Objective To analyze CT findings of insulinoma,and to summarize the causes of missed diagnosis of nontypical insuli noma. Methods Clinical and CT manifestations of 18 patients with 18 insulinomas were analyzed retrospectively which were proved by surgery and pathology,and the causes of the missed diagnosis of nontypical insulinoma were also summarized. Results 10 patients with 10 insulinoma underwent CT plain scan with isodensity in 9 and slightly lower density in 1 with thread-like capsule. Other 18 patients underwent enhanced CT scan, 10 of whom showed obvious enhancement in arterial phase with isodentisy in 6 and slightly higher density in 4 in portal phase, and isodensity in 10 in delayed phase. 4 lesions showed mild-to-moderate enhancement in arterial phase with slightly higher density than normal pancreas in 2 and isodentisy in 2 in portal phase,and slightly higher density than nor mal pancreas in 1 and similar density to pancreas in 3 in delayed phase. In portal phase, the enhanced degree in 8 was similar to the pancreas,and that in 6 was slightly higher or higher than that of pancreas. In delayed phase, 13 were similar to the pancreas and other 1 was higher than that. 3 of 18 lesions were easily missed,and 4 lesions with missed diagnosis showed isodensity on plain CT and en hanced CT,and were further detected by other imaging methods. Conclusion Multiphase enhancement CT scanning can be used as the first choice for the insulinoma.
Journal of Practical Radiology