OBJECTIVETo evaluate the spiral CT and its reconstruction techniques in diagnosis and localization of gastrointestinal stromal tumor originated in the small intestine.

METHODSThe data of spiral CT scan and MPR, STS-MIP of 24 patients with gastrointestinal stromal tumor in the small intestine confirmed pathologically were analyzed retrospectrvely.

RESULTSOf 24 cases, 1 had multiple tumor, while the other 23 had single one. Seventeen of these tumors were benign and 7 malignant, with 2 in the duodenum, 12 in the jejunum and 10 in the ileum. The range of tumor diameters was from 2.5 to 12 cm. The main clinical characters of the tumors on the CT image: (1) The tumor of 15 cases located outside of the enteric cavity, 7 inside of the enteric cavity or presented as thicken bowel wall and 2 showed as niche sign. (2) The tumor shape of 19 cases were round-like, and 5 lobulated or irregular. (3) The tumor density of 12 cases was homegeneous, 7 heterogeneous and 5 map-like in the center. (4) The tumor enhancement style in 19 cases were homegeneous in dynamic enhanced scan, and 16 were slightly or mildly heterogeneous in the artery phase but apparently enhanced in the venous and equilibrium phase, with 5 showed as fast-in fast-out enhanced mode. Of those, one showed obvious enhancement in artery phase, while 2 did not. (5) The tumor of 2 cases had no clear margin and had invaded the surrounding tissue. (6) The arteries supplying tumors in 20 cases were demonstrated by multiple planar reconstruction (MPR), sliding thin slab-maximum intensity projection (STS-MIP). The accuracy of diagnosis and localization of gastrointestinal stromal tumor in the small intestine by spiral CT scan combined with MPR, STS-MIP were 91.7% (22/24) and 95.8% (23/24), respectively.

CONCLUSIONSpiral CT and its reconstruction techniques (MPR, STS-MIP) can play an important role in the differential diagnosis and localization of gastrointestinal stromal tumor originated in the small intestine.