Abstract: Objective To investigate the value of 64-slice spiral computed tomography in the diagnosis of cavemous transformation of portal vein（CTPV）. Methods A 64-slices spiral CT scanner was used to perform plain and three-phase contrast enhanced abdominal scanning in 22 patients with CTPV. Image post-processing techniques，including MPR，MIP and VR，were applied to depict the abnormal portal vein and its collateral vessels. Results The portal vein was not clearly seen on plain in 22 cases，while multiple soft tissue nodules and strips were found in the porta hepatis region. On dynamic enhanced scans，abnormal hepatic perfusion during arterial phase in 6 cases was demonstrated. On portal vein phase images the main trunk of portal vein and/or its left and right branches were dilated with filling defects in 11 cases. Inconspicuous portal veins were demonstrated. The main trunk of portal vein looked thin in 4 cases. The main trunk of portal vein was lumen stenosis as a result of tumor-infiltrating in 1 case. Pericholedochal venous plexus（86.36％），cystic vein（77.27％）and esophageal gastric veins（77.27％）were dilated and varicose， looking like clusters of spots and reticule. The courses and extents of the varicose vessels were directly demonstrated with MPR，MIP and VR techniques. Conclusion 64-slice spiral computed tomography can accurately show the location and the extent of CTPV. It can also optimize the collateral vessels of CTPV，so it is an effective examination method to diagnose CTPV.

Key words: Cavernous transformation of portal vein, Collateral vessels, Tomography, X-ray computed