New model for analysis of dynamic contrast-enhanced MRI data distinguishes metastatic from nonmetastatic transplanted rodent prostate tumors.
Dynamic contrast-enhanced MRI (DCEMRI) data were acquired from metastatic and nonmetastatic tumors in rodents to follow the uptake and washout of a low-molecular-weight contrast agent (Gd-DTPA) and a contrast agent with higher molecular weight (P792). The concentration vs. time curves calculated for the tumor rims and centers were analyzed using the two-compartment model (TCM) and a newly developed empirical mathematical model (EMM). The EMM provided improved fits to the experimental data compared to the TCM. Parameters derived from the empirical model showed that the contrast agent washout rate was significantly slower in metastatic tumors than in nonmetastatic tumors for both Gd-DTPA (P < 0.03) and P792 (P < 0.04). The effects of the tumor on blood flow in "normal" tissue immediately adjacent to the tumors were evident: Gd-DTPA uptake and washout rates were much lower in muscle near the tumor (P < 0.05) than normal muscle farther from the tumor. The results suggest that accurate fits of DCEMRI data provide kinetic parameters that distinguish between metastatic and relatively benign cancers. In addition, a comparison of the dynamics of Gd-DTPA and P792 provides information regarding the microenvironment of tumors.
Department of Radiology, University of Chicago, Chicago, Illinois 60637, USA. xfan@midway.uchicago.edu
Xiaobing
X
Fan
Milica
M
Medved
Jonathan N
JN
River
Marta
M
Zamora
Claire
C
Corot
Philippe
P
Robert
Philippe
P
Bourrinet
Martin
M
Lipton
Rita M
RM
Culp
Gregory S
GS
Karczmar
D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D019786:Gadolinium DTPA; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D008954:Models, Biological; D008970:Molecular Weight; D019042:Muscle Neoplasms / Q000098:blood supply / Q000556:secondary*; D018482:Muscle, Skeletal / Q000098:blood supply / Q000601:surgery*; D009368:Neoplasm Transplantation / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology*; D051381:Rats; D013997:Time Factors; D014407:Tumor Cells, Cultured
D003287:Contrast Media; D019786:Gadolinium DTPA