Image Segmentation for Review of Cerebral Apoplexy

Brain computed tomography (CT) provides a medical imaging tool for reviewing cerebral apoplexy. It is of strong clinical significance to study the key techniques for lesion segmentation and feature selection of cerebral apoplexy. Most of the previous research fail to fully utilized the other prior information, or apply to the changing feature analysis on multiple lesion images generated in the rehabilitation process. Therefore, this paper aims to develop an image segmentation method for review of cerebral apoplexy. Based on the correlation between image series, the authors proposed a segmentation method for CT images of cerebral apoplexy, and developed a way to extract and select the changing lesion features, which assists with the diagnosis of cerebral apoplexy rehabilitation. The image segmentation and feature selection results were obtained through experiments, revealing the effectiveness of our method.

New Acoustic Beams Designed for Rapid Lesion Formation: Limitations Near the Skin During Multiple Lesion Treatments

New Acoustic Beams Designed for Rapid Lesion Formation: Limitations Near the Skin During Multiple Lesion Treatments

New Acoustic Beams Designed for Rapid Lesion Formation: Limitations Near the Skin During Multiple Lesion Treatments

New Acoustic Beams Designed for Rapid Lesion Formation: Limitations Near the Skin During Multiple Lesion Treatments

Association between fluid-attenuated inversion recovery vascular hyperintensity and outcome varies with different lesion patterns in patients with intravenous thrombolysis

Background and purposeTo evaluate relationship between fluid-attenuated inversion recovery vascular hyperintensity (FVH) after intravenous thrombolysis and outcomes in different lesion patterns on diffusion-weighted imaging (DWI).MethodsPatients with severe internal carotid or intracranial artery stenosis who received intravenous thrombolysis from March 2012 to April 2019 were analysed. They were divided into four groups by DWI lesion patterns: border-zone infarct (BZ group), multiple lesions infarct (ML group), large territory infarct (LT group), and single cortical or subcortical lesion infarct (SL group). Logistic regression was performed to identify risk factors for outcome (unfavourable outcome, modified Rankin Scale (mRS) ≥2; poor outcome, mRS ≥3).ResultsFinally, 203 participants (63.3±10.2 years old; BZ group, n=72; ML group, n=64; LT group, n=37; SL group, n=30) from 1190 patient cohorts were analysed. After adjusting for confounding factors, FVH (+) was associated with unfavourable outcome in total group (OR 3.02; 95% CI 1.49 to 6.13; p=0.002), BZ group (OR 4.22; 95% CI 1.25 to 14.25; p=0.021) and ML group (OR 5.44; 95% CI 1.41 to 20.92; p=0.014) patients. FVH (+) was associated with poor outcome in total group (OR 2.25; 95% CI 1.01 to 4.97; p=0.046), BZ group (OR 5.52; 95% CI 0.98 to 31.07; p=0.053) and ML group (OR 4.09; 95% CI 1.04 to 16.16; p=0.045) patients, which was marginal significance. FVH (+) was not associated with unfavourable or poor outcome in LT and SL groups.ConclusionThis study suggests that association between FVH and outcome varies with different lesion patterns on DWI. The presence of FVH after intravenous thrombolysis may help to identify patients who require close observations in the hospitalisation in patients with border-zone and multiple lesion infarcts.

Correlation of Computational Instantaneous Wave-Free Ratio with Fractional Flow Reserve for Intermediate Multi-Vessel Coronary Disease

This study computationally assesses the accuracy of an instantaneous wave-free ratio (iFR) threshold range compared to standard modalities such as fractional flow reserve (FFR) and coronary flow reserve (CFR) for multiple intermediate lesions near the left main (LM) coronary bifurcation. iFR is an adenosine-independent index encouraged for assessment of coronary artery disease, but different thresholds are debated. This becomes particularly challenging in multi-vessel disease when sensitivity to downstream lesions is unclear. Idealized LM coronary arteries with 34 different intermediate stenoses were created and categorized (Medina) as single and multiple lesion groups. Computational fluid dynamics modeling was performed with physiologic boundary conditions using an open source software (SimVascular; simtk.org) to solve the time-dependent Navier-Stokes equations. A strong linear relationship between iFR and FFR was observed among studied models, indicating computational iFR values of 0.92 and 0.93 are statistically equivalent to an FFR of 0.80 in single and multiple lesion groups, respectively. At the clinical FFR value (i.e. 0.8), a triple-lesion group had smaller CFR compared to the single and double lesion groups (e.g. triple=3.077 vs. single=3.133 and double=3.132). In general, the effect of additional intermediate downstream lesions (minimum lumen area >3 mm2) was not statistically significant for iFR and CFR. A computational iFR of 0.92 best predicts an FFR 0.80 and may be recommended as threshold criteria for computational assessment of LM stenosis following additional validation using patient-specific models.