The aim of this study was to develop a nomogram to predict the risk of developing clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreaticoduodenectomy (PD) using preoperative clinical and imaging data.

The data of 205 patients were retrospectively analyzed, randomly divided into training (n = 125) and testing groups (n = 80). The patients' preoperative laboratory indicators, preoperative clinical baseline data, and preoperative imaging data [enhanced computed tomography (CT), enhanced magnetic resonance imaging (MRI)] were collected. Univariate analyses combined with multivariate logistic regression were used to identify the independent risk factors for CR-POPF. These factors were used to train and validate the model and to develop the risk nomogram. The area under the curve (AUC) was used to measure the predictive ability of the models. The integrated discrimination improvement index (IDI) and decision curve analysis (DCA) were used to assess the clinical feasibility of the nomogram in relation to five other models established in literature.

CT visceral fat area (P = 0.014), the pancreatic spleen signal ratio on T1 fat-suppressed MRI sequences (P < 0.001), and CT main pancreatic duct diameter (P = 0.001) were identified as independent prognostic factors and used to develop the model. The final nomogram achieved an AUC of 0.903. The IDI and DCA showed that the nomogram outperformed the other five CR-POPF models in the training and testing cohorts.

The nomogram achieved a superior predictive ability for CR-POPF following PD than other models described in literature. Clinicians can use this simple model to optimize perioperative planning according to the patient's risk of developing CR-POPF.

Postoperative pancreatic fistula (POPF) is one of the serious complications of pancreatic surgery. When POPF occurs and becomes severe, it causes secondary complications and a longer treatment period. We previously reported a correlation between pancreatic fibrosis and magnetic resonance imaging (MRI) findings, and MRI may have the potential to predict POPF. This study aimed to assess the predictive ability of the pancreas-to-muscle signal intensity ratio on T₁-weighted MRI (SIR on T₁-w MRI) for POPF after distal pancreatectomy (DP).

This single-institution retrospective study comprised 117 patients who underwent DP. It was conducted between 2010 and 2021 at the Gifu University Hospital. We statistically analyzed pre-, intra-, and postoperative factors to assess the correlation with POPF.

According to the definition and grading of the International Study Group of Pancreatic Fistula (ISGPF), 29 (24.8%) of the 117 patients had POPF grades B and C. In the univariate analysis, POPF was significantly associated with the pancreas-to-muscle SIR on T₁-w MRI, the drainage fluid amylase concentration (D-Amy) levels on postoperative day (POD) 1 and 3, white blood cell count on POD 1 and 3, C-reactive protein level on POD 3, and heart rate on POD 3. In multivariate analysis, only the pancreas-to-muscle SIR on T₁-w MRI (>1.37; odds ratio [OR] 23.25; 95% confidence interval [CI] 3.93-454.03; p < 0.01) and D-Amy level on POD 3 (>737 U/l; OR 3.91; 95% CI 1.02-16.36; p = 0.046) were identified as independent predictive factors.

The pancreas-to-muscle SIR on T₁-w MRI and postoperative D-Amy levels were able to predict the development of POPF after DP. The pancreas-to-muscle SIR on T₁-w MRI may be a potential objective biomarker reflecting pancreatic status.

Postoperative pancreatic fistula (POPF) is the most serious complication of distal pancreatectomy (DP). When POPF occurs and becomes severe, it causes secondary complications and leads to a longer treatment period. This study aimed to identify early predictive factors of POPF after DP for pancreatic cancer (PC).

This retrospective, single-institution study comprised of 55 patients with PC who underwent DP between 2010 and 2021 at the Gifu University Hospital. We statistically analyzed pre-, intra-, and post-operative factors to identify early predictive factors for POPF.

According to the definition and grading of the International Study Group of Pancreatic Fistula (ISGPF), 12 (21.8%) of 55 patients had POPF grades B and C. In the univariate analysis, POPF was significantly associated with the pancreas-to-muscle signal intensity ratio on T ₁ -weighted magnetic resonance imaging (SIR on T ₁ -w MRI), the drainage fluid amylase (D-Amy) levels on postoperative day 3 (POD3), C-reactive protein (CRP) on POD3, and heart rate on POD3. In multivariate analysis, pancreas-to-muscle SIR on T ₁ -w MRI [>1.37; odds ratio (OR)=17.08; 95% confidence interval (CI)=1.64-598.16; p=0.02], D-Amy levels on POD3 (>1,200 U/l; OR=20.00; 95% CI=1.73-563.83; p=0.02) and heart rate on POD3 (>100 bpm; OR=15.33; 95% CI=1.53-258.45; p=0.02) were identified as independent early predictive factors.

Preoperative pancreas-to-muscle SIR on T ₁ -w MRI and postoperative D-Amy levels and heart rate significantly correlated with POPF after DP for PC. Postoperative management based on these predictive factors may improve the postoperative course.

To evaluate the potential value of magnetic resonance imaging (MRI) for predicting postoperative pancreatic fistula (POPF) in patients with pancreatic cancer (PC) and non-pancreatic cancer (non-PC).

This retrospective study was approved by the institutional review board and written informed consent was waived. Forty patients underwent pancreatoduodenectomy due to PC (n=31) and non-PC (n=9). The pancreas-to-muscle signal intensity ratio (SIR) on three-dimensional (3D)- fast field echo (FFE) T1-, in- and opposed-phase T1-, and T2-weighted images, as well as the apparent diffusion coefficient (ADC) value of the pancreas were measured. The frequency of POPF and MRI measurements were compared between patients with PC and non-PC. The MRI measurements were also compared with the grade of pancreatic fibrosis on pathological findings, fat deposition, and interstitial oedema.

The frequency of POPF was significantly higher in patients with non-PC than in those with PC (p=0.0067), with an odds ratio of 10.4. The SIR on 3D-FFE T1-weighted images was significantly higher in patients with non-PC (p=0.0001) and those with POPF (p=0.017) than in those with PC and those without POPF, respectively. Multiple regression analysis demonstrated that the SIR on 3D-FFE T1-weighted image was independently associated with the grade of pancreatic fibrosis (p<0.0001).

The frequency of POPF was significantly higher in patients with non-PC than in those with PC was inversely related to the grade of pancreatic fibrosis. The SIR on 3D-FFE T1-weighted image might be a potential imaging biomarker for predicting POPF.

To evaluate the diagnostic performance of noncontrast-enhanced magnetic resonance imaging (MRI) to grade pancreatic fibrosis and to assess hemoglobin (Hb) A1c values.

Twenty-nine consecutive patients with pancreatic or biliary malignancy who underwent pancreatectomy were evaluated. Patients were classified into three groups: HbA1c < 5.7 (group 1), 5.7 ≤ HbA1c < 6.5 (group 2), and HbA1c ≥ 6.5 (group 3). MRI of the pancreas was performed using a 1.5T MR system. The pancreas-to-muscle signal intensity ratio (SIR) on in- and opposed-phase T1 -, T2 -, and diffusion-weighted images, as well as the apparent diffusion coefficient were calculated. MRI measurements, degrees of pancreatic fibrosis, and HbA1c values were compared using multiple regression analysis and Kruskal-Wallis test.

The pancreatic fibrosis grade was negatively correlated with the SIR on in-phase T1 -weighted images (r = -0.67, P = 0.0002). The pancreatic fibrosis grade and HbA1c value were negatively correlated with the SIR on opposed-phase T1 -weighted images (r = -0.47, P = 0.019 and r = -0.51, P = 0.0089, respectively). SIRs on in- and opposed-phase T1 -weighted images were significantly lower in group 3 than in groups 1 and 2 (P < 0.05).

The pancreas-to-muscle SIRs on in- and opposed-phase T1 -weighted images could be a potential biomarker for pancreatic fibrosis and elevated HbA1c values.

To compare 2D spoiled dual gradient-echo (SPGR-DE) and 3D SPGR-DE with fat and water separation for the assessment of focal and diffuse fatty infiltration of the liver.

A total of 227 consecutive patients (141 men; 56 ± 14 years) underwent clinically indicated liver MRI at 1.5 T including multiple-breath-hold 2D SPGR-DE and single-breath-hold 3D SPGR-DE with automatic reconstruction of fat-only images. Two readers assessed the image quality and number of fat-containing liver lesions on 2D and 3D in- and opposed-phase (IP/OP) images. Liver fat content (LFC) was quantified in 138 patients without chronic liver disease from 2D, 3D IP/OP, and 3D fat-only images.

Mean durations of 3D and 2D SPGR-DE acquisitions were 23.7 ± 2.9 and 97.2 ± 9.1 s respectively. The quality of all 2D and 3D images was rated diagnostically. Three-dimensional SPGR-DE revealed significantly more breathing artefacts resulting in lower image quality (P < 0.001); 2D and 3D IP/OP showed a similar detection rate of fat-containing lesions (P = 0.334) and similar LFC estimations (mean: +0.4 %; P = 0.048). LFC estimations based on 3D fat-only images showed significantly higher values (mean: 2.7 % + 3.5 %) than those from 2D and 3D IP/OP images (P < 0.001).

Three dimensional SPGR-DE performs as well as 2D SPGR-DE for the assessment of focal and diffuse fatty infiltration of liver parenchyma. The 3D SPGR-DE sequence used was quicker but more susceptible to breathing artefacts. Significantly higher LFC values are derived from 3D fat-only images than from 2D or 3D IP/OP images.

To identify characteristic magnetic resonance (MR) features of focal autoimmune pancreatitis (f-AIP) useful for differentiation from pancreatic cancer (PC).

We retrospectively analyzed MR imaging findings of 20 f-AIP lesions and 40 PC lesions smaller than 40 mm in diameter. On fat-suppressed T2-weighted images and dynamic contrast-enhanced fat-suppressed T1-weighted images (DCE-T1WI), we classified MR features of internal signal intensity for each lesion into homogeneous, speckled, or target type. We assessed the sensitivity, specificity, and accuracy of these findings in the diagnosis of f-AIP. We also investigated the incidence of previously reported findings for differentiation between f-AIP and PC.

Speckled enhancement within a hypointense or isointense lesion on pancreatic phase DCE-T1WI (speckled type) was observed more frequently in f-AIP than in PC, with high sensitivity, high specificity, and high accuracy. Hypointensity to hyperintensity surrounding a less enhanced focal area on DCE-T1WIs (target type) and upper stream main pancreatic duct dilatation were observed more frequently in PC than in f-AIP.

Speckled enhancement inside an f-AIP lesion on pancreatic phase DCE-T1WI was useful for differentiation from PC.

Post-operative pancreatic fistula (POPF) is one of the most fearful complications which may occur after pancreaticoduodenectomy (PD). The methods used to predict POPF pre-operatively have not been studied in great detail. We analyzed correlation between various parameters related to PD including pre-operative magnetic resonance imaging (MRI) signal intensity (SI), pathology of pancreatic fibrosis and occurrence rates of POPF, and verified that MRI SI results could be the determining values for pre-operative prediction of POPF.

From January 2005 to August 2006, we retrospectively examined 43 cases of PDs by reviewing abdominal MRI findings, degree of fibrosis of remnant pancreatic stump, and other surgery-related parameters.

POPF encountered in PD were 11 cases (25.6%). Operation time and degree of fibrosis of remnant pancreatic cut surface were related to POPF (P= 0.030, P= 0.010). The pancreas-liver SI ratio (PLSI) between fistula group and no fistula group was -0.0009 +/- 0.2 and -0.1297 +/- 0.2, respectively (P= 0.0004). The pancreas-spleen SI ratio (PSSI) in each group was 0.423 +/- 0.25 and 0.288 +/- 0.32, respectively (P= 0.014). Using quantitative analysis, the SI ratios were 1.27 and 0.66 in each group (P= 0.013).

When analyzing the results of POPF in 43 patients who underwent PD, PLSI, PSSI and qualitative analysis, fistula group differed significantly from no fistula group. Using these results, it will be helpful for us to predict the occurrence of POPF pre-operatively using MRI in PD patients.

The diagnosis and surgical management of insulinomas associated with multiple endocrine neoplasia type 1 (MEN1) pose additional problems in children because of the long-term risk of recurrence of other pancreatic and non-pancreatic tumors. We report a diagnostic confirmation by laparoscopic ultrasound of an insulinoma and its successful removal by laparoscopic enucleation in an 8- year-old boy who was admitted to our hospital with a history of recurrent episodes of absences, headache, and visual and auditive disturbances diagnosed as hyperinsulinism-related hypoglycemia. Magnetic resonance imaging of the pancreas showed a small contrast-enhancing lesion in the body of the pancreas, suspected for insulinoma. MEN1 was genetically proven by direct DNA testing. A pancreatic tumor can arise before the age of 10 in patients with MEN1 and can be surgically treated by a laparoscopical approach.

Pancreatic cancer remains the fourth most common cause of cancer death. Surgery remains the only option for cure. Accurate diagnosis and staging are essential for appropriate management of patients with pancreatic cancer. This paper reviews the state of the art for imaging modalities in the diagnosis and staging of pancreatic adenocarcinoma. The crucial role of CT has increased with the new generation of multidetector CT.

MR imaging is a valuable tool in the assessment of the full spectrum of pancreatic diseases. MR imaging techniques are sensitive for the evaluation of pancreatic disorders in the following settings: (1) TI-weighted fat-suppressed and dynamic gadolinium-enhanced SGE imaging for the detection of chronic pancreatitis, ductal adeno-carcinoma, and islet-cell tumors; (2) T2-weighted fat-suppressed imaging and T2-weighted breath-hold imaging for the detection of islet-cell tumors;and (3) precontrast breath-hold SGE imaging for the detection of acute pancreatitis. Relatively specific morphologic and signal intensity features permit characterization of acute pancreatitis,chronic pancreatitis, ductal adenocarcinoma, insulinoma, gastrinoma, glucagonoma, microcystic cystadenoma, macrocystic cystadenoma, and solid and papillary epithelial neoplasm. MR imaging is effective as a problem-solving modality because it distinguishes chronic pancreatitis from normal pancreas and chronic pancreatitis with focal enlargement from pancreatic cancer in the majority of cases.MR imaging studies should be considered in the following settings: (1) in patients with elevated serum creatinine, allergy to iodine contrast, or other contraindications for iodine contrast administration; (2) in patients with prior CT imaging who have focal enlargement of the pancreas with no definable mass; (3) in patients in whom clinical history is worrisome for malignancy and in whom findings on CT imaging are equivocal or difficult to interpret; and (4) in situations requiring distinction between chronic pancreatitis with focal enlargement and pancreatic cancer. Patients with biochemical evidence of islet-cell tumors should be examined by MR imaging as the first-line imaging modality because of the high sensitivity of MR imaging for detecting the presence of islet-cell tumors and determining the presence of metastatic disease.

To evaluate the accuracy of signal intensity (SI) analysis on unenhanced fat-suppressed T1-weighted MR images in the diagnosis of pancreatic disease and to compare subjective interpretation with different quantitative measurements.

The pancreas was evaluated in 159 patients (86 normal and 73 with pancreatic disease) with spoiled gradient echo (GRE) T1-weighted fat saturation MR images. The relative SI of the pancreas to liver and spleen was quantitatively measured using regions of interest (ROIs) and qualitatively assessed by two independent observers.

The mean values between a normal and an abnormal pancreas with pancreas-liver ratios of 0.14 +/- 0.37 vs. -0.32 +/- 0.24, respectively, and pancreas-spleen ratios of 0.89 +/- 0.55 vs. 0.02 +/- 0.43, respectively, were significantly different (P < 0.001). The pancreas-liver SI ratio was significantly better than the pancreas-spleen ratio throughout the disease group (area under the receiver operating characteristic (ROC) curve +/- SD; 0.92 +/- 0.02 for pancreas-liver vs. 0.86 +/- 0.03 for pancreas-spleen, P < 0.01), and after excluding cases of acute pancreatitis (0.96 +/- 0.02 for pancreas-liver vs. 0.89 +/- 0.03 for pancreas-spleen, P < 0.01). There was no statistically significant difference between quantitative and qualitative analysis (area under the ROC curve +/- SD; 0.93 +/- 0.02 vs. 0.93 +/- 0.02 for the entire disease group; excluding acute pancreatitis 0.96 +/- 0.02 vs 0.97 +/- 0.02) for the diagnosis of pancreatic disease when using liver as internal standard. The interobserver concordance was very good (kappa > 0.71). The sensitivity of visual liver comparison was 80% in the entire disease group and 91% after the cases of acute pancreatitis were excluded, while specificity was 93%.

The pancreas-liver ratio is the best quantitative means of distinguishing normal from abnormal pancreas. Visual observation by experienced observers (qualitative measurement) was just as accurate as quantitative measurement. Detection of pancreatic pathology can be made with high accuracy by visually comparing the SI of the pancreas with that of the normal liver.

MR imaging has made significant advances in recent years, with an increasingly important role in the detection, characterization, and staging of pancreatic diseases. MRI is appealing as a noninvasive imaging modality as it can evaluate the pancreas, the vasculature, and the pancreaticobiliary ducts in a single examination. Advantages of MRI include its excellent soft tissue contrast resolution and anatomic detail and absence of ionizing radiation. This article reviews the utility of MRI and its use not only as a problem-solving tool but its potential use as a primary examination (similar to CT) in a wide variety of pancreatic diseases.

To compare the effectiveness of thin-section helical CT and MR imaging with gadolinium-enhanced dynamic technique and MR cholangiopancreatography (MRCP) in the examination of patients with intraductal papillary mucinous tumors.

Helical CT, dynamic MR imaging, and MRCP of 25 intraductal papillary mucinous tumors were compared with ERCP and surgical findings.

The duodenal papilla was identified by helical CT and dynamic MR imaging in 11 (44%) and 20 (80%) of the 25 patients, respectively (p<0.05). The main pancreatic duct was visualized on helical CT, dynamic MR imaging, and MRCP in all patients (100%): 25 (96.2%), 24 (92.3%), and 26 (100%) cystic lesions were depicted, respectively. A communicating duct between the main pancreatic duct and the cystic lesion was visualized on helical CT, dynamic MR imaging, and MRCP in 14 (53.8%), 11 (42.3%), and 15 (55.7%) lesions, respectively. The papillary projections corresponding to 3 mm or larger papillary neoplasms were depicted on helical CT and MR imaging in 7 patients (25%).

MR imaging was equal or slightly superior to thin-section helical CT in the evaluation of intraductal papillary mucinous tumors.

This article reviews the current practical MRI techniques in assessment of the pancreas. With the comprehensive "one-stop-shopping" approach, the great majority of pancreatic diseases can be detected and characterized by the use of a combination of T1, T2-weighted, MRCP, and fat-suppressed T1-weighted dynamic post-gadolinium SGE sequences. This approach may provide the clinician with information regarding the site, nature, and staging of pancreatic tumor in a single setting. In many institutions worldwide, however, including our own, CT remains the main imaging method for the assessment of acute pancreatic diseases, due largely to its wide availability. MR imaging is reserved for the indications listed above, most importantly, the detection of small and non-organ-deforming pancreatic ductal adenocarcinoma, islet cell tumors, choledocholithiasis and pancreatic duct calculi, cholangiocarcinomas, and in cases of pancreatic head enlargement with no mass discernable on CT.

Neuroendocrine tumours of the pancreas are rare and are frequently difficult to demonstrate. Several imaging modalities have been used to demonstrate these tumours, but recent reports have suggested that MRI may have an important role in their localization. We review the spectrum of MRI appearances of pancreatic neuroendocrine tumours.

The aim of the study was to find the fast magnetic resonance imaging (MRI) sequence with the best conspicuity of pancreatic lesions at 1.0 T and 1.5 T. A total of 51 patients were studied. At 1.0 T, 22 patients with verified malignant pancreatic lesions were studied using the T1-weighted breath-hold spoiled Gradient Echo 2D FLASH(75) or FLASH(80) sequences, both non-enhanced and enhanced with gadolinium. The relative signal intensity difference (SIDR) between lesion and pancreas was measured. At 1.5 T, 20 patients with primary malignant lesions of the pancreas, and nine patients with 13 benign cystic lesions were examined with the breath-hold T2-weighted TrueFISP, HASTE, T1-weighted 2D FLASH(80) and FLASH(50) fat saturation sequences, the latter also enhanced. The signal intensity (SI) values of the pancreas and lesions as well as the pancreatic standard deviation (S.D.) were assessed, and the contrast-to-noise ratio (C/N) was determined. Statistical significances were calculated using an analysis of variance. No statistically significant difference between the sequences used in the conspicuity of cancer was found, either at 1.0 T or at 1.5 T. At 1.5 T, the T2-weighted TrueFISP and HASTE sequences could differentiate benign, cystic lesions from malignant lesions.

To compare the efficacy of dynamic contrast-enhanced MR imaging and spin-echo T1-weighted with and without fat-saturated MR imaging in the detection and staging of pancreatic adenocarcinoma.

Spin-echo T1-weighted, fat-saturated T1-weighted and dynamic breath-hold 2D-FLASH MR imaging were performed in 25 patients with pancreatic adenocarcinoma. MR images were analysed by calculating the CNR between tumor and normal portion of the pancreas. The CNRs calculated at each sequences were compared. A total of 16 out of 25 patients underwent surgery. Preoperative staging according to TNM classification was also done in patients undergoing surgery.

The CNR was significantly different (P<0.05) in the arterial phase of dynamic MR images. The accuracy of 'T' staging was 75% for SE T1-W, fat-saturated T1-W and arterial phase of dynamic MR images.

The CNRs between pancreatic carcinoma and normal pancreas is significantly higher in dynamic MR sequences than the SE T1-W, fat-saturated T1-W sequences. However, the accuracy of tumor staging according to TNM is equivocal to SE T1-W and fat-saturated T1-W images.

Malignant lesions of the biliary tract are a frequent occurrence, typically presenting with clinical findings of obstructive jaundice. The authors discuss the role of MR cholangiopancreatography (MRCP) as a second level diagnostic technique, which can provide information regarding not only the location, but also the cause of the obstruction. This can be obtained if MRCP is considered as part of a complete study of the upper abdomen, with acquisition of T1- and T2-weighted images. The "all-in-one" approach may provide the identification, characterization, and staging of the lesion, giving the clinician all the information necessary for the planning of adequate treatment. Typical MR features of cholangiocarcinoma are provided, as well as conventional MR and MRCP findings in pancreatic carcinoma, periampullary carcinoma, and biliary obstruction secondary to hilar lymphadenopathy and metastatic lesions.

To compare a T1-weighted, three-dimensional (3D), gradient-echo (GRE) sequence for magnetic resonance (MR) imaging of the body (volumetric interpolated breath-hold examination, or VIBE) with a two-dimensional (2D) GRE breath-hold equivalent.

Twenty consecutive patients underwent 1.5-T MR imaging. The examinations included pre- and postcontrast (20 mL gadopentetate dimeglumine) fat-saturated 2D GRE breath-hold imaging and fat-saturated volumetric interpolated breath-hold imaging before, during (arterial phase), and after injection, with thin (2-mm source images) and thick (8-mm reconstruction images) sections. The three images were compared qualitatively and quantitatively (signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]).

Qualitatively, the 2-mm source images had poorer pancreatic edge definition on precontrast images compared with the other two data sets (P < .05). On gadolinium-enhanced images, scores for clarity of pancreatic edge, number of vessels visualized, and arterial ghosting were significantly lower for the postcontrast 2D GRE images. Quantitatively, SNR measurements in the liver, aorta, and renal cortex on pre- and postcontrast images were significantly higher for the 8-mm reconstruction images than for the 2D GRE or 2-mm source images (P < .05). Aorta-to-fat CNR was significantly higher on the 8-mm reconstruction images.

Fat-saturated volumetric interpolated breath-hold images have quality comparable to that of conventional fat-saturated 2D GRE images.

To compare contrast material-enhanced thin-section helical CT with breath-hold contrast-enhanced MR imaging for sensitivity in the detection of pancreatic adenocarcinoma and for accuracy in local tumor staging.

Fifty-seven patients (37 men, 20 women aged 42-28 years) suspected of having pancreatic adenocarcinoma were examined. The final diagnosis was confirmed at surgery to be pancreatic cancer in 31 patients; the other 26 patients were deemed not to have pancreatic cancer. All patients underwent both CT and MR imaging (turbo spin-echo and fast low-angle shot) studies. Image quality and pancreatic enhancement were subjectively evaluated. All CT scans and MR images were assessed by two independent observers by using a five-point scale for the detection of tumor and of invasion into the peripancreatic tissue, portal vein, and/or peripancreatic artery. Receiver operating characteristic curves for CT and MR imaging were analyzed.

At visual analysis, pancreatic enhancement at CT and at MR imaging was comparable, but depiction of vessels was superior at helical CT. Detectability of tumor was comparable. Helical CT was significantly superior to MR imaging in diagnostic imaging of invasion into the peripancreatic tissue, portal vein, and/or peripancreatic artery (P < .01).

Thin-section dynamic CT is more sensitive than MR imaging for detection of peripancreatic and vascular invasion in patients with pancreatic cancer.

This study compared one routine T2-weighted fast spin echo (T2FSE) sequence with a breath-hold T2FSE (BH T2FSE) sequence of the female pelvis for image quality, uterine anatomy, lesion detection, and signal intensity measurements. Thirty-two consecutive women (mean age 41.7 years) were imaged at 1.5 T with one high-resolution routine T2FSE sequence and one BH T2FSE sequence in the sagittal plane as part of comprehensive pelvic magnetic resonance imaging. The different image sets were rated separately for imaging characteristics (overall image quality, uterine anatomy definition, lesion detection, and free fluid conspicuity) and then compared side by side. The image sets were also compared for artifacts (ghosting, blurring, pulsatility, and chemical shift misregistration). Signal-to-noise (S/N) and signal difference-to-noise (SD/N) ratios were calculated for the different uterine zones, uterine abnormalities, free fluid, rectus abdominis muscle, and bladder. Contrast-to-noise ratios (CNRs) were calculated for uterine abnormalities. Twenty-eight uterine abnormalities were detected in 20 patients and included leiomyomata (13 patients), adenomyosis (7 patients), benign endometrial polyps (6 patients), endometrial carcinoma (1 patient), and pregnancy (1 patient). BH T2FSE was superior or equivalent to T2FSE for overall image quality in 23/32 patients (71.8%), uterine anatomy definition in 19/32 patients (59.3%), and lesion detection in 13/20 patients (65%). BH T2FSE performed less well than T2FSE for free fluid conspicuity in 5/5 (100%) patients. BH T2FSE was equivalent to or less affected than T2FSE for ghosting artifact in 24/32 patients (75%) and blurring artifact in 29/32 patients (90.6%). Pulsatility and chemical shift artifacts were not problematic for either image set. S/N and SD/N were higher for all BH T2FSE determinations compared with T2FSE. For the endometrium, junctional zone, myometrium, and bladder, these differences were statistically significant. There were no statistically significant differences for CNR between the two image sets, although BH T2FSE values for leiomyomata, adenomyosis, and abnormal endometria were higher than those calculated for T2FSE. All pathology detected with T2FSE was detected on BH T2FSE despite the breath-hold sequence's inherently poorer spatial resolution compared with the non-breath-hold sequence. BH T2FSE may be able to replace T2FSE for some uterine applications with a substantial time savings.

The purpose of this study was to compare contrast-enhanced GRE and conventional SE (CSE) fat-suppressed T1-weighted techniques in the evaluation of head and neck lesions. A hybrid, opposed phase, frequency-selective, fat-suppressed fast multiplanar spoiled GRE (FMPSPGR) sequence was compared with a fat-suppressed CSE sequence.

Thirty-two patients with head and neck pathology were evaluated with both fat-suppressed CSE and FMPSPGR sequences. Regions of interest obtained by two viewers in consensus were used to establish contrast-to-noise (CNR) and signal-to-noise ratios for both sequences. Three neuroradiologists also independently reviewed the images for quality of fat suppression, lesion conspicuity, and potential pitfalls.

The CNR of the FMPSPGR sequence was superior to that of the fat-suppressed CSE sequence. Subjectively, all three reviewers rated the FMPSPGR sequence as having fat suppression equal to or better than that in the CSE sequence in 94% of cases. Imaging times for the FMPSPGR sequence were 60-75% faster than those for the CSE sequence.

Enhanced imaging of the head and neck region using an opposed phase, fat-suppressed GRE sequence results in improved fat suppression compared with the CSE technique, with substantial savings in imaging time.

Our goal was to determine the efficacy of a dedicated protocol for pancreatic MRI using fat suppression, oblique plane orientation, and barium as an oral contrast agent.

Fifty-two patients were enrolled in our study. In each patient, the stomach and duodenum were opacified with 300 ml oral barium. In all patients conventional SE T1- and T2-weighted images and fat-suppressed axial and oblique T1-weighted images of the upper abdomen and the pancreas, respectively, were obtained. The different T1-weighted sequences were compared for visualization of the pancreas and for lesion conspicuity. Oblique images were obtained in a plane parallel to the overall axis of the pancreas. All sequences were qualitatively assessed by two independent blinded readers and statistically compared.

The combination of fat suppression and oblique imaging significantly improved the visualization of the different anatomic portions of the normal pancreas as well as pathologic findings in the pancreas in 70-92% of the cases compared with conventional axial T1-weighted imaging (p < 0.001) and in 52-75% of the cases compared with axial fat-suppressed T1-weighted imaging (p < 0.001), respectively. Increased image noise and blurring artifacts resulted in slight image degradation after Gd-DTPA administration. Barium as a duodenal contrast agent was beneficial for delineation of the pancreatic head from the adjacent bowel structures.

In pancreatic imaging, fat-suppressed T1-weighted imaging is superior to conventional T1-weighted imaging, and oblique imaging is superior to axial imaging. Intravenous Gd-DTPA administration was useful only in selected cases.

This article reviews the currently available MR imaging techniques that are useful for the detection and characterization of focal and diffuse liver pathology. The implementation and clinical utility of various T1-weighted, T2-weighted, T2*-weighted, and MR angiographic sequences are described.

The purpose of this study was to compare the value of dynamic magnetic resonance imaging (MRI) and fat suppression in detecting a pancreatic tumor. The subjects were 19 patients with invasive ductal adenocarcinoma and six patients with islet cell tumor where diagnosis was established pathologically. Breath-hold gradient echo images, breath-hold gradient echo images with fat suppression and breath-hold gradient echo images with dynamic enhancement at 1.5 T were obtained for all patients. The efficacies of these three imaging techniques were compared by calculating the contrast-to-noise ratio, as indicative of conspicuousness between a tumor-affected and a normal pancreas. As for adenocarcinoma, our results indicated that the usefulness in detecting the tumor was high, decreasing in the order dynamic contrast images > fat suppression images > plain images, and that the difference between any two of these three types of image was statistically significant. On the other hand, these imaging techniques showed no statistically significant difference in detecting islet cell tumors. In conclusion, dynamic MRI is the best method for detecting pancreatic adenocarcinoma. As the fat suppression technique has the advantage of being non-invasive, this method is suitable for screening studies of pancreatic adenocarcinoma. However, no advantage was recognized in using the fat suppression technique for detecting an islet cell tumor in comparison with plain MRI.

MRI of the pancreas and bile ducts is becoming more widely used due to recent advances in surface coils, breath-hold imaging techniques, and magnetic resonance cholangiopancreatography (MRCP). MRI provides a comprehensive and accurate examination for the detection, staging, and characterization of a variety of developmental, inflammatory, and neoplastic processes that involve the pancreas.

A new method is introduced for water-fat imaging. With three acquisitions, a general direct phase encoding (DPE) of the chemical shift information is achieved. Pixels containing both water and fat are solved directly. Pixels with only a single component are resolved with local and global orientation filters, which use phase information from neighboring pixels. The fact that a single component is more likely to be water than fat in living tissues is also useful. A second pass solution yields water and fat images with superior signal-to-noise ratio. Unlike other methods, DPE does not rely on the error-prone phase unwrapping; also, it easily handles disconnected tissues. Because the magnetization vectors of water and fat are sampled not only at parallel or antiparallel, they can be not only separated but also identified respectively, which is desirable for routine clinical work. DPE has been implemented on several imagers at various field strengths and has been demonstrated in a large number of clinical cases to be useful and robust in various parts of the body.

Reliable fat suppression is especially important with fast imaging techniques such as echo-planar (EPI), spiral, and fast spin-echo (FSE) T2-weighted imaging. Spectral-spatial excitation has a number of advantages over spectrally selective presaturation techniques, including better resilience to B0 and B1 inhomogeneity. In this paper, a FSE sequence using a spectral-spatial excitation pulse for superior fat suppression is presented. Previous problems maintaining the CPMG condition are solved using simple methods to accurately program radio-frequency (RF) phase. Next an analysis shows how B0 eddy currents can reduce fat suppression effectiveness for spectral-spatial pulses designed for conventional gradient systems. Three methods to compensate for the degradation are provided. Both the causes of the degradation and the compensation techniques apply equally to gradient-recalled applications using these pulses. These problems do not apply to pulses designed for high-speed gradient systems. The spectral-spatial FSE sequence delivers clinically lower fat signal with better uniformity than spectrally selective pre-saturation techniques.

The purpose of this study was to evaluate the ability of in-phase spoiled gradient echo combined with chemically selective fat suppression or out-of-phase spoiled gradient echo MR images to characterize small renal masses as angiomyolipomas. Eleven patients with a total of 35 small (< 1.5 cm) angiomyolipomas underwent MR examination at 1.5T. Eight patients had solitary and three patients had multiple angiomyolipomas. One of the patients with multiple angiomyolipomas had tuberous sclerosis and the number of angiomyolipomas were quantified as 20. MR examinations included in-phase spoiled gradient echo (all patients), chemically selective fat suppressed spin echo (six patients), chemically selective fat suppressed spoiled gradient echo (three patients), selective water excitation spoiled gradient echo (one patient) and out-of-phase spoiled gradient echo (seven patients). Angiomyolipomas were minimally (4 lesions) or moderately (31 lesions) high in signal intensity relative to renal cortex on in-phase spoiled gradient echo images. On out-of-phase spoiled gradient echo images, demonstration of signal void fat-water phase cancellation was present in all eight lesions in the seven patients who were imaged with this sequence. Small lesion size rendered the entire angiomyolipoma signal void in seven of these eight lesions due to phase cancellation artifact. Signal void phase cancellation of lesion border or signal void of the entire angiomyolipoma resulted in high lesion conspicuity in all lesions. Mild loss of signal intensity was observed in 7 lesions and moderate loss of signal intensity noted in 25 lesions on chemically selective fat suppressed images. On chemically selective fat-suppressed images, seven lesions were difficult to identify due to limited signal differences between medium intensity cortex and low intensity angiomyolipomas (six lesions in two patients) and moderate breathing artifact (one lesion in one patient). Characterization of small renal masses as angiomyolipomas may be reliably performed using the combination of in-phase and fat-attenuating MR sequences. Consistent image quality and high conspicuity of fat-water phase cancellation interfaces renders out-of-phase imaging a reliable fat attenuating method to demonstrate the presence of fat in small angiomyolipomas. Breath-hold fat-suppressed spoiled gradient echo is also effective; however, this technique demonstrates less signal loss in fatty lesions and is subject to problems with inhomogeneity of fat suppression.

It is shown that the maximum average-data-collection-speed (ADCS) of multisection 2D hybrid-RARE sequences is independent of TR and TEeff, and a monotonically increasing function of echo-train-length (ETL). This result was used in the design of an optimized T1-weighted hybrid-RARE sequence that produces 20 images of the abdomen in 31 s divided into four breath-hold periods. The resulting ADCS is 58 lines in k-space per second. Twenty-four subjects (2 healthy volunteers and 22 patients) were imaged with a protocol that also included: (a) breath-hold T1-weighted FLASH which acquires data at 34 lines in k-space per second (49 s scan time), and (b) T1-weighted conventional spin-echo (9:44 minutes scan time) with respiratory compensation. The experiments show that this T1-weighted-hybrid-RARE sequence has: (1) a level of T1 weighting that is comparable with the conventional sequences, (2) very low vulnerability to susceptibility artifacts, (3) high data acquisition efficiency, and (4) higher SNR than T1-weighted-FLASH. In conclusion, the T1-weighted-hybrid-RARE sequence described herein is an efficacious and reproducible technique for rapid imaging of the upper abdomen during suspended respiration.

The increased efficiency of MRI data acquisition has had a substantial impact on clinical MRI of the abdomen. Five particular applications that have thus been affected include breath-hold imaging of liver lesions (including detection, characterization, and biopsy), MR cholangiopan- creatography, practical chemical shift imaging (including liver and adrenal glands), dynamic imaging after contrast media injection, and MR angiography.

This prospective study evaluates the ability of MRI using T1-weighted fat-suppressed spin-echo (T1FS) and dynamic gadolinium chelate (Gd) enhanced spoiled-gradient echo (SGE) to detect the presence of pancreatic tumor in patients in whom spiral CT findings are inconclusive. Sixteen consecutive patients who underwent spiral CT and had findings that were considered inconclusive for pancreatic tumor underwent MR within 2 weeks of CT. Spiral CT and MR images were interpreted in prospective fashion by separate individual investigators blinded to the results of the other imaging modality. CT was performed on a spiral CT scanner. MRI was performed on on a 1.5-T MR machine. Imaging sequences included T1FS pre-Gd and post-Gd and SGE pre-Gd and immediately post-Gd. Data were analyzed using receiver operating characteristic (ROC) analysis. Confirmation was obtained by pancreatic biopsy (n = 4), surgical resection (n = 1), and clinical imaging (n = 4) or clinical follow-up (n = 7). MRI was superior to spiral CT (P = .027) in this selected patient group at detecting or excluding pancreatic tumor by ROC analysis, with areas under the curve of .982 and .764, respectively, which was significant (P = .041). The greatest advantage of MRI was in patients in whom spiral CT demonstrated enlargement of the pancreatic head without clear definition of tumor, which was significant (P = .033). In 10 patients with this CT appearance, MRI demonstrated a high confidence for presence of tumor in four and a high confidence of absence in six. Association of imaging findings with patient diagnosis was significant for MRI (P = .001) but not significant for CT (P = .148). The results of our study suggest that MRI may add significant diagnostic information in patients in whom spiral CT is inconclusive for the presence of pancreatic tumor. The greatest advantage of MRI was in the evaluation of patients in whom spiral CT findings revealed an indeterminate enlarged pancreatic head.

To compare liver enhancement and lesion-liver contrast on T1-weighted (T1W) gradient recalled echo (GRE), spin-echo (SE) and fat-suppressed SE (FS-SE) pulse sequences at Manganese-DPDP (Mn-DPDP) enhanced magnetic resonance (MR) imaging of the liver. PATIENTS AND METHODS. Twenty-one patients with known liver lesions were administered 5 mumol/kg of Mn-DPDP. TIW GRE (78/2.3/80 degrees), SE and F-SE (300/12) images were obtained before and 15 min after Mn-DPDP. Signal/noise ratio (SNR) and lesion-liver contrast/noise ratio (CNR) were calculated for each pulse sequence.

Liver SNR (n = 21) and lesion-liver CNR (n = 10) increased significantly after Mn-DPDP on all three pulse sequences (P < 0.0001). Liver SNR was highest on the FS-SE and GRE pulse sequences (FS-SE = 43.8, GRE = 38.4, SE = 29.2). Lesion-liver CNR was highest on the FS-SE pulse sequence (FS-SE = -29.3, SE = -23.2, GRE = -19.8), which was significantly higher than the GRE pulse sequence (P < 0.05).

The T1-weighted fat-suppressed SE (FS-SE) pulse sequence provides highest liver enhancement and lesion-liver contrast and is recommended for Mn-DPDP enhanced MR imaging.

We evaluated the usefulness of dynamic 3-dimensional Fourier transformation (3DFT) fast low angle shot (FLASH) MR imaging using gadopentetate dimeglumine (Gd-DTPA) to assess the extent of pancreatic cancer.

Breath-hold 3DFT-FLASH MR images (20/4; 25 degrees flip angle; 7 partitions; 3-5-mm slice thickness) were obtained before the ++administration of 0.1 mmol/kg of Gd-DTPA, just after (early phase), and 1 and 2 min (late phases) after in 14 patients with pancreatic cancer. All patients underwent surgical removal or laparotomy. We compared the findings of T1-, T2-, and postcontrast T1-weighted spin-echo (conventional SE) and 3DFT-FLASH imaging with histologic or surgical findings.

Dynamic MR images could delineate the pancreatic tumors more clearly than the conventional SE images, and were useful for diagnosing vessel invasion. The contrast-to-noise ratio between the pancreatic cancer and the surrounding pancreatic parenchyma was significantly higher with the dynamic 3DFT-FLASH image than with the conventional SE images (p<0.01).

Dynamic 3DFT-FLASH MR imaging with Gd-DTPA is useful in delineating and evaluating the extent of pancreatic cancer.

A double-echo two-excitation pulse sequence encoding fat and water signals for a phase-sensitive three-point Dixon-type analysis (DE-3PD) was developed and implemented on a 1.5 T MR imager. Data processing was performed using a previously developed two-dimensional (2D) region-growing algorithm, adapted to use double-echo data. Density-, T1-, and T2-weighted fat suppression images were obtained from six volunteers using the new fat suppression method. The images were compared with corresponding images obtained using frequency-selective excitation fat suppression (FATSAT) and a single-echo three-point-Dixon method (SE-3PD). The results demonstrate that the DE-3PD sequence shortens the imaging time by one-third compared with the SE-3PD method, without loss in image quality. The data also show that a 2D region-growing algorithm effectively unwraps the phase of DE-3PD data sets, and that results of DE-3PD fat signal suppression are consistently better than those obtained using a standard FATSAT method. The authors conclude that the double-echo sequence provides density-, T1-, and T2-weighted images that appear to be promising for routine clinical applications.

Suspected pelvic endometriosis was prospectively evaluated in 31 women with T1- and T2-weighted conventional spin-echo (CSE) magnetic resonance imaging alone and in combination with T1-weighted fat-suppressed (T1FS) and gadolinium-enhanced T1FS (Gd-T1FS) spin-echo techniques. Images were grouped for interpretation and comparison as follows: (a) CSE alone, (b) CSE/T1FS, and (c) CSE/T1FS/Gd-T1FS. All patients underwent surgery within 3 months of imaging, and 21 patients were found to have endometriosis: 59 endometriomas (26 large and 33 small) and 51 sites of implants were seen. With CSE images, 23 large and six small endometriomas were detected. With CSE/T1FS images, 25 large and 14 small endometriomas were identified. With CSE/T1FS/Gd-T1FS images, 24 large and 14 small endometriomas were detected and ill-defined areas of enhancement were noted in 22 sites throughout the pelvis. These corresponded to endometriotic implants seen at surgery in 14 sites. The sensitivity, specificity, and accuracy, respectively, for the detection of endometriosis were 76%, 60%, and 71% for CSE, 86%, 50%, and 74% for CSE/T1FS, and 81%, 50%, and 71% for CSE/T1FS/Gd-T1FS images. No significant differences (P > .1) between image combinations for correctly identifying patients with and without endometriosis were seen. The difference in sensitivity between CSE and CSE/T1FS and between CSE and CSE/T1FS/Gd-T1FS images for detecting small endometriomas was significant (P = .03).

To determine whether signal intensity (SI) of the pancreas that was less than that of liver on T1-weighted fat-suppressed (T1FS) magnetic resonance (MR) images could be used to help predict the presence of pancreatic disease, three blinded independent observers graded pancreatic SI relative to liver and/or renal cortex in 89 patients on T1FS images. Results were correlated with patient age and diagnosis. Among the 47 patients with a clinically normal pancreas, pancreatic SI was higher than that of liver in 42 and equal to that of liver in the rest, none of whom had evidence of fatty pancreas. These five patients had a mean age of 71 years, compared with 55 years for patients whose pancreas was more intense than liver (P = .02). Of the 42 patients with a clinically abnormal pancreas, only eight had pancreatic SI higher than that of liver. The positive predictive value for normal pancreas of an SI higher than that of liver was 84% and the positive predictive value for abnormal pancreas of an SI less than or equal to that of liver was 88%, with an overall accuracy of 86%. If normal pancreatic SI is defined as higher than that of liver for patients younger than 60 years and as equal to or higher than that of liver for patients older than 60 years, the positive predictive value of normal SI becomes 76%, the positive predictive value of decreased SI becomes 100%, and the overall accuracy becomes 83%.(ABSTRACT TRUNCATED AT 250 WORDS)

Seven patients who had functioning or non-functioning endocrine pancreatic tumours were investigated by magnetic resonance imaging. Combinations of fat suppressed T1 weighted spin echo and gradient recalled echo (n = 7), T2 weighted spin echo (n = 3) and gadolinium diethylamine triamine pentaacetic acid (Gd-DTPA) enhanced fat suppressed T1 images were acquired. Magnetic resonance imaging detected five of seven tumours prospectively (three of which were smaller than 10 mm) and a further 10 mm tumour retrospectively. Tumours were low signal on T1 weighted images and showed enhancement after Gd-DTPA. On T2 weighted images one tumour was hyperintense, and two were isointense with normal pancreas. Computed tomography, transabdominal ultrasound and angiography were performed in six patients but detected only one tumour each. Intraoperative palpation and ultrasound detected all tumours. If pre-operative imaging is required magnetic resonance imaging is the technique of choice to detect small endocrine pancreatic tumours.