Diagnosis of synthetic vascular graft infection: comparison of CT and gallium scans.

Abstract

Sixteen patients were examined with both abdominal CT and 67Ga scintigraphy for suspected synthetic vascular graft infection. Two patients were studied twice, yielding a total of 18 paired tests. A total of 25 grafts were analyzed. The results of CT and 67Ga scintigraphy were compared for grafts in specific anatomic locations including the retroperitoneum, groin, and abdominal wall, and for combined sites. When all locations were considered as a group, CT had a sensitivity of 100% and specificity of 72%; 67Ga scintigraphy had a sensitivity of 78% and specificity of 94%. 67Ga scintigraphy proved to be more specific than CT (p less than .05) for combined sites, but no significant difference in sensitivities was demonstrated, possibly because of the small number of infected grafts in our study. No differences in sensitivities or specificities were statistically significant when grafts in individual anatomic sites were analyzed. Since no significant difference between the sensitivities of CT and 67Ga scanning was demonstrated in our study, although the number of infected grafts was small, CT is recommended as the initial examination when graft infection is suspected because it can be performed immediately. 67Ga scintigraphy remains an important complementary test, adding specificity to the diagnostic workup.