Shayandokht Taleb

Acute Ischemic Stroke Infarct Topology: Association with Lesion Volume and Severity of Symptoms at Admission and Discharge

BACKGROUND AND PURPOSE: Acute stroke presentation and outcome depend on both ischemic infarct volume and location. We aimed to determine the association between acute ischemic infarct topology and lesion volume and stroke severity at presentation and discharge. MATERIALS AND METHODS: Patients with acute ischemic stroke who underwent MR imaging within 24 hours of symptom onset or last seen well were included. Infarcts were segmented and coregistered on the Montreal Neurological Institute-152 brain map. Voxel-based analyses were performed to determine the distribution of infarct lesions associated with larger volumes, higher NIHSS scores at admission and discharge, and greater NIHSS/volume ratios. RESULTS: A total of 238 patients were included. Ischemic infarcts involving the bilateral lentiform nuclei, insular ribbons, middle corona radiata, and right precentral gyrus were associated with larger infarct volumes (average, 76.7 ± 125.6 mL versus 16.4 ± 24.0 mL, P < .001) and higher admission NIHSS scores. Meanwhile, brain stem and thalami infarctions were associated with higher admission NIHSS/volume ratios. The discharge NIHSS scores were available in 218 patients, in whom voxel-based analysis demonstrated that ischemic infarcts of the bilateral posterior insular ribbons, middle corona radiata, and right precentral gyrus were associated with more severe symptoms at discharge, whereas ischemic lesions of the brain stem, bilateral thalami, and, to a lesser extent, the middle corona radiata were associated with higher ratios of discharge NIHSS score/infarct volume. CONCLUSIONS: Acute ischemic infarcts of the insulae, lentiform nuclei, and middle corona radiata tend to have larger volumes, more severe presentations, and worse outcomes, whereas brain stem and thalamic infarcts have greater symptom severity relative to smaller lesion volumes.

Middle Cerebral Artery Residual Contrast Stagnation on Noncontrast CT Scan Following Endovascular Treatment in Acute Ischemic Stroke Patients

We evaluated the relationship between middle cerebral artery (MCA) residual contrast stagnation on immediate postprocedural noncontrast CT scan and intraparenchymal hemorrhage (IPH) after endovascular treatment in acute ischemic stroke patients.

Comparison of Traditional and Emerging Surgical Therapies for Lower Urinary Tract Symptoms in Men: A Review

Lower urinary tract symptoms (LUTS) are one of the most common health issues in men and pose a significant economic challenge in healthcare. Transurethral resection of the prostate (TURP) remains the gold standard surgical treatment for medically refractive LUTS secondary to benign prostatic hyperplasia. The institution of medical therapy and the development of several minimally invasive surgical therapies (MISTs) began in the 1980’s and 1990’s. Together, these therapies brought about a change in the natural course of the disease, stimulating investigation into the economic consequences of various management approaches. TURP has been observed to have higher complication rates, but better efficacy and lower retreatment rates compared to MISTs. Staying abreast of the evolving understanding of LUTS and the alternative treatment options is imperative for radiologists.

Susceptibility-diffusion mismatch in middle cerebral artery territory acute ischemic stroke: clinical and imaging implications

Background Recent studies have suggested a correlation between susceptibility–diffusion mismatch and perfusion–diffusion mismatch in acute ischemic stroke patients. Purpose To determine the clinical and imaging associations of susceptibility-diffusion mismatch in patients with acute ischemic stroke in the middle cerebral artery (MCA) territory. Material and Methods Consecutive patients with MCA territory acute ischemic stroke, who had magnetic resonance imaging (MRI) performed with susceptibility-weighted imaging (SWI) and diffusion-weighted imaging (DWI) within 24 h of symptom onset or time last-seen-well, were included. Two neuroradiologists reviewed SWI scans for SWI–DWI mismatch defined by regionally increased vessel number or diameter on SWI extending beyond the DWI hyperintensity territory in the affected hemisphere. The stroke severity at admission was evaluated using the National Institutes of Health Stroke Scale (NIHSS) score. Poor clinical outcome was defined by a 3-month modified Rankin Scale (mRS) score >2. Results The SWI–DWI mismatch was identified in 44 (29.3%) of 150 patients included in this study. Patients with SWI–DWI mismatch had smaller admission infarct volumes (31.2 ± 44.7 versus 55.9 ± 117.7 mL, P = 0.045) and were younger (60.4 ± 18.9 versus 67.1 ± 15.5, P = 0.026). After correction for age, admission NIHSS score, and infarct volume, the SWI–DWI mismatch was associated with a 22.6% lower rate of poor clinical outcome using propensity score matching (P = 0.032). In our cohort, thrombolytic therapy showed no significant effect on outcome. Conclusion The presence of SWI–DWI mismatch in acute MCA territory ischemic infarct is associated with smaller infarct volume. Moreover, SWI–DWI mismatch was associated with better outcome after correction for infarct size, severity of admission symptoms, and age.

Multivariate Prognostic Model of Acute Stroke Combining Admission Infarct Location and Symptom Severity: A Proof-of-Concept Study

BACKGROUND The information on topographic distribution of acute ischemic infarct can contribute to prediction of functional outcome. We aimed to develop a multivariate model for stroke prognostication, combining admission clinical and imaging variables, including the infarct topology. METHODS Acute ischemic stroke patients without baseline functional disability who had magnetic resonance imaging within 24 hours of onset or last-seen-well were included. The admission stroke severity was determined using the National Institutes of Health Stroke Scale (NIHSS) score. The relation between infarct location and outcome was assessed using both voxel-based and visual atlas-based analyses. The disability/death was defined by a modified Rankin Scale score greater than 2 at 3-month follow-up. RESULTS Among 198 patients included in this study, higher admission NIHSS score (P < .001), larger infarct volume (P < .001), and major arterial occlusions (P < .001) were associated with disability/death in univariate analyses. On voxel-based analysis, infarcts in the middle centrum semiovale, insula, and midbrain/pons were associated with higher rates of disability/death. In multivariate analysis, admission NIHSS score (P < .001), infarction of insula (P = .005), and midbrain/pons (P = .006) were independent predictors of disability/death. In receiver operating characteristics analysis, a simple 0-to-3 scoring system using these 3 variables had an area under the curve of .812 for prediction of disability/death (P < .001). CONCLUSIONS Admission symptom severity, infarction of insula, and midbrain/pons were independent predictors of clinical outcome in acute ischemic stroke patients. The methodology of this hypothesis-generating study can help conceive quantitative population-based probabilistic models for prognostication or treatment triage in stroke patients, combining admission clinical and imaging findings-including infarct topography.

The Effects of DWI-Infarct Lesion Volume on DWI-FLAIR Mismatch: Is There a Need for Size Stratification?

The lack of fluid‐attenuated inversion‐recovery (FLAIR) hyperintensity in areas of diffusion‐weighted imaging (DWI) high signal, or DWI‐FLAIR mismatch, is a potential imaging biomarker for timing of stroke onset. We aimed to determine the effects of DWI infarct lesion volume on DWI‐FLAIR mismatch and its accuracy for identification of strokes within intravenous (IV) the thrombolytic therapy window.

Interhemispheric Asymmetry in Distribution of Infarct Lesions among Acute Ischemic Stroke Patients Presenting to Hospital

BACKGROUNDS This study aimed to investigate the possible asymmetric distribution of acute ischemic infarct lesions between patients with right-sided stroke versus left-sided stroke. METHODS Acute ischemic stroke patients with unilateral infarct who underwent magnetic resonance imaging scan within 24 hours of onset were included. Infarct lesions were segmented on diffusion-weighted-imaging series and coregistered on the MNI-152 brain map. After flipping all lesions to the left side, voxel-based analysis was performed to evaluate for asymmetric distribution of infarct lesions using the stroke side as an independent variable. Symptom severity at admission was evaluated using the National Institutes of Health Stroke Scale score, and early clinical outcome with the modified Rankin Scale score at discharge. RESULTS Of the 218 patients included in this study, 110 had right-sided ischemic infarcts whereas 108 had left-sided ischemic infarcts. There was no significant difference between patients with right-sided stroke versus left-sided stroke in terms of admission symptom severity, rate of treatment, stroke risk factors, and early clinical outcome. However, voxel-based analysis showed that ischemic infarcts of insular ribbon and lentiform nucleus were asymmetrically more common on the left-sided stroke compared to the right-sided stroke. The admission symptoms were more severe among patients with left insular ribbon and lentiform nucleus infarct compared to those with infarction of mirrored right anatomical regions (P = .019). CONCLUSIONS Acute ischemic infarcts of the left insular ribbon and lentiform nucleus are asymmetrically more common compared to mirrored counterpart regions, presumably due to more severe symptoms at presentation. Otherwise, distribution of symptomatic infarcts to the rest of the brain is roughly symmetric.

Susceptible vessel sign: identification of arterial occlusion and clinical implications in acute ischaemic stroke

AIM To determine the accuracy of the susceptible vessel sign (SVS) in the detection of arterial occlusion and its clinical implication in acute ischaemic stroke. MATERIALS AND METHODS Consecutive ischaemic stroke patients who underwent magnetic resonance imaging (MRI) with susceptibility-weighted imaging (SWI) within 24 hours of symptom onset or time last-seen-well were included. Two independent neuroradiologists reviewed the SWI for evidence of the SVS. Admission stroke severity was determined by the National Institute of Health Stroke Scale (NIHSS) scores, and poor clinical outcome was defined by a 3-months modified Rankin scale (mRS) score >2. RESULTS The SVS was identified in 26 (12%) of 213 patients with substantial inter-reviewer agreement. The SVS had 99% specificity, 88% negative predictive value (NPV), 51% sensitivity, and 92% positive predictive value (PPV) for detection of acute arterial occlusions. In consecutive stroke patients, the presence of SVS was associated with higher admission NIHSS scores (median 9 versus 3, p<0.001), arterial occlusion (92% versus 12%, p<0.001), larger infarct volume (162±180 ml versus 25±48 ml, p=0.001), and higher rate of poor clinical outcome at 3-months follow-up (58% versus 25%, p=0.001). In the subset of patients with acute arterial occlusion (n=47), the SVS was associated with higher admission NIHSS scores (median of 10 versus 3, p=0.038) and larger infarct volumes (173±184 ml versus 76±112 ml, p=0.034). CONCLUSIONS The SVS is a highly specific sign of occlusive arterial thrombus, and is associated with larger infarct volume and more severe presentation in a series of consecutive stroke patients, as well as in the subgroup of patients with acute arterial occlusion.