The aim of this study was to compare respiratory-triggered diffusion-weighted imaging with simultaneous-multislice acceleration (SMS-RT-DWI
) to a standard free-breathing echoplanar DWI
) for 3 T renal imaging
with respect to image quality and artifacts.
Materials and Methods
A total of 40 patients who had undergone renal magnetic resonance imaging were included in this retrospective analysis of a prospectively planned cohort study. All examinations were performed on a 3 T whole-body magnetic resonance system. Both s-DWI
were obtained and images were independently reviewed by 2 radiologists on a 5-point Likert scale with respect to overall preference and image quality, renal edge and parenchymal sharpness, cortico-medullary differentiation, and sequence-related artifacts. Furthermore, discernibility of renal lesions was assessed. The signal-to-noise ratio (SNR) was measured from SNR maps. The derived mean apparent diffusion coefficients were also compared. Qualitative parameters were assessed with the Wilcoxon rank-sum test, and quantitative parameters, with the Student t
Overall image quality, renal edge, and parenchymal sharpness of SMS-RT-DWI
were rated as superior to s-DWI
by the readers, with fewer sequence-related artifacts (P
< 0.01 for all). Lesion discernibility was significantly improved for SMS-RT-DWI
< 0.01). Both readers preferred SMS-RT-DWI
in all cases (40/40). The acquisition time for SMS-RT-DWI
was 30% shorter than for s-DWI
. Mean SNR heterogeneity of SMS-RT-DWI
= 800 s/mm2
was statistically significantly lower than s-DWI
, whereas mean SNR was significantly higher for SMS-RT-DWI
. Mean apparent diffusion coefficient values from both sequences were comparably homogeneous throughout the kidneys.
Simultaneous multislice DWI
of the kidney at 3 T with respiratory triggering
yields substantially improved image quality and lesion discernibility compared with standard single-shot echoplanar DWI
with a 30% reduction in scan acquisition time.