Functional magnetic resonance imaging in an animal model of pancreatic cancer.
OBJECTIVE
To test the hypotheses that diffusion weighed (DW)- and transcatheter intraarterial perfusion (TRIP)-magnetic resonance imaging (MRI) can each be used to assess regional differences in tumor function in an animal pancreatic cancer model.


METHODS
VX2 tumors were implanted in pancreata of 6 rabbits. MRI and digital subtraction angiography (DSA) were performed 3 wk following implantation. With a 2-French catheter secured in the rabbit's gastroduodenal artery, each rabbit was transferred to an adjacent 1.5T MRI scanner. DW- and TRIP-MRI were performed to determine if necrotic tumor core could be differentiated from viable tumor periphery. For each, we compared mean differences between tumor core/periphery using a 2-tailed paired t-test (alpha = 0.05). Imaging was correlated with histopathology.


RESULTS
Tumors were successfully grown in all rabbits, confirmed by necropsy. On DW-MRI, mean apparent diffusion coefficient (ADC) value was higher in necrotic tumor core (2.1 +/- 0.3 mm(2)/s) than in viable tumor periphery (1.4 +/- 0.5 mm(2)/s) (P < 0.05). On TRIP-MRI, mean perfusion values was higher in tumor periphery (110 +/- 47 relative units) than in tumor core (66 +/- 31 relative units) (P < 0.001).


CONCLUSIONS
Functional MRI can be used to differentiate necrotic from viable tumor cells in an animal pancreatic cancer model using ADC (DW-MRI) and perfusion (TRIP-MRI) values.
Lewandowski
Robert J
RJ
Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA. r-lewandowski@northwestern.edu
Eifler
Aaron C
AC
Bentrem
David J
DJ
Chung
Johnathan C
JC
Wang
Dingxin
D
Woloschak
Gayle E
GE
Yang
Guang-Yu
GY
Ryu
Robert
R
Salem
Riad
R
Larson
Andrew-C
AC
Omary
Reed-A
RA
D015901:Angiography, Digital Subtraction; D000818:Animals; D002404:Catheterization; D004195:Disease Models, Animal; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009336:Necrosis; D010190:Pancreatic Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology*; D011817:Rabbits