Combined hepatocyte-selective and blood-pool contrast agents for the CT detection of experimental liver tumors in rabbits.
OBJECTIVE
To determine the imaging characteristics of a new computed tomographic (CT) contrast material with both hepatocyte-selective and blood-pool components (iodinated triglyceride (ITG)-dual) versus standard iohexol.


METHODS
VX2 carcinoma was inoculated in seven rabbits. Animals underwent nonenhanced, iohexol-enhanced (600 mg of iodine per kilogram of body weight), and ITG-dual-enhanced (blood-pool moiety, 100 mg of iodine per kilogram; hepatocyte-selective moiety, 100 or 200 mg of iodine per kilogram, injected 90 minutes apart) helical CT. Livers were removed, preserved in formalin, suspended in agar, and sectioned transversely at 3-mm intervals. Attenuation values for normal liver and tumors were obtained, and blinded readers evaluated images for lesions by using a modified free-response receiver operating characteristic (ROC) method.


RESULTS
A total of 47 separate tumor sites were detected at pathologic examination. ITG-dual-enhanced scans obtained with 300 mg of iodine per kilogram demonstrated similar liver opacification to iohexol-enhanced scans obtained with 600 mg of iodine per kilogram, but with less lesion enhancement, which resulted in better liver-to-lesion contrast. Blinded readers had a higher sensitivity, accuracy, and area under the ROC curve for ITG-dual-enhanced scans as compared with iohexol-enhanced scans (P: <.01).


CONCLUSIONS
ITG-dual-enhanced CT quantitatively and qualitatively improved liver lesion detection versus iohexol-enhanced CT. Future clinical trials with various human tumor types after potential approval for human use are needed to determine the ultimate role of this or other dual-mechanism contrast materials.
Weichert
J P
JP
Department of Radiology, University of Wisconsin, Madison 53792, USA. jpweichert@facstaff.wisc.edu
Lee
F T
FT
Chosy
S G
SG
Longino
M A
MA
Kuhlman
J E
JE
Heisey
D M
DM
Leverson
G E
GE
D000818:Animals; D003287:Contrast Media; D006801:Humans; D007472:Iohexol; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000000981:diagnostic imaging* / Q000473:pathology; D011817:Rabbits; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014280:Triglycerides
C101471:2-oleoylglycerol-1,3-bis(7-(3-amino-2,4-6-triiodophenyl)heptanoate); D003287:Contrast Media; D014280:Triglycerides; D007472:Iohexol