Subjective vs. objective evaluation of gallbladder opacification during oral cholecystography in comparative clinical trials: implications for studies involving visual assessment.

Radiographs and CT images taken during oral cholecystography in dogs were interpreted in an independent, blind fashion by three radiologists on two occasions and visual assessment of gallbladder density compared to the actual CT values. While there was significant intra- and inter-observer variation, the mean scores for the observers' interpretations of both radiographs and prints correlated well with the actual CT values (p less than 0.05). In five out of six comparisons between first and second readings, the observers gave a lower score on the second reading. The considerable variation reflects the problems inherent in subjective evaluation of agents that produce small but measurable differences in radiographic density. Studies involving such subjective data have to be carefully designed in order to obtain meaningful results.

Spontaneous resolution of colonic strictures caused by necrotizing enterocolitis: therapeutic implications.

Colonic strictures are now a well recognized complication in infants surviving necrotizing enterocolitis. We describe the clinical course of seven infants with colonic strictures after necrotizing enterocolitis. Only two demonstrated the finding of fixed fibrotic stricture described in the literature, while the remaining five showed atypical radiographic and pathologic features. Two of the five showed partial or spontaneous resolution of post-necrotizing enterocolitis colonic stenoses on follow-up barium enema studies. In three of four patients with colonic resections, the histopathologic examination revealed a surprising absence of irreversible fibrosis or cicatrix formation. Current surgical practice dictates elective resection of these narrowed colonic segments. The radiologic and pathologic findings in our series of patients suggest surgical resection may be unnecessary in selected cases.