Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Multicenter Study
Multicenter validation of automated detection of paramagnetic rim lesions on brain MRI in multiple sclerosis.
Paramagnetic rim lesions (PRLs) are an MRI biomarker of chronic inflammation in people with multiple sclerosis (MS). PRLs may aid in the diagnosis and prognosis of MS. However, manual identification of PRLs is time-consuming and prone to poor interrater reliability. To address these challenges, the Automated Paramagnetic Rim Lesion (APRL) algorithm was developed to automate PRL detection. The primary objective of this study is to evaluate the accuracy of APRL for detecting PRLs in a multicenter setting. ⋯ Our study demonstrated APRL's capability to differentiate between PRLs and lesions without paramagnetic rims in a multicenter study. Automated identification of PRLs offers greater efficiency over manual identification and could facilitate large-scale assessments of PRLs in clinical trials.
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Multicenter Study
Intracerebral hemorrhage risk after adjunct intraarterial thrombolysis in thrombectomy-treated acute ischemic stroke.
Intraarterial thrombolysis as an adjunct to mechanical thrombectomy is increasingly being considered to enhance reperfusion in acute ischemic stroke patients. Intraarterial thrombolysis may increase the risk of post-thrombectomy intracerebral hemorrhage (ICH) in certain patient subgroups. ⋯ In patients undergoing mechanical thrombectomy, the risk of any ICH and symptomatic ICH was not increased with intraarterial thrombolysis, including in those who had already received IV thrombolytics.
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Observational Study
Continuous transcranial ultrasound in large vessel stroke: Image guidance for high-intensity focused sonothrombolysis.
Sonothrombolysis is a potential adjunctive therapy for large vessel occlusion (LVO) stroke. Bedside ultrasound image-guided high-intensity focused ultrasound (HIFU) therapy could deliver higher energy therapeutic ultrasound to the thrombus with higher precision than what was previously accomplished in human trials. The aim is to test the feasibility of diagnostic transcranial contrast-enhanced ultrasound (CEUS) to image the occlusion site and continuously maintain the guidance image on-target for a sufficient exposure time for HIFU to be effective during LVO stroke evaluation and treatment. ⋯ This feasibility study explored the use of diagnostic transcranial CEUS for continuous imaging of occlusion sites in LVO strokes. Challenges in maintaining target image during HIFU were identified, highlighting the need for technical advances for clinical application.
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Susceptibility estimates derived from quantitative susceptibility mapping (QSM) images for the cerebral cortex and major subcortical structures are variably reported in brain magnetic resonance imaging (MRI) studies, as average of all ( μ all ${{{{\mu}}}_{{\mathrm{all}}}}$ ), absolute ( μ abs ${{{{\mu}}}_{{\mathrm{abs}}}}$ ), or positive- ( μ p ${{{{\mu}}}_{\mathrm{p}}}$ ) and negative-only ( μ n ${{{{\mu}}}_{\mathrm{n}}}$ ) susceptibility values using a region of interest (ROI) approach. This pilot study presents a reliability analysis of currently used ROI-QSM metrics and an alternative ROI-based approach to obtain voxel-weighted ROI-QSM metrics ( μ wp ${{{{\mu}}}_{{\mathrm{wp}}}}$ and μ wn ${{{{\mu}}}_{{\mathrm{wn}}}}$ ). ⋯ Among the evaluated ROI-QSM metrics, μ all ${{{{\mu}}}_{{\mathrm{all}}}}$ and μ abs ${{{{\mu}}}_{{\mathrm{abs}}}}$ estimates were less reliable, whereas separating positive and negative values (using μ p , μ n , μ wp , μ wn ${{{{\mu}}}_{\mathrm{p}}},\ {{{{\mu}}}_{\mathrm{n}}},\ {{{{\mu}}}_{{\mathrm{wp}}}},\ {{{{\mu}}}_{{\mathrm{wn}}}}$ ) improved the reproducibility within, and the comparability between, subjects, even when reducing the slice thickness. These preliminary findings may offer valuable insights toward standardizing ROI-QSM metrics across different patient cohorts and imaging settings in future clinical MRI studies.
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To develop and test a decision tree for predicting contrast enhancement quality and shape using precontrast magnetic resonance imaging (MRI) sequences in a large adult-type diffuse glioma cohort. ⋯ The proposed EPDT has high accuracy in predicting enhancement patterns of gliomas irrespective of rater experience.