Dataset Information

Evaluation of infarct core and ischemic penumbra by absolute quantitative cerebral dynamic susceptibility contrast perfusion magnetic resonance imaging using self-calibrated echo planar imaging sequencing in patients with acute ischemic stroke.

ABSTRACT:

Background

It has been hypothesized that an absolute quantitative dynamic susceptibility contrast (DSC) cerebral perfusion-weighted imaging (PWI) technique based on self-calibrated echo-planar imaging (EPI) could be a reliable measurement of quantitative cerebral blood flow (qCBF) and quantitative cerebral blood volume (qCBV). This study aimed to investigate the clinical value of this technique in offering a unique insight into ischemic stroke (IS) pathophysiology and improving the sensitivity of IS diagnosis.

Methods

A total of 14 patients with IS who underwent routine magnetic resonance imaging (MRI) and Self-CALibrated EPI Perfusion-Weighted Imaging (SCALE-PWI) scanning were prospectively recruited as a consecutive convenience sample. qCBF and qCBV maps were processed immediately online after the scan. Then, 2 radiologists independently drew the region of interest (ROI) of the infarct core, ischemic penumbra, and the contralateral normal tissues on each map for the statistical analyses. The paired-samples t-test, Wilcoxon signed-rank test, independent-samples t-test, and receiver operating characteristic (ROC) curve were performed. A value of P<0.05 was considered statistically significant with 95% confidence intervals (CI).

Results

All the values of qCBF and qCBV in the lesions were lower than those in the contralateral normal tissues (all P<0.05). The values of qCBF and qCBV in the infarct core were lower than those in the ischemic penumbra (mean values: 16.42 vs. 21.54 mL/100 g/min, P=0.013; 1.23 vs. 1.47 mL/100 g, P=0.049, respectively). The qCBF threshold of the infarct core was 18.18 mL/100 g/min (sensitivity, 71.40%; specificity, 64.30%) and the qCBF threshold of the ischemic penumbra was 28.09 mL/100 g/min (sensitivity, 78.60%; specificity, 85.70%).

Conclusions

Different from the previous semi-quantitative measurement, the SCALE-PWI technique has the potential to provide absolute quantitative hemodynamic information which may be used to detect the infarct core and ischemic penumbra in a relatively short scan time.

SUBMITTER: Ma X

PROVIDER: S-EPMC9338368 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature

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Publications

Evaluation of infarct core and ischemic penumbra by absolute quantitative cerebral dynamic susceptibility contrast perfusion magnetic resonance imaging using self-calibrated echo planar imaging sequencing in patients with acute ischemic stroke.

Ma Xiaoyue X Wang Yan Y Wang Mengke M Zhang Menghuan M Meng Nan N Zhang Long L Zhang Jinlong J Dou Shewei S Wang Meiyun M

Quantitative imaging in medicine and surgery 20220801 8

<h4>Background</h4>It has been hypothesized that an absolute quantitative dynamic susceptibility contrast (DSC) cerebral perfusion-weighted imaging (PWI) technique based on self-calibrated echo-planar imaging (EPI) could be a reliable measurement of quantitative cerebral blood flow (qCBF) and quantitative cerebral blood volume (qCBV). This study aimed to investigate the clinical value of this technique in offering a unique insight into ischemic stroke (IS) pathophysiology and improving the sensi ...[more]

PMID: 35919056

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Project description:BACKGROUND AND PURPOSE:Acidification of the tumor microenvironment from abnormal metabolism along with angiogenesis to meet metabolic demands are both hallmarks of malignant brain tumors; however, the interdependency of tumor acidity and vascularity has not been explored. Therefore, our aim was to investigate the association between pH-sensitive amine chemical exchange saturation transfer echoplanar imaging (CEST-EPI) and relative cerebral blood volume (CBV) measurements obtained from dynamic susceptibility contrast (DSC) perfusion MRI in patients with gliomas. MATERIALS AND METHODS:In this retrospective study, 90 patients with histologically confirmed gliomas were scanned between 2015 and 2018 (median age, 50.3 years; male/female ratio = 59:31). pH-weighting was obtained using chemical exchange saturation transfer echo-planar imaging estimation of the magnetization transfer ratio asymmetry at 3 ppm, and CBV was estimated using DSC-MR imaging. The voxelwise correlation and patient-wise median value correlation between the magnetization transfer ratio asymmetry at 3 ppm and CBV within T2-hyperintense lesions and contrast-enhancing lesions were evaluated using the Pearson correlation analysis. RESULTS:General colocalization of elevated perfusion and high acidity was observed in tumors, with local intratumor heterogeneity. For patient-wise analysis, median CBV and magnetization transfer ratio asymmetry at 3 ppm within T2-hyperintense lesions were significantly correlated (R = 0.3180, P = .002), but not in areas of contrast enhancement (P = .52). The positive correlation in T2-hyperintense lesions remained within high-grade gliomas (R = 0.4128, P = .001) and in isocitrate dehydrogenase wild-type gliomas (R = 0.4300, P = .002), but not in World Health Organization II or in isocitrate dehydrogenase mutant tumors. Both magnetization transfer ratio asymmetry at 3 ppm and the voxelwise correlation between magnetization transfer ratio asymmetry and CBV were higher in high-grade gliomas compared with low-grade gliomas in T2-hyperintense tumors (magnetization transfer ratio asymmetry, P = .02; Pearson correlation, P = .01). The same trend held when comparing isocitrate dehydrogenase wild-type gliomas and isocitrate dehydrogenase mutant gliomas (magnetization transfer ratio asymmetry, P = .04; Pearson correlation, P = .01). CONCLUSIONS:A positive linear correlation between CBV and acidity in areas of T2-hyperintense, nonenhancing tumor, but not enhancing tumor, was observed across patients. Local heterogeneity was observed within individual tumors.

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Project description:BackgroundMagnetic resonance elastography (MRE) is an imaging technique that can noninvasively assess the shear properties of the intervertebral disc (IVD). Unlike the standard gradient recalled echo (GRE) MRE technique, a spin-echo echo-planar imaging (SE-EPI) sequence has the potential to improve imaging efficiency and patient compliance.PurposeTo validate the use of an SE-EPI sequence for MRE of the IVD compared against the standard GRE sequence.Study typeCross-over.SubjectsTwenty-eight healthy volunteers (15 males and 13 females, age range: 19-55).Field strength/sequence3 T; GRE, SE-EPI with breath holds (SE-EPI-BH) and SE-EPI with free breathing (SE-EPI-FB) MRE sequences.AssessmentMRE-derived shear stiffnesses were calculated via principal frequency analysis. SE-EPI derived shear stiffness and octahedral shear strain signal-to-noise ratios (OSS-SNR) were compared against those derived using the GRE sequence. The reproducibility and repeatability of SE-EPI stiffness measurements were determined. Shear stiffness was evaluated in the nucleus pulposus (NP) and annulus fibrosus (AF) regions of the disc. Scan times between sequences were compared.Statistical testsLinear mixed models, Bland-Altman plots, and Lin's concordance correlation coefficients (CCCs) were used with P < 0.05 considered statistically significant.ResultsGood correlation was observed between shear stiffnesses derived from the SE-EPI sequences with those derived from the GRE sequence with CCC values greater than 0.73 and 0.78 for the NP and AF regions, respectively. OSS-SNR was not significantly different between GRE and SE-EPI sequences (P > 0.05). SE-EPI sequences generated highly reproducible and repeatable stiffness measurements with CCC values greater than 0.97 in the NP and AF regions and reduced scan time by at least 51% compared to GRE. SE-EPI-BH and SE-EPI-FB stiffness measurements were similar with CCC values greater than 0.98 for both regions.Data conclusionSE-EPI-based MRE-derived stiffnesses were highly reproducible and repeatable and correlated with current standard GRE MRE-derived stiffness estimates while reducing scan times.Level of evidence1 TECHNICAL EFFICACY STAGE: 1.

Dataset Information

Evaluation of infarct core and ischemic penumbra by absolute quantitative cerebral dynamic susceptibility contrast perfusion magnetic resonance imaging using self-calibrated echo planar imaging sequencing in patients with acute ischemic stroke.

Background

Methods

Results

Conclusions

Publications

Evaluation of infarct core and ischemic penumbra by absolute quantitative cerebral dynamic susceptibility contrast perfusion magnetic resonance imaging using self-calibrated echo planar imaging sequencing in patients with acute ischemic stroke.

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