Assessment of monochromatic CT value and spectrum energy curve in the differential diagnosis of splenomegaly / 实用放射学杂志

ABSTRACT

Objective To determine the utility of single energy CT value and spectrum energy curve in identifying different cause of diffuse spleen enlargement.Methods 43 patients confirmed by either surgical pathology,aspiration biopsy or clinical comprehensive diagnosis and follow-up were assessed,including lymphoma with spleen infiltration(lymphoma group,n=18) and cirrhotic splenomegaly(liver cirrhosis group,n=25).All patients underwent upper abdomen CT scans in GSI mode and the GSI data were transferred to the Workstation AW 4.6 to acquire single energy CT value(40-140 keV,10 keV's interval) and spectrum energy curve of the spleen on the venous phase.All single energy CT values and the slope of curves were comparatively analyzed through independent-samples t test.The diagnostic efficiency were evaluated by ROC analysis.Results Under 40-140 keV energy range,single energy CT values were significantly lower in the lymphoma group than in the liver cirrhosis group(all P＜0.05).The spectrum energy curve were both types of decreasing.Under 40-90 keV,100-140 keV energy range,the slop of curves in the lymphoma group(2.42 ± 0.70,0.27± 0.08) were also significantly lower than in the liver cirrhosis group (3.11 ± 0.62,0.34± 0.07),respectively(all P ＜0.05).When the slope of curve under 40-90 keV energy range was selected as a diagnostic indicator,the area under the curve(AUC) would reach 0.77.If threshold value of 1.39 was taken,the sensitivity and specificity would be equal to 86 ％ and 64 ％,respectively.Conclusion Single energy CT value and spectrum energy curve are helpful for differentiation of lymphoma with spleen infiltration from cirrhotic splenomegaly.