Whole-Body Diffusion Imaging Applying Simultaneous Multi-Slice Excitation

Abstract

Purpose: The purpose of this study was to examine the feasibility of a fast protocol for whole-body diffusion-weighted imaging (WB-DWI) using a slice-accelerated echo-planar sequence, which, when using comparable image acquisition parameters, noticeably reduces measurement time compared to a conventional WB-DWI protocol. Materials and Methods: A single-shot echo-planar imaging sequence capable of simultaneous slice excitation and acquisition was optimized for WB-DWI on a 3?T MR scanner, with a comparable conventional WB-DWI protocol serving as the reference standard. Eight healthy individuals and one oncologic patient underwent WB-DWI. Quantitative analysis was carried out by measuring the apparent diffusion coefficient (ADC) and its coefficient of variation (CV) in different organs. Image quality was assessed qualitatively by two independent radiologists using a 4-point Likert scale. Results: Using our proposed protocol, the scan time of the WB-DWI measurement was reduced by up to 25.9?%. Both protocols, the slice-accelerated protocol and the conventional protocol, showed comparable image quality without statistically significant differences in the reader scores. Similarly, no significant differences of the ADC values of parenchymal organs were found, whereas ADC values of brain tissue were slightly higher in the slice-accelerated protocol. Conclusion: It was demonstrated that slice-accelerated DWI can be applied to WB-DWI protocols with the potential to greatly reduce the required measurement time, thereby substantially increasing clinical applicability. Key Points ??Whole-body diffusion-weighted imaging (WB-DWI) using simultaneous multi-slice and blipped-CAIPIRINHA reduces the measurement time strongly without having a significant impact on image quality. ??The reduction in measurement time might strongly contribute to the clinical applicability of WB-DWI. ??However, further refinement of the slice-accelerated EPI sequence, and the WB-DWI protocol applying this sequence type seems necessary; and the value of such WB-DWI protocols for assessment of systemic oncological diseases needs to be investigated in further clinical studies. Citation Format: ??Kenkel D, Wurnig MC, Filli L et?al. Whole-Body Diffusion Imaging Applying Simultaneous Multi-Slice Excitation. Fortschr R?ntgenstr 2016; 188: 381???388

Multi-band whole-body diffusion-weighted imaging with inversion recovery fat saturation: Effects of respiratory compensation

“…Taron et al [ 11 ] investigated DWI with SMS on a 3 T PET/MRI system (whole-body, 5–6 stations, SPAIR) and found that in oncological patients, SMS produced lower image quality and more artefacts. Kenkel et al [ 14 ] performed whole-body DWI with SMS and SPAIR at 3 T after failure to produce sufficient image quality with IR fat saturation. They found acquisition time to be reduced by 29 % without significant differences in image quality.…”

“…Previous studies outside the brain e.g. [ 8 , [10] , [11] , [12] , [13] , [14] ]) have all applied SMS to DWI with SPAIR fat saturation. In addition, most studies have focused either on single organs or regions and have been performed mainly at 3 T [ 16 ].…”

Performance of an Automated Versus a Manual Whole-Body Magnetic Resonance Imaging Workflow

“…24,25 In a whole-body diffusion-weighted echo-planar imaging protocol, the image acquisition time of the diffusion-weighted imaging sequence with an acceleration factor of 3 could be reduced by 26%. 26 In a study of diffusion-tensor imaging (DTI) of the muscles of the lower leg, the simultaneous multislice acceleration technique allowed an image acquisition time reduction of 48% compared with conventional, nonaccelerated DTI (7 minutes 24 seconds vs 3 minutes 53 seconds). 27 Although DTI is not part of our standard MRI protocol for the assessment of myopathies, it proved to be a feasible method for the detection of muscle changes 28,29 and may be an important part of future WB-MRI protocols.…”

Whole-body diffusion magnetic resonance imaging with simultaneous multi-slice excitation in children and adolescents

“…This technique has already been established for MRI [ 18 ], and its advantages have been outlined in various studies on different organ systems, such as the liver [ 19 ], breast [ 20 ] and skeletal system [ 21 ], but mainly in adult patients. Kenkel et al showed both a drastic reduction in the duration of whole-body MRI using SMS-DWI and its clinical applicability in adults [ 22 ]. Tabari et al and, more recently, Glutig et al demonstrated the benefit of simultaneous multi-slice abdominal MRI during childhood and adolescence using the kidney as an example in patients with cystic fibrosis and tuberous sclerosis complex [ 23 , 24 ].…”