Dynamic CT of hepatic abscesses: significance of transient segmental enhancement.

OBJECTIVE. The purpose of this study was to evaluate dynamic CT findings of hepatic abscesses. especially segmental hepatic enhancement. and to clarif y the cause. MATERIALS AND METHODS. Twenty-four abscesses in eight patients were examine d by early (30 sec) acid late phase (90 sec) dynamic CT. Patients underwent abscess drainage (n = 1), hepatic resection (li = 2), or antibiotic therap y (II = 5). CT during arterial portography and CT during hepatic arteriogra phy were performed in one patient. We retrospectively observed the frequenc y and changes of segmental hepatic enhancement on dynamic CT and determined its cause using radiologic and pathologic correlation. RESULTS. Sixteen abscesses (67%) showed transient segmental hepatic enhance ment and three abscesses showed only segmental hepatic enhancement in the e arly phase. Four abscesses in one patient who underwent CT during arterial portography and CT during hepatic arteriography showed a segmental perfusio n defect on CT during arterial portography and segmental enhancement on CT during hepatic arteriography, On follow-up dynamic CT performed 10-17 days after the initial CT. segmental hepatic enhancement surrounding hepatic abs cesses decreased or disappeared in all abscesses. Pathologic examination of two patients showed marked inflammatory cell infiltration with stenosis of portal venules a within the portal tracts surrounding hepatic abscesses wi thout definite inflammation in the liver parenchyma. CONCLUSION. Segmental hepatic enhancement on dynamic CT is frequently assoc iated with hepatic abscesses and may be caused by decreased portal Row resu lting from inflammation of the portal tracts.