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1.  Diffusion-Weighted MRI Monitoring of Pancreatic Cancer Response to Radiofrequency Heat-Enhanced Intratumor Chemotherapy 
NMR in biomedicine  2013;26(12):10.1002/nbm.3014.
To evaluate the feasibility of using diffusion-weighted MRI to monitor the early response of pancreatic cancers to radiofrequency heat (RFH)-enhanced chemotherapy.
Human pancreatic carcinoma cells (PANC-1) in different groups and twenty four mice with pancreatic cancer xenografts in four groups were treated by phosphate buffered saline (PBS) as a control, RFH at 42 °C, gemcitabine and gemcitabine plus RFH at 42°C. One day before and 1, 7, and 14 days after the treatment, diffusion-weighted MR imaging and T2 weighted imaging were applied to monitor the apparent diffusion coefficients (ADCs) of tumors and tumors growth. MRI findings were correlated with results of tumors apoptosis analysis.
Of the in vitro experiments, quantitative viability assay showed lower relative cell viabilities treated by gemcitabine plus RFH at 42°C, compared to those by RFH only and gemcitabine only (37% ± 5% vs 65% ± 4% and 58% ± 8%, p < 0.05). Of the in vivo experiments, the combination therapy resulted in smaller relative tumor volume than RFH-only and chemotherapy-only (0.82 ± 0.17 vs 2.23 ± 0.90 and 1.64 ± 0.44, p = 0.003). In vivo 14T MRI demonstrated a remarkable decrease of ADCs at day 1 and increased ADCs at days 7 and 14 in the combination therapy group. The apoptosis index in the combination therapy group was significantly higher than those in the groups of chemotherapy-only, RFH-only and PBS treatments (37% ± 6% vs 20% ± 5%, 8% ± 2%, and 3% ± 1%, p < 0.05).
This study confirms that it is feasible to use MRI to monitor RFH-enhanced chemotherapy on pancreatic cancers, which may present new options for efficient treatment of pancreatic malignancies using MR/RF-integrated local chemotherapy.
PMCID: PMC3838434  PMID: 24038282
2.  MRI-Monitored Intra-Shunt Local Agent Delivery of Motexafin Gadolinium: Towards Improving Long-Term Patency of TIPS 
PLoS ONE  2013;8(2):e57419.
Transjugular intrahepatic portosystemic shunt (TIPS) has become an important and effective interventional procedure in treatment of the complications related to portal hypertension. Although the primary patency of TIPS has been greatly improved due to the clinical application of cover stent-grafts, the long-term patency is still suboptimal. This study was to investigate the feasibility of using magnetic resonance imaging (MRI)-monitored intra-shunt local agent delivery of motexafin gadolinium (MGd) into shunt-vein walls of TIPS. This new technique aimed to ultimately inhibit shuntstenosis of TIPS.
Human umbilical vein smooth muscle cells (SMCs) were incubated with various concentrations of MGd, and then examed by confocal microscopy and T1-map MRI. In addition, the proliferation of MGd-treated cells was evaluated. For in vivo validation, seventeen pigs underwent TIPS. Before placement of the stent, an MGd/trypan-blue mixture was locally delivered, via a microporous balloon, into eleven shunt-hepatic vein walls under dynamic MRI monitoring, while trypan-blue only was locally delivered into six shunt-hepatic vein walls as serve as controls. T1-weighted MRI of the shunt-vein walls was achieved before- and at different time points after agent injections. Contrast-to-noise ratio (CNR) of the shunt-vein wall at each time-point was measured. Shunts were harvested for subsequent histology confirmation.
Principal Findings
In vitro studies confirmed the capability of SMCs in uptaking MGds in a concentration-dependent fashion, and demonstrated the suppression of cell proliferation by MGds as well. Dynamic MRI displayed MGd/blue penetration into the shunt-vein walls, showing significantly higher CNR of shunt-vein walls on post-delivery images than on pre-delivery images (49.5±9.4 vs 11.2±1.6, P<0.01), which was confirmed by histology.
Results of this study indicate that MRI-monitored intra-shunt local MGd delivery is feasible and MGd functions as a potential therapeutic agent to inhibit the proliferation of SMCs, which may open alternative avenues to improve the long-term patency of TIPS.
PMCID: PMC3585394  PMID: 23468986
3.  MRI of Auto-Transplantation of Bone Marrow-Derived Stem-Progenitor Cells for Potential Repair of Injured Arteries 
PLoS ONE  2012;7(2):e31137.
This study was to validate the feasibility of using clinical 3.0T MRI to monitor the migration of autotransplanted bone marrow (BM)-derived stem-progenitor cells (SPC) to the injured arteries of near-human sized swine for potential cell-based arterial repair.
The study was divided into two phases. For in vitro evaluation, BM cells were extracted from the iliac crests of 13 domestic pigs and then labeled with a T2 contrast agent, Feridex, and/or a fluorescent tissue marker, PKH26. The viability, the proliferation efficiency and the efficacies of Feridex and/or PKH26 labeling were determined. For in vivo validation, the 13 pigs underwent endovascular balloon-mediated intimal damages of the iliofemoral arteries. The labeled or un-labeled BM cells were autotransplanted back to the same pig from which the BM cells were extracted. Approximately three weeks post-cell transplantation, 3.0T T2-weighted MRI was performed to detect Feridex-created signal voids of the transplanted BM cells in the injured iliofemoral arteries, which was confirmed by subsequent histologic correlation.
Principal Findings
Of the in vitro study, the viability of dual-labeled BM cells was 95–98%. The proliferation efficiencies of dual-labeled BM cells were not significantly different compared to those of non-labeled cells. The efficacies of Feridex- and PKH26 labeling were 90% and 100%, respectively. Of the in vivo study, 3.0T MRI detected the auto-transplanted BM cells migrated to the injured arteries, which was confirmed by histologic examinations.
This study demonstrates the capability of using clinical 3.0T MRI to monitor the auto-transplantation of BM cells that migrate to the injured arteries of large animals, which may provide a useful MRI technique to monitor cell-based arterial repair.
PMCID: PMC3281926  PMID: 22363566
4.  Magnetic Resonance Imaging of Bone Marrow Cell-Mediated Interleukin-10 Gene Therapy of Atherosclerosis 
PLoS ONE  2011;6(9):e24529.
A characteristic feature of atherosclerosis is its diffuse involvement of arteries across the entire human body. Bone marrow cells (BMC) can be simultaneously transferred with therapeutic genes and magnetic resonance (MR) contrast agents prior to their transplantation. Via systemic transplantation, these dual-transferred BMCs can circulate through the entire body and thus function as vehicles to carry genes/contrast agents to multiple atherosclerosis. This study was to evaluate the feasibility of using in vivo MR imaging (MRI) to monitor BMC-mediated interleukin-10 (IL-10) gene therapy of atherosclerosis.
For in vitro confirmation, donor mouse BMCs were transduced by IL-10/lentivirus, and then labeled with a T2-MR contrast agent (Feridex). For in vivo validation, atherosclerotic apoE−/− mice were intravenously transplanted with IL-10/Feridex-BMCs (Group I, n = 5) and Feridex-BMCs (Group II, n = 5), compared to controls without BMC transplantation (Group III, n = 5). The cell migration to aortic atherosclerotic lesions was monitored in vivo using 3.0T MRI with subsequent histology correlation. To evaluate the therapeutic effect of BMC-mediated IL-10 gene therapy, we statistically compared the normalized wall indexes (NWI) of ascending aortas amongst different mouse groups with various treatments.
Principal Findings
Of in vitro experiments, simultaneous IL-10 transduction and Feridex labeling of BMCs were successfully achieved, with high cell viability and cell labeling efficiency, as well as IL-10 expression efficiency (≥90%). Of in vivo experiments, MRI of animal groups I and II showed signal voids within the aortic walls due to Feridex-created artifacts from the migrated BMCs in the atherosclerotic plaques, which were confirmed by histology. Histological quantification showed that the mean NWI of group I was significantly lower than those of group II and group III (P<0.05).
This study has confirmed the possibility of using MRI to track, in vivo, IL-10/Feridex-BMCs recruited to atherosclerotic lesions, where IL-10 genes function to prevent the progression of atherosclerosis.
PMCID: PMC3168522  PMID: 21915349
5.  Cardiovascular magnetic resonance of quinticuspid aortic valve with aortic regurgitation and dilated ascending aorta 
We report a rare case of a quinticuspid aortic valve associated with regurgitation and dilation of the ascending aorta, which was diagnosed and post-surgically followed up by cardiovascular magnetic resonance and dual source computed tomography.
PMCID: PMC2734562  PMID: 19671181

Results 1-5 (5)