To determine the feasibility of diffusion-weighted MR imaging using sensitivity-encoding technique (ASSET-DWI) indepicting gastric cancer, and explore the clinical value of this technique.
Material and methods
Twenty-three patients with gastric cancer were examined at 1.5T. One DWI sequence (Se1) and three ASSET-DWI sequences with different NEXs (Se2: 1NEX; Se3: 2NEXs; Se4: 4NEXs) were employed to generate diffusion-weighted images (Table.1). Table.1 Parameters of different DWI sequences Sequence ASSET NEX Imaging time (sec) Breath-holds 1 NO 1 12 1 2 YES 1 10 1 3 YES 2 21 1-2 4 YES 4 41 2-3 When the acquisition time exceeded 15 seconds, the sequence will be separated to 2-3 breath-holds using a...
Four patients cannot endure the examination, and three showed no signal differences on all DWI images, which were all discarded from our study. Finally 16 patients enrolled into the study. The EPI-related artifacts and image distortion of ASSET-DWI was reduced compared to that without ASSET (p<0.01) (Table.2). Table.2 Image quality of different DWI sequences Sequence CNR Ca-GW Grade of artifacts 1 2 3 1 12.77±4.25 4 7 5 2 12.16±3.75 0 6 10 3 14.91±7.03 2 8 6 4 17.65±7.59 11 5 0 P value <0.01...
High quality ASSET-DWI imaging of gastric cancer can be achieved through the combination of separate breath-holds and multi-NEX technique. Four NEXs and 2-3 separated breath-holds are recommended. The diffusion-weighted MR imaging can provide functional parameters for the diagnosis of gastric cancer .
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XiaoPeng Zhang, Professor of Peking University; Director of radiology department, Peking University School & Beijing Cancer Hospital Lei Tang, Doctor Candidate of Peking University YingShi Sun, Doctor Candidate of Peking University Fei Sun, Doctor of GE healthcare