Authors:
H. Brodoefel1, M. Vogel2, W. Bethge2, C. Faul2, M. Wehrmann2, C. Claussen2, M. S. Horger2; 1Boston, MA/US, 2Tuebingen/DE
DOI:
10.1594/ecr2008/C-487
Methods and Materials
Abdominal CT scans were obtained in 20 patients with early and 15 with late-onset GvHD.
Scans were interactively analyzed by two radiologists, blinded to both clinical information and pathology results.
The gut was subdivided into 9 segments. In contrast enhanced scans, intestinal segments were evaluated for the presence of pathological wall thickening (> 3 mm), abnormal wall enhancement, excessive fluid-filling, bowel dilatation (> 3 cm in the small, > 8 cm in the large bowel) and reduction of ileo-mucosal folds.
The distribution of bowel wall abnormalities was scored into continuous or discontinuous. Both native and contrast enhanced examinations were assessed for the presence of the target-sign.
Attenuation of pathological bowel wall was recorded in the mucosal area of maximum intensity. Maximal wall thickness of abnormal loops was, likewise, recorded in all examinations.
Extraintestinal pathologies were assessed and included the comb sign, the misty mesentery sign, ascites, enhancement of the urinary bladder or biliary tract (visual assessment), gallbladder thickening (>3 mm) or dilatation of the common bile duct (>9 mm).
For the establishment of CT severity scores, threshold values were defined for such continuous variables as attenuation of bowel wall in unenhanced (>33 HU) or enhanced examinations (>92 HU), wall thickness (>0.6) and total number of abnormal segments (>4). The pathologies integrated into a comprehensive and a more practical CT score are evident from Table 3. The straightforward and more limited CT score was designed by combining only those predictor variables which proved to have an individual significant association with clinical or pathology grading.
Distinct CT abnormalities as well as CT-scores integrating multiple pathologies were correlated with overall clinical, clinical gut or histopathology grading which was available for all patients.