Fungal liver infection in immunocompromised patients: depiction with multiphasic contrast-enhanced helical CT

PURPOSE: To retrospectively assess multiphasic (nonenhanced, arterial phase, and portal venous phase) computed tomography (CT) of the liver for depiction of hepatic fungal infection in immunocompromised patients. MATERIALS AND METHODS: The institutional ethics review board approved the study and waived the requirement for informed consent. Sixty multiphasic hepatic CT examinations were performed in 39 immunocompromised patients who fulfilled the criteria for having probable or proved fungal liver infection. The detection and conspicuity of focal liver lesions were assessed on scans obtained during each CT phase. The lesion enhancement pattern was determined, and, accordingly, lesions were stratified into two groups: lesions suggestive of infection (with ring enhancement patterns or high attenuation) and nonspecific hypoattenuating lesions. Statistical analyses were performed by using logistic regression with generalized estimating equations. RESULTS: A total of 536 liver lesions detected at 36 CT examinations with results positive for fungal infection were assessed. All 36 (100%) examinations yielded positive results during the arterial phase, whereas 25 (69%) of them yielded positive results during the portal venous phase (P < .001). At lesion-by-lesion analysis, the arterial phase scans depicted significantly more lesions (483 of 536 [90%]) than the portal venous phase (329 of 536 [61%]) and nonenhanced (265 of 465 [57%]) scans (P < .001 for both comparisons). In addition, on arterial phase scans, 386 of 483 lesions, as compared with 134 of 329 lesions on portal venous phase scans (P < .001), were judged to have an enhancement pattern suggestive of infection. The CT phases did not differ significantly in terms of the conspicuity of detected lesions. CONCLUSION: In patients suspected of having hepatic fungal infection, arterial phase CT depicts significantly more hepatic lesions than does CT performed during the other phases, and it reveals more lesions with enhancement patterns suggestive of infection. Arterial phase CT should be performed in addition to portal venous phase CT in patients suspected of having hepatic fungal infection.