Role of pulmonary perfusion magnetic resonance imaging for the diagnosis of pulmonary hypertension:A review

Among five types of pulmonary hypertension,chronic thromboembolic pulmonary hypertension(CTEPH)is the only curable form,but prompt and accurate diagnosis can be challenging.Computed tomography and nuclear medicine-based techniques are standard imaging modalities to non-invasively diagnose CTEPH,however these are limited by radiation exposure,subjective qualitative bias,and lack of cardiac functional assessment.This review aims to assess the methodology,diagnostic accuracy of pulmonary perfusion imaging in the current literature and discuss its advantages,limitations and future research scope.

Classification of breast lesions based on a dual S-shaped logistic model in dynamic contrast enhanced magnetic resonance imaging

This study proposes a novel dual S-shaped logistic model for automatically quantifying the characteristic kinetic curves of breast lesions and for distinguishing malignant from benign breast tumors on dynamic contrast enhanced (DCE) magnetic resonance (MR) images.D(,) is the diagnostic parameter derived from the logistic model.Significant differences were found in D(,) between the malignant benign groups.Fisher's Linear Discriminant analysis correctly classified more than 90% of the benign and malignant kinetic breast data using the derived diagnostic parameter (D(,)).Receiver operating characteristic curve analysis of the derived diagnostic parameter (D(,)) indicated high sensitivity and specificity to differentiate malignancy from benignancy.The dual S-shaped logistic model was effectively used to fit the kinetic curves of breast lesions in DCE-MR.Separation between benign and malignant breast lesions was achieved with sufficient accuracy by using the derived diagnostic parameter D(,) as the lesion's feature.The proposed method therefore has the potential for computer-aided diagnosis in breast tumors.

Diagnostic Value of Quantitative Parameters of DCE-MRI in Endometrial Carcinoma and Its Correlation with Clinicopathological Factors

In the study,108 patients with endometrial cancer were selected as the observation group,and 105 patients with benign endometrial lesions were selected as the control group.After DCE-MRI examination,it was found that the volume transfer constant(K^(trans)),rate constant(K_(e))and extracellular space volume ratio(V_(e))in the observation group were higher than those in the control group(P<0.05).The area under curve(AUC)of combined K^(trans),K_(e) and V_(e) values in the diagnosis of endometrial cancer was 0.841.The values of K^(trans),K_(e )and V_(e) were positively correlated with the clinical stage and the degree of muscular invasion,but negatively correlated with the degree of differentiation(P<0.05).The results of the study suggested that DCE-MRI quantitative parameters have a certain value in the differential diagnosis of endometrial cancer,which helped to further distinguish the degree of muscular invasion,clinical stage,and differentiation of endometrial cancer patients.

Real-time monitoring of tumor vascular disruption induced by radiofrequency assisted gadofullerene

The anti-vascular therapy has been extensively studied for high performance tumor therapy by suppressing the tumor angiogenesis or cutting off the existing tumor vasculature. We have previously reported a novel anti-tumor treatment technique using radiofrequency （RF）-assisted ga- dofullerene nanocrystals （GFNCs） to selectively disrupt the tumor vasculature. In this work, we further revealed the changes on morphology and functionality of the tumor vas-culature during the high-performance RF-assisted GFNCs treatment in vivo. Here, a dearly evident mechanism of this technique in tumor vascular disruption was elucidated. Based on the H22 tumor bearing mice with dorsal skin flap chamber （DSFC） mode] and the dynamic contrast enhanced magnetic resonance imaging （DCE-MRI） technique, it was revealed that the GFNCs would selectively inset in the gaps of tumor vas-culature due to the innately incomplete structures and unique microenvironment of tumor vasculature,＇ and they damaged the surrounding endothelia cells excited by the RF to induce a phase transition accompanying with size expansion. Soon afterwards, the blood flow of the tumor blood vessels was permanently shut off, causing the entire tumor vascular net- work to collapse within 24 h after the treatment. The RF-as- sistant GFNCs technique was proved to aim at the tumor vasculatnre precisely, and was harmless to the normal vascu- lature. The current studies provide a rational explanation on the high efficiency anticancer activity of the RF-assisted GFNCs treatment, suggesting a novel technique with potent clinical application.

Neovascularization in the carotid atherosclerotic plaque is not associated with inflammatory cell aggregation

Background Monocytes and macrophages in atherosclerotic plaque lead to plaque instability.The aim of the study was to determine if plaque neovascularization led to inflammation.Methods Patients were consecutively enrolled if their carotid intimal media thickness was ＞2 mm,as revealed by duplex ultrasound.The patients then underwent dynamic contrast enhanced magnetic resonance imaging （DCE MRI） and fluorine-18 fluorodeoxyglucose （18F-FDG） positron emission tomography combined with computed tomography （PET CT）.A target to background ratio （TBR） of ＞1.25 or ＜1.25 served as the cutoff point for the presence and absence of inflammation,respectively.Results Twenty-six patients underwent bilateral carotid DCE MRI and 24 patients also underwent PET CT.One hundred and fifty-five plaques were evaluated by both DCE MRI and PET CT.There was no significant difference in plaque morphology between the TBR ＞1.25 （n=61） and TBR ＜1.25 （n=94） groups.No significant differences were found in plasma volume and transfer constant between the TBR ＞1.25 and TBR ＜1.25 groups.Conclusion Our study did not find a significant correlation between plaque neovascularization and the aggregation of inflammatory cells.