Upper abdominal gadoxetic acid-enhanced and diffusion-weighted MRI for the detection of gastric cancer: Comparison with two-dimensional multidetector row CT.
OBJECTIVE
To evaluate the diagnostic performance of abdominal magnetic resonance imaging (MRI) for the detection of gastric cancer in comparison with that of two-dimensional (2D) multidetector row computed tomography (CT).


METHODS
The study included 189 patients with 170 surgically confirmed gastric cancers and 19 patients without gastric cancer, all of whom underwent gadoxetic acid-enhanced MRI with diffusion-weighted (DW) imaging, and multidetector contrast-enhanced abdominal CT imaging. Two observers independently analysed three sets of images (CT set, conventional MRI set, and combined conventional and DW MRI set). A five-point scale for likelihood of gastric cancer was used. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were evaluated. Quantitative [apparent diffusion coefficient (ADC) analyses with Mann-Whitney U-test were conducted for gastric cancers and the nearby normal gastric wall.


RESULTS
The diagnostic accuracy and sensitivity for detection of gastric cancer were significantly higher on combined conventional and DW MRI set (77.8-78.3%; 75.3-75.9%) than the CT imaging set (67.7-71.4%; 64.1-68.2%) or the conventional MRI set (72-73%; 68.8-70%; p < 0.01). In particular, for gastric cancers with pT2 and pT3, the combined conventional and DW MRI set (91.6-92.6%) yielded significantly higher sensitivity for detection of gastric cancer than did the CT imaging set (76.8-81.1%) by both observers (p < 0.01). The mean ADC of gastric cancer lesions (1 ± 0.23 × 10(-3) mm(2)/s) differed significantly from that of normal gastric wall (1.77 ± 0.25 × 10(-3) mm(2)/s; p < 0.01).


CONCLUSIONS
Abdominal MRI with DW imaging was more sensitive for the detection of gastric cancer than 2D-multidetector row CT or conventional MRI alone.
Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710, South Korea.
K M
KM
Jang
Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710, South Korea. Electronic address: kshyun@skku.edu.
S H
SH
Kim
Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710, South Korea.
S J
SJ
Lee
Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710, South Korea.
M W
MW
Lee
Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710, South Korea.
D
D
Choi
Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710, South Korea.
K M
KM
Kim
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013270:Stomach / Q000000981:diagnostic imaging / Q000473:pathology; D013274:Stomach Neoplasms / Q000175:diagnosis*
D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA