Clinical Trials Study
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World J Radiol. Jun 28, 2014; 6(6): 374-380
Published online Jun 28, 2014. doi: 10.4329/wjr.v6.i6.374
Feasibility study of computed vs measured high b-value (1400 s/mm²) diffusion-weighted MR images of the prostate
Leonardo K Bittencourt, Ulrike I Attenberger, Daniel Lima, Ralph Strecker, Andre de Oliveira, Stefan O Schoenberg, Emerson L Gasparetto, Daniel Hausmann
Leonardo K Bittencourt, Daniel Lima, Emerson L Gasparetto, CDPI Ressonância Magnética, Avenida das Américas, 4666 Barra da Tijuca, RJ 22631-000, Brazil
Ulrike I Attenberger, Stefan O Schoenberg, Daniel Hausmann, Institute of Clinical Radiology and Nuclear Medicine, University of Heidelberg, University Hospital Mannheim, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
Ralph Strecker, Siemens Healthcare Brazil, Avenida Mutinga, 3800 Jardim Santo Elias, SP 05110-902, Brazil
Andre de Oliveira, Siemens AG Healthcare Sector, Henkestrasse 127, D-91052 Erlangen, Germany
Author contributions: Bittencourt LK and Hausmann D contributed equally to this work; Bittencourt LK, Hausmann D, Strecker R, de Oliveira A, Gasparetto EL designed the research; Hausmann D, Bittencourt LK and Strecker R performed the research; Hausmann D, Strecker R and de Oliveira A analyzed the data; Hausmann D, Bittencourt LK, Lima D, Schoenberg S, Attenberger UI and Strecker R wrote the paper.
Correspondence to: Dr. Daniel Hausmann, MD, Institute of Clinical Radiology and Nuclear Medicine, University of Heidelberg, University Hospital Mannheim, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany. daniel.hausmann@medma.uni-heidelberg.de
Telephone: +49-621-3832276 Fax: +49-621-3833817
Received: January 24, 2014
Revised: March 23, 2014
Accepted: April 17, 2014
Published online: June 28, 2014
Abstract

AIM: To evaluate the impact of computed b = 1400 s/mm2 (C-b1400) vs measured b = 1400 s/mm2 (M-b1400) diffusion-weighted images (DWI) on lesion detection rate, image quality and quality of lesion demarcation using a modern 3T-MR system based on a small-field-of-view sequence (sFOV).

METHODS: Thirty patients (PSA: 9.5 ± 8.7 ng/mL; 68 ± 12 years) referred for magnetic resonance imaging (MRI) of the prostate were enrolled in this study. All measurements were performed on a 3T MR system. For DWI, a single-shot EPI diffusion sequence (b = 0, 100, 400, 800 s/mm²) was utilized. C-b1400 was calculated voxelwise from the ADC and diffusion images. Additionally, M-b1400 was acquired for evaluation and comparison. Lesion detection rate and maximum lesion diameters were obtained and compared. Image quality and quality of lesion demarcation were rated according to a 5-point Likert-type scale. Ratios of lesion-to-bladder as well as prostate-to-bladder signal intensity (SI) were calculated to estimate the signal-to-noise-ratio (SNR).

RESULTS: Twenty-four lesions were detected on M-b1400 images and compared to C-b1400 images. C-b1400 detected three additional cancer suspicious lesions. Overall image quality was rated significantly better and SI ratios were significantly higher on C-b1400 (2.3 ± 0.8 vs 3.1 ± 1.0, P < 0.001; 5.6 ± 1.8 vs 2.8 ± 0.9, P < 0.001). Comparison of lesion size showed no significant differences between C- and M-b1400 (P = 0.22).

CONCLUSION: Combination of a high b-value extrapolation and sFOV may contribute to increase diagnostic accuracy of DWI without an increase of acquisition time, which may be useful to guide targeted prostate biopsies and to improve quality of multiparametric MRI (mMRI) especially under economical aspects in a private practice setting.

Keywords: Prostate cancer, Magnetic resonance imaging, Diffusion-weighted imaging, Ultra-high b-values, Extrapolated b-values

Core tip: Prostate cancer is the most common malignant tumor entity in males. Combination of a high b-value extrapolation and small-field-of-view sequence readout may contribute to increase diagnostic accuracy of diffusion-weighted images without an increase of acquisition time, which may be useful to guide targeted prostate biopsies and to improve quality of multiparametric magnetic resonance imaging especially under economical aspects in a private practice setting.