Predictive value of dynamic contrast-enhanced MRI of original plaque on carotid artery in-stent restenosis / 上海交通大学学报（医学版）

Objective: To explore the value of dynamic contrast-enhanced MR imaging (DCE-MRI) of original plaque to predict carotid artery in-stent restenosis (ISR). Methods: Forty cases of the patients with carotid atherosclerosis who were to undergo the carotid artery stenting (CAS) were included in this study. All participants underwent vessel wall MR imaging (VW-MRI) and DCE-MRI within one week before CAS. Carotid digital subtraction angiography (DSA) were performed at the sixth month to reassess the stenosis of stent. The correlation between DCE-MRI and ISR was evaluated. Results: The level of Ktran in ISR group was significantly higher than that in non-ISR group (P=0.000), and so was the vP (P=0.037). Ktrans could independently predict ISR (OR=1.43, 95%CI 1.17-1.56, P=0.012), and the cut-off value of Ktrans was 0.09 min-1 (sensitivity=100%, specificity=87.5%). Conclusion: Intraplaque inflammation may lead to excessive intimal hyperplasia after ISR. Ktrans could be a risk predictor of ISR with high sensitivity and specificity. DCE-MRI could be an effective tool to predict ISR.

Multi-time DCE-MRI and pathological characteristics of rabbit model bearing liver VX2 tumor / 吉林大学学报(医学版)

Objective To observe the growth characteristics and multi-time dynamic contrast-enhanced MR(DCE-MR)findings of rabbit VX2 liver tumor on MR imaging, and to provide a reliable basis for the values of MR in assessment of non-surgical treatment effect of rabbit VX2 liver tumor.Methods 10 rabbit VX2 liver tumor models were established by liver tissue embedding through laparotomy under direct vision and DCE-MRI scaning was performed at the 2nd,3rd,4th and 5th week after establishment.The tumor volume (V)and tumor growth rate (TGR)were calculated at different time points and the signal characteristics were analyzed on MR imaging;then all the rabbits were excuted and HE staining were performed to observe the cancer cells in different places with microscope.Results The TGR at the 3rd week after establishment (404.16%±114.64%)was significantly higher than that at the 4th week (223.49%±65.90%)(t=3.417,P<0.05).The tumors with well-boundary were rim-like enhanced significantly and the central parts were not enhanced on DCE-MR imaging,and the parts between the edge and centre of tumors were heterogeneously mild enhanced. The HE staining results showed that 6 cases of tumor were squamous cell carcinoma and the cells were distributed densely in the edge,the cancer cells and necrosis were distributed equally in the parts between the edge and centre of tumors and the centre of tumors were necrosis parts.Conclusion The rabbit VX2 liver tumor grows rapidly at the 3rd week after establishment, and its histological features can be better reflected by DCE-MRI.

Dynamic Contrast-Enhanced MRI for Monitoring Antiangiogenic Treatment: Determination of Accurate and Reliable Perfusion Parameters in a Longitudinal Study of a Mouse Xenograft Model

OBJECTIVE: To determine the reliable perfusion parameters in dynamic contrast-enhanced MRI (DCE-MRI) for the monitoring antiangiogenic treatment in mice. MATERIALS AND METHODS: Mice, with U-118 MG tumor, were treated with either saline (n = 3) or antiangiogenic agent (sunitinib, n = 8). Before (day 0) and after (days 2, 8, 15, 25) treatment, DCE examinations using correlations of perfusion parameters (Kep, Kel, and AH from two compartment model; time to peak, initial slope and % enhancement from time-intensity curve analysis) were evaluated. RESULTS: Tumor growth rate was found to be 129% +/- 28 in control group, -33% +/- 11 in four mice with sunitinib-treatment (tumor regression) and 47% +/- 15 in four with sunitinib-treatment (growth retardation). Kep (r = 0.80) and initial slope (r = 0.84) showed strong positive correlation to the initial tumor volume (p < 0.05). In control mice, tumor regression group and growth retardation group animals, Kep (r : 0.75, 0.78, 0.81, 0.69) and initial slope (r : 0.79, 0.65, 0.67, 0.84) showed significant correlation with tumor volume (p < 0.01). In four mice with tumor re-growth, Kep and initial slope increased 20% or greater at earlier (n = 2) than or same periods (n = 2) to when the tumor started to re-grow with 20% or greater growth rate. CONCLUSION: Kep and initial slope may a reliable parameters for monitoring the response of antiangiogenic treatment.

Multidisciplinary Functional MR Imaging for Prostate Cancer

Various functional magnetic resonance (MR) imaging techniques are used for evaluating prostate cancer including diffusion-weighted imaging, dynamic contrast-enhanced MR imaging, and MR spectroscopy. These techniques provide unique information that is helpful to differentiate prostate cancer from non-cancerous tissue and have been proven to improve the diagnostic performance of MRI not only for cancer detection, but also for staging, post-treatment monitoring, and guiding prostate biopsies. However, each functional MR imaging technique also has inherent challenges. Therefore, in order to make accurate diagnoses, it is important to comprehensively understand their advantages and limitations, histologic background related with image findings, and their clinical relevance for evaluating prostate cancer. This article will review the basic principles and clinical significance of functional MR imaging for evaluating prostate cancer.

Preoperative diagnosis for space occupying lesion of the liver / 中华普通外科杂志

Objective To study the imaging characters and pathological diagnosis for space occupying lesions of the liver with atypical clinical and laboratory features.Methods We retrospectively analyzed the clinical data and treatment of 40 patients with space occupying lesions of the liver in which preoperative correct diagnosis was difficult,the imageological appearances and the final pathological diagnosis of these 40 space occupying lesions were compared,the specificity of B-ultrasonotomography、dynamic contrast-enhanced CT and MR scanning in identifying lesions was evaluated.Results All lesions were surgically resected.On pathology there were 22 hepatocellular carcinomas,7 macroregenerative nodules,2 focal nodular hyperplasias,2 cholangiocellular carcinomas,2 hemangiomas,2 regenerative nodules and 1 hepatocellular adenoma,1 hepatic peliosis,1 antixenic nodule.The specificity of the Bultrasonotomography for all lesions was only 20%;dynamic contrast-enhanced CT has low specificity in differential diagnosis of liver carcinoma and macroregenerative nodule and the overall specificity was 42.5%;dynamic contrast-enhanced MR scanning has excellent capability in differential diagnosing of all lesions and its specificity was 92.5%.Conclusion The preoperative diagnosis for some space occupying lesions of the liver is difficult,the differential diagnosis of these lesions should be emphasized,the dynamic contrastenhanced MR scanning for space occupying lesions of the liver has high specificity.