Objective： To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging（DCEMRI） for predicting tumor response to radiotherapy in patients with suspected primary central nervous system（CNS） ...Objective： To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging（DCEMRI） for predicting tumor response to radiotherapy in patients with suspected primary central nervous system（CNS） germ cell tumors（GCTs）.Methods： DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic（ROC） curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve.Results： A significant elevation in transfer constant（K^trans） and extravascular extracellular space（Ve）（P=0.000）, as well as a significant reduction in rate constant（Kep）（P=0.000） was observed in tumors. K^trans, relative K^trans, and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative K^trans showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value（PPV） of 95.8%, and negative predictive value（NPV） of 100%.Conclusions： Relative K^trans appeared promising in predicting tumor response to radiation therapy（RT）. It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT.展开更多
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 ...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.展开更多
In many areas of oncology, dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) has proven to be a clinically useful, non-invasive functional imaging technique to quantify tumor vasculature and tumor perfusio...In many areas of oncology, dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) has proven to be a clinically useful, non-invasive functional imaging technique to quantify tumor vasculature and tumor perfusion characteristics. Tumor angiogenesis is an essential process for tumor growth, proliferation, and metastasis. Malignant lesions demonstrate rapid extravasation of contrast from the intravascular space to the capillary bed due to leaky capillaries associated with tumor neovascularity. DCE-MRI has the potential to provide information regarding blood flow, areas of hypoperfusion, and variations in endothelial permeability and microvessel density to aid treatment selection, enable frequent monitoring during treatment and assess response to targeted therapy following treatment. This review will discuss the current status of DCE-MRI in cancer imaging, with a focus on its use in imaging prostate malignancies as well as weaknesses that limit its widespread clinical use. The latest techniques for quantification of DCE-MRI parameters will be reviewed and compared.展开更多
Background The degree of pathological microvascular proliferation is an important element in evaluation of the astrocytoma grade. This study was aimed to quantitatively assess the microvascular permeability of brain a...Background The degree of pathological microvascular proliferation is an important element in evaluation of the astrocytoma grade. This study was aimed to quantitatively assess the microvascular permeability of brain astrocytoma with the volume transfer constant （Ktrans） and volume of extravascular extracellular space per unit volume of tissue （Ve） from dynamic contrast-enhanced magnetic resonance imaging （DCE-MRI） and to evaluate the effectiveness of the Ktr^n＇ and Ve in the grading of astrocytoma. Methods The highest values of the Kt~~s and Ve of 67 patients with astrocytoma （27 with grade II, 12 with grade III, and 28 with grade IV） were obtained. The comparisons of the differences of the Ktrans and Ve between the different grades were conducted using the Mann-Whitney rank-sum tests. Spearman＇s rank correlation coefficients were determined between Ktrans values, Ve values and astrocytoma grades. Receiver operating characteristic （ROC） curve analyses were performed to determine the cut-off values for the Ktrans and Ve to distinguish between the different grades of astrocytoma. Results There were significant differences （P〈0.001） between the different grades in the Ktrans values and Ve values, except for grades III and IV. The Ktrans values and Ve values were both correlated with astrocytoma grades （both P〈0.001）. The ROC curve analyses showed that the cut-off values for the Ktrans and Ve provided the best combination of sensitivity and specificity in distinguishing between grade II and grade III or IV astrocytomas. Conclusions DCE-MRI can play an important role in assessing the microvascular permeability and the grading of brain astrocytoma.展开更多
基金supported by Beijing Natural Science Foundation(No.7122029)
文摘Objective： To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging（DCEMRI） for predicting tumor response to radiotherapy in patients with suspected primary central nervous system（CNS） germ cell tumors（GCTs）.Methods： DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic（ROC） curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve.Results： A significant elevation in transfer constant（K^trans） and extravascular extracellular space（Ve）（P=0.000）, as well as a significant reduction in rate constant（Kep）（P=0.000） was observed in tumors. K^trans, relative K^trans, and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative K^trans showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value（PPV） of 95.8%, and negative predictive value（NPV） of 100%.Conclusions： Relative K^trans appeared promising in predicting tumor response to radiation therapy（RT）. It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT.
文摘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.
文摘In many areas of oncology, dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) has proven to be a clinically useful, non-invasive functional imaging technique to quantify tumor vasculature and tumor perfusion characteristics. Tumor angiogenesis is an essential process for tumor growth, proliferation, and metastasis. Malignant lesions demonstrate rapid extravasation of contrast from the intravascular space to the capillary bed due to leaky capillaries associated with tumor neovascularity. DCE-MRI has the potential to provide information regarding blood flow, areas of hypoperfusion, and variations in endothelial permeability and microvessel density to aid treatment selection, enable frequent monitoring during treatment and assess response to targeted therapy following treatment. This review will discuss the current status of DCE-MRI in cancer imaging, with a focus on its use in imaging prostate malignancies as well as weaknesses that limit its widespread clinical use. The latest techniques for quantification of DCE-MRI parameters will be reviewed and compared.
文摘Background The degree of pathological microvascular proliferation is an important element in evaluation of the astrocytoma grade. This study was aimed to quantitatively assess the microvascular permeability of brain astrocytoma with the volume transfer constant （Ktrans） and volume of extravascular extracellular space per unit volume of tissue （Ve） from dynamic contrast-enhanced magnetic resonance imaging （DCE-MRI） and to evaluate the effectiveness of the Ktr^n＇ and Ve in the grading of astrocytoma. Methods The highest values of the Kt~~s and Ve of 67 patients with astrocytoma （27 with grade II, 12 with grade III, and 28 with grade IV） were obtained. The comparisons of the differences of the Ktrans and Ve between the different grades were conducted using the Mann-Whitney rank-sum tests. Spearman＇s rank correlation coefficients were determined between Ktrans values, Ve values and astrocytoma grades. Receiver operating characteristic （ROC） curve analyses were performed to determine the cut-off values for the Ktrans and Ve to distinguish between the different grades of astrocytoma. Results There were significant differences （P〈0.001） between the different grades in the Ktrans values and Ve values, except for grades III and IV. The Ktrans values and Ve values were both correlated with astrocytoma grades （both P〈0.001）. The ROC curve analyses showed that the cut-off values for the Ktrans and Ve provided the best combination of sensitivity and specificity in distinguishing between grade II and grade III or IV astrocytomas. Conclusions DCE-MRI can play an important role in assessing the microvascular permeability and the grading of brain astrocytoma.
