Significant acute GvHD presents in 15-50% of patients who receive hematopoietic cell transplantation (HCT) 1. Classically, GvHD is divided into acute and chronic, based on the time of onset. While acute GvHD is defined as disease occurring within the first 100 days of onset, the chronic form is traditionally described as presenting beyond 100 days 2. This understanding of GvHD is based on experience gained during decades of myeloablative HCT. However, in the past decade, the introduction of non-myeloablative HCT has led to a fundamental...

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...

Frequent intestinal abnormalities included wall thickening, abnormal enhancement, and excessive fluid-filling (94%, 89%, 94%; Table 1). Bile tract abnormality proved the commonest extra-intestinal finding (74%; Table 2). Both, measurements or frequencies of intestinal or extraintestinal abdominal CT findings were not significantly different between subgroups of early or late-onset acute GvHD (Table 1 and 2). Among intestinal CT findings, wall thickness and mucosal attenuation in unenhanced scans were significantly related to gut (P=0.012; 0.0001), overall clinical (P=0.044; 0.009) and pathological grading (P=0.018; 0.012). In addition, the...

Acute intestinal GvHD typically demonstrates with combined pathology to small and large bowel in a frequently discontinuous distribution, moderate wall thickening with strong mucosal enhancement and the scarcity of extraintestinal findings other than involvement of the biliary tract. The pattern of presentation is independent of its time of onset and thus facilitates differential diagnosis of late-onset acute GvHD. Correlation of CT morphology with clinical and pathological grading is important in terms of prognosis and guiding the therapeutic approach.