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.

Value of dynamic contrast-enhanced MRI in selecting sclerosants for endovascular sclerosis of venous malformation / 上海交通大学学报（医学版）

Objective: To evaluate the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in predicting the efficacy of foam sclerotherapy and selecting sclerosants for endovascular sclerosis of venous malformations. Methods: A retrospective analysis was conducted for 56 patients with venous malformations who underwent intravascular sclerotherapy and DCE-MRI examination from January 2018 to June 2019 in Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine. All the patients were firstly treated with foam sclerotherapy. During the surgery, the surgeons determined whether to subsequently use ethanol, depending on the immediate therapeutic effect of foam sclerotherapy. Among them the 40 cases were treated with foam sclerotherapy only (foam sclerotherapy group) and the other 16 cases (ethanol group) with subsequent ethanol. The basic characteristics and DCE-MRI parameters of the two groups were compared. Logistic regression was used to analyze the risk factors of selecting different sclerosing agents, and the receiver operator characteristic curve was applied to assess the efficacy of these risk factors. Results: There were no significant differences in the gender, age, lesion location, pre-treatment volume and presence or absence of phleboliths between foam sclerotherapy group and ethanol group. The lesion classification, maximum intensity time ratio (MITR) and peak enhancement percentage showed significant differences between the two groups. Multivariate Logistic regression analysis showed that the lesion classification and MITR were two independent factors for the selection of sclerosing agents. The area under curve (AUC) of MITR was 0.947, while the AUC of lesion classification was 0.844. After the combination of these two parameters, the AUC was 0.969 with the sensitivity of 93.8% and the specificity of 90.0%. Conclusion: DCE-MRI can be helpful for clinical selection of appropriate sclerosing agents to improve the effectiveness of venous malformations treatment.

Early Prediction of Response to Neoadjuvant Chemotherapy Using Dynamic Contrast-Enhanced MRI and Ultrasound in Breast Cancer

OBJECTIVE: To determine the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and DCE ultrasound (DCE-US) for predicting response to neoadjuvant chemotherapy (NAC) in breast cancer patients. MATERIALS AND METHODS: This Institutional Review Board-approved prospective study was performed between 2014 and 2016. Thirty-nine women with breast cancer underwent DCE-US and DCE-MRI before the NAC, follow-up DCE-US after the first cycle of NAC, and follow-up DCE-MRI after the second cycle of NAC. DCE-MRI parameters (transfer constant [Ktrans], reverse constant [kep], and leakage space [Ve]) were assessed with histograms. From DCE-US, peak-enhancement, the area under the curve, wash-in rate, wash-out rate, time to peak, and rise time (RT) were obtained. After surgery, all the imaging parameters and their changes were compared with histopathologic response using the Miller-Payne Grading (MPG) system. Data from minor and good responders were compared using Wilcoxon rank sum test, chi-square test, or Fisher's exact test. Receiver operating characteristic curve analysis was used for assessing diagnostic performance to predict good response. RESULTS: Twelve patients (30.8%) showed a good response (MPG 4 or 5) and 27 (69.2%) showed a minor response (MPG 1–3). The mean, 25th, 50th, and 75th percentiles of Ktrans and Kep of post-NAC DCE-MRI differed between the two groups. These parameters showed fair to good diagnostic performance for the prediction of response to NAC (AUC 0.76–0.81, p ≤ 0.007). Among DCE-US parameters, the percentage change in RT showed fair prediction (AUC 0.71, p = 0.023). CONCLUSION: Quantitative analysis of DCE-MRI and DCE-US was helpful for early prediction of response to NAC.

Intravoxel Incoherent Motion MR Imaging in the Head and Neck: Correlation with Dynamic Contrast-Enhanced MR Imaging and Diffusion-Weighted Imaging

OBJECTIVE: To investigate the correlation between perfusion- and diffusion-related parameters from intravoxel incoherent motion (IVIM) and those from dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted imaging in tumors and normal muscles of the head and neck. MATERIALS AND METHODS: We retrospectively enrolled 20 consecutive patients with head and neck tumors with MR imaging performed using a 3T MR scanner. Tissue diffusivity (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) were derived from bi-exponential fitting of IVIM data obtained with 14 different b-values in three orthogonal directions. We investigated the correlation between D, f, and D* and model-free parameters from the DCE-MRI (wash-in, Tmax, Emax, initial AUC60, whole AUC) and the apparent diffusion coefficient (ADC) value in the tumor and normal masseter muscle using a whole volume-of-interest approach. Pearson's correlation test was used for statistical analysis. RESULTS: No correlation was found between f or D* and any of the parameters from the DCE-MRI in all patients or in patients with squamous cell carcinoma (p > 0.05). The ADC was significantly correlated with D values in the tumors (p 0.05, respectively). CONCLUSION: Intravoxel incoherent motion shows no significant correlation with model-free perfusion parameters derived from the DCE-MRI but is feasible for the analysis of diffusivity in both tumors and normal muscles of the head and neck.

Assessment of Blood-Brain Barrier Permeability by Dynamic Contrast-Enhanced MRI in Transient Middle Cerebral Artery Occlusion Model after Localized Brain Cooling in Rats

OBJECTIVE: The purpose of this study was to evaluate the effects of localized brain cooling on blood-brain barrier (BBB) permeability following transient middle cerebral artery occlusion (tMCAO) in rats, by using dynamic contrast-enhanced (DCE)-MRI. MATERIALS AND METHODS: Thirty rats were divided into 3 groups of 10 rats each: control group, localized cold-saline (20℃) infusion group, and localized warm-saline (37℃) infusion group. The left middle cerebral artery (MCA) was occluded for 1 hour in anesthetized rats, followed by 3 hours of reperfusion. In the localized saline infusion group, 6 mL of cold or warm saline was infused through the hollow filament for 10 minutes after MCA occlusion. DCE-MRI investigations were performed after 3 hours and 24 hours of reperfusion. Pharmacokinetic parameters of the extended Tofts-Kety model were calculated for each DCE-MRI. In addition, rotarod testing was performed before tMCAO, and on days 1-9 after tMCAO. Myeloperoxidase (MPO) immunohisto-chemistry was performed to identify infiltrating neutrophils associated with the inflammatory response in the rat brain. RESULTS: Permeability parameters showed no statistical significance between cold and warm saline infusion groups after 3-hour reperfusion 0.09 ± 0.01 min-1 vs. 0.07 ± 0.02 min-1, p = 0.661 for K(trans); 0.30 ± 0.05 min-1 vs. 0.37 ± 0.11 min-1, p = 0.394 for kep, respectively. Behavioral testing revealed no significant difference among the three groups. However, the percentage of MPO-positive cells in the cold-saline group was significantly lower than those in the control and warm-saline groups (p < 0.05). CONCLUSION: Localized brain cooling (20℃) does not confer a benefit to inhibit the increase in BBB permeability that follows transient cerebral ischemia and reperfusion in an animal model, as compared with localized warm-saline (37℃) infusion group.

Preliminary clinical study of primary liver cancer using 3 Tesla dynamic enhanced MR imaging / 医学研究生学报

Objective Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is a novel functional imaging tech-nique for assessing the property of the tissue vessel .This study was to investigate whether DCE-MRI can manifest the angiogenesis of pri-mary liver cancer in the aspect of vascular permeability so as to provide more objective diagnostic information for the evaluation of primary liver cancer . Methods Twenty-one patients with primary liver cancer underwent DCE-MRI.The region of interest ( ROI) was placed in the whole tumor, the hot spot of the tumor and the adjacent liver parenchyma .Tissue 4D software package was used for the post-pro-cessing of the DCE-MRI images, the quantitative parameters including transfer constant (Ktrans), rate constant (Kep) and tumor extravas-cular extracellular space volume (Ve), and such semi-quantitative parameter as the initial area under the contrast concentration versus time curve (iAUC). Results The mean Ktrans, Kep, Ve and iAUC values were (0.124 ±0.057)/min, (0.632 ±0.158)/min, (0.205 ±0.098) and (10.009 ±6.201) in the adjacent liver parenchyma , (0.196 ±0.109)/min, (0.546 ±0.214)/min, (0.424 ± 0.160) and (13.675 ±6.113) in the whole tumor, and (0.422 ±0.170)/min, (0.780 ±0.308)/min, (0.589 ±0.116) and (35.663 ±19.086) in the hot spot of the tumor .All the parameters were significantly higher in the hot spot of the tumor than in the whole tumor (P<0.05), and so were Ktrans and Ve in the whole tumor than in the adjacent liver parenchyma (P<0.05), but Ktrans, Ve, and iAUC were markedly lower in the adjacent liver parenchyma than in the hot spot of the tumor (P<0.05). Conclusion Analysis of the vascular permeability of the tissue using DCE-MRI parameters can indirectly reflect the angiogenesis of the tumor and contribute to the evaluation of primary liver cancer , while monitoring the DCE-MRI pa-rameters of the hot spots of the tumor may allow more accurate evalua-tion of primary liver cancer .

DCE-MRI features and ADC value analysis in triple-negative breast cancer and HER-2 overexpression subtype of breast cancer / 实用放射学杂志

Objective To analyze the DCE-MRI features and ADC value in triple-negative breast cancer and HER-2 overexpres-sion breast cancer,and to improve the j udgment of both characteristic in MRI.Methods To analyse the DCE-MRI imaging of TNBC and HER-2 overexpression breast cancer,measured the ADC value and compared the statistics.Results Compared with the shape, margin,the way of enhancement and ADC value of the TNBC and HER-2 overexpression breast cancer,the distinction has statisti-cally significant(P0.05).Conclusion DCE-MRI features of the shape,margin,the way of enhancement and ADC values were useful for the diagnosis of TNBC and HER-2 overexpression breast cancer.

Diffusion-weighted and Dynamic Contrast-enhanced MRI of Metastatic Bone Tumors: Correlation of the Apparent Diffusion Coefficient, K(trans) and ve values

PURPOSE: To investigate whether quantitative parameters derived from Diffusion-weighted magnetic resonance imaging (DW-MRI) correlate with those of Dynamic contrast-enhanced MRI (DCE-MRI). MATERIALS AND METHODS: Thirteen patients with pathologically or clinically proven bony metastasis who had undergone MRI prior to treatment were included. The voxel size was 1.367 x 1.367 x 5 mm. A dominant tumor was selected and the apparent diffusion coefficient (ADC) value and DCE-MRI parameters were obtained by matching voxels. DCE-MRI data were analyzed yielding estimates of K(trans) (volume transfer constant) and ve. (extravascular extracellular volume fraction). Statistical analysis of ADC, K(trans), and ve value was conducted using Pearson correlation analyses. RESULTS: Fifteen lesions in pelvic bones were evaluated. Of these, 11 showed a statistically significant correlation (P < 0.05) between ADC and K(trans). The ADC and K(trans) were inversely related in 7 lesions and positively related in 4 lesions. This did not depend on the primary cancer or site of metastasis. The ADC and ve of 9 lesions correlated significantly. Of these, 4 lesions were inversely related and 5 lesions were positively related. CONCLUSION: Unlike our theoretic hypothesis, there was no consistent correlation between ADC values and K(trans) or between ADC values and ve in metastatic bone tumors.

Noninvasive functional imaging techniques: positron emission tomography (PET), magnetic resonance spectroscopy (MRS), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) / 中国临床药理学与治疗学

In the pharmaceutical industry, there is currently increasing interest in noninvasive functional imaging techniques as potential early indicators of drug effects in patients. PET allows one to monitor absolute concentrations of radiolabeled drugs and metabolites, or of ligands to specific receptors, in tissues, and to visualize their distribution three-dimensionally. MRS is capable of monitoring metabolic conversions in vivo without labeling. DCE-MRI shows the distribution of small-molecular, hydrophilic weight contrast agents between blood plasma and interstitial space in tissue in real time and can be used to detect effects of antivascular or anti-angiogenic compounds.