• Journal of the Korean Society of Radiology
• /
• v.84 no.2
• /
• pp.441-453
• /
• 2023

Purpose To evaluate the development, location, and volume of a VX2 carcinoma using four inoculation methods in a rabbit brain. Materials and Methods Inoculation of a VX2 cell suspension was performed 1) on the appointed day, 2) seven days after storing a VX2 carcinoma in a freezer or 3) seven days after storing a VX2 carcinoma in a deep freezer after sacrificing the donor rabbits. 4) Without sacrificing the rabbits, the VX2 cell suspension was obtained using a gun biopsy, inoculation was performed on the appointed day. MR imaging was performed 10 days after inoculation. Brain tissues were obtained the day after. The development, location, and volume of the tumor were evaluated. Results Seventeen of the 18 rabbits inoculated on the appointed day developed tumors (average tumor volume, 106.32 mm³). One of five inoculated seven days after storing the VX2 tumor in the freezer, and three of five inoculated seven days after storing the VX2 tumor in the deep freezer developed tumors. Inoculation with a VX2 cell suspension obtained with a gun biopsy from five rabbits revealed development of tumors in only two rabbits. The tumors mostly developed in the superficial cortex. Conclusion TVX2 rabbit brain tumor model is easy to develop and revealed variable reproducibility. This model can be applicable in radiologic imaging, treatment planning, interventional treatment and drug delivery research. VX2 cell can be successfully innoculated into the brain using variable methods under researcher's variable conditions.

• Proceedings of the KSMRM Conference
• /
• 2000.11a
• /
• pp.55-56
• /
• 2000

• Proceedings of the KSMRM Conference
• /
• 2000.11a
• /
• pp.24-25
• /
• 2000

• Journal of Veterinary Clinics
• /
• v.23 no.4
• /
• pp.388-392
• /
• 2006

To verify the solitary nodular hepatocellular tumor model induced by intraparenchymal VX2 tumor cell injection and assess the diagnostic imaging character by computed tomography in rabbits. The tumor cell fragment ($1{\sim}2mm^3$) was loaded in Seldinger needle and directly implanted into the livers of 80 New Zealand white rabbits. The tumor size and patterns of tumor growth were evaluated using spiral computed tomography (CT) at 1, 2, and 3 weeks after tumor implantation. A solitary nodular tumor was successfully created in 82.5% (66/80). The mortality rate was 5% (4/80). The tumor sizes measured were 7.46.3, 14.210.8, 16.212.6 cm at 1, 2, and 3 weeks after tumor implantation on arterial phase CT images. The tumors were round to oval shape with peripheral enhancement and central hypoattenuation on arterial phase, and hypoatteuated wash-out pattern on portal phase. It is considered that inoculation of tumor fragment loaded in Seldinger needle is useful and practical method for creating a solitary hepatic tumor. And CT scanning are valuable to investigate the hepatic tumor and compatible to the observations on macro-and microscopic findings.

• Investigative Magnetic Resonance Imaging
• /
• v.8 no.1
• /
• pp.32-41
• /
• 2004

Purpose : To measure the NMR relaxation properties of MnPC, to observe the characteristics of liver enhancement patterns on MR images in experimentally implanted rabbit VX2 tumor model, and to estimate the possibility of tissue specific contrast agent for MnPC in comparison with the hepatobiliary agent. Materials and Methods : Phthalocyanine (PC) was chelated with paramagnetic ions, manganese (Mn). 2.01 g (5.2 mmol) of phthalocyanine was mixed with 0.37 g (1.4 nlmol) of Mn chloride at $310^{\circ}C$ for 36 hours and then purified by chromatography ($CHCl_3:\;CH_3OH=98:2$, volume ratio) to obtain 1.04 g $(46\%)$ of MnPC (molecular weight = 2000 daltons). The T1/T2 relaxivity (R1/R2) for MnPC were determined at a 1.5 T (64 MHz) MR spectrometer. VX2 tumor model was experimentally implanted in the liver parenchyma of rabbits. All MR studies were performed on 1.5 T. The human extremity radio frequency coil of a bird cage type was employed. MR images were acquired at 17 to 24 days after VX2 carcinoma implantation.4 mmol/kg MnPC and 0.01 mmol/kg Mn-DPDP were injected via the ear vein of rabbits. T1-weighted images were obtained with spin-echo (TR/TE=516/14 msec) and fast multiplanar spoiled gradient recalled (TR/TE : 80/4 msec, $60^{\circ}$ flip angle) pulse sequence. Fast spin-echo (TR/TE=1200/85 msec) was used to obtain the T2-weighted images. Results : The value of T1/T2 relaxivity (R1/R2) of MnPC was $7.28\;mM^{-1}S^{-1}$ and $55.56\;mM^{-1}S^{-1}$ respectively at 1.5 T (64 MHz). Because the T2 relaxivity of MnPC that bonded strongly, covalently manganese with phthalocyanine was very high, the signal intensity of liver parenchyma was decreased on postcontrast T2-weighted images and we could easily distinguish the VX2 carcinoma within the liver parenchyma. When MnPC was administrated intravenously, the tumor margin delineation was more remarkable than Mn-DPDP-enhanced images. The enhancement of liver parenchyma with MnPC persisted at relatively high levels over at least one hour after injection of the contrast agents. Conclusion : The hepatic uptake and biliary excretion of MnPC, which are similar to Mn-DPDP, suggest that this agent is a new liver-specific agent. Also, MnPC seems to be used as a dual contrast agent (T1 and T2) with high T2 relaxivity. However, it is warranted that MnPC needs further investigation as a potential contrast agent for MR imaging of the liver. That is, further characterizations of MnPC are needed in vivo and in vitro before clinical trials. The diagnostic potential of MnPC will also have to be examined more in the animal models of additional types.

• Proceedings of the KSMRM Conference
• /
• 1999.11a
• /
• pp.31-31
• /
• 1999

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.3
• /
• pp.1191-1196
• /
• 2015

Background: Epidermal growth factor-like domain multiple 7 (EGFL7), recently identified as a secreted protein regulated by oxygen exposure, plays a critical role in promoting metastasis of hepatocellular carcinoma (HCC). Transcatheter arterial embolization (TAE) is widely used for treatment of HCC, resulting in hypoxia in tumors and surrounding liver tissues. Accordingly, we proposed the hypothesis that there could be a relationship between expression of EGFL7 and response to TAE. Materials and Methods: We established a rabbit VX2 liver tumor model using percutaneous puncture technique guided by computed tomography. TAE and sham embolization were performed and the results were confirmed by MRI 3 weeks after inoculation. We investigated the EGFL7 expression of the two groups at 6h and 3 days after intervention by means of immunohistochemistry and Western blotting. Results: Immunohistochemical staining demonstrated that the levels of EGFL7 protein significantly increased in the TAE-treated tumors compared with the control group at 6 hours (P=0.031) and 3 days (P=0.020) after intervention. Meanwhile, the relative EGFL7 protein detected in TAE group also up-regulated compared with the control group at 6 hours (P=0.020) and 3 days (P=0.024) after intervention. Conclusions: This study reveals an increase of EGFL7 expression in rabbit VX2 liver tumors after TAE. The role of EGFL7 in HCC, especially its biological behavior after TAE, needs further investigation.

• Journal of radiological science and technology
• /
• v.35 no.2
• /
• pp.165-172
• /
• 2012

We investigated the vascular characteristics of tumors and normal tissue using perfusion CT in the rabbit brain tumor model. The VX2 carcinoma concentration of $1{\times}10^7$ cells/ml(0.1ml) was implanted in the brain of nine New Zealand white rabbits (weight: 2.4kg-3.0kg, mean: 2.6kg). The perfusion CT was scanned when the tumors were grown up to 5mm. The tumor volume and perfusion value were quantitatively analyzed by using commercial workstation (advantage windows workstation, AW, version 4.2, GE, USA). The mean volume of implanted tumors was $316{\pm}181mm^3$, and the biggest and smallest volumes of tumor were 497 $mm^3$ and 195 $mm^3$, respectively. All the implanted tumors in rabbits are single-nodular tumors, and intracranial metastasis was not observed. In the perfusion CT, cerebral blood volume (CBV) were $74.40{\pm}9.63$, $16.08{\pm}0.64$, $15.24{\pm}3.23$ ml/100g in the tumor core, ipsilateral normal brain, and contralateral normal brain, respectively ($p{\leqq}0.05$). In the cerebral blood flow (CBF), there were significant differences between the tumor core and both normal brains ($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($962.91{\pm}75.96$ vs. $357.82{\pm}12.82$ vs. $323.19{\pm}83.24$ ml/100g/min). In the mean transit time (MTT), there were significant differences between the tumor core and both normal brains ($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($4.37{\pm}0.19$ vs. $3.02{\pm}0.41$ vs. $2.86{\pm}0.22$ sec). In the permeability surface (PS), there were significant differences among the tumor core, ipsilateral and contralateral normal brains ($47.23{\pm}25.45$ vs. $14.54{\pm}1.60$ vs. $6.81{\pm}4.20$ ml/100g/min)($p{\leqq}0.05$). In the time to peak (TTP) were no significant differences among the tumor core, ipsilateral and contralateral normal brains. In the positive enhancement integral (PEI), there were significant differences among the tumor core, ipsilateral and contralateral brains ($61.56{\pm}16.07$ vs. $12.58{\pm}2.61$ vs. $8.26{\pm}5.55$ ml/100g). ($p{\leqq}0.05$). In the maximum slope of increase (MSI), there were significant differences between the tumor core and both normal brain($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($13.18{\pm}2.81$ vs. $6.99{\pm}1.73$ vs. $6.41{\pm}1.39$ HU/sec). Additionally, in the maximum slope of decrease (MSD), there were significant differences between the tumor core and contralateral normal brain($p{\leqq}0.05$), but no significant differences between the tumor core and ipsilateral normal brain($4.02{\pm}1.37$ vs. $4.66{\pm}0.83$ vs. $6.47{\pm}1.53$ HU/sec). In conclusion, the VX2 tumors were implanted in the rabbit brain successfully, and stereotactic inoculation method make single-nodular type of tumor that was no metastasis in intracranial, suitable for comparative study between tumors and normal tissues. Therefore, perfusion CT would be a useful diagnostic tool capable of reflecting the vascularity of the tumors.