixed injection duration and patients’ body weight tailored dose of contrast material. Univariate and multivariate linear regression analyses were performed between all patient characteristics and the contrast-enhanced CT number of portal vein and hepatic parenchyma during HAP. Results Univariate linear regression analysis demonstrated statistically significant correlations between the CT number of hepatic parenchyma, and the body mass index (BMI), body surface area (BSA), and total body weight (TBW) (all P < 0.001) during HAP. However, multivariate linear regression analysis showed that the BMI or BMI and age were of independent predictive values (P < 0.001). Also, only the age was independently and negatively related to the CT number of portal vein enhancement during HAP (r = 0.240, P < 0.05) according to univariate linear regression analysis. Conclusions Univariate linear regression analysis revealed a significant inverse correlation between portal vein CT value and age. By multivariate linear regression analysis, only the BMI and age were significantly correlated with liver parenchymal enhancement, while gender, TBW, BSA, and HT were not.
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Kuba T, Tokushige A, Murayama S, Ueda S. Proposal of a novel protocol using estimated cardiac index fractional dose to improve aortic contrast enhancement for early-phase dynamic CT. Medicine (Baltimore) 2022; 101:e29410. [PMID: 35758375 PMCID: PMC9276326 DOI: 10.1097/md.0000000000029410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 04/18/2022] [Indexed: 11/25/2022] Open
Abstract
Maximum aortic computed tomography value (CTV) is difficult to control because of variations in cardiac function and patient physique. Therefore, to improve early-phase aortic enhancement on dynamic computed tomography (CT), we developed an estimated cardiac index fractional dose (eciFD). The eciFD protocol is a novel and original protocol for administering fractional dose (FD), representing the amount of iodine per unit body weight per injection duration, based on cardiac index (cardiac output divided by body surface area) as estimated by age in early-phase dynamic CT. At the time of administration, by selecting FD based on the patient's age and selecting a parameter that can achieve this FD, an aortic CTV ≥300 HU (ACTV≥300) can be obtained. This study aimed to investigate aortic enhancement on CT angiography using the eciFD protocol.This retrospective study investigated 291 consecutive patients who underwent dynamic CT from neck to abdomen after recommendation of the eciFD protocol at our institution. We compared early-phase aortic CTV distributions by scan delay between an eciFD group (eciFD applied, n = 135) and a non-eciFD group (eciFD not applied, n = 80). The effect of eciFD on early-phase ACTV≥300 was evaluated using logistic regression analysis adjusted for several potentially meaningful clinical confounders related to aortic CTV, namely male sex, heart rate ≤80 beats/min, estimated glomerular filtration rate ≤40 mL/min, use of eciFD, bolus tracking (BT), history of myocardial infarction, and order from the emergency center.The eciFD protocol was a significant factor for early-phase ACTV≥300 after adjusting for several confounders (odds ratio 3.03; 95% confidence intervals 1.59-5.77; P = .001). No interaction was seen between BT and eciFD protocol (p for interaction = 0.76). In terms of CTV distribution, with both a fixed scan delay time and BT, the eciFD group showed a high aortic CTV. The combination of eciFD protocol with BT provided a particularly high percentage of patients with ACTV≥300 (86.4%).The eciFD protocol was useful for improving aortic contrast enhancement. These findings need to be validated in a randomized controlled study.
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Affiliation(s)
- Tadashi Kuba
- Department of Clinical Research and Quality Management, Graduate School of Medical Science, University of the Ryukyus, Okinawa, Japan
| | - Akihiro Tokushige
- Department of Clinical Pharmacology and Therapeutics, Graduate School of Medical Science, University of the Ryukyus, Okinawa, Japan
| | - Sadayuki Murayama
- Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Okinawa, Japan
| | - Shinichiro Ueda
- Department of Clinical Pharmacology and Therapeutics, Graduate School of Medical Science, University of the Ryukyus, Okinawa, Japan
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Watanabe S, Sakaguchi K, Murata D, Ishii K. Deep learning-based Hounsfield unit value measurement method for bolus tracking images in cerebral computed tomography angiography. Comput Biol Med 2021; 137:104824. [PMID: 34488029 DOI: 10.1016/j.compbiomed.2021.104824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 08/28/2021] [Accepted: 08/28/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Patient movement during bolus tracking (BT) impairs the accuracy of Hounsfield unit (HU) measurements. This study assesses the accuracy of measuring HU values in the internal carotid artery (ICA) using an original deep learning (DL)-based method as compared with using the conventional region of interest (ROI) setting method. METHOD A total of 722 BT images of 127 patients who underwent cerebral computed tomography angiography were selected retrospectively and divided into groups for training data, validation data, and test data. To segment the ICA using our proposed method, DL was performed using a convolutional neural network. The HU values in the ICA were obtained using our DL-based method and the ROI setting method. The ROI setting was performed with and without correcting for patient body movement (corrected ROI and settled ROI). We compared the proposed DL-based method with settled ROI to evaluate HU value differences from the corrected ROI, based on whether or not patients experienced involuntary movement during BT image acquisition. RESULTS Differences in HU values from the corrected ROI in the settled ROI and the proposed method were 23.8 ± 12.7 HU and 9.0 ± 6.4 HU in patients with body movement and 1.1 ± 1.6 HU and 3.9 ± 4.7 HU in patients without body movement, respectively. There were significant differences in both comparisons (P < 0.01). CONCLUSION DL-based method can improve the accuracy of HU value measurements for ICA in BT images with patient involuntary movement.
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Affiliation(s)
- Shota Watanabe
- Division of Positron Emission Tomography, Institute of Advanced Clinical Medicine, Kindai University Hospital, 377-2 Ohno-Higashi, Osakasayama, Osaka, 589-8511, Japan; Radiology Center, Kindai University Hospital, 377-2 Ohno-Higashi, Osakasayama, Osaka, 589-8511, Japan.
| | - Kenta Sakaguchi
- Radiology Center, Kindai University Hospital, 377-2 Ohno-Higashi, Osakasayama, Osaka, 589-8511, Japan.
| | - Daisuke Murata
- Radiology Center, Kindai University Hospital, 377-2 Ohno-Higashi, Osakasayama, Osaka, 589-8511, Japan.
| | - Kazunari Ishii
- Department of Radiology, Kindai University Faculty of Medicine, 377-2 Ohno-Higashi, Osakasayama, Osaka, 589-8511, Japan.
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Chiba A, Harada K, Ohashi Y, Numasawa K, Imai T, Hayasaka S. Evaluation of computed tomography arterial portography scan timing using different bolus tracking methods. Radiol Phys Technol 2020; 13:92-97. [DOI: 10.1007/s12194-020-00556-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 01/30/2020] [Accepted: 02/01/2020] [Indexed: 01/21/2023]
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Radiation dose optimization for the bolus tracking technique in abdominal computed tomography: usefulness of real-time iterative reconstruction for monitoring scan. Radiol Phys Technol 2016; 10:155-160. [DOI: 10.1007/s12194-016-0378-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 09/14/2016] [Accepted: 09/14/2016] [Indexed: 10/20/2022]
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Hoshino T, Ichikawa K, Hara T, Terakawa S, Hosomi K, Nishimura K, Takayama K. Optimization of scan timing for aortic computed tomographic angiography using the test bolus injection technique. Acta Radiol 2016; 57:829-36. [PMID: 26468389 DOI: 10.1177/0284185115608659] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 08/24/2015] [Indexed: 11/17/2022]
Abstract
BACKGROUND With fast computed tomography (CT), it is possible for the scanning to outpace the contrast medium bolus during aortic CT angiography (CTA). PURPOSE To evaluate the effectiveness of a new method for reducing the risk of outpacing in which the scan start timing (ST) and speed can be estimated from the peak enhancement time measured at the femoral artery using a single test-bolus injection (femoral artery test injection method [FTI method]). MATERIAL AND METHODS In 30 cases of aortic CTA, we measured the time to peak enhancement at the femoral artery (TPF) and the ascending aorta (TPA) with test-bolus injection performed twice in each examination. From the resultant linear relationship between TPF and transit time (TT = TPF - TPA), we developed a method for determining the ST and TT from TPF. One hundred patients were assigned to two groups: FTI and bolus tracking (BT), each with 50 patients. CT values were measured in main vessels (ascending aorta, descending aorta, femoral artery). The CT values of the vessels and the rate of cases with more than 300 HU (good cases) were compared between the two groups. RESULTS The enhancement in the FTI method was significantly higher than that of the BT method (average CT values: FTI, 388.3 ± 52.4; BT, 281.2 ± 59.1; P < 0.001). The rates of good cases for FTI and BT were 86.0% and 46.0%, respectively. CONCLUSION The FTI method was very effective in reducing the risk of outpacing of the contrast medium transit in aortic CTA without the need for an additional contrast medium dose.
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Affiliation(s)
- Takashi Hoshino
- Department of Radiology, Ishinkai Yao General Hospital, Osaka, Japan
- Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Katsuhiro Ichikawa
- Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Takanori Hara
- Department of Medical Technology, Nakatsugawa Municipal General Hospital, Nakatsugawa, Gifu, Japan
| | - Shoichi Terakawa
- Department of Radiology, Osaka City General Hospital, Osaka, Japan
| | - Kazuhiro Hosomi
- Department of Radiology, Ishinkai Yao General Hospital, Osaka, Japan
| | - Kenji Nishimura
- Department of Radiology, Ishinkai Yao General Hospital, Osaka, Japan
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Sänger PW, Freesmeyer M. Early Dynamic 68Ga-DOTA-D-Phe1-Tyr3-Octreotide PET/CT in Patients With Hepatic Metastases of Neuroendocrine Tumors. Clin Nucl Med 2016; 41:447-53. [PMID: 26859210 DOI: 10.1097/rlu.0000000000001154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND AIMS Whole-body PET with Ga-DOTA-D-Phe-Tyr-octreotide (Ga-DOTATOC) and contrast-enhanced CT (ceCT) are considered a standard for the staging of neuroendocrine tumors (NETs). This study sought to verify whether early dynamic (ed) Ga-DOTATOC PET/CT can reliably detect liver metastases of NETs (hypervascular, nonhypervascular; positive or negative for somatostatin receptors) and to verify if the receptor positivity has a significant impact on the detection of tumor hypervascularization. METHODS Twenty-seven patients with NET were studied by ceCT and standard whole-body PET according to established Ga-DOTATOC protocols. In addition, edPET data were obtained by continuous scanning during the first 300 seconds after bolus injections of the radiotracer. Early dynamic PET required an additional low-dose, native CT image of the liver for the purpose of attenuation correction. Time-activity and time-contrast curves were obtained, the latter being calculated by the difference between tumor and reference regions. RESULTS Early dynamic PET/CT proved comparable with ceCT in readily identifying hypervascular lesions, irrespective of the receptor status, with activities rising within 16 to 40 seconds. Early dynamic PET/CT also readily identified nonhypervascular, receptor-positive lesions. Positive image contrasts were obtained for hypervascular, receptor-positive lesions, whereas early negative contrasts were obtained for nonhypervascular, receptor-negative lesions. CONCLUSIONS The high image contrast of hypervascular NET metastases in early arterial phases suggests that edPET/CT can become a useful alternative in patients with contraindications to ceCT. The high density of somatostatin receptors did not seem to interfere with the detection of the lesion's hypervascularization.
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Evaluation of A New Bolus Tracking–Based Algorithm for Predicting A Patient-Specific Time of Arterial Peak Enhancement in Computed Tomography Angiography. Invest Radiol 2015; 50:531-8. [DOI: 10.1097/rli.0000000000000160] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Freesmeyer M, Winkens T, Schierz JH. Contrast between hypervascularized liver lesions and hepatic parenchyma: early dynamic PET versus contrast-enhanced CT. Ann Nucl Med 2014; 28:664-8. [PMID: 24903245 DOI: 10.1007/s12149-014-0862-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 05/18/2014] [Indexed: 12/12/2022]
Abstract
OBJECTIVES To detect hypervascularized liver lesions, early dynamic (ED) (18)F-FDG PET may be an alternative when contrast-enhanced (CE) imaging is infeasible. This retrospective pilot analysis compared contrast between such lesions and liver parenchyma, an important objective image quality variable, in ED PET versus CE CT. MATERIALS AND METHODS Twenty-eight hypervascularized liver lesions detected by CE CT [21 (75%) hepatocellular carcinomas; mean (range) diameter 4.9 ± 3.5 (1-14) cm] in 20 patients were scanned with ED PET. Using regions of interest, maximum and mean lesional and parenchymal signals at baseline, arterial and venous phases were calculated for ED PET and CE CT. RESULTS Lesional/parenchymal signal ratio was significantly higher (P < 0.005) with ED PET versus CE CT at the arterial phase and similar between the methods at the venous phase. CONCLUSION In liver imaging, ED PET generates greater lesional-parenchymal contrast during the arterial phase than does CE CT; these observations should be formally, prospectively evaluated.
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Affiliation(s)
- Martin Freesmeyer
- Clinic of Nuclear Medicine, Jena University Hospital, Bachstrasse 18, 07740, Jena, Germany,
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Patient body weight-tailored contrast medium injection protocol for the craniocervical vessels: a prospective computed tomography study. PLoS One 2014; 9:e88867. [PMID: 24558438 PMCID: PMC3928316 DOI: 10.1371/journal.pone.0088867] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 01/13/2014] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES To evaluate body weight-tailored contrast medium (CM) administration for computed tomography angiography (CTA) of the craniocervical vessels. METHODS Institutional review board approval was obtained, and all patients gave written informed consent. Sixty patients were consecutively assigned to one of three dose groups (20 patients per group) with CM doses of Visipaque 270® (iodixanol 270 mg/ml) tailored to body weight at doses of 1.5, 1.0, or 0.5 ml/kg. Region-of-interest (ROI) analysis of maximum enhancement (ME) was conducted, and signal-to-noise-ratios (SNR) and contrast-to-noise-ratios (CNR) were calculated. Retrospective comparison was performed with three matched control groups examined with a standard CM dose (80 ml of Visipaque 270®). Image quality was rated by two neuroradiologists blinded to the CM dose used. Interrater reliability was calculated using kappa statistics. RESULTS Body weight/BMI and ME were inversely correlated in the three control groups receiving the standard dose (r = -0.544/-0.597/-0.542/r = -0.358/r = -0.424/r = -0.280). Compared to standard dose, 1.5 ml/kg produced higher ME, SNR, and CNR in the anterior circulation (p≤0.038), 1.0 ml/kg had higher ME in cervical and medium-sized cerebral arteries (p≤0.034), and 0.5 ml/kg had lower ME, SNR and CNR for medium-sized cerebral arteries (p≤0.049). ME, SNR, and CNR were the same for 1.5 ml/kg and 1.0 ml/kg (p≥0.24), and both had higher values compared to 0.5 ml/kg (p≤0.043/p≤0.028). In patients with BMI>25, 1.5 ml/kg and 1.0 ml/kg produced higher ME than standard dose (p<0.001/p = 0.008), but ME in patients with BMI>25 did not differ between group 1 and group 2 (p = 0.673). In patients with BMI≤25, 1.5 ml/kg and 1.0 ml/kg produced ME comparable to standard dose (p = 0.132/p = 0.403). Regardless of patient weight, 0.5 ml/kg yielded lower ME than standard dose (p = 0.019/0.002). CONCLUSIONS Craniocervical CTA with a body weight-tailored CM dose of 1.0 ml/kg (270 mg iodine/ml) reduces iodine load in patients weighing <80 kg while producing ME similar to standard dose and improves ME in patients with BMI>25.
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Nakaura T, Nagayoshi Y, Awai K, Utsunomiya D, Kawano H, Ogawa H, Yamashita Y. Myocardial bridging is associated with coronary atherosclerosis in the segment proximal to the site of bridging. J Cardiol 2014; 63:134-9. [DOI: 10.1016/j.jjcc.2013.07.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 06/15/2013] [Accepted: 07/13/2013] [Indexed: 11/26/2022]
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Patient-Tailored Scan Delay for Multiphase Liver CT: Improved Scan Quality and Lesion Conspicuity With a Novel Timing Bolus Method. AJR Am J Roentgenol 2014; 202:318-23. [DOI: 10.2214/ajr.12.9676] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Huang RY, Chai BB, Lee TC. Effect of region-of-interest placement in bolus tracking cerebral computed tomography angiography. Neuroradiology 2013; 55:1183-8. [PMID: 23842989 DOI: 10.1007/s00234-013-1228-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 06/26/2013] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Premature or delayed triggering of semiautomatic contrast tracking during intracranial computed tomographic angiography can occur due to artifact from dense contrast in the superior vena cava or brachiocephalic veins near the anterior aortic arch. We determine if placement of bolus tracking region-of-interest in the posterior thoracic aorta can prevent suboptimal intracranial arterial opacification. METHODS Intracranial computed tomography angiographies from 80 patients performed on the same scanner were retrospectively evaluated. Thirty-seven consecutive patients with bolus tracking region-of-interest (ROI) placed in the anterior thoracic aorta (group A) and 43 consecutive patients with ROI placed in the posterior thoracic arch (group B) were identified. Two neuroradiologists scored the quality of intracranial computed tomography angiography on a four-point scale. Quantitative measurement of intracranial arterial opacification was also performed. The proportions of patients with poorest quality score as well as the proportions of the patients with the worst degree of intracranial arterial opacification (<10th percentile) were compared between groups A and B using two-sample proportion test. RESULTS Qualitative evaluation of the intracranial computed tomography angiography showed 4 (11%) patients in group A with poor quality (score of 1), while all patients in group B scored 2 or higher (p = 0.028). Seven (19%) patients in group A had the lowest quantitative score (mean arterial opacification < 10th percentile) while 1 (2.5%) patient in group B had the lowest score (p = 0.018). CONCLUSION Bolus tracking in the posterior thoracic aorta reduces the chance of suboptimal intracranial computed tomography angiography.
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Affiliation(s)
- Raymond Y Huang
- Division of Neuroradiology, Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA, 02115, USA,
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Sun K, Liu GR, Li YC, Han RJ, Cui LF, Ma LJ, Li LG, Li CY. Intravenous Contrast Material Administration at High-pitch Dual-source CT Coronary Angiography: Bolus-tracking Technique with Shortened Time of Respiratory Instruction Versus Test Bolus Technique. ACTA ACUST UNITED AC 2012; 27:225-31. [DOI: 10.1016/s1001-9294(13)60006-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ohira G, Shuto K, Kono T, Tohma T, Gunji H, Narushima K, Imanishi S, Fujishiro T, Tochigi T, Hanaoka T, Miyauchi H, Hanari N, Matsubara H, Yanagawa N. Utility of arterial phase of dynamic CT for detection of intestinal ischemia associated with strangulation ileus. World J Radiol 2012; 4:450-4. [PMID: 23251723 PMCID: PMC3524511 DOI: 10.4329/wjr.v4.i11.450] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 09/23/2012] [Accepted: 09/30/2012] [Indexed: 02/06/2023] Open
Abstract
AIM: To clarify the usefulness of arterial phase scans in contrast computed tomography (CT) imaging of strangulation ileus in order to make an early diagnosis.
METHODS: A comparative examination was carried out with respect to the CT value of the intestinal tract wall in each scanning phase, the CT value of the content in the intestinal tract, and the CT value of ascites fluid in the portal vein phase for a group in which ischemia was observed (Group I) and a group in which ischemia was not observed (Group N) based on the pathological findings or intra-surgical findings. Moreover, a comparative examination was carried out in Group I subjects for each scanning phase with respect to average differences in the CT values of the intestinal tract wall where ischemia was suspected and in the intestinal tract wall in non-ischemic areas.
RESULTS: There were 15 subjects in Group I and 30 subjects in Group N. The CT value of the intestinal tract wall was 41.8 ± 11.2 Hounsfield Unit (HU) in Group I and 69.6 ± 18.4 HU in Group N in the arterial phase, with the CT value of the ischemic bowel wall being significantly lower in Group I. In the portal vein phase, the CT value of the ischemic bowel wall was 60.6 ± 14.6 HU in Group I and 80.7 ± 17.7 HU in Group N, with the CT value of the ischemic bowel wall being significantly lower in Group I; however, no significant differences were observed in the equilibrium phase. The CT value of the solution in the intestine was 18.6 ± 9.5 HU in Group I and 10.4 ± 5.1 HU in Group N, being significantly higher in Group I. No significant differences were observed in the CT value of the accumulation of ascites fluid. The average difference in the CT values between the ischemic bowel wall and the non-ischemic bowel wall for each subject in Group I was 33.7 ± 20.1 HU in the arterial phase, being significantly larger compared to the other two phases.
CONCLUSION: This is a retrospective study using a small number of subjects; however, it suggests that there is a possibility that CT scanning in the arterial phase is useful for the early diagnosis of strangulation ileus.
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Robinson TJ, Robinson JD, Hippe DS, Mitsumori LM. Challenges to protocol optimization due to unexpected variation of CT contrast dose amount and flow. J Digit Imaging 2012; 26:402-5. [PMID: 23143417 DOI: 10.1007/s10278-012-9544-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
High-quality computed tomography (CT) exams are critical to maximizing radiologist's interpretive ability. Exam quality in part depends on proper contrast administration. We examined injector data from consecutive abdominal and pelvic CT exams to analyze variation in contrast administration. Discrepancies between intended IV contrast dose and flow rate with the actual administered contrast dose and measured flow rate were common. In particular, delivered contrast dose discrepancies of at least 10% occurred in 13% of exams while discrepancies in flow rate of at least 10% occurred in 42% of exams. Injector logs are useful for assessing and tracking this type of variability which may confound contrast administration optimization and standardization efforts.
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Affiliation(s)
- Tracy J Robinson
- Department of Radiology, University of Washington, 1959 NE Pacific St., BB308, Box 357115, 98195, Seattle, WA, USA.
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Takumi K, Fukukura Y, Shindo T, Kumagae Y, Tateyama A, Kamiyama T, Nakajo M. Feasibility of a fixed scan delay technique using a previous bolus tracking technique data for dynamic hepatic CT. Eur J Radiol 2012; 81:2996-3001. [PMID: 22749800 DOI: 10.1016/j.ejrad.2012.02.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 02/02/2012] [Accepted: 02/03/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVE To compare the quality of contrast enhancement and hepatic CT images acquired using bolus tracking technique at two different time points and those acquired with fixed scan delay technique using a previous bolus tracking data. MATERIALS AND METHODS Fifty patients who underwent 3 different hepatic CT exams (25-s fixed injection of 600 mg iodine (I)/kg or 100mL of 370 mg I/mL nonionic contrast medium) were enrolled. The first and second exams were performed with a bolus tracking technique. The third exam was performed with a fixed scan delay technique using the first exam data. Differences in attenuation values in the abdominal organs were examined and evaluated visually on hepatic arterial phase images. RESULTS There was no significant difference in the mean 50-HU threshold times between the first and second bolus tracking exams with intra-patient differences between them (1.3±0.9 s). No significant intra-patient differences were noted in organ attenuation and visual evaluation on hepatic arterial phase images between the 3 exams. CONCLUSION The fixed scan delay technique using a previous bolus tracking data is feasible for hepatic CT exams to follow up hepatocellular carcinoma.
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Affiliation(s)
- Koji Takumi
- Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City 890-8544, Japan.
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21
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Eisa F, Brauweiler R, Peetz A, Hupfer M, Nowak T, Kalender WA. Optical tracking of contrast medium bolus to optimize bolus shape and timing in dynamic computed tomography. Phys Med Biol 2012; 57:N173-82. [DOI: 10.1088/0031-9155/57/10/n173] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Nakaura T, Awai K, Yanaga Y, Namimoto T, Utsunomiya D, Hirai T, Sugiyama S, Ogawa H, Aoyama M, Yamashita Y. Low-dose contrast protocol using the test bolus technique for 64-detector computed tomography coronary angiography. Jpn J Radiol 2011; 29:457-65. [PMID: 21882087 DOI: 10.1007/s11604-011-0579-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 02/23/2011] [Indexed: 11/26/2022]
Abstract
PURPOSE We evaluated low-contrast injection protocols for coronary computed tomography angiography (CTA) using a 64-detector scanner and the test bolus technique. MATERIALS AND METHODS We randomly assigned 60 patients undergoing coronary CTA to one of two contrast material (CM) injection protocols. For the low-contrast dose protocol (P(low)), the patients received injections of iohexol-350 [0.7 ml/kg body weight (BW)] during 9 s, and the test-bolus technique was used. Under the conventional protocol (P(conv)), they received iohexol-350 (1.0 ml/kg BW) during 15 s, and bolus tracking was used. We compared the protocols for attenuation values in the ascending aorta and coronary arteries and for the amount of CM required. RESULTS There was no significant difference in the mean CT attenuation of the ascending aorta and coronary arteries between the P(low) and P(conv) groups. The amount of CM was significantly less with P(low) than with P(conv) [49.7 ± 6.4 ml (main bolus: 39.7 ± 6.4 ml) vs. 57.0 ± 10.1 ml, P < 0.01]. CONCLUSION With 64-detector CTA of the heart, the low-dose and short-injection-duration protocol with the test-injection technique provides vessel attenuation comparable to that obtained with the standard-dose protocol with the bolus-tracking technique.
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Affiliation(s)
- Takeshi Nakaura
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
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Marin D, Nelson RC, Guerrisi A, Barnhart H, Schindera ST, Passariello R, Catalano C. 64-section multidetector CT of the upper abdomen: optimization of a saline chaser injection protocol for improved vascular and parenchymal contrast enhancement. Eur Radiol 2011; 21:1938-47. [DOI: 10.1007/s00330-011-2139-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/19/2011] [Accepted: 04/04/2011] [Indexed: 11/30/2022]
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Camera L, Paoletta S, Mollica C, Milone F, Napolitano V, De Luca L, Faggiano A, Colao A, Salvatore M. Screening of pancreaticoduodenal endocrine tumours in patients with MEN 1: multidetector-row computed tomography vs. endoscopic ultrasound. Radiol Med 2011; 116:595-606. [PMID: 21286942 DOI: 10.1007/s11547-011-0636-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 05/25/2010] [Indexed: 12/17/2022]
Abstract
PURPOSE The authors compared multidetector-row computed tomography (MDCT) and endoscopic ultrasound (EUS) in the identification of pancreaticoduodenal endocrine tumours (PETs) in patients with multiple endocrine neoplasia type 1 (MEN 1). MATERIALS AND METHODS Fourteen consecutive patients (eight men and six women, aged 26-54 years) with MEN 1 underwent MDCT performed with a 4- (n=5) or 64- (n=9) detector-row system and EUS done with a radial transducer (7.5-20 MHz) within 7-28 days of each other. Prior to MDCT examination, patients were given 750 cc of water and asked to lie down in the right lateral decubitus for 15 min. Multiphase MDCT images were acquired both before and after the injection of nonionic iodinated contrast material (2 cc/kg) at an injection rate of 4 ml/s, with technical parameters and scan delay varying in relation to the system used. Images were all reconstructed at 3-mm intervals for the three phases (arterial, pancreatic and portal) and evaluated on a dedicated workstation. RESULTS MDCT detected a total of 25 PETs (3-18 mm) in nine patients. Of these lesions, nine were situated within the duodenal wall and 16 in either the pancreatic head (n=3), body (n=7), or tail (n=6). Three additional lesions were detected retrospectively after EUS imaging. Most (18/22, 81%) were hypervascular nodules, and four appeared as either hypoattenuating or cystic lesions. EUS detected a total of 32 PETs (2-18 mm) in 11 patients. Most lesions (29/32, 90%) appeared hypoechoic and were situated in the duodenal wall (n=15) or in either the pancreatic head (n=10), body (n=6) or tail (n=1). CONCLUSIONS Our preliminary data indicate that MDCT is complementary to EUS in the identification of PETs in MEN-1 patients.
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Affiliation(s)
- L Camera
- Dipartimento di Scienze Bio-Morfologiche e Funzionali, Sez. di Diagnostica per Immagini e Radioterapia (Ed. 10), Università degli Studi di Napoli Federico II, Via S. Pansini 5, 80131, Napoli, Italy.
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Yamaguchi I, Kidoya E, Suzuki M, Kimura H. Optimizing scan timing of hepatic arterial phase by physiologic pharmacokinetic analysis in bolus-tracking technique by multi-detector row computed tomography. Radiol Phys Technol 2010; 4:43-52. [DOI: 10.1007/s12194-010-0105-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 08/30/2010] [Accepted: 08/31/2010] [Indexed: 11/29/2022]
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Bae KT. Intravenous contrast medium administration and scan timing at CT: considerations and approaches. Radiology 2010; 256:32-61. [PMID: 20574084 DOI: 10.1148/radiol.10090908] [Citation(s) in RCA: 717] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The continuing advances in computed tomographic (CT) technology in the past decades have provided ongoing opportunities to improve CT image quality and clinical practice and discover new clinical CT imaging applications. New CT technology, however, has introduced new challenges in clinical radiology practice. One of the challenges is with intravenous contrast medium administration and scan timing. In this article, contrast medium pharmacokinetics and patient, contrast medium, and CT scanning factors associated with contrast enhancement and scan timing are presented and discussed. Published data from clinical studies of contrast medium and physiology are reviewed and interpreted. Computer simulation data are analyzed to provide an in-depth analysis of various factors associated with contrast enhancement and scan timing. On the basis of basic principles and analysis of the factors, clinical considerations and modifications to protocol design that are necessary to optimize contrast enhancement for common clinical CT applications are proposed.
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Affiliation(s)
- Kyongtae T Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
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Nakai M, Sato M, Ikoma A, Nakata K, Sahara S, Takasaka I, Minamiguchi H, Kawai N, Sonomura T, Kishi K. Triple-phase computed tomography during arterial portography with bolus tracking for hepatic tumors. Jpn J Radiol 2010; 28:149-56. [PMID: 20182850 DOI: 10.1007/s11604-009-0399-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2009] [Accepted: 11/13/2009] [Indexed: 01/16/2023]
Abstract
PURPOSE The purpose of this study was to assess the usefulness of triple-phase computed tomography during arterial portography (CTAP) using a bolus-tracking technique. MATERIAL AND METHODS The subjects were 60 patients with hepatic tumors: 20 patients with metastatic liver tumors with a normal liver and 40 with hypervascular hepatocellular carcinoma (HCC) with liver cirrhosis. The region of interest was set in the portal vein, and CTAP was automatically started after the triggering threshold (180 HU) was reached. Three scans were performed: early phase (E), hepatic parenchymal phase (HP), and late phase (L). The scan start time of E-CTAP was measured. The detection rates of the HCC nodules were evaluated during each CTAP phase. RESULTS CTAP was performed by bolus tracking without failure in any of the patients. The mean scan start times in the normal liver group and liver cirrhosis group were 14.3 +/- 1.34 s and 18.5 +/- 2.46 s, respectively, which were significantly different from each other. The detection rates of HCC nodules for E-CTAP, HP-CTAP, and L-CTAP were 29.6%, 100%, and 83.3%, respectively. CONCLUSION The bolus-tracking technique enabled us to perform CTAP with optimal timing regardless of the portal blood flow dynamics.
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Affiliation(s)
- Motoki Nakai
- Department of Radiology, Wakayama Medical University, Wakayama, Japan.
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Pancreatic adenocarcinoma: a comparison of automatic bolus tracking and empirical scan delay. ACTA ACUST UNITED AC 2009; 35:548-55. [DOI: 10.1007/s00261-009-9560-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2008] [Revised: 04/13/2009] [Accepted: 06/23/2009] [Indexed: 10/20/2022]
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Value of customized scan timing determined by tracking liver enhancement in oncology patients. J Comput Assist Tomogr 2009; 33:253-8. [PMID: 19346855 DOI: 10.1097/rct.0b013e318177e5c7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To assess the value of liver parenchyma enhancement tracking for liver multidetector computed tomography (CT) in patients with potential hypoattenuating liver metastases. MATERIALS AND METHODS Institutional review board approved this Health Insurance Portability and Accountability Act-compliant study. We reviewed the chest-abdomen-pelvis CTs of 120 consecutive patients scanned on 16-/64-row multidetector CT after receiving 52 g I in 50 seconds. Liver scanning started 65 seconds after injection-start in 59 patients, whereas in 61 patients, scanning started automatically when liver enhancement reached 50 Hounsfield units on low-dose continuous attenuation tracking. Enhancement of liver parenchyma, aorta, portal, and hepatic veins was measured. Two readers graded conspicuity and recorded attenuation of hypoattenuating lesions. RESULTS We identified 663 metastases in 74 patients. Scan-delay range in the triggered group was 53 to 83 seconds. Compared with the fixed-delay group, in the triggered group, mean number of metastases per patient with metastases was larger, liver attenuation and enhancement were higher, and median metastasis conspicuity grade was higher (all P < 0.05). CONCLUSIONS Automatic scan triggering based on liver parenchyma enhancement tracking produces consistently higher liver parenchymal enhancement and increased metastasis conspicuity than fixed delay.
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Contrast Injection Protocols for Coronary Computed Tomography Angiography Using a 64-Detector Scanner: Comparison Between Patient Weight-Adjusted- and Fixed Iodine-Dose Protocols. Invest Radiol 2008; 43:512-9. [PMID: 18580334 DOI: 10.1097/rli.0b013e3181727505] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Comparison between one-route and two-route injection for liver and aortic enhancement using MDCT. AJR Am J Roentgenol 2008; 190:W323-6. [PMID: 18492873 DOI: 10.2214/ajr.07.3047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of our study was to evaluate whether simultaneous injection into cubital veins bilaterally at one half of the standard injection rate achieves similar hepatic and aortic enhancement on MDCT as the conventional injection rate into a single cubital vein. MATERIALS AND METHODS Thirty-two patients underwent multiphase MDCT because they were suspected of having a hepatic tumor. Patients were assigned to one of the following two groups: group A, 100 mL of 370 mg I/mL of contrast medium injected into a unilateral cubital vein (one-route) via a 20-gauge cannula at a rate of 4 mL/s; or group B, 50 mL of contrast medium injected into the cubital veins bilaterally (two-route) via 24-gauge cannulas at 2 mL/s. Peak contrast enhancement of the liver and abdominal aorta for groups A and B was measured using regions of interest and compared; arrival time of the contrast media was also compared using a bolus-tracking system. Analysis was performed using Wilcoxon's signed rank test. RESULTS Peak aortic enhancement of groups A and B was 367 +/- 67 H and 361 +/- 113 H (p = 0.61, not significant), respectively, and peak hepatic enhancement of groups A and B was 56 +/- 11 H and 56 +/- 16 H (p = 0.88, not significant), respectively. Mean arrival time to the aorta of group B (19.4 +/- 3.4 seconds) was significantly later compared with that of group A (15.5 +/- 3.5 seconds) (p = 0.005). CONCLUSION The slower two-route injection produced the same aortic and hepatic enhancement as the faster one-route method with faster injection, but the arrival time of the contrast medium was later using the two-route method.
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Chu LL, Joe BN, Westphalen ACA, Webb EM, Coakley FV, Yeh BM. Patient-specific Time to Peak Abdominal Organ Enhancement Varies with Time to Peak Aortic Enhancement at MR Imaging. Radiology 2007; 245:779-87. [PMID: 17911535 DOI: 10.1148/radiol.2451061585] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
PURPOSE To retrospectively evaluate the relationship between the times to peak enhancement of the liver, pancreas, and jejunum with respect to the time to peak aortic enhancement at magnetic resonance (MR) imaging. MATERIALS AND METHODS The committee on human research approved this study and waived written informed consent. This study was HIPAA compliant. The study retrospectively identified 141 patients (63 men, 78 women; mean age, 57 years) who underwent abdominal MR imaging by using a test bolus that was monitored approximately every second for 2 minutes with a spoiled gradient-echo T1 transverse section through the upper abdomen. The times to peak enhancement of the aorta, liver, pancreas, and jejunum were recorded and correlated with the time to peak aortic enhancement, age, and sex by means of univariate and multivariate linear regression analyses. RESULTS The mean time to peak aortic enhancement was 21.1 seconds (range, 8.7-41.8 seconds). The times to peak enhancement of the liver, pancreas, and jejunum were positively and linearly correlated with the time to peak aortic enhancement (r = 0.69, 0.86, and 0.80, respectively, all P < .001) and were 3.39, 1.64, and 2.04 times longer than the time to peak aortic enhancement, respectively. Age, sex, and history of heart disease did not give additional predictive information for determining the time to peak visceral enhancement. CONCLUSION The times to peak enhancement of the liver, pancreas, and jejunum are linearly related to that of the aorta. These results could potentially allow tailored patient- and organ-specific scan delay optimization at contrast material-enhanced MR image evaluation.
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Affiliation(s)
- Lisa L Chu
- Department of Radiology, University of California-San Francisco, 505 Parnassus Ave, Box 0628, C-324C, San Francisco, CA 94143-0628, USA
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Sultana S, Awai K, Nakayama Y, Nakaura T, Liu D, Hatemura M, Funama Y, Morishita S, Yamashita Y. Hypervascular Hepatocellular Carcinomas: Bolus Tracking with a 40-Detector CT Scanner to Time Arterial Phase Imaging. Radiology 2007; 243:140-7. [PMID: 17329690 DOI: 10.1148/radiol.2431060069] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate prospectively bolus tracking to time hepatic arterial phase (HAP) imaging of hypervascular hepatocellular carcinomas (HCCs) with a 40-detector computed tomographic (CT) scanner. MATERIALS AND METHODS This study received institutional review board approval; informed consent was obtained. The study included 192 patients (123 men, 69 women; mean age, 67.6 years) with known or suspected HCC who underwent dynamic CT, including HAP scanning; CT depicted 111 hypervascular HCCs in 72 patients. Scanning was performed with a 40-detector CT scanner, and bolus tracking was used to time the start of HAP imaging. Patients were randomly assigned to five protocols; HAP scanning was started at a specified interval after trigger threshold was reached: 9 seconds (protocol A), 12 seconds (protocol B), 15 seconds (protocol C), 18 seconds (protocol D), or 21 seconds (protocol E). Trigger threshold level was set at 100 HU above aortic baseline CT number. Enhancement values in the aorta and the tumor-liver contrast (TLC) were measured. Dunnett multiple comparisons were performed to compare enhancement values among the five protocols. RESULTS Mean scanning time for the whole liver was 2.1 seconds. Mean enhancement value of the aorta in protocols A, B, C, D, and E were 284.3 HU +/- 54.7, 293.8 HU +/- 51.0, 308.7 HU +/- 55.9, 291.5 HU +/- 42.2, and 235.5 HU +/- 51.2, respectively. Aortic enhancement was significantly lower in protocol E than in protocol A (P < .01); there was no significant difference between protocols A and B, A and C, and A and D. Mean TLCs in protocols A, B, C, D, and E were 23.4 HU +/- 7.6, 35.5 HU +/- 14.0, 36.2 HU +/- 6.8, 47.2 HU +/- 19.2, and 35.1 HU +/- 15.8, respectively. A significant difference was found only between protocols A and D (P < .01). CONCLUSION Peak TLC during the HAP occurred 18 seconds after triggering.
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Affiliation(s)
- Shamima Sultana
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-2 Honjyo, Kumamoto 860-8556, Japan
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Schoellnast H, Deutschmann HA, Berghold A, Fritz GA, Schaffler GJ, Tillich M. MDCT Angiography of the Pulmonary Arteries: Influence of Body Weight, Body Mass Index, and Scan Length on Arterial Enhancement at Different Iodine Flow Rates. AJR Am J Roentgenol 2006; 187:1074-8. [PMID: 16985159 DOI: 10.2214/ajr.05.0714] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The purpose of this study was to assess whether body weight, body mass index, and scan length influence arterial enhancement during CT angiography (CTA) of the pulmonary arteries at different iodine flow rates. MATERIALS AND METHODS CTA examinations of the pulmonary arteries performed for routine clinical care of 120 patients between March and December 2003 were retrospectively evaluated. Patients had received either 120 mL of contrast medium with an iodine concentration of 300 mg I/mL (group A) or 90 mL of contrast medium with an iodine concentration of 400 mg I/mL (group B). The iodine dose was 36 g, and the injection rate was 4 mL/s in all examinations. The iodine flow rate was 1.2 g I/s in group A and 1.6 g I/s in group B. Arterial attenuation along the z-axis was measured per patient, and the influence of body weight, body mass index, and scan length on enhancement of the pulmonary arteries in the two groups was assessed. RESULTS In group A and in group B, body weight and body mass index correlated significantly with mean enhancement along the z-axis (r = -0.35 and -0.26 for group A and -0.48 and -0.40 for group B). Scan length showed no correlation with pulmonary attenuation. Mean pulmonary artery enhancement was significantly higher in group B with a difference of 51 H compared with group A. CONCLUSION Pulmonary artery attenuation in CTA of the pulmonary arteries shows a small but significant correlation with body weight and body mass index independently of the iodine flow rate used. A higher iodine flow rate improves pulmonary artery enhancement.
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Sandstede JJW, Werner A, Kaupert C, Roth A, Jenett M, Harz C, Hahn D. A prospective study comparing different iodine concentrations for triphasic multidetector row CT of the upper abdomen. Eur J Radiol 2006; 60:95-9. [PMID: 16879942 DOI: 10.1016/j.ejrad.2006.05.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Revised: 05/20/2006] [Accepted: 05/23/2006] [Indexed: 11/20/2022]
Abstract
OBJECTIVES To investigate the effect of different iodine concentrations at either constant injection or iodine administration rates but constant total iodine load on contrast enhancement of liver, pancreas and spleen by multidetector row CT. MATERIALS AND METHODS One hundred and twenty consecutive patients (70+/-6 years) underwent triphasic liver CT at a four-channel multidetector-row CT using the non-ionic contrast medium iopromide. Patients were divided into six equal groups-I: 150 ml, 240 mg/ml at 4 ml/s; II: 120 ml, 300 mg/ml at 4 ml/s; III: 97.3 ml, 370 mg/ml at 4 ml/s; IV: 150 ml, 240 mg/ml at 5 ml/s; V: 120 ml, 300 mg/ml, 60 ml at 6 ml/s, 60 ml at 3 ml/s; VI: 97.3 ml, 370 mg/ml at 3.3 ml/s. ROIs were measured in the liver, the pancreas, and the spleen in unenhanced, arterial, portal venous, and equilibrium phase. RESULTS At a constant injection rate of 4 ml/s, pancreatic enhancement over baseline only in the arterial phase was significantly higher at 370 mg/ml (58+/-15 HU versus 59+/-18 HU versus 74+/-20 HU for groups I-III, respectively (p<0.02)). Comparison of different iodine concentrations at constant iodine administration rate (groups II, IV and VI) and of all six protocols revealed no significant differences at either phase. CONCLUSIONS At a constant iodine load and constant injection rates, the high-iodinated contrast agent iopromide at 370 mg/ml improves pancreatic enhancement in the arterial phase. At constant iodine load and constant iodine administration rates, there is no significant effect of different iodine concentrations.
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Affiliation(s)
- Joern J W Sandstede
- Department of Radiology, University of Wuerzburg, Josef-Schneider-Strasse 2, Wuerzburg, Germany.
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Kim MJ, Choi JY, Lim JS, Kim JY, Kim JH, Oh YT, Yoo EH, Chung JJ, Kim KW. Optimal Scan Window for Detection of Hypervascular Hepatocellular Carcinomas During MDCT Examination. AJR Am J Roentgenol 2006; 187:198-206. [PMID: 16794177 DOI: 10.2214/ajr.05.0257] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to define the optimal scan window for acquiring arterial phase images in the detection of hypervascular hepatocellular carcinomas (HCCs). MATERIALS AND METHODS Biphasic arterial phase CT examinations were performed using a 16-MDCT scanner on 198 patients (159 men and 39 women; mean age, 59 years; age range, 25-82 years) with nodular HCC. All examinations were performed after administering 120-150 mL of a nonionic contrast media (370 mg I/mL) at a rate of 3-4 mL/s. The scan delay--the interval between when the bolus-tracking program detected the threshold enhancement of 100 H in the abdominal aorta and the start of the first arterial scan-was progressively lengthened by 2-second intervals, from 10 seconds in group 1 to 20 seconds in group 6. The second arterial phase scan was started 6 seconds after the end of the early scan. A tube collimation of 1.5 mm, a table feed of 18 mm per rotation, an image thickness of 3 mm, and 3-mm increments were used. The duration of each phase scan was 4.5-8.8 seconds. Tumor-to-liver attenuation difference (TLAD) at the first (TLAD1) and second (TLAD2) arterial phase images were compared lesion by lesion. Four observers assigned subjective ratings of visual conspicuity and individual preferences for each phase in each group. RESULTS The mean threshold time (100 H) was 18.4 +/- 3.1 seconds, and 97% of patients were within the range of 13-24 seconds. The mean TLAD1 of groups 3 to 6 and the mean TLAD2 of groups 1 to 5 were all comparable; they were also all significantly (p < 0.005) higher than the mean TLAD1 of groups 1 and 2 and the mean TLAD2 of group 6. In groups 1 and 2, the mean TLAD2 was significantly higher than the mean TLAD1 (p < 0.001); in groups 5 and 6, the mean TLAD1 was significantly higher than the mean TLAD2 (p < 0.001). In groups 3 and 4, the mean TLAD1 and TLAD2 were similar. The visual conspicuity and individual preferences were higher for the first-phase image in groups 3 to 6 and the second-phase image in groups 1 and 2. CONCLUSION The optimal scan window for arterial phase images in the detection of HCC seems to be approximately 14-30 seconds from the 100-H threshold.
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Affiliation(s)
- Myeong-Jin Kim
- Department of Diagnostic Radiology, Severance Hospital, Yonsei University College of Medicine, Seodaemun-ku Shinchon-dong 134, Seoul, 120-752, South Korea.
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Guan YS, Hu Y, Liu Y. Multidetector-row computed tomography in the management of hepatocellular carcinoma with transcatheter arterial chemoembolization. J Gastroenterol Hepatol 2006; 21:941-6. [PMID: 16724976 DOI: 10.1111/j.1440-1746.2006.04474.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
With the introduction of spiral computed tomography and the development of novel imaging technology in recent years, multidetector-row computed tomography (MDCT) has increasingly been used for the diagnosis of various lesions, especially hepatocellular carcinoma (HCC), due to its volume acquisitions, short scanning time, and especially its double-phase scanning nature, which takes advantage of the dual blood supply of liver. Multidetector-row computed tomography is used to classify HCC into several types based on the blood supply and the histological characteristics of HCC. The evaluation of HCC by MDCT provides crucial clues for the doctors to adopt correct clinical management strategies such as the selection of the appropriate dose of lipiodol before transcatheter arterial chemoembolization (TACE) and the prediction of the prognosis of HCC after TACE. The MDCT scanning allows doctors to choose the region of interest and to evaluate the blood supply according to the lipiodol uptake in order to decide whether there is recrudescence and whether a repeated therapy should be taken. This review describes MDCT, its biphasic scanning, its evaluation of blood supply in HCC and the subsequent classification of HCC, its therapeutic significance before TACE and the prognostic value after TACE.
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Affiliation(s)
- Yong-Song Guan
- Department of Interventional Radiology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China.
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Winterer JT, Kotter E, Ghanem N, Langer M. Detection and characterization of benign focal liver lesions with multislice CT. Eur Radiol 2006; 16:2427-43. [PMID: 16724204 DOI: 10.1007/s00330-006-0247-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 02/17/2006] [Accepted: 03/02/2006] [Indexed: 12/27/2022]
Abstract
MDCT is a rapidly evolving technique that significantly improves CT imaging for several indications including depiction of focal benign lesions. Imaging mainly profits from improved longitudinal spatial resolution allowing high-quality non-axial reformations and 3D reconstructions and CT angiography as well as rapid accurate multiphase imaging with short breath-holding periods. This review provides an overview of the current status of MDCT with respect to liver imaging and the implications for characterizing benign focal liver lesions. MDCT currently allows the acquisition of thin slices in daily routine diagnostics providing an improved detection rate of small liver lesions. Whereas large benign focal liver lesions exhibit typical patterns of morphology, attenuation and perfusion, which also may be assessed with single-slice scanners, small lesions remain challenging even with MDCT, since the specific criteria for confident diagnosis become more ambiguous. Here, MR imaging provides more detailed information about tissue components and the availability of liver-specific contrast agents, adding further impact to this technique. With respect to dose considerations, the number of necessary multiphase scans as well as the application of very thin collimation should be strictly checked for each patient undergoing MDCT based on the individual clinical situation and question.
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Affiliation(s)
- J T Winterer
- Department of Diagnostic Radiology, Hugstetter Str. 55, D-79106, Freiburg, Germany.
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Kim MJ, Chung YE, Kim KW, Chung JJ, Lim JS, Oh YT, Kim JH. Variation of the Time to Aortic Enhancement of Fixed-Duration Versus Fixed-Rate Injection Protocols. AJR Am J Roentgenol 2006; 186:185-92. [PMID: 16357400 DOI: 10.2214/ajr.04.0923] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The objective of the study was to clarify whether a fixed-duration injection protocol is useful in determining the optimal scan delay time without the need for a bolus-tracking technique. MATERIALS AND METHODS Three hundred eighteen patients underwent a helical CT examination using a bolus-tracking technique. All the examinations were performed after administering a nonionic contrast medium (300 or 370 mg I/mL; 2 mL/kg of body weight for patients weighing < or = 75 kg, 150 mL for those weighing > 75 kg). The patients were assigned to one of three groups according to the injection protocol. The injection rate was alternated to 3 or 4 mL/sec in group 1. The injection duration was 38 or 47 sec in groups 2 and 3, respectively. The aortic arrival time and the 100-H threshold time in each patient were measured. The mean values and the variations in the aortic arrival time and 100-H threshold time according to the injection protocols and the contrast media were compared. RESULTS The mean variations (+/- SD) of aortic arrival times and 100-H thresholds in group 2 (aortic arrival time = 16.1 +/- 2.7 sec, 100-H threshold time = 19.6 +/- 2.9 sec) were smaller than in groups 1 (16.3 +/- 3.0 sec and 19.9 +/- 3.7 sec, respectively) and 3 (16.8 +/- 3.5 sec and 20.4 +/- 4.1 sec, respectively). However, the range of aortic arrival times and 100-H threshold times was more than 10 sec for all groups. The mean aortic arrival time and 100-H threshold time for all patients were 16.5 and 20.0 sec, respectively, and did not vary significantly with the injection protocol and concentration of contrast medium. CONCLUSION The individual variations of the aortic arrival and 100-H threshold times can be reduced using a fixed-duration injection technique, but there are still substantial variations. Therefore, a bolus-tracking technique is recommended for optimal timing of arterial phase scanning.
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Affiliation(s)
- Myeong-Jin Kim
- Department of Diagnostic Radiology, Severance Hospital and Research Institute of Radiological Science, Yonsei University College of Medicine, Seodaemun-ku Shinchon-dong 134, Seoul 120-752, Republic of Korea.
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Yamaguchi I, Ishida T, Kidoya E, Higashimura K, Suzuki M. [Method for determining scan timing based on analysis of formation process of the time-density curve]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2005; 61:260-7. [PMID: 15753867 DOI: 10.6009/jjrt.kj00003326664] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
A strict determination of scan timing is needed for dynamic multi-phase scanning and 3D-CT angiography (3D-CTA) by multi-detector row CT (MDCT) . In the present study, contrast media arrival time (T(AR)) was measured in the abdominal aorta at the bifurcation of the celiac artery for confirmation of circulatory differences in patients. In addition, we analyzed the process of formation of the time-density curve (TDC) and examined factors that affect the time to peak aortic enhancement (T(PA)). Mean T(AR) was 15.57+/-3.75 s. TDCs were plotted for each duration of injection. The rising portions of TDCs were superimposed on one another. TDCs with longer injection durations were piled up upon one another. Rise angle was approximately constant in response to each flow rate. Rise time (T(R)) showed a good correlation with injection duration (T(ID)). T(R) was 1.01 TID (R(2)=0.994) in the phantom study and 0.94 T(ID)-0.60 (R(2)=0.988) in the clinical study. In conclusion, for the selection of optimal scan timing it is useful to determine T(R) at a given point and to determine the time from T(AR).
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Atasoy C, Akyar S. Multidetector CT: contributions in liver imaging. Eur J Radiol 2005; 52:2-17. [PMID: 15380843 DOI: 10.1016/j.ejrad.2004.03.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Revised: 03/15/2004] [Accepted: 03/18/2004] [Indexed: 01/25/2023]
Abstract
Multidetector CT has had great impact in the evaluation of the liver. Increased speed combined with thin slice collimation improved the spatial and temporal resolution, which in turn provided a higher sensitivity in the detection of focal lesions, particularly for the hepatocellular cancer (HCC) in patients with cirrhosis. There is no consensus as to whether the so-called "double arterial phase scanning" improves the detection rate of hepatocellular cancers, and the majority of the more recent studies suggest acquiring only the late arterial phase images along with the portal venous phase images. However, if the patient is a surgical candidate, the early arterial phase images must also be obtained, because they provide better pre-surgical mapping of the hepatic arteries. In primary and metastatic liver tumors, arterial and portal venous phase images should be acquired with thin collimation and overlapping reconstruction. Maximum intensity projection and volume rendering methods demonstrate the three-dimensional anatomy of the hepatic arteries, portal and hepatic veins successfully, which provide useful information before hepatic resection or intraarterial chemotherapy. In living donor candidates, early arterial and portal venous phase images obtained with thin collimation and overlapping reconstruction are used to reconstruct three-dimensional images with maximum intensity and volume rendering methods. These have a high sensitivity to detect hepatic artery, portal and hepatic vein variations, which could render the surgery difficult or even impossible. Portal venous phase images can also be used to measure total and lobar liver volumes. A virtual hepatectomy plane can be simulated on the three-dimensional model of the liver and hepatic veins, and when necessary, its location can be modified according to the metabolic needs of the recipient and donor. Thin collimation and better temporal resolution may also have beneficial effects in the characterization of liver lesions.
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Affiliation(s)
- Cetin Atasoy
- Department of Radiology, Ibn-i Sina Hospital, Ankara University School of Medicine, 06100 Sihhiye, Ankara, Turkey.
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Sandstede JJW, Kaupert C, Roth A, Jenett M, Harz C, Hahn D. Comparison of different iodine concentrations for multidetector row computed tomography angiography of segmental renal arteries. Eur Radiol 2005; 15:1211-4. [PMID: 15678319 DOI: 10.1007/s00330-005-2677-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Revised: 12/28/2004] [Accepted: 01/11/2005] [Indexed: 11/28/2022]
Abstract
The aims of this study were (1) to assess the diagnostic performance of multidetector row computed tomography angiography (CTA) on imaging of renal artery branches and (2) to investigate the effect of different iodine concentrations at constant total iodine load and either constant injection rates or constant iodine administration rates. A number of 120 consecutive patients (71+/-6 years of age) underwent CTA of renal arteries (collimation 4 x 1 mm) using the nonionic contrast medium iopromide, and were divided into six equal groups: 1: 150 ml, 240 mg/ml at 4 ml/s; 2: 120 ml, 300 mg/ml at 4 ml/s; 3: 97.3 ml, 370 mg/ml at 4 ml/s; 4: 150 ml, 240 mg/ml at 5 ml/s; 5: 120 ml, 300 mg/ml, 60 ml at 6 ml/s, 60 ml at 3 ml/s; 6: 97.3 ml, 370 mg/ml at 3.3 ml/s. The image quality of the main renal arteries (n=240) and their first-order to fourth-order branches was scored as 0 for no visualization, 1 for only visualization, and 2 for diagnostic. All main renal arteries were diagnostic. First-order branches had score 2 in 38/40, 40/40, 37/40, 38/40, 39/40, and 40/40 patients for groups 1-6, respectively (p=0.34). Second-order branches were imaged best in group 2 (p<0.002)). Third-order branches had score 2 in only 1/40, 5/40, 1/40, 2/40, 0/40, and 2/40 renal arteries. Fourth-order branches were not imaged diagnostically. At a constant total iodine load, the main renal arteries and their first-order branches achieved diagnostic image quality at all iodine concentrations in four-channel multidetector row CTA for the protocols tested. Second-order renal artery branches were imaged best at 120 ml contrast medium with an iodine concentration of 300 mg/ml at 4 ml/s.
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Awai K, Inoue M, Yagyu Y, Watanabe M, Sano T, Nin S, Koike R, Nishimura Y, Yamashita Y. Moderate versus High Concentration of Contrast Material for Aortic and Hepatic Enhancement and Tumor-to-Liver Contrast at Multi–Detector Row CT. Radiology 2004; 233:682-8. [PMID: 15486215 DOI: 10.1148/radiol.2333031617] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively evaluate aortic and hepatic enhancement and depiction of hypervascular hepatocellular carcinoma (HCC) between two contrast materials with moderate and high iodine concentrations when administered at same iodine dose and injection duration at multi-detector row helical computed tomography (CT). MATERIALS AND METHODS Institutional review board approval and informed patient consent were obtained. One hundred eighty-six patients were studied, and 67 patients with hypervascular HCC were identified. Ninety-four patients were assigned to receive iohexol 350 (mg iodine per milliliter) with protocol A; 92, iohexol 300 with protocol B. In both protocols, iohexol with same iodine load per weight (518 mg/kg) was administered with same injection duration (25 seconds). Multiphase CT scanning was started 10, 20, 50, and 180 seconds after the trigger (threshold level set at increase of 100 HU over baseline CT number of aorta). Enhancement of aorta and liver was measured in 186 patients. Tumor-to-liver contrast was measured in 67 patients with hypervascular HCC. Statistical analysis was performed with Mann-Whitney U test. RESULTS Medians of aortic enhancement during four phases were 325, 185, 112, and 69 HU with protocol A. Corresponding values were 344, 266, 121, and 73 HU with protocol B. During all phases, aortic enhancement was significantly higher with protocol B (P = .046, P < .001, P < .001, and P = .002). Hepatic enhancement during four phases was 6, 21, 48, and 34 HU with protocol A. Corresponding values were 3, 17, 47, and 35 HU with protocol B. Hepatic enhancement was significantly higher with protocol A during first and second phases (P < .001 for both), although there was no significant difference between protocols during third and fourth phases (P = .778 and P = .178, respectively). Medians of tumor-to-liver contrast during four phases were 22, 34, 0.5, and -1.1 HU with protocol A. Corresponding values were 23, 45, 0, and -8.6 HU with protocol B. Tumor-to-liver contrast was significantly higher with protocol B during second phase (P = .049), although there was no difference between protocols during other phases. CONCLUSION When total iodine dose was adjusted to body weight and injection duration was fixed, rapid administration of moderate concentration of contrast material was more effective for depiction of hypervascular HCC than was high concentration of contrast material.
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Affiliation(s)
- Kazuo Awai
- Department of Radiology, Kinki University School of Medicine, 2-23 Ono-higashi, Osaka-Sayama, Osaka 589-8511, Japan
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Cademartiri F, Nieman K, van der Lugt A, Raaijmakers RH, Mollet N, Pattynama PMT, de Feyter PJ, Krestin GP. Intravenous Contrast Material Administration at 16–Detector Row Helical CT Coronary Angiography: Test Bolus versus Bolus-tracking Technique. Radiology 2004; 233:817-23. [PMID: 15516601 DOI: 10.1148/radiol.2333030668] [Citation(s) in RCA: 203] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To compare test bolus and bolus-tracking techniques for intravenous contrast material administration at 16-detector row computed tomographic (CT) coronary angiography. MATERIALS AND METHODS This study had institutional review board approval, and patients gave informed consent. Thirty-eight patients (mean age, 60 years; three women) were randomized into two groups according to bolus timing technique: group 1 (20-mL test bolus with 100-mL main bolus) and group 2 (bolus tracking with 100-mL main bolus). All patients underwent electrocardiography-gated 16-detector row CT coronary angiography with 12 detectors (collimation, 0.75 mm; rotation time, 420 msec). In group 1, test bolus peak attenuation was used as a delay, while in group 2, a +100-HU threshold in ascending aorta triggered angiographic acquisition, with an additional 4-second delay for patient instruction. Attenuation was measured in the longitudinal direction throughout the examination in three main vessels: ascending aorta (region of interest [ROI] 1), descending aorta (ROI 2), and main pulmonary artery (ROI 3). Mean attenuation and slope of bolus geometry curve were calculated in each patient and ROI. Attenuation at origin of coronary arteries was measured. Student t test was used to compare results. RESULTS Mean scan delay was 6 seconds longer in group 2 (P < .05). Average attenuation values were 306.6 HU +/- 44.0 (standard deviation) and 328.2 HU +/- 58.6 (P > .05) in ROI 1, 291.6 HU +/- 45.1 and 326.4 HU +/- 62.6 (P > .05) in ROI 2, and 354.7 HU +/- 78.0 and 305.3 HU +/- 71.4 (P < .05) in ROI 3 for groups 1 and 2, respectively. Average slope values were 5.8 and -0.8 (P < .05) in ROI 1, 7.7 and 0.7 (P < .05) in ROI 2, and -1.0 and -13.3 (P < .05) in ROI 3 for groups 1 and 2, respectively. Average attenuation values in left main, left anterior descending, and left circumflex arteries were higher in group 2 (P < .05); there were no differences (P > .05) between groups in right coronary artery. CONCLUSION Bolus-tracking yields more homogeneous enhancement than does the test bolus technique.
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Affiliation(s)
- Filippo Cademartiri
- Department of Radiology, Erasmus Medical Center, Dr Molenwaterplein 40, 3015 GD Rotterdam, the Netherlands.
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Suzuki H, Oshima H, Shiraki N, Ikeya C, Shibamoto Y. Comparison of two contrast materials with different iodine concentrations in enhancing the density of the the aorta, portal vein and liver at multi-detector row CT: a randomized study. Eur Radiol 2004; 14:2099-104. [PMID: 15309493 DOI: 10.1007/s00330-004-2439-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2004] [Revised: 07/11/2004] [Accepted: 07/15/2004] [Indexed: 10/26/2022]
Abstract
This work investigates differences in contrast enhancement of the aorta, portal vein and liver by two different concentrations of contrast materials using an automatic bolus tracking technique. Seventy patients were assigned randomly into one of two groups. Contrast materials with iodine concentrations of 300 and 370 mg/ml were administered to patients in groups A and B, respectively. The total iodine load (600 mg/kg) and injection time (30 s) were identical. Differences in the increase of the Hounsfield unit of the aorta, portal vein and liver between the two groups were examined by t-test. There were no significant differences between the two groups in any of the contrast enhancements of the aorta, portal vein and liver parenchyma at all phases, except for enhancement of the portal vein at the late arterial phase. Females showed better contrast enhancement of the aorta and portal vein than males. With the same iodine dose and injection time, the concentration of contrast materials did not seem to influence the efficacy of contrast enhancement of the aorta, portal vein and liver, except for the portal vein at the late arterial phase. Planning of protocols for contrast media injection may be made irrespective of the iodine concentrations.
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Affiliation(s)
- Hiromasa Suzuki
- Department of Radiology, Nagoya City University Medical School, 1 Kawasumi, Mizuho-cho, Mizuho-ku, 467-8601 Nagoya, Japan.
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Cademartiri F, Mollet N, van der Lugt A, Nieman K, Pattynama PMT, de Feyter PJ, Krestin GP. Non-invasive 16-row multislice CT coronary angiography: usefulness of saline chaser. Eur Radiol 2003; 14:178-83. [PMID: 14689227 DOI: 10.1007/s00330-003-2188-x] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2003] [Revised: 10/10/2003] [Accepted: 11/17/2003] [Indexed: 11/28/2022]
Abstract
The aim of this study was to investigate the usefulness of saline chaser in 16-row multislice CT (16-MSCT) coronary angiography. Forty-two patients were divided into two groups for contrast material (CM) administration: group 1 (140 ml at 4 ml/s) and group 2 (100 ml at 4 ml/s followed by 40 ml of saline chaser at 4 ml/s). All patients underwent retrospectively ECG-gated 16-MSCT coronary angiography. The attenuation at the origin coronary vessels was assessed. Three regions of interest (ROIs) were drawn throughout the data set: (a) ascending aorta (ROI 1); (b) descending aorta (ROI 2); and (c) pulmonary artery (ROI 3). The attenuation in the superior vena cava was recorded (ROI 4). The average attenuation and the slope were calculated in each ROI and differences were assessed with a Student's t test. The average attenuation in the coronary vessels was not significantly different in the two groups. The average attenuations in ROI 1 were 325 and 327 HU, in ROI 2 were 328 and 329 HU and in ROI 3 were 357 and 320 HU, for groups 1 and 2, respectively (p>0.05). The slopes in ROI 1 were -0.2 and 1.1, in ROI 2 were 2.8 and 2.1 (p>0.05) and in ROI 3 were 3.9 and -9.0 (p<0.05), for groups 1 and 2, respectively. The average attenuations in ROI 4 were 927 and 643 HU (p<0.05), for groups 1 and 2, respectively. One hundred milliliters of CM with 40 ml of saline chaser provides the same attenuation as 140 ml of CM (35% less) with decreased hyper-attenuation in the superior vena cava.
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Affiliation(s)
- Filippo Cademartiri
- Department of Radiology, Erasmus Medical Center, Dr Molenwaterplein 40, 3015 Rotterdam, The Netherlands.
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Kim JK, Park SY, Kim HJ, Kim CS, Ahn HJ, Ahn TY, Cho KS. Living donor kidneys: usefulness of multi-detector row CT for comprehensive evaluation. Radiology 2003; 229:869-76. [PMID: 14593192 DOI: 10.1148/radiol.2293021098] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate in living renal donors the usefulness of multi-detector row computed tomography (CT) in the assessment of renal vasculature and the upper urinary tract. MATERIALS AND METHODS Four-channel multi-detector row CT scans were obtained in 77 patients. Vascular phase scans were used for CT angiography; excretory phase scans, for CT urography. At CT angiography, two independent observers evaluated the number of arteries and veins and the presence of early-branching arteries. CT urographic images were evaluated with regard to the opacification of the urinary tract and for abnormalities. Findings of CT angiography and urography were compared with surgical findings. Interobserver agreement between CT angiographic and surgical findings was quantified with weighted kappa statistics. Sensitivity and specificity of CT angiography in identifying supernumerary vessels and early-branching arteries were also evaluated. To evaluate the radiation dose to patients, weighted CT dose index (DI) was assessed for each scan. RESULTS Agreement between CT angiographic and surgical findings was excellent for the number of renal arteries (kappa = 0.896) and veins (kappa = 0.843). Detection rate of CT angiography was 98% (89 of 91) for arteries and 98% (83 of 85) for veins. The respective sensitivity and specificity of CT angiography were 86% (12 of 14) and 100% (65 of 65) for supernumerary arteries, 100% (11 of 11) and 100% (66 of 66) for early-branching arteries, and 75% (six of eight) and 100% (69 of 69) for supernumerary veins. At CT urography, collecting systems and proximal ureters were well opacified in all patients; two patients had underrotated kidneys without obstruction. The weighted CT DI was 10.19 mGy for unenhanced and excretory phase scans and 12.88 mGy for the vascular phase scan. CONCLUSION Multi-detector row CT can help assess well the renal vasculature and the urinary tract of living renal donors.
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Affiliation(s)
- Jeong-Kon Kim
- Departments of Radiology and Urology, Asan Medical Center, University of Ulsan, 388-1 Poongnap-dong, Songpa-gu, Seoul 138-736, Korea
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Schoellnast H, Tillich M, Deutschmann HA, Stessel U, Deutschmann MJ, Schaffler GJ, Schoellnast R, Uggowitzer MM. Improvement of parenchymal and vascular enhancement using saline flush and power injection for multiple-detector-row abdominal CT. Eur Radiol 2003; 14:659-64. [PMID: 14566425 DOI: 10.1007/s00330-003-2085-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2002] [Revised: 04/17/2003] [Accepted: 09/01/2003] [Indexed: 12/11/2022]
Abstract
The aim of this study was to determine if a saline solution flush following low dose contrast material bolus improves parenchymal and vascular enhancement during abdominal multiple detector-row computed tomography (MDCT). Forty-one patients (24 men and 17 women; mean age 49 years, age range 27-86 years) underwent abdominal MDCT (collimation 4x5 mm, 15-mm table increment, reconstruction interval 5 mm, gantry rotation period 0.8 s) with a single- as well as with a double syringe power injector. Indication for examination were benign and malignant tumors and inflammatory diseases. Patients received 100 ml nonionic contrast material (300 mgI/ml) alone or pushed with 20 ml saline solution. Mean enhancement values for both protocols were measured in the liver, the spleen, the pancreas, the renal cortex, the portal vein, the inferior vena cava and the abdominal aorta. Double syringe power-injector protocol led to significantly higher parenchymal and vascular enhancement than single syringe power-injector protocol (p<0.05). The improvement in mean enhancement of the liver was 9 +/- 9 HU, of the spleen 8 +/- 10 HU, of the pancreas 7 +/- 9 HU, and of the renal cortex 8 +/- 20 HU. The improvement in mean enhancement of the portal vein was 10 +/- 17 HU of the inferior vena cava 8 +/- 13 HU and of the abdominal aorta 10 +/- 17 HU. The use of a double syringe power injector with saline flush following contrast material bolus significantly improves parenchymal and vascular enhancement during contrast-enhanced abdominal MDCT with low iodine doses.
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Affiliation(s)
- Helmut Schoellnast
- Department of Radiology, University Hospital of Graz, Auenbruggerplatz 9, 8036 Graz, Austria.
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Zhao H, Zhou KR, Yan FH. Role of multiphase scans by multirow-detector helical CT in detecting small hepatocellular carcinoma. World J Gastroenterol 2003; 9:2198-201. [PMID: 14562377 PMCID: PMC4656462 DOI: 10.3748/wjg.v9.i10.2198] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To evaluate the role of multiphasic scanning by multirow-detector helical CT (MDCT) in detecing small hypervascular hepatocellular carcinoma (SHCC).
METHODS: Multiphasic scanning was carried out in 75 patients with SHCC with Marconi MX8000 CT scanner. The early arterial phase (EAP), late arterial phase (LAP) and the portal venous phase (PVP) scans were started at 21 s, 34 s and 85 s respectively. The mean difference of CT values between tumor and liver parenchyma for each scanning phase was measured, and the sensitivity of detection of SHCC in each of these phases and in the combined phase was calculated and statistically analyzed.
RESULTS: The mean difference of CT values between tumor and liver parenchyma was significant in 71 lesions ≥ 1 cm in three phases (P < 0.05). In 91 tumor foci, the detectability of SHCC was 45.1%, 83.5% and 92.3% in EAP, LAP and double arterial phases (DAP), respectively. The early arterial phase plus the portal venous phase and the double arterial phase plus the portal venous phase were 94.5%, 97.8%, respectively. Whereas the detectability in LAP plus PVP and in DAP plus PVP had no statistical difference.
CONCLUSION: The utility of faster speed and thinner slice MDCT and multiphase scanning protocol can improve the detectability of hypervascular small hepatocellular carcinoma. Among which LAP is superior to EAP in depicting the lesions.
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Affiliation(s)
- Hong Zhao
- Department of Radiology, First Hospital, Shanxi Medical College, Taiyuan 030001, Shanxi Province, China.
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Awai K, Hori S. Effect of contrast injection protocol with dose tailored to patient weight and fixed injection duration on aortic and hepatic enhancement at multidetector-row helical CT. Eur Radiol 2003; 13:2155-60. [PMID: 12736754 DOI: 10.1007/s00330-003-1904-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2002] [Revised: 01/02/2003] [Accepted: 03/03/2003] [Indexed: 11/25/2022]
Abstract
The aim of this study was to investigate the effect of a contrast material injection protocol with dose and injection rate of contrast material tailored to patient weight (dose tailored to patient weight and fixed injection duration). Hepatic helical CT was performed in 92 patients with chronic liver damage with a dose of 1.4 ml (518 mgI) at a rate of 0.056 ml/s per kilogram body weight of Iopamidol 370. Attenuation values of liver and aorta were measured for calculation of maximum aortic and hepatic enhancement, time to maximum hepatic enhancement, and end of hepatic arterial phase. Correlation coefficients between the injection rate and the four parameters were r=0.008, 0.057, 0.167, and 0.036, and there were no statistically significant correlations between the injection rates and the four parameters. In our injection protocol, uniform temporal scan window may be achieved and the injection rate can be reduced in lighter patients without reducing the degree of enhancement in the aorta and the liver.
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Affiliation(s)
- Kazuo Awai
- Department of Radiology, Kinki University School of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, 589-8511 Osaka, Japan.
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