BACKGROUND AND PURPOSE There is need to improve image acquisition speed for MR imaging in evaluation of patients with acute ischemic stroke. The purpose of this study was to evaluate the feasibility of a 3T MR stroke protocol that combines low-dose contrast-enhanced MRA and dynamic susceptibility contrast perfusion, without additional contrast. METHODS Thirty patients with acute stroke who underwent 3T MR imaging followed by DSA were retrospectively enrolled. TOF-MRA of the neck and brain and 3D contrast-enhanced MRA of the craniocervical arteries were obtained. A total of 0.1 mmol/kg of gadolinium was used for both contrast-enhanced MRA (0.05 mmol/kg) and dynamic susceptibility contrast perfusion (0.05 mmol/kg) (referred to as half-dose). An age-matched control stroke population underwent TOF-MRA and full-dose (0.1 mmol/kg) dynamic susceptibility contrast perfusion. The cervicocranial arteries were divided into 25 segments. Degree of arterial stenosis on contrast-enhanced MRA and TOF-MRA was compared with DSA. Time-to-maximum maps (>6 seconds) were evaluated for image quality and hypoperfusion. Quantitative analysis of arterial input function curves, SNR, and maximum T2* effects were compared between half- and full-dose groups. RESULTS The intermodality agreements (k) for arterial stenosis were 0.89 for DSA/contrast-enhanced MRA and 0.63 for DSA/TOF-MRA. Detection specificity of >50% arterial stenosis was lower for TOF-MRA (89%) versus contrast-enhanced MRA (97%) as the result of overestimation of 10% (39/410) of segments by TOF-MRA. The DWI-perfusion mismatch was identified in both groups with high interobserver agreement (r = 1). There was no significant difference between full width at half maximum of the arterial input function curves (P = .14) or the SNR values (0.6) between the half-dose and full-dose groups. CONCLUSIONS In patients with acute stroke, combined low-dose contrast-enhanced MRA and dynamic susceptibility contrast perfusion at 3T is feasible and results in significant scan time and contrast dose reductions.
Background/Aim:The prevalence of acute upper gastrointestinal bleeding (AUGIB) has undergone a change after implementation of eradication therapy for Helicobacter pylori in peptic ulcers effective prevention of esophageal variceal bleeding and eventually, progressive use of low dose aspirin and other nonsteroidal antiinflammatory drugs (NSAIDs). To evaluate this subject, we performed a prospective study in two main University Hospitals of Shiraz (the largest city of southern Iran).Materials and Methods:All adults who were admitted in emergency room with impression of AUGIB and existing patients who developed AUGIB were included in the study. Gastroscopy was done with a follow-up for the next 15 days.Results:572 patients (mean age: 54.9 years) entered in the study. The most common presenting symptom was hematemesis or coffee-ground vomits (68%). 75% of patients gave history of consumption of low dose aspirin or other NSAIDs regularly. Gastric and/or duodenal ulcers were the most common causes (252/572, 44%) of AUGIB (Gastric ulcer: 173/572, 30% and duodenal ulcer: 93/572, 16%, respectively). Esophageal varices were the third common cause (64/572, 11%). 36 (6%) of the patients died. Mean age of these patients was higher than the patients who were alive (64.8 vs. 54.2 years, P = 0.001). Other than age, orthostatic hypotension on arrival (267/536 vs. 24/36, P = 0.018) and consumption of steroids (43/536 vs. 10/36, P = 0.001) were significant factors for increasing mortality.Conclusions:The most common cause of AUGIB, secondary only to NSAIDs consumption, is gastric ulcer. Mortality of older patients, patients who consumed NSAIDs and steroids concomitantly, and patients with hemodynamic instability on arrival were higher.
BackgroundIntravenous (IV) tissue plasminogen activator (rt-PA) is a proven therapy for stroke in the acute treatment window. Recent published data has shown efficacy for embolectomy for acute ischemic strokes within up to six, 16 and 24 hours in the anterior circulation but there is no guideline for optimal therapy for patients with posterior circulation stroke, specifically basilar artery occlusion (BAO) outside the standard IV rt-PA treatment window.AimTo evaluate differences in outcomes between maximal medical treatment versus thrombectomy in BAO.MethodWe retrospectively evaluated prospectively collected acute stroke code patients from our stroke registry from 7/2004 to 7/2016. Patients who received IV rt-PA were excluded. Patients with evidence of posterior circulation ischemia and a hyper dense artery sign on initial non-contrast CT were included as a surrogate for direct vessel data before 2014. Patients after 9/2014 were selected by evidence of BAO on vessel imaging. All patients were categorized either as endovascular therapy or standard medical treatment alone. Demographics, hospital discharge location and Modified Rankin Scale (mRS) at 90 days were compared. Two-sample t-test and Fisher’s exact test compared continuous and categorical variables across groups respectively.ResultsA total of 18 patients were included (three embolectomy and 15 medical therapy only). There were no significant differences in demographic data (age, gender, race, ethnicity, blood pressure, diabetes mellitus, hypertension, atrial fibrillation, tobacco use, alcohol use and initial NIHSS). Results for outcome and efficacies showed no statistical difference between medical management and endovascular intervention for functional outcome mRS (0-3) at 90 days (p = 0.2) and discharge location of home/inpatient rehabilitation vs other locations (p = 0.52).ConclusionsOur single-center review showed the expected transition from predominantly medically treated posterior circulation BAOs, to a mixed pattern including embolectomy. Although the sample size was small, this study also illustrates the lack of clear efficacy data for optimal treatment strategies, and the ongoing treatment challenges in posterior circulation stroke population in a population of patients outside the rt-PA window.
Background and purposeStroke in young individuals is a serious public health burden. This study aimed to characterise the various phenotypes of ischaemic stroke in a young urban population (≤50 years old) using the ASCOD classification system, which assigns a score to five stroke categories: atherosclerosis, small vessel disease (SVD), cardioembolism, other and dissection. Within each category, a numerical score represents the degree of causality attributed to the stroke.MethodsThis retrospective study cohort was composed of patients from an urban tertiary care academic centre. Cases were selected by searching Get With the Guidelines database for adults ≤50 years old with ischaemic stroke. The study sample included 175 ischaemic strokes in 157 patients, with 16 subjects re-infarcting. Using retrospective chart review, each stroke was scored according to the ASCOD classification system. Multivariable logistic regression analyses were performed to explore each ASCOD category’s association with causal risk factors.ResultsOf possible causal mechanisms, defined as receiving a grade 1 or 2, a cardiovascular aetiology was most prevalent (25.7%), followed by SVD (22.3%), and closely by atherosclerosis (21.1%). Of general phenotypes, defined as receiving a grade 1 or 2 or 3, atherosclerosis was the most prevalent (51.4%), followed by SVD (47.4%), cardioembolism (42.3%) and other (35.4%). 31.6% of all strokes were of unclear aetiology. Subjects between 45 and 50 years old were more likely to develop a cardioembolic or SVD stroke when compared with subjects <45 years old.ConclusionThis study took a novel approach to ASCOD phenotyping, allowing several observations: (1) In patients with advanced atherosclerosis receiving the score A1, the vast majority had systemic atherosclerosis in multiple vascular territories; (2) the cardiac score C2(6), defined as a radiographic pattern highly suggestive of a central embolic source, may overestimate the prevalence of true cardiac disease; (3) incidental laboratory findings may detect some underlying pathology, but causality to the stroke is unlikely.
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