Feasibility of diffusion-weighted imaging under split breath-hold acquisition and postprocessing (DWI-SBAP): an attempt to suppress hepatic pseudo-anisotropy.
OBJECTIVE
To suppress hepatic pseudo-anisotropy, which is a specific artifact in diffusion-weighted imaging (DWI) of the liver obtained under respiratory triggering, the authors developed a novel acquisition technique for DWI that we termed "diffusion-weighted imaging under split breath-hold acquisition and postprocessing" (DWI-SBAP). We evaluated its feasibility in this study.


METHODS
Of 113 patients whose hepatic DWI under respiratory triggering (RT-DWI) showed prominent hepatic pseudo-anisotropy, 35 were included in the study. DWI-SBAP was additionally performed in these patients. Two radiologists visually evaluated the RT-DWI and DWI-SBAP from the viewpoints of the degree of pseudo-anisotropy and the image quality of trace images of both sequences. During evaluation of the image quality of trace images, both pseudo-anisotropy and slice misregistration artifacts were taken into consideration.


RESULTS
The pseudo-anisotropy seen was significantly lower in DWI-SBAP than that in RT-DWI. Regarding visual evaluation of the trace images, the image quality of DWI-SBAP was superior to that of RT-DWI, although misregistration artifacts were observed in DWI-SBAP trace images of two patients.


CONCLUSIONS
DWI-SBAP is a feasible technique for obtaining fine abdominal DWI and is effective in suppressing hepatic pseudo-anisotropy. To use this sequence in the clinical scenario, we believe it is necessary to develop a method of generating apparent diffusion coefficient maps and simultaneous use of slice tracking techniques.
Nasu
Katsuhiro
K
Department of Diagnostic Radiology, Tsukuba University School of Medicine, Tsukuba, 305-8575, Japan. kanasu-u3@md.tsukuba.ac.jp
Kuroki
Yoshifumi
Y
Minami
Manabu
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016880:Anisotropy; D016477:Artifacts; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008113:Liver Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric