Improvement of renal diffusion-weighted magnetic resonance imaging with readout-segmented echo-planar imaging at 3T.
OBJECTIVE
To assess the feasibility of a respiratory-gated implementation of readout-segmented SE-EPI (RESOLVE) for renal diffusion-weighted imaging (DWI) by comparison with single-shot SE-EPI (ss-EPI) in a phantom, healthy volunteers and chronic kidney disease (CKD) patients.


METHODS
A fluid-filled phantom, 20 healthy volunteers and 10 CKD patients were scanned with the same parameters and coils on a 3T MR system with 3 DW sequences (b-values=0, 300, 500, 900s/mm(2)): a standard ss-EPI (Reference EPI), a ss-EPI with higher resolution, bandwidth and acceleration factor (HR-EPI) and RESOLVE with the same spatial resolution as HR-EPI but a segmentation of the readout into 5 shots. Geometric distortions, image blurring using a 'Canny' edge detection based measure, cortico-medullary differentiation measured on b0 images and ADC quantification were compared between the 3 sequences using one-way analysis of variance (ANOVA) with post-hoc Bonferroni (p<0.05 was taken as statistically significant).


RESULTS
RESOLVE reduced significantly geometric distortions and blurring and improved, in the volunteers and patients, the sharpness score by 56% on average in comparison to ss-EPI (p=0.02). In healthy volunteers, the cortico-medullary differentiation with RESOLVE was also possible on a wider range of b-values (p<0.02) with ADC values (in 10(-6)mm(2)/s) of 1994±246 in the cortex and 1762±238 in the medulla (p<0.001). In CKD patients, ADC values (in 10(-6)mm(2)/s) from the RESOLVE sequence were not different between the cortex (1755±145) and the medulla (1799±163, p=0.49).


CONCLUSIONS
Despite a longer scan time, RESOLVE enhanced significantly the quality of renal diffusion-weighted images by improving the difference in SI and ADC between the renal cortex and medulla in healthy volunteers. In CKD patients, RESOLVE showed a disappearance of this cortico-medullary ADC difference. These improvements justify further clinical studies.
Division of Radiology, Department of Radiology and Medical Informatics, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland. Electronic address: Iris.Friedli@unige.ch.
Iris
I
Friedli
Division of Radiology, Department of Radiology and Medical Informatics, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland.
Lindsey A
LA
Crowe
Division of Radiology, Department of Radiology and Medical Informatics, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland.
Magalie
M
Viallon
Siemens AG, Healthcare Sector, Erlangen, Germany.
David A
DA
Porter
Division of Nephrology, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland.
Pierre-Yves
PY
Martin
Division of Nephrology, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland.
Sophie
S
de Seigneux
Division of Radiology, Department of Radiology and Medical Informatics, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland. Electronic address: Jean-Paul.Vallee@hcuge.ch.
Jean-Paul
JP
Vallée
D000328:Adult; D000704:Analysis of Variance; D016477:Artifacts; D038524:Diffusion Magnetic Resonance Imaging; D017352:Echo-Planar Imaging; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007668:Kidney / Q000473:pathology*; D008297:Male; D019047:Phantoms, Imaging; D051436:Renal Insufficiency, Chronic / Q000473:pathology*; D015203:Reproducibility of Results; D055815:Young Adult
Artifacts; Diffusion-weighted MRI; RESOLVE; Readout-segmented EPI; Renal