Transient Inhomogeneous Contrast Enhancement of the Spleen on Arterial Phase of Spiral CT

ABSTRACT

PURPOSE: To assess the relationship between splenic transient inhomogeneous contrast enhancement(CE) on the arterial phase of spiral CT, and splenic volume, and to classify the CE pattern in liver cirrhosis. MATERIALS AND METHODS: We measured the splenic volume of 120 patients, 60 showed inhomogeneous splenic CE on arterial phase,and 60 showed homogeneous splenic CE. CT scans with intrinsic splenic pathology were excluded. Sixteen patients with clinically confirmed liver cirrhosis were included. Splenic volumes of the inhomogeneous and homogeneous CE group were compared. The inhomogeneous group was divided into three grades according to areas of non-enhanced portion (grade I, focal geographic ; grade II, multifocal patchy, grade III, extensive serpentine inhomogeneous CE) , and these were correlated with splenic volume. RESULTS: Among the 60 inhomogeneous CE scans, 23 cases(38.3%) showed splenomegaly (spleen volume>220cm3); in contrast, this applied to only 8 cases (13.3%) of the 60 homogeneous CE scans. Mean splenic volume in the inhomogeneous CE group (226.74+/-129.78cm3) was greater than in the homogeneous CE group (184.56+/-77.44cm3) (p<0.033). A larger splenic volume and extensive inhomogeneous CE(grade III) were noted, and most liver cirrhosis patients(14/16) were grade III. Three such patients who had shown inhomogeneous splenic CE on arterial phase showed inhomogeneous CE even on portal phase. CONCLUSION: Inhomogeneous splenic CE on arterial phase was more common in cases of an enlarged spleen, and more extensive in liver cirrhosis. These findings suggest hemodynamic change of the spleen may be a contributory factor.