CT depiction of experimental liver tumors: contrast enhancement with hepatocyte-selective iodinated triglyceride
F T Lee1, S G Chosy, S G Naidu
1Department of Radiology, University of Wisconsin Hospital and Clinics, Madison 53792-3252, USA.
Purpose:
To compare findings at computed tomography (CT) enhanced with a hepatocyte-selective contrast agent (iodinated triglyceride) and/or iohexol and at CT during arterial portography (CTAP).
Materials And Methods:
Rabbit livers were directly inoculated with VX2 carcinoma. Results were compared for five helical CT examinations: unenhanced CT, iohexol-enhanced CT (600 mg iodine per kilogram of body weight [mg I/kg]), CTAP (with iohexol [600 mg I/kg]), triglyceride-enhanced CT (126 mg I/kg), and dual-contrast-enhanced CT (triglyceride plus iohexol [425 mg I/kg]). Attenuation of normal liver and tumor were compared with analysis of variance techniques and blinded reader evaluations.
Results:
Normal liver attenuation was greatest at CTAP (127.3 HU +/- 5.3 [mean +/- standard error of the mean]), followed by dual-contrast-enhanced CT (112.4 HU +/- 1.2), iohexol-enhanced CT (97.9 HU +/- 2.2), triglyceride-enhanced CT (82.3 HU +/- 1.1), and unenhanced CT (54.9 HU +/- 1.8). Liver-to-lesion attenuation difference at triglyceride-enhanced CT was significantly greater than at iohexol-enhanced CT (P < .05), and attenuation differences at dual-contrast-enhanced CT were comparable to those at CTAP. Tumors did not enhance at triglyceride-enhanced CT, which increased conspicuity. Sensitivity values for lesion detection at dual-contrast-enhanced CT were greater than those at iohexol-enhanced CT or at CTAP (P < .05).
Conclusion:
At CT enhanced with triglyceride (especially when combined with iohexol), sensitivity values and liver-to-lesion attenuation differences were greater with lower iodine doses than with iohexol or at CTAP.
