Diffusion weighted whole body imaging with background body signal suppression (DWIBS): technical improvement using free breathing, STIR and high resolution 3D display.
OBJECTIVE
To examine a new way of body diffusion weighted imaging (DWI) using the short TI inversion recovery-echo planar imaging (STIR-EPI) sequence and free breathing scanning (diffusion weighted whole body imaging with background body signal suppression; DWIBS) to obtain three-dimensional displays.


METHODS
1) Apparent contrast-to-noise ratios (AppCNR) between lymph nodes and surrounding fat tissue were compared in three types of DWI with and without breath-holding, with variable lengths of scan time and slice thickness. 2) The STIR-EPI sequence and spin echo-echo planar imaging (SE-EPI) sequence with chemical shift selective (CHESS) pulse were compared in terms of their degree of fat suppression. 3) Eleven patients with neck, chest, and abdominal malignancy were scanned with DWIBS for evaluation of feasibility. Whole body imaging was done in a later stage of the study using the peripheral vascular coil.


RESULTS
The AppCNR of 8 mm slice thickness images reconstructed from 4 mm slice thickness source images obtained in a free breathing scan of 430 sec were much better than 9 mm slice thickness breath-hold scans obtained in 25 sec. High resolution multi-planar reformat (MPR) and maximum intensity projection (MIP) images could be made from the data set of 4 mm slice thickness images. Fat suppression was much better in the STIR-EPI sequence than SE-EPI with CHESS pulse. The feasibility of DWIBS was showed in clinical scans of 11 patients. Whole body images were successfully obtained with adequate fat suppression.


CONCLUSIONS
Three-dimensional DWIBS can be obtained with this technique, which may allow us to screen for malignancies in the whole body.
Department of Radiology, Tokai University School of Medicine, Bouseidai, Isehara-shi, Kanagawa 259-1193, JAPAN.
Taro
T
Takahara
Yutaka
Y
Imai
Tomohiro
T
Yamashita
Seiei
S
Yasuda
Seiji
S
Nasu
Marc
M
Van Cauteren
D000008:Abdominal Neoplasms / Q000175:diagnosis; D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D000368:Aged; D002675:Child, Preschool; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012119:Respiration; D013679:Technology, Radiologic / Q000379:methods; D013899:Thoracic Neoplasms / Q000175:diagnosis
D003287:Contrast Media