Free-breathing diffusion-weighted imaging for the assessment of inflammatory activity in Crohn's disease.
OBJECTIVE
To investigate the application of free-breathing diffusion-weighted MR imaging (DWI) to the assessment of disease activity in Crohn's disease.


METHODS
Thirty-one patients with Crohn's disease were investigated using free-breathing DWI without special patient preparation or IV or intraluminal contrast agent. The bowel was divided into seven segments, and disease activity was assessed visually on DWI. For quantitative analysis, the apparent diffusion coefficient (ADC) was measured in each segment. The findings of a conventional barium study or surgery were regarded as the gold standard for evaluating the diagnostic ability of DWI to assess disease activity.


RESULTS
Upon visual assessment, the sensitivity, specificity, and accuracy for the detection of disease-active segments were 86.0, 81.4, and 82.4%, respectively. In the quantitative assessment, the ADC value in the disease-active area was lower than that in disease-inactive area in small and large bowels (1.61 +/- 0.44 x 10(-3) mm(2)/s versus 2.56 +/- 0.51 x 10(-3) mm(2)/s in small bowel and 1.52 +/- 0.43 x 10(-3) mm(2)/s versus 2.31 +/- 0.59 x 10(-3) mm(2)/s in large bowel, respectively, P<0.001).


CONCLUSIONS
Free-breathing DWI is useful in the assessment of Crohn's disease. The accuracy of DWI is high in evaluating disease activity, especially in the small bowel, and the ADC may facilitate quantitative analysis of disease activity.
Kiryu
Shigeru
S
Department of Radiology, Institute of Medical Science, University of Tokyo, Tokyo, Japan. kiryu-tky@umin.ac.jp
Dodanuki
Keiichi
K
Takao
Hidemasa
H
Watanabe
Makoto
M
Inoue
Yusuke
Y
Takazoe
Masakazu
M
Sahara
Rikisaburo
R
Unuma
Kiyohito
K
Ohtomo
Kuni
K
D003424:Crohn Disease / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity