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

• Published in: Academic radiology Vol. 14; no. 6; pp. 643 - 650
• Main Authors: Tsushima, Yoshito, MD, Takano, Akie, MD, Taketomi-Takahashi, Ayako, MD, Endo, Keigo, MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-06-2007
• Subjects: abdomen; Abdomen - pathology; Abdominal Neoplasms - diagnosis; Adult; Aged; Aged, 80 and over; Area Under Curve; Bone Neoplasms - diagnosis; Bone Neoplasms - secondary; Carcinoma - diagnosis; Diffusion Magnetic Resonance Imaging - methods; diffusion-weighted imaging; Digestive System Neoplasms - diagnosis; Digestive System Neoplasms - secondary; Echo-Planar Imaging - methods; Female; Humans; Lymphoma - diagnosis; Male; malignant tumor; Mass Screening - instrumentation; Mass Screening - methods; Middle Aged; MRI; Observer Variation; Radiography, Abdominal - methods; Radiology; Retrospective Studies; ROC Curve; screening; Sensitivity and Specificity; Tomography, X-Ray Computed - methods; Urogenital Neoplasms - diagnosis; screening; malignant tumor; MRI; diffusion-weighted imaging; abdomen
• ISSN: 1076-6332; 1878-4046
• DOI: 10.1016/j.acra.2007.02.006

Rationale and Objectives 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. Materials and 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/mm2 ) 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.