In vivo diffusion-weighted imaging of liver tumor necrosis in the VX2 rabbit model at 1.5 Tesla.
OBJECTIVE
We sought to demonstrate the feasibility of using single-shot spin-echo echo-planar imaging for imaging liver tumor necrosis in the in vivo VX2 rabbit model at 1.5 T.


METHODS
VX2 liver tumors were grown in 4 rabbits. Diffusion-weighted images (DWIs) were acquired during breath-hold using twice refocused SE-EPI (b = 0, 700, 1400 seconds/mm). Anatomic images for tumor size measurements were acquired using T2W TSE. Rabbits were euthanized for subsequent necropsy. Viable and necrotic tumor tissue ADC measurements were performed with reference to hematoxylin and eosin pathology.


RESULTS
A total of 8 tumors were grown with diameters ranging from 1.2 to 5.3 cm. Viable and necrotic tumor compartments were clearly differentiated. Apparent diffusion coefficient in necrotic tumor cores, 1.26 +/- 0.11 x 10 mm/s, were significantly greater than those in surrounding viable tumor tissues, 0.74 +/- 0.06 x 10 mm/s (mean +/- SD, P < 0.05).


CONCLUSIONS
In vivo DWI of liver tumor necrosis in the VX2 rabbit model is feasible using a 1.5 T clinical magnetic resonance imaging scanner. DWI may permit longitudinal assessment of liver tumor therapies in both preclinical and clinical studies.
Deng
Jie
J
Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Il 60611, USA.
Rhee
Thomas K
TK
Sato
Kent T
KT
Salem
Riad
R
Haines
Kenneth
K
Paunesku
Tatjana
T
Mulcahy
Mary F
MF
Miller
Frank H
FH
Omary
Reed A
RA
Larson
Andrew C
AC
D000818:Animals; D045744:Cell Line, Tumor; D005240:Feasibility Studies; D007091:Image Processing, Computer-Assisted; D008113:Liver Neoplasms / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009336:Necrosis; D011817:Rabbits