Discriminant analysis to classify glioma grading using dynamic contrast-enhanced MRI and immunohistochemical markers

Introduction  

The purpose of the present study was to look for the possible predictors which might discriminate between high- and low-grade gliomas by pooling dynamic contrast-enhanced (DCE)-perfusion derived indices and immunohistochemical markers.     

Measurements of diagnostic examination performance and correlation analysis using microvascular leakage,cerebral blood volume,and blood flow derived from 3T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in glial tumor grading

Introduction  

To assess the diagnostic accuracy of microvascular leakage (MVL), cerebral blood volume (CBV) and blood flow (CBF) values derived from dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MR imaging) for grading of cerebral glial tumors, and to estimate the correlation between vascular permeability/perfusion parameters and tumor grades.     

Comparison of cerebral blood volume and vascular permeability from dynamic susceptibility contrast-enhanced perfusion MR imaging with glioma grade

BACKGROUND AND PURPOSE: Relative cerebral blood volume (rCBV) and vascular permeability (K(trans)) permit in vivo assessment of glioma microvasculature. We assessed the associations between rCBV and K(trans) derived from dynamic, susceptibility-weighted, contrast-enhanced (DSC) MR imaging and tumor grade and between rCBV and K(trans). METHODS: Seventy-three patients with primary gliomas underwent conventional and DSC MR imaging. rCBVs were obtained from regions of maximal abnormality for each lesion on rCBV color maps. K(trans) was derived from a pharmacokinetic modeling algorithm. Histopathologic grade was compared with rCBV and K(trans) (Tukey honestly significant difference). Spearman and Pearson correlation factors were determined between rCBV, K(trans), and tumor grade. The diagnostic utility of rCBV and K(trans) in discriminating grade II or III tumors from grade I tumors was assessed by logistic regression. RESULTS: rCBV was significantly different for all three grades (P 相似文献   

Comparison of cerebral blood volume and permeability in preoperative grading of intracranial glioma using CT perfusion imaging

Introduction Regional cerebral blood volume (rCBV) and permeability surfaces (rPS) permit in vivo assessment of glioma microvasculature, which provides quite important pathophysiological information in grading gliomas. The aim of our study was to simultaneously examine rCBV and rPS in glioma patients to determine their correlation with histological grade using CT perfusion imaging.Methods A total of 22 patients with gliomas underwent multislice CT perfusion imaging preoperatively. Low-grade and high-grade groups were categorized corresponding to WHO grade II gliomas and WHO grade III or IV gliomas, respectively, as determined by histopathological examination. rCBVs and rPSs were obtained from regions of maximal abnormality in tumor parenchyma on CBV and PS color perfusion maps. Perfusion parameters were compared using the Kruskal-Wallis test in order to evaluate the differences in relation to tumor grade. The Pearson coefficients of rCBV and rPS for each tumor grade were assessed using SPSS 13.0 software.Results rCBV and rPS provided significant P-value in differentiating glioma grade (low-grade gliomas 3.28±2.01 vs 2.12±3.19 ml/100 g/min, high-grade gliomas 8.87±4.63 vs 12.11±3.18 ml/100 g/min, P<0.05). Receiver operating characteristic (ROC) curves revealed better specificity and sensitivity in PS than in CBV for glioma grade. A significant correlation between rCBV and rPS was observed in high-grade gliomas (r=0.684). rCBVs in oligodendrogliomas were higher than in other low-grade gliomas, whereas their rPS values did not show a parallel difference.Conclusion Perfusion CT provides useful information for glioma grading and might have the potential to significantly impact clinical management and follow-up of cerebral gliomas.Presented at the 91st Meeting of the Radiological Society of North America, Chicago, IL, 27 November to 3 December 2005.     

3.0TDCE-MRI及DTI在胶质瘤分级中的价值

目的：探讨动态增强磁共振成像(DCE-MRI)及扩散张量成像(DTI)在胶质瘤分级中的价值。方法31例胶质瘤患者行3.0T DCE-MRI 及 DTI 检查,测量定量参数包括：容量转移常数(Ktrans )、血管外细胞外间隙容积比(Ve )、速率常数(Kep )、对比剂浓度下峰面积(iAUC)及相对各向异性分数(rFA)。低级别、高级别胶质瘤组间 DCE-MRI、rFA 参数与微血管密度(MVD)、微血管结构(MVS)相关性评估采用 Spearman 相关性检验。结果胶质瘤分级与 MVD 计数和 MVS 改变呈正相关。14例低级别胶质瘤的 Ktrans 值、Kep 值、Ve 值、iAUC 值及 rFA 值分别为(0.02±0.01)min-1、1.82(0.18~8.54)min-1、0.05±0.03、2.47±1.66和0.55±0.22;17例高级别胶质瘤参数值分别为(0.11±0.02)min-1、1.31(0.12~7.58)min-1、0.28±0.10、10.84±6.46和0.28±0.08。各参数值组间除 Kep 外,其他参数差异均有统计学意义(P <0.05)。Ktrans 、Ve 、iAUC 值与 MVD 计数及 MVS 呈正相关(P <0.05),rFA 值与MVD 计数及 MVS 呈负相关(P <0.01)。结论DCE-MRI、DTI 定量参数对胶质瘤分级以及肿瘤新生血管增生、血管微结构改变都有重要的评估价值。     

Comparison of arterial spin-labeling techniques and dynamic susceptibility-weighted contrast-enhanced MRI in perfusion imaging of normal brain tissue

OBJECTIVES: To evaluate relative cerebral blood flow (rCBF) in normal brain tissue using arterial spin-labeling (ASL) methods and first-pass dynamic susceptibility-weighted contrast-enhanced (DSC) magnetic resonance imaging (MRI). METHODS: Sixty-two patients with brain metastases were examined on a 1.5 T-system up to 6 times during routine follow-up after stereotactic radiosurgery. Perfusion values in normal gray and white matter were measured using the ASL techniques ITS-FAIR in 38 patients, Q2TIPS in 62 patients, and the first-pass DSC echo-planar (EPI) MRI after bolus administration of gadopentetate dimeglumine in 42 patients. Precision of the ASL sequences was tested in follow-up examinations in 10 healthy volunteers. RESULTS: Perfusion values in normal brain tissue obtained by all sequences correlated well by calculating Pearson's correlation coefficients (P < 0.0001) and remained unchanged after stereotactic radiosurgery as shown by analysis of variance (P > 0.05). CONCLUSION: Both ASL and DSC EPI MRI yield highly comparable perfusion values in normal brain tissue.     

比较动态磁敏感加权对比增强磁共振（扫描）方法：建议测量脑肿瘤相对脑血容量

目的 采用动态敏感加权对比增强磁共振成像，通过改变数据采集及后处理方法能否评估脑肿瘤相对脑血容量（rCBV）。材料和方法 本研究经研究机构审查委员会同意，遵从HIPAA，受试者签署知情同意书。用4种采集方法收集22例高级别胶质瘤病人数据。     

Prognostic value of preoperative dynamic contrast-enhanced MRI perfusion parameters for high-grade glioma patients

Introduction

The prognostic value of the dynamic contrast-enhanced (DCE) MRI perfusion and its histogram analysis-derived metrics is not well established for high-grade glioma (HGG) patients. The aim of this prospective study was to investigate DCE perfusion transfer coefficient (K^trans), vascular plasma volume fraction (v_p), extracellular volume fraction (v_e), reverse transfer constant (k_ep), and initial area under gadolinium concentration time curve (IAUGC) as predictors of progression-free (PFS) and overall survival (OS) in HGG patients.

Methods

Sixty-nine patients with suspected anaplastic astrocytoma or glioblastoma underwent preoperative DCE-MRI scans. DCE perfusion whole tumor region histogram parameters, clinical details, and PFS and OS data were obtained. Univariate, multivariate, and Kaplan–Meier survival analyses were conducted. Receiver operating characteristic (ROC) curve analysis was employed to identify perfusion parameters with the best differentiation performance.

Results

On univariate analysis, v_e and skewness of v_p had significant negative impacts, while k_ep had significant positive impact on OS (P < 0.05). v_e was also a negative predictor of PFS (P < 0.05). Patients with lower v_e and IAUGC had longer median PFS and OS on Kaplan–Meier analysis (P < 0.05). K^trans and v_e could also differentiate grade III from IV gliomas (area under the curve 0.819 and 0.791, respectively).

Conclusions

High v_e is a consistent predictor of worse PFS and OS in HGG glioma patients. v_p skewness and k_ep are also predictive for OS. K^trans and v_e demonstrated the best diagnostic performance for differentiating grade III from IV gliomas.

     

Intracranial mass lesions: dynamic contrast-enhanced susceptibility-weighted echo-planar perfusion MR imaging

Dynamic contrast agent-enhanced perfusion magnetic resonance (MR) imaging provides physiologic information that complements the anatomic information available with conventional MR imaging. Analysis of dynamic data from perfusion MR imaging, based on tracer kinetic theory, yields quantitative estimates of cerebral blood volume that reflect the underlying microvasculature and angiogenesis. Perfusion MR imaging is a fast and robust imaging technique that is increasingly used as a research tool to help evaluate and understand intracranial disease processes and as a clinical tool to help diagnose, manage, and understand intracranial mass lesions. With the increasing number of applications of perfusion MR imaging, it is important to understand the principles underlying the technique. In this review, the essential underlying physics and methods of dynamic contrast-enhanced susceptibility-weighted echo-planar perfusion MR imaging are described. The clinical applications of cerebral blood volume maps obtained with perfusion MR imaging in the differential diagnosis of intracranial mass lesions, as well as the pitfalls and limitations of the technique, are discussed. Emphasis is on the clinical role of perfusion MR imaging in providing insight into the underlying pathophysiology of cerebral microcirculation.     

Fluctuations in tumor blood perfusion assessed by dynamic contrast-enhanced MRI.

Temporal heterogeneity in blood perfusion is a common phenomenon in tumors, but data characterizing the nature of the blood flow fluctuations are sparse. This study investigated the occurrence of blood flow fluctuations in A-07 melanoma xenografts by using gadopentetate dimeglumine (Gd-DTPA)-based dynamic contrast-enhanced MRI (DCE-MRI). Each tumor was subjected to two DCE-MRI acquisitions separated by 1 hour. The data were processed by Kety analysis and resulted in two E.F images (E is the initial extraction fraction of Gd-DTPA and F is the perfusion) and two lambda images (lambda is the partition coefficient of Gd-DTPA) for each tumor. The E . F images were used to determine the changes in blood perfusion arising in the time between the two imaging sequences. The lambda images were used to control the reproducibility of the experimental procedure. The study showed that DCE-MRI with subsequent Kety analysis is a useful method for detection of blood flow fluctuations in A-07 tumors, and strongly suggested that the peripheral regions of A-07 tumors are more exposed to temporal changes in blood perfusion than are the central regions.     

Diagnostic examination performance by using microvascular leakage,cerebral blood volume,and blood flow derived from 3-T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in the differentiation of glioblastoma multiforme and brain metastasis

Introduction  

Conventional magnetic resonance (MR) imaging has limited capacity to differentiate between glioblastoma multiforme (GBM) and metastasis. The purposes of this study were: (1) to compare microvascular leakage (MVL), cerebral blood volume (CBV), and blood flow (CBF) in the distinction of metastasis from GBM using dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MRI), and (2) to estimate the diagnostic accuracy of perfusion and permeability MR imaging.     

Cerebral blood flow,blood volume,and vascular permeability of cerebral glioma assessed with dynamic CT perfusion imaging

We report dynamic CT perfusion imaging assessment of hemodynamics in a patient with a high-grade cerebral glioma and compare our results to those of previously published studies.     

Assessment of irradiated brain metastases by means of arterial spin-labeling and dynamic susceptibility-weighted contrast-enhanced perfusion MRI: initial results

RATIONALE AND OBJECTIVES: To assess if preradiation and early follow-up measurements of relative regional cerebral blood flow (rrCBF) can predict treatment outcome in patients with cerebral metastases and to evaluate rrCBF changes in tumor and normal tissue after stereotactic radiosurgery using arterial spin-labeling (ASL) and first-pass dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion MRI. METHODS: In 25 patients with a total of 28 brain metastases, DSC MRI and ASL perfusion MRI using the Q2TIPS sequence were performed with a 1.5-T unit. Measurements were performed prior to and at 6 weeks, 12 weeks, and 24 weeks after stereotactic radiosurgery. Follow-up examinations were completely available in 25 patients for Q2TIPS and 17 patients with 18 metastases for DSC MRI. The rrCBF of the metastases and the normal brain tissue was determined by a region-of-interest analysis. rrCBF values were correlated with the treatment outcome that was classified according to tumor volume changes at 6 months. RESULTS: The alteration of the rrCBF at the 6-week follow-up was highly predictive for treatment outcome. A decrease of the rrCBF value predicted tumor response correctly in all metastases for Q2TIPS and in 13 of 16 metastases for DSC MRI. The pretherapeutic rrCBF was not able to predict treatment outcome. The rrCBF values in normal brain tissue affected by radiation doses less than 0.5 Gy remained unchanged after therapy. CONCLUSION: These preliminary results suggest that ASL and DSC MRI techniques determining rrCBF changes in brain metastases after stereotactic radiosurgery allow the prediction of treatment outcome.     

Validation of Fourier decomposition MRI with dynamic contrast-enhanced MRI using visual and automated scoring of pulmonary perfusion in young cystic fibrosis patients

Purpose

To validate Fourier decomposition (FD) magnetic resonance (MR) imaging in cystic fibrosis (CF) patients with dynamic contrast-enhanced (DCE) MR imaging.

Materials and methods

Thirty-four CF patients (median age 4.08 years; range 0.16–30) were examined on a 1.5-T MR imager. For FD MR imaging, sets of lung images were acquired using an untriggered two-dimensional balanced steady-state free precession sequence. Perfusion-weighted images were obtained after correction of the breathing displacement and Fourier analysis of the cardiac frequency from the time-resolved data sets. DCE data sets were acquired with a three-dimensional gradient echo sequence. The FD and DCE images were visually assessed for perfusion defects by two readers independently (R1, R2) using a field based scoring system (0–12). Software was used for perfusion impairment evaluation (R3) of segmented lung images using an automated threshold. Both imaging and evaluation methods were compared for agreement and tested for concordance between FD and DCE imaging.

Results

Good or acceptable intra-reader agreement was found between FD and DCE for visual and automated scoring: R1 upper and lower limits of agreement (ULA, LLA): 2.72, −2.5; R2: ULA, LLA: ±2.5; R3: ULA: 1.5, LLA: −2. A high concordance was found between visual and automated scoring (FD: 70–80%, DCE: 73–84%).

Conclusions

FD MR imaging provides equivalent diagnostic information to DCE MR imaging in CF patients. Automated assessment of regional perfusion defects using FD and DCE MR imaging is comparable to visual scoring but allows for percentage-based analysis.     

Cerebral perfusion imaging using contrast-enhanced MRI

New developments in fast magnetic resonance imaging (MRI) have enabled imaging of cerebral haemodynamics. This article describes the theory behind perfusion imaging and provides an overview of the most commonly used MRI technique. Limitations of this technique are described, and the potential clinical applications are discussed, with particular attention to the role of perfusion imaging in the context of stroke and brain tumour.