ObjectiveThe purpose of this study was to prospectively compare pre-operative computed tomography (CT) perfusion parameters with tumor grade from colorectal adenocarcinoma (CRC) and to correlate pre-operative CT perfusion parameters with microvessel density (MVD) to evaluate angiogenesis in CRC.Materials and MethodsPre-operative perfusion CTs were performed with a 64-channel multidetector row CT in 27 patients (17 women and 10 men; age range 32-82 years) who were diagnosed with CRC involving the sigmoid and rectum between August 2006 and November 2007. All patients underwent surgery without pre-operative chemotherapy or radiation therapy. Dynamic perfusion CTs were performed for 65 seconds after intravenous injection of contrast medium (100 mL, 300 mg of iodine per mL, 5 mL/sec). Before surgery, blood flow (BF), blood volume, mean transit time (MTT), and permeability-surface area product were measured in the tumor. After surgery, one gastrointestinal pathologist evaluated tumor grade and performed immunohistochemical staining using CD 34 to determine MVD in each tumor. The Kruskal-Wallis test was used to compare CT perfusion parameters with tumor grade, and Pearson's correlation analysis was used to correlate CT perfusion parameters with MVD.ResultsIn 27 patients with CRC, tumor grading was as follows: well differentiated (n = 8); moderately differentiated (n = 15); and poorly differentiated (n = 4). BF was higher in moderately differentiated CRC than well differentiated and poorly differentiated CRCs (p = 0.14). MTT was shorter in moderately differentiated than well differentiated and poorly differentiated CRCs (p = 0.039). The MVD was greater in poorly differentiated than well differentiated and moderately differentiated CRCs (p = 0.034). There was no significant correlation between other perfusion parameters and tumor grade. There was no significant correlation between CT perfusion parameters and MVD.ConclusionBF and MTT measurement by perfusion CT is effective in predicting moderately differentiated CRCs. However, perfusion CT is limited in distinguishing well differentiated and poorly differentiated CRCs. Pre-operative perfusion CT does not reflect the MVD of CRCs.

Patent ductus venosus is a rare form of congenital portosystemic shunt from the fetal umbilical vein to the inferior vena cava. The reported surgical treatments include ligation, banding, and liver transplantation. In addition, transcatheter closure with a coil, stent, or original Amplatzer vascular plug (AVP) has been reported. The AVP II, a redesigned version of the original vascular plug with a finer more densely woven nitinol wire and a large diameter (up to 22 mm) is available. This reported case is the first successful occlusion of a large patent ductus venosus with the new AVP II.

ObjectiveTo access the feasibility of clinically available 3T MRI to detect the migration of labeled neural stem cells (NSCs) in intracerebral hemorrhage (ICH) in a rat model.Materials and MethodsThe ethics committee of our institution approved this study. ICH was induced by the injection of collagenase type IV into the right striatum of ten Sprague-Dawley rats. Human NSCs conjugated with Feridex (super-paramagnetic iron oxide: SPIO) were transplanted into the left striatum one week after ICH induction. MRI was performed on a 3T scanner during the first, second, third, fourth, and sixth weeks post-transplantation. MRI was obtained using coronal T2- and T2*-weighted sequences. Two rats were sacrificed every week after in vivo MRI in order to analyze the histological findings.ResultsICH in the right striatum was detected by MRI one and two weeks after transplantation without migration of the NSCs. There was no migration of the NSCs as seen on the histological findings one week after transplantation. The histological findings two weeks after transplantation showed a small number of NSCs along the corpus callosum. On MRI three weeks after transplantation, there was a hypointense line along the corpus callosum and decreased signal intensity in the right periventricular region. Histological findings three weeks after transplantation confirmed the presence of the hypointense line representing SPIO-labeled NSCs. MRI four and six weeks after transplantation showed a hypointense spot in the right periventricular region. The histological findings four and six weeks after transplantation showed the presence of prominent NSCs in the right periventricular region.Conclusion3T MRI can detect the migration of NSCs in rats with ICH along the corpus callosum. Therefore, 3T MRI could be feasible for detecting the migration of NSCs in the clinical setting of stem cell therapy.

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ObjectiveTo evaluate the effectiveness of ultrasound-guided radiofrequency (RF) ablation in patients with incompletely treated hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE) and to evaluate possible prognostic factors for this therapy.Subjects and MethodsThirty nine patients with incompletely treated single HCC (≤ 5 cm) after TACE were treated with RF ablation. All patients were evaluated for complete tumor ablation rate, local recurrence-free rate, overall survival rate, and complications. Local recurrence-free rate and overall survival rate were calculated using the Kaplan-Meier method. The possible prognostic factors of local recurrence-free rate and survival rate were analyzed using Cox proportional-hazards regression model.ResultsThe complete tumor ablation rate was 92.3%. Local recurrence-free rates for 1-, 2-, 3-, and 5-years were 81.7%, 63.1%, 53.6%, and 35.7%, respectively. One-, 2-, 3-, and 5-year overall survival rates were 96.9%, 82.9%, 67.8%, and 48.4%, respectively. Among prognostic factors included in the analysis, only tumor diameter (≤ 2 cm versus > 2 cm) was statistically significant in terms of predicting local recurrence. Complications were observed in two patients, one with liver abscess and the other with portal venous thrombosis.ConclusionUltrasound-guided RF ablation could be effective and safe in treating incompletely treated HCC after TACE. The diameter of HCC was a significant prognostic factor for local recurrence.