Hayrapet Kalashyan

Single sweep three-dimensional carotid ultrasound: Reproducibility in plaque and artery volume measurements

BACKGROUNDnThere is a need for non-invasive and accurate techniques for assessment of severity of atherosclerotic disease in the carotid arteries. Recently an automated single sweep three-dimensional ultrasound (3D US) technique became available. The aims of this study were to evaluate the feasibility and reproducibility of the automated single sweep method in a cohort of patients undergoing clinically indicated carotid ultrasound.nnnMETHODSnConsecutive patients with a history of stroke or transient ischemic attack (TIA) and having a plaque in the internal carotid artery (ICA) were recruited for this study. Imaging was performed using a Philips iU 22 ultrasound system equipped with the single sweep volumetric transducer vL 13-5. Analysis was performed offline with software provided by the manufacturer. Two independent observers performed all measurements.nnnRESULTSnOf 137 arteries studied (from 79 patients), plaque and artery volumes could be measured in 106 (77%). Reproducibility of plaque volume measurements was assessed in 82 arteries. Bland-Altman analysis demonstrated good inter-observer reproducibility with limits of agreement -0.06 to +0.07 ml. The mean percentage difference between two observers was 5.6% ± 6.0%. Reproducibility of artery volume measurement was assessed in 31 cases. Bland-Altman analysis demonstrated limits of agreement from -0.15 to +0.15 ml. The mean percentage difference was 6.4 ± 5.9%.nnnCONCLUSIONnThe new automated single sweep 3D ultrasound is feasible in the majority of patients. Good reproducibility in plaque and artery volume measurements makes this technique suitable for serial assessment of carotid plaques.

Early Rivaroxaban Use After Cardioembolic Stroke May Not Result in Hemorrhagic Transformation: A Prospective Magnetic Resonance Imaging Study.

Background and Purpose— Early anticoagulation after cardioembolic stroke remains controversial because of the potential for hemorrhagic transformation (HT). We tested the safety and feasibility of initiating rivaroxaban ⩽14 days after cardioembolic stroke/transient ischemic attack. Methods— A prospective, open-label study of patients with atrial fibrillation treated with rivaroxaban ⩽14 days of transient ischemic attack or ischemic stroke (National Institute of Health Stroke Scale <9). All patients underwent magnetic resonance imaging <24 hours of rivaroxaban initiation and day 7. The primary end point was symptomatic HT at day 7. Results— Sixty patients (mean±SD age 71±19 years, 82% stroke/18% transient ischemic attack) were enrolled. Median (interquartile range) time from onset to rivaroxaban was 3 (5) days. At treatment initiation, median National Institute of Health Stroke Scale was 2 (4), and median diffusion-weighted imaging volume was 7.9 (13.7) mL. At baseline, HT was present in 25 (42%) patients (hemorrhagic infarct [HI]1=19, HI2=6). On follow-up magnetic resonance imaging, no patients developed symptomatic HT. New asymptomatic HI1 developed in 3 patients, and asymptomatic progression from HI1 to HI2 occurred in 5 patients; otherwise, HT remained unchanged at day 7. Conclusions— These data support the safety of rivaroxaban initiation ⩽14 days of mild–moderate cardioembolic stroke/transient ischemic attack. Magnetic resonance imaging evidence of petechial HT, which is common, does not appear to increase the risk of symptomatic HT.

Mobile stroke unit triage of patients with a suspected stroke: a novel solution to reducing suspected stroke admissions in busy emergency departments

Background Evaluation of patients with a suspected stroke is one of the most common neurological emergencies requiring rapid, comprehensive assessment by the stroke service to determine patient eligibility for timely reperfusion therapies. Prehospital evaluation may help to improve patient selection and reduce avoidable admissions to overcapacity emergency departments. Methods and results We report on our early experience of prehospital triage of patients with a suspected stroke using a mobile stroke unit (MSU) equipped with CT scanner in rural Alberta. During the initial 4 months of operation, 28 patients were evaluated by the team in the MSU. Eight patients were within the time window of thrombolysis and were treated with intravenous tissue plasminogen activator in the MSU. No patients suffered haemorrhage or any other complications. Fourteen patients with multiple aetiologies (stroke mimics 6, transient ischaemic attacks 2, subacute stroke outside thrombolysis window 2, intracranial haemorrhage 3 and cerebral contusion 1) were assessed in the field and transferred to the tertiary hospital. Six patients after assessment and imaging were repatriated back to the local hospital as they were deemed stroke mimics or were outside of the reperfusion window. Conclusions The MSU offers a novel approach to performing timely evaluation and treatment of patients with a suspected stroke in rural settings and may help reduce admissions to overcapacity tertiary care facilities.

Left ventricular relative wall thickness versus left ventricular mass index in non-cardioembolic stroke patients.

AbstractIn non-cardioembolic stroke patients, the cardiac manifestations of high blood pressure are of particular interest. Emerging data suggest that echocardiographically determined left ventricular hypertrophy is independently associated with risk of ischemic stroke.The primary objective of this study was to evaluate the frequency of different patterns of left ventricular (LV) remodeling and hypertrophy in a group of consecutive patients admitted with non-cardioembolic stroke or transient ischemic attack (TIA). In particular, we were interested in how often the relative wall thickness (RWT) was abnormal in patients with normal LV mass index (LVMI). As both abnormal RWT and LVMI indicate altered LV remodeling, the secondary objective of this research was to study whether a significant number of patients would be missing the diagnosis of LV remodeling if the RWT is not measured.All patients were referred within 48u200ahours after a stroke or a TIA for a clinically indicated transthoracic echocardiogram. The echocardiographic findings of consecutive patients with non-cardioembolic stroke or TIA were analyzed.All necessary measurements were performed in 368 patients, who were enrolled in the study. Mean age was 63.7u200a±u200a12.5 years, 64.4% men. Concentric remodeling carried the highest frequency, 49.2%, followed by concentric hypertrophy, 30.7%, normal pattern, 15.5%, and eccentric hypertrophy, 4.1%. The frequency of abnormal left ventricular RWT (80.4%) was significantly higher than that of abnormal LVMI (35.3%), (McNemar Pu200a<u200a0.05).In this group of non-cardioembolic stroke patients, abnormal LV remodeling as assessed by relative wall thickness is very frequent. As RWT was often found without increased LV mass, the abnormal left ventricular geometry may be missed if RWT is not measured or reported.

Comparison of Carotid Doppler Ultrasound to Other Angiographic Modalities in the Measurement of Carotid Artery Stenosis: Carotid Doppler Ultrasound versus Other Angiographic Modalities

The purpose of this study was to compare Doppler ultrasound (DUS) to other angiographic modalities: computed tomography angiography (CTA), magnetic resonance angiography (MRA), and digital subtraction angiography (DSA).

Three-Dimensional and Conventional Carotid Ultrasound for Assessment of Carotid Plaque in a Stroke Patient: A Simple Way to Validate Findings

Single-sweep automated 3-D ultrasound is a new imaging modality for the assessment of carotid plaque. Its most important application is the measurement of the plaque volume. To our knowledge, to date there is not a widely accepted gold standard to validate 3-D plaque volume measurement. We compared the findings of 2-dimensional and 3-D carotid ultrasound imaging with those of postsurgical plaque specimen using a simple method.