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Updated: Apr 25, 2026
Registered Bioimaging of Nanomaterials for Diagnostic and Therapeutic Monitoring
Published on: December 9, 2010
Diffusion-weighted MRI of the prostate: advantages of Zoomed EPI with parallel-transmit-accelerated 2D-selective
Kolja M Thierfelder1, Michael K Scherr, Mike Notohamiprodjo
1Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Grosshadern Campus, Marchioninistr. 15, 81377, Munich, Germany, kolja.thierfelder@med.uni-muenchen.de.
Objectives:
The purpose of our study was to evaluate the use of 2D-selective, parallel-transmit excitation magnetic resonance imaging (MRI) for diffusion-weighted echo-planar imaging (pTX-EPI) of the prostate, and to compare it to conventional, single-shot EPI (c-EPI).
Methods:
The MRI examinations of 35 patients were evaluated in this prospective study. PTX-EPI was performed with a TX-acceleration factor of 1.7 and a field of view (FOV) of 150 × 90 mm(2), whereas c-EPI used a full FOV of 380 × 297 mm(2). Two readers evaluated three different aspects of image quality on 5-point Likert scales. To quantify distortion artefacts, maximum diameters and prostate volume were determined for both techniques and compared to T2-weighted imaging.
Results:
The zoomed pTX-EPI was superior to c-EPI with respect to overall image quality (3.39 ± 0.62 vs 2.45 ± 0.67) and anatomic differentiability (3.29 ± 0.65 vs 2.41 ± 0.65), each with p < 0.0001. Artefacts were significantly less severe in pTX-EPI (0.93 ± 0.73 vs 1.49 ± 1.08), p < 0.001. The quantitative analysis yielded a higher agreement of pTX-EPI with T2-weighted imaging than c-EPI with respect to coronal (ICCs: 0.95 vs 0.93) and sagittal (0.86 vs 0.73) diameters as well as prostate volume (0.94 vs 0.92). Apparent diffusion coefficient (ADC) values did not differ significantly between the two techniques (p > 0.05).
Conclusions:
Zoomed pTX-EPI leads to substantial improvements in diffusion-weighted imaging (DWI) of the prostate with respect to different aspects of image quality and severity of artefacts.
Key Points:
Recent technical developments in MRI allow the use of accelerated, spatially-selective excitation (parallel-transmit, pTX). pTX can be used for zoomed echo-planar prostate imaging (pTX-EPI). pTX-EPI improves different aspects of image quality in prostate MRI. Distortion artefacts are reduced by the use of pTX-EPI in prostate MRI. Further studies should aim at assessing the diagnostic accuracy of pTX-EPI.
Insights
Parallel-transmit excitation echo-planar imaging (pTX-EPI) significantly improves prostate diffusion-weighted imaging quality and reduces artifacts compared to conventional EPI. This advanced MRI technique offers better anatomical detail and lesion visualization.
Area of Science:
- Radiology
- Medical Imaging
- Magnetic Resonance Imaging
Background:
- Diffusion-weighted imaging (DWI) is crucial for prostate cancer assessment.
- Conventional single-shot echo-planar imaging (c-EPI) is limited by distortion artifacts.
- Parallel-transmit (pTX) excitation offers potential for accelerated and improved MRI sequences.
Purpose of the Study:
- To evaluate the utility of 2D-selective, parallel-transmit excitation MRI for prostate DWI (pTX-EPI).
- To compare the image quality and artifact levels of pTX-EPI against conventional c-EPI.
- To assess the quantitative agreement of pTX-EPI and c-EPI with T2-weighted imaging.
Main Methods:
- Prospective evaluation of 35 patients undergoing prostate MRI.
- Acquisition of DWI using both zoomed pTX-EPI (acceleration factor 1.7) and c-EPI (full FOV).
- Qualitative assessment of image quality and artifact severity by two readers using Likert scales.
- Quantitative comparison of distortion artifacts, diameters, and prostate volume against T2-weighted imaging.
Main Results:
- pTX-EPI demonstrated superior overall image quality (3.39 vs 2.45) and anatomic differentiability (3.29 vs 2.41) (p < 0.0001).
- Artifacts were significantly reduced in pTX-EPI (0.93 vs 1.49) (p < 0.001).
- pTX-EPI showed higher agreement with T2-weighted imaging for coronal and sagittal diameters and prostate volume (ICCs 0.95-0.94 vs 0.93-0.92).
- Apparent diffusion coefficient (ADC) values did not differ significantly between techniques.
Conclusions:
- Zoomed pTX-EPI significantly enhances DWI of the prostate.
- pTX-EPI improves image quality and reduces distortion artifacts compared to c-EPI.
- Further studies are warranted to assess the diagnostic accuracy of pTX-EPI in prostate MRI.
