Gradient recalled echo MRI (GRE) has been shown to be as accurate as CT for the detection of acute intracerebral hemorrhage (ICH). However, because of the differences in the signal parameter being ...detected, apparent hemorrhage size is expected to vary by imaging modality, with GRE providing larger volumes attributable to susceptibility effects.
Image data from patients participating in 3 ICH studies were retrospectively reviewed. Patients with acute ICH were included if (1) concurrent MRI and CT were performed within 72 hours of symptom onset, and (2) each modality was performed within 240 minutes of each other. ICH volumes were calculated using a semiautomated image analysis program. The least squares method was used to develop a conversion equation based on a linear regression of GRE volume on CT volume.
Thirty-six patients met inclusion criteria. MRI was performed first in 18, CT first in 18. Mean hemorrhage volume was 25.2 cc (range 0.1 to 83.9 cc) on CT and 32.7 cc (range 0.1 to 98.7 cc) measured on GRE. A linear relationship defined by CT Volume=GRE Volume*0.8 (Spearman's correlation coefficient=0.992, P<0.001) was derived.
Acute ICH volumes as measured on GRE pulse sequences are consistently larger than CT volumes. A simple mathematical conversion model has been developed: CT volume=0.8*GRE volume. This formula can be used in studies using both imaging modalities, across different studies, or to track ICH growth over time independent of imaging modality in an individual patient.
We surveyed urine microbiota of females diagnosed with interstitial cystitis/bladder pain syndrome (IC/BPS) and matched control participants enrolled in the National Institutes of Health (NIH) ...Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network using the culture-independent methodology. Midstream urine specimens were analyzed with the Plex-ID molecular diagnostic platform that utilizes polymerase chain reaction⁻electrospray ionization⁻time-of-flight⁻mass spectrometry (PCR-ESI-TOF MS) to provide a comprehensive identification of bacterial and select fungal species. IC/BPS and control participants were evaluated for differences (presence, diversity, and abundance) in species and genus. Urine specimens obtained from 181 female IC/BPS and 182 female control participants detected a total of 92 species (41 genera). Mean (SD) species count was 2.49 (1.48) and 2.30 (1.28) among IC/BPS and control participants, respectively. Overall species composition did not significantly differ between IC/BPS and control participants at any level (
= 0.726 species level,
= 0.222 genus level). IC/BPS participants urine trended to an overabundance of
(
= 0.09) detected but had a lower prevalence of
compared with control participants (
= 0.002). The relative abundance data analysis mirrored the prevalence data differences with no significant differences in most species or genus abundance other than
and
(
= 0.08 and
= 0.001, respectively). No cause and/or effect conclusion can be drawn from this observation, but it suggests that a more comprehensive evaluation (vaginal, bowel, catheterized bladder and/or tissue-based specimens) of the lower urinary tract microbiota in IC/BPS patients is warranted.
The Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network has yielded neuroimaging and urinary biomarker findings that highlight unique alterations in brain structure ...and in urinary proteins related to tissue remodeling and vascular structure in patients with Urological Chronic Pelvic Pain Syndrome (UCPPS). We hypothesized that localized changes in diffusion tensor imaging (DTI) measurements might be associated with corresponding changes in urinary protein levels in UCPPS. To test this hypothesis, we created statistical parameter maps depicting the linear correlation between DTI measurements (fractional anisotropy (FA) and apparent diffusion coefficient (ADC)) and urinary protein quantification (MMP2, MMP9, NGAL, MMP9/NGAL complex, and VEGF) in 30 UCPPS patients from the MAPP Research Network, after accounting for clinical covariates. Results identified a brainstem region that showed a strong correlation between both ADC (R2 = 0.49, P<0.0001) and FA (R2 = 0.39, P = 0.0002) with urinary MMP9 levels as well as a correlation between both ADC (R2 = 0.42, P = 0.0001) and FA (R2 = 0.29, P = 0.0020) and urinary MMP9/NGAL complex. Results also identified significant correlations between FA and urinary MMP9 in white matter adjacent to sensorimotor regions (R2 = 0.30, P = 0.002; R2 = 0.36, P = 0.0005, respectively), as well as a correlation in similar sensorimotor regions when examining ADC and urinary MMP2 levels (R2 = 0.42, P<0.0001) as well as FA and urinary MMP9/NGAL complex (R2 = 0.33, P = 0.0008). A large, diffuse cluster of white matter was identified as having a strong correlation between both ADC (R2 = 0.35, P = 0.0006) and FA (R2 = 0.43, P<0.0001) with urinary NGAL levels. In contrast, no significant association between DTI measurements and VEGF was observed. Results suggest that elevated MMP9 or MMP9/NGAL in UCPPS may be related to degenerative neuronal changes in brainstem nuclei through excitotoxicity, while also facilitating synaptic plasticity in sensorimotor regions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Purpose We examined symptom variability in men and women with urological chronic pelvic pain syndrome. We describe symptom fluctuations as related to early symptom regression and its effect on ...estimated 1-year symptom change. We also describe a method to quantify patient specific symptom variability. Materials and Methods Symptoms were assessed biweekly in 424 subjects with urological chronic pelvic pain syndrome during 1 year. To evaluate the impact of early symptom regression subjects were classified as improved, no change or worse according to the rate of change using 1) all data, 2) excluding week 0 and 3) excluding weeks 0 and 2. Patient specific, time varying variability was calculated at each interval using a sliding window approach. Patients were classified as high, medium or low variability at each time and ultimately as high or low variability overall based on the variability for the majority of contacts. Results Prior to excluding early weeks to adjust for early symptom regression 25% to 38% and 5% to 6% of patients were classified as improved and worse, respectively. After adjustment the percent of patients who were improved or worse ranged from 15% to 25% and 6% to 9%, respectively. High and low variability phenotypes were each identified in 25% to 30% of participants. Conclusions Patients with urological chronic pelvic pain syndrome show symptom variability. At study enrollment patients had worse symptoms on average, resulting in a regression effect that influenced the estimated proportion of those who were improved or worse. Prospective studies should include a run-in period to account for regression to the mean and other causes of early symptom regression. Further, symptom variability may be quantified and used to characterize longitudinal symptom profiles of urological chronic pelvic pain syndrome.
To study phosphorus and glucose metabolism in whole-brain slices of otherwise healthy patients with dementia of the Alzheimer type (DAT) and healthy controls.
We used proton nuclear magnetic ...resonance imaging phosphorus spectroscopy and positron emission tomography to study in vivo brain phosphorus and glucose metabolism.
Whole-brain slice phosphorus metabolism was studied in nine drug free patients with mild to moderately severe dementia of the Alzheimer type (DAT) and in eight age- and sex-matched healthy controls. Mean ages (+/- SD) of the patients and controls were 60 +/- 10 years and 64 +/- 16 years, respectively. Positron emission tomography was used to study cerebral glucose metabolism in seven of the patients with DAT and seven of the healthy controls.
Patients with DAT had significant brain glucose hypometabolism compared with controls, but there was no significant group difference in any phosphorus metabolite concentration or ratio in the same volume of brain tissue. Also, within patients with DAT there was no correlation between any phosphorus metabolite concentration or ratio and either severity of dementia or glucose metabolism.
We suggest glucose metabolism is reduced early in DAT (reflecting decreased basal synaptic functioning) and is unrelated to a rate limitation in glucose delivery, abnormal glucose metabolism, or abnormal coupling between oxidation and phosphorylation. Normal or near-normal levels of phosphorus metabolites are maintained in mild, moderate, and severe DAT. Therefore, altered high-energy phosphate levels are not a consequence of reduced glucose metabolism in DAT, and do not play a major role in the pathophysiology of the disorder, at least in whole-brain sections.
ABSTRACT
BACKGROUND
We examined the correlation of angiographic collaterals in acute stroke with the presence, extent, and distribution of white matter changes, so‐called Leukoaraiosis, in an effort ...to determine if Leukoaraiosis indicates chronic cerebral hypoperfusion and/or is associated with the development of cerebral collateral circulation.
METHODS
Consecutive acute strokes due to large‐vessel occlusion on angiography had preprocedure CT or MRI white matter changes graded utilizing the Fazekas scale incorporating deep and periventricular components. Angiographic collaterals evaluated with a 5‐point scale were correlated with leukoaraiosis.
RESULTS
Collaterals were evaluated in 102 cases (51 men, 51 women; mean age 66 (SD 18) years with acute occlusions of the proximal middle cerebral artery (MCA) (47%), distal internal carotid artery (ICA) (28%), distal MCA (9%), basilar (7%), proximal ICA (7%), vertebral (1%), posterior cerebral artery (PCA) (1%), and common carotid artery (CCA) (1%). Collateral grade was well distributed across the scale. Periventricular and deep white matter changes were evident in 34% and 51% of cases, respectively. Collateral grade exhibited no relationship with either the presence or extent of periventricular disease (P= .772, r= .029) or deep white matter changes (P= .559, r=−.059).
CONCLUSIONS
Leukoaraisosis exhibits no overt relationship with the extent of collaterals measured at angiography in acute ischemic stroke. Chronic small‐vessel disease may be a distinct pathophysiologic entity unrelated to arteriogenesis and compensatory aspects of collateral flow.
Abstract only Background: Identifying patient characteristics that predict outcomes in acute ischemic stroke may assist in triaging those who are candidates for endovascular therapies. We sought to ...identify predictors of outcome in the overall Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE) cohort and compare results to the previously validated Totaled Health Risks in Vascular Events (THRIVE) score. Methods: MR RESCUE randomized 118 acute ischemic stroke patients with multimodal imaging to embolectomy or standard care within 8 hours of onset. For this analysis, we investigated 17 baseline variables (e.g. age, predicted core volume, time to enrollment) and 8 intermediate variables (e.g. hemorrhagic transformation, day 7 recanalization, final infarct volume) with the potential to impact outcomes (day 90 mRS). The baseline variables were analyzed employing bivariate and multivariate methods (random forest and logistic regression). Two models were developed, one including only significant baseline variables, and the second also incorporating significant intermediate variables. Results: A multivariate model (Table) employing only baseline covariates achieved an overall accuracy (C statistic) of 85% in predicting poor outcome (day 90 mRS 3-6) compared to 80.5% for the THRIVE score. A second model (Table) adding significant intermediate variables achieved 89% accuracy in predicting day 90 mRS. Conclusions: In the MR RESCUE trial, advanced imaging variables, including predicted core volume and site of vessel occlusion, contributed to a highly accurate multivariable model of outcome. In the development phase, this model achieved higher accuracy than the THRIVE score. Future studies are needed to validate this model in an independent cohort.
Although magnesium is neuroprotective in animal stroke models, no clinical benefit was confirmed in the Intravenous Magnesium Efficacy in Stroke (IMAGES) trial of acute stroke patients. The Magnetic ...Resonance in IMAGES (MR IMAGES) substudy investigated the effects of magnesium on the imaging surrogate outcome of infarct growth.
IMAGES trial patients in participating centers were randomized to receive either intravenous magnesium or placebo within 12 hours of stroke onset. Infarct growth was defined as volume difference between baseline diffusion-weighted imaging and day 90 fluid-attenuated inversion recovery image lesions. Patients who died were imputed the largest infarct growth observed.
Among the 90 patients included in the primary analysis, there was no difference in infarct growth (median absolute growth, P=0.639; median percentage growth, P=0.616; proportion with any growth, P=0.212) between the 46 treated with magnesium and 44 with placebo. Infarct growth correlated with NIHSS score change from baseline to day 90. There was a trend showing baseline serum glucose correlated with infarct growth with magnesium treatment, but not in the placebo group. The mismatch frequency was reduced from 73% to 47% by increasing the mismatch threshold from >20% to >100% of core volume.
Infarct growth, confirmed here as a surrogate for clinical progression, was similar between magnesium and placebo treatment, paralleling the main IMAGES trial clinical outcomes. Glucose was a covariate for infarct growth with magnesium treatment. A more stringent mismatch threshold to define penumbra more appropriately would have excluded half of the patients in this 12-hour time window stroke study.
Abstract only Purpose: Ischemic stroke patients with low cerebral blood volume (CBV), low apparent diffusion coefficient (ADC) and increased microvascular permeability (K2) have increased risk of ...parenchymal hemorrhage (PH) after recanalization therapies. We have developed a predictive model to examine the risk of PH following revascularization therapies using combined MR perfusion and diffusion biomarkers. Methods: Voxel-based values of rCBV, K2, and ADC from the infarction core were obtained using pre-treatment MRI data from patients enrolled in the Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE) clinical trial. Using histogram analyses the 10 th and 90 th percentile values were calculated for the rCBV, ADC, and K2 variables for each patient. The associations between PH and extreme values of CBV (10%rCBV), ADC (10%ADC), and K2 (90%K2) in each patient were assessed in univariate and multivariate analyses. Receiver operating characteristic (ROC) analysis was performed to determine the optimal parameter/s and threshold for predicting PH. Results: In 83 patients included in this analysis, 20 (24%, 13 PH1, 7 PH2) developed PH. Univariate analysis showed significantly lower 10%rCBV and 10%ADC values and significantly higher 90%K2 values in patients with PH. After controlling for age, baseline NIHSS, infarct volume, and status of recanalization, multivariate logistic regression analysis identified 10%rCBV (p=0.002) and 90%K2 (p=0.03), but not 10%ADC (p=0.07), as independent predictors of PH. For 10%RCBV, ROC analysis showed the greatest AUC (0.87) at a threshold < 0.45 with sensitivity/specificity of 95%70%. For 90%K2, the greatest AUC (0.75) was obtained at a threshold of > 0.27 with sensitivity/specificity of 90%/60%. In a separate model, a combined K2-rCBV classifier remained the single independent predictor of PH (OR=33). Conclusion: Our results suggest that combined increased permeability and decreased rCBV derived from MR perfusion can be used for risk stratification in patients with AIS before undergoing revascularization therapies.
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