Comparison between 3-Scan Trace and Diagonal Body Diffusion-Weighted Imaging Acquisitions: A Phantom and Volunteer Study

Abstract

Diagonal diffusion-weighted imaging (dDWI) uses simultaneous maximized application of 3 orthogonal gradient systems as opposed to sequential acquisition in 3 directions in conventional 3-scan trace DWI (tDWI). Several theoretical advantages of dDWI vs. tDWI include reduced artifacts and increased sharpness. We compared apparent diffusion coefficient (ADC) quantification and image quality between monopolar dDWI and tDWI in a dedicated diffusion phantom (b = 0/500/900/2000 s/mm 2 ) and in the abdomen (b = 50/400/800 s/mm 2 ) and pelvis (b = 50/1000/1600 s/mm 2 ) of 2 male volunteers at 1.5 T and 3.0 T. Phantom estimated signal-to-noise ratio (eSNR) was also measured. Two independent observers assessed the image quality on a 5-point scale. In the phantom, image quality was similar between tDWI and dDWI, with equivalent ADC quantification (mean coefficient of variation [CV] between sequences: 1.4% ± 1.2% at 1.5 T and 0.7% ± 0.7% at 3.0 T). Phantom eSNR was similar for both tDWI and dDWI, except for a significantly lower eSNR for b900 of dDWI at 3.0 T (P = .006). In the volunteers, the CV values between tDWI and dDWI were higher than those in the phantom (CV range: abdominal organs, 1.3%-13.3%; pelvic organs, 0.6%-5.7%). A trend toward significant better image quality for dDWI compared with tDWI was observed for b800 (abdomen) at 3.0 T and for b1000 and b1600 (pelvis) at 1.5 T (P = .063 to .066). Our data suggest that dDWI may provide better image quality than tDWI without affecting ADC quantification, needing confirmation in a future clinical study.

Prediction of hepatocellular carcinoma response to 90Yttrium radioembolization using volumetric ADC histogram quantification: preliminary results

“…Acceptable interplatform reproducibility in ADC values has been reported, including between 1.5 T and 3 T systems [37–41]. Recently, we have reported excellent inter-platform reproducibility (1.5 T vs 3 T) of ADC using a dedicated DWI phantom (coefficient of variation CV < 7%), as well as in healthy volunteers (CV < 13.5%) [39].…”

Modulating Diffusion-Weighted Magnetic Resonance Imaging for Screening in Oncologic Tertiary Prevention

“…In addition, complex averaging with phase correction is performed for opt-DWI in form of an adaptive combination, which can improve contrast-to-noise ratio and provide more exact ADC values by removing signal offsets. 29,30 A phantom and volunteer study at 3 T already demonstrated the superiority of diagonal DWI versus trace DWI regarding image quality, 31 and Corcuera-Solano et al 32 showed a comparable image quality while at the same time reducing the acquisition time in prostate MRI. The acquisition time is of special importance in daily clinical practice.…”

Image quality evaluation of diffusion-weighted imaging in bladder cancer: a comparison between integrated slice-specific dynamic shimming and single-shot echo-planar imaging

“…This scheme switches all 3 gradients simultaneously rather than sequentially with maximum amplitude; hence, it allows a lower echo time than does 3-scan trace and significantly reduces the scan time. Some studies reported that diagonal-DWI (d-DWI) demonstrated equivalent tumor detection, image quality, and ADC values as did the 3-scan trace DWI (t-DWI) with substantially reduced acquisition time (19,20).…”

“…This reduction of d-DWI acquisition time can be achieved at a cost of lower SNR compared to t-DWI. Theoretically, to preserve SNR, the averages of d-DWI should be increased by a factor of 3 compared to t-DWI because the loss in SNR has a factor of √3 due to the single diffusion acquisition compared with the sequential acquisition of 3 diffusion directions in t-DWI (20). Although higher averages were set for iShim DWI compared to SS-EPI DWI to compensate for the loss in SNR, Siemens engineers chose a lower number of averages by factors of 2-2.5 to shorten the total scan time.…”