Body diffusion-weighted MR imaging using high b-value for malignant tumor screening: usefulness and necessity of referring to T2-weighted images and creating fusion images.
OBJECTIVE
To evaluate the potential usefulness of high b-value body diffusion-weighted images (DWIs) as a screening tool in the depiction of abdominal malignant tumors.


METHODS
We selected 110 abdominal magnetic resonance examinations (1.5 T; 60 men; age range, 25-90 years) with and without malignant tumors (n = 37 and n = 73, respectively). Axial DWIs were obtained by single-shot spin-echo (SE) type echo planar imaging (EPI) sequence with inversion pulse (repetition time, 6,800 msec; echo time, 100 msec; T1, 150 msec; b value, 1,000 sec/mm(2)) without breath-holding. Two radiologists independently interpreted the DWIs, T2-weighted images (T2-WI), all three types of images including DWIs, T2-WIs, and fusion images at the same time (DWIs + T2-WIs + fusion) with 7-14 days' interval, and the diagnostic confidence for each patient was scored.


RESULTS
The area under the curve (AUC) of the composite receiver operating characteristic (ROC) curve of DWIs + T2-WIs + fusion (0.904) was significantly higher than those of DWIs (0.720; P < .001) and T2-WIs (0.822; P < .05). Both sensitivity and specificity were higher in DWIs + T2-WIs + fusion (89.5% and 81.9%, respectively) compared with those of DWIs (72.4% and 59.0%; P < .01 and P < .001, respectively).


CONCLUSIONS
Abdominal high b-value DWIs have a high sensitivity and specificity for malignant tumors when T2-WIs are referred and image fusion technique is employed, suggesting that it may potentially be a new screening tool.
Tsushima
Yoshito
Y
Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Hospital, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan. yoshito@xa2.so-net.ne.jp
Takano
Akie
A
Taketomi-Takahashi
Ayako
A
Endo
Keigo
K
D000005:Abdomen / Q000473:pathology; D000008:Abdominal Neoplasms / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000556:secondary; D002277:Carcinoma / Q000175:diagnosis*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004067:Digestive System Neoplasms / Q000175:diagnosis* / Q000556:secondary; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008223:Lymphoma / Q000175:diagnosis*; D008297:Male; D008403:Mass Screening / Q000295:instrumentation / Q000379:methods; D008875:Middle Aged; D015588:Observer Variation; D012372:ROC Curve; D011860:Radiography, Abdominal / Q000379:methods; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods; D014565:Urogenital Neoplasms / Q000175:diagnosis*