A comparison of 3D-CTA and 4D-CE-MRA for the dynamic monitoring of angiogenesis in a rabbit VX2 tumor.
OBJECTIVE
To compare three-dimensional computed tomography angiography (3D-CTA) and four-dimensional contrast-enhanced magnetic resonance angiography (4D-CE-MRA) for the in vivo monitoring of tumor angiogenesis.


METHODS
VX2 tumors were implanted into the right thigh muscle of 30 New Zealand white rabbits. The animals were randomly assigned to 5 groups, which, respectively, were scanned by 3D-CTA and 4D-CE-MRA on day 4, 7, 10, 13, or 16 after tumor implantation. After scanning, tumors were resected and processed for conventional histology and CD-31 immunohistochemistry. Tumor volume measurements derived from CT and MR imaging were compared with histopathological data. The minimum tumor diameter and the number of new tumor blood vessels detectable by 3D-CTA and 4D-CE-MRA were also compared.


RESULTS
There were no significant differences in the tumor volume measurements derived from CT, MR, and histological analysis. The minimum diameter of tumor vessels detectable by 3D-CTA (0.68 ± 0.07 mm) was significantly less than that by 4D-CE-MRA (0.85 ± 0.12 mm) (P=0.005). The number of tumor vessels detected by each imaging method was not significantly different until day 13 after implantation, when 3D-CTA detected a greater number (P<0.001). The morphologic process of tumor angiogenesis was demonstrated dynamically by 3D-CTA and 4D-CE-MRA in vivo.


CONCLUSIONS
Tumor angiogenesis can be dynamically monitored in vivo by 3D-CTA and 4D-CE-MRA. Of the two methods, 3D-CTA has better spatial resolution, but 4D-CE-MRA allows temporal resolution of tumor angiogenesis.
Wang
Han
H
Department of Radiology, Shanghai Jiaotong University Affiliated First People’s Hospital, Hanning Road, 100 - 200080 Shanghai, China. bingowh@hotmail.com
Zheng
Lin-Feng
LF
Feng
Yan
Y
Xie
Xue-Qian
XQ
Zhao
Jing-Long
JL
Wang
Xi-Fu
XF
Zhang
Gui-Xiang
GX
D000465:Algorithms; D000792:Angiography / Q000379:methods; D000818:Animals; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D009374:Neoplasms, Experimental / Q000098:blood supply / Q000150:complications / Q000175:diagnosis*; D009389:Neovascularization, Pathologic / Q000175:diagnosis* / Q000209:etiology; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*