Comparison of transcatheter intraarterial perfusion MR imaging and fluorescent microsphere perfusion measurements during transcatheter arterial embolization of rabbit liver tumors.
OBJECTIVE
Transcatheter intraarterial perfusion (TRIP) magnetic resonance (MR) imaging is clinically used in the interventional MR imaging setting to verify distribution of injected embolic or chemoembolic material during liver-directed transcatheter therapies and to monitor reductions in perfusion. The accuracy of this technique remains unknown. In the present study, rabbit VX2 liver tumors were used to test the hypothesis that TRIP MR imaging accurately measures changes in tumor perfusion during transcatheter arterial embolization (TAE), with injection of fluorescent microspheres used as the gold-standard technique.


METHODS
Five New Zealand White rabbits were used for this study (two donor rabbits and three with VX2 liver tumors). In three rabbits with implanted VX2 liver tumors, catheters were superselectively placed under digital subtraction angiographic guidance into the left hepatic artery supplying the targeted tumor. Fluorescent microspheres were injected into each rabbit's left ventricle before and after TAE. TRIP MR images were obtained at baseline and after embolizations for all rabbits with intraarterial injections of 2.5% gadopentetate dimeglumine solution. Linear regression was used to compare relative reductions in tumor perfusion between TRIP MR imaging and fluorescent microspheres. Results were considered statistically significant at a P value less than .05.


RESULTS
There was good correlation between TRIP MR imaging and fluorescent microsphere measurements of reduction in tumor perfusion (r = 0.722, P < .012).


CONCLUSIONS
TRIP MR imaging provides accurate semiquantitative measurement of perfusion reduction during TAE in rabbit liver tumors.
Virmani
Sumeet
S
Department of Radiology, Northwestern University, 448 E Ontario St, Suite 700, Chicago, Illinois 60611, USA.
Wang
Dingxin
D
Harris
Kathleen R
KR
Ryu
Robert K
RK
Sato
Kent T
KT
Lewandowski
Robert J
RJ
Nemcek
Albert A
AA
Szolc-Kowalska
Barbara
B
Woloschak
Gayle
G
Salem
Riad
R
Larson
Andrew C
AC
Omary
Reed A
RA
D015901:Angiography, Digital Subtraction; D000818:Animals; D045744:Cell Line, Tumor; D003287:Contrast Media / Q000008:administration & dosage; D004621:Embolization, Therapeutic; D005456:Fluorescent Dyes / Q000008:administration & dosage*; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006499:Hepatic Artery / Q000000981:diagnostic imaging; D007269:Injections, Intra-Arterial; D016014:Linear Models; D008102:Liver Circulation; D008114:Liver Neoplasms, Experimental / Q000098:blood supply* / Q000473:pathology / Q000628:therapy*; D018810:Magnetic Resonance Angiography; D008863:Microspheres; D011817:Rabbits; D015203:Reproducibility of Results
D003287:Contrast Media; D005456:Fluorescent Dyes; D019786:Gadolinium DTPA