Diffusion-weighted Imaging Hyperintensity Research Articles

Hippocampal diffusion abnormality after febrile status epilepticus is related to subsequent epilepsy.

To assess hippocampal signal changes on diffusion-weighted imaging (DWI) during the acute period after febrile status epilepticus (FSE) and to examine the relationship between DWI and subsequent epilepsy. A prospective, multicenter study of children with a first episode of FSE was performed. The patients underwent magnetic resonance imaging (MRI) within 3days of FSE, and signal intensity was evaluated on DWI. Electroencephalography studies within 3days of FSE were also assessed. Nine to 13years after FSE, information on subsequent epilepsy was obtained. Twenty-two children with FSE were evaluated. DWI showed unilateral hippocampal hyperintensity in six patients (27%). Three of six patients with hippocampal hyperintensity had ipsilateral thalamic hyperintensity. On EEG within 3days of FSE, five of six patients with hippocampal hyperintensity had ipsilateral focal slowing, spikes, or attenuation. Nine to 13years later, the outcomes could be determined in five patients with hippocampal hyperintensity and in 10 without. All 5 patients with hippocampal hyperintensity had hippocampal atrophy and developed focal epilepsy, whereas only 1 of 10 patients without hippocampal hyperintensity developed epilepsy (P=0.002). Ictal semiology was concordant with temporal lobe seizures in all patients. Ipsilateral temporal epileptiform abnormalities were seen on EEG in four of five at last follow-up. Acute DWI hippocampal hyperintensity was seen in 27% of patients with FSE. Acute DWI hyperintensity suggests cytotoxic edema caused by prolonged seizure activity. Hippocampal DWI hyperintensity is related to mesial temporal lobe epilepsy and can be a target of neuroprotective treatments to prevent the onset of epilepsy.

Clinical relevance of acute cerebral microinfarcts in vascular cognitive impairment.

To determine the occurrence of acute cerebral microinfarcts (ACMIs) in memory clinic patients and relate their presence to vascular risk and cognitive profile, CSF and neuroimaging markers, and clinical outcome. The TRACE-VCI study is a memory clinic cohort of patients with vascular brain injury on MRI (i.e., possible vascular cognitive impairment [VCI]). We included 783 patients (mean age 67.6 ± 8.5, 46% female) with available 3T diffusion-weighted imaging (DWI). ACMIs were defined as supratentorial DWI hyperintensities <5 mm with a corresponding hypo/isointense apparent diffusion coefficient signal and iso/hyperintense T2*-weighted signal. A total of 23 ACMIs were found in 16 of the 783 patients (2.0%). Patients with ACMIs did not differ in vascular risk or cognitive profile, but were more often diagnosed with vascular dementia (odds ratio [OR] 5.1; 95% confidence interval [CI] 1.4-18.9, p = 0.014). ACMI presence was associated with lower levels of β-amyloid (p < 0.004) and with vascular imaging markers (lacunar infarcts: OR 3.5, CI 1.3-9.6, p = 0.015; nonlacunar infarcts: OR 4.1, CI 1.4-12.5, p = 0.012; severe white matter hyperintensities: OR 4.8, CI 1.7-13.8, p = 0.004; microbleeds: OR 18.9, CI 2.5-144.0, p = 0.0001). After a median follow-up of 2.1 years, the risk of poor clinical outcome (composite of marked cognitive decline, major vascular event, death, and institutionalization) was increased among patients with ACMIs (hazard ratio 3.0; 1.4-6.0, p = 0.005). In patients with possible VCI, ACMI presence was associated with a high burden of cerebrovascular disease of both small and large vessel etiology and poor clinical outcome. ACMIs may thus be a novel marker of active vascular brain injury in these patients.

Reversible splenial lesion syndrome associated with acute Mycoplasma pneumoniae-associated encephalitis: A report of four cases and literature review.

Reversible splenial lesion syndrome (RESLES) is a rare clinico-radiological syndrome that is defined as reversible lesions that involve the splenium of the corpus callosum (SCC). RESLES has been reported in patients with a broad spectrum of diseases and conditions, including infections, hypoglycemia and poisoning. The present report described four RESLES cases triggered by Mycoplasma pneumoniae (M. pneumoniae) and discussed the associated diagnostic challenges. Four cases of acute M. pneumoniae-associated encephalitis that displayed RESLES were reviewed. The clinical presentations were nonspecific in these patients. However, magnetic resonance imaging (MRI) revealed consistent lesions in the SCC with a hyperintensity in diffusion-weighted imaging (DWI) and hypointensities in T1WI, which disappeared after a variable lapse. Treatment with azithromycin or combined treatment with immunomodulatory agents if necessary led to a good prognosis. The present findings indicated that radiological diagnosis of RESLES should be considered in patients with M. pneumoniae-associated encephalitis. Furthermore, serum Mycoplasma antibody is important for the diagnosis of M. pneumoniae-associated encephalitis.

Diagnostic Value of Diffusion-Weighted Imaging and Apparent Diffusion Coefficient in Assessment of the Activity of Crohn Disease: 1.5 or 3 T.

ObjectiveThe objective of this study is to evaluate the role of diffusion-weighted imaging (DWI) in assessment of the activity of Crohn disease (CD) and to explore differences between DWI in 3 T and 1.5 T.MethodsPostcontrast magnetic resonance enterography with DWI of 72 patients with pathological proof of CD was retrospectively evaluated for restricted diffusion qualitatively and quantitavely in 3 T (n = 40) and 1.5 T (n = 32). Magnetic resonance activity score of 7 or higher was used as reference of activity.ResultsFifty-five patients had active lesions. Diffusion-weighted imaging hyperintensity showed sensitivity (100%, 100%) and specificity (88.89%, 100%) in 1.5/3 T for activity assessment. Mean ± SD apparent diffusion coefficient for active lesions was 1.21 ± 0.42 and 1.28 ± 0.59 × 10−3 mm2/s in 1.5 and 3 T, respectively. The proposed cutoff values of 1.35 and 1.38 × 10−3 mm2/s in 1.5 and 3 T, respectively, had sensitivity (80%, 93%), specificity (100%, 90%), accuracy (88%, 93%), and no significant difference in accuracy between 1.5/3 T (P = 0.48).ConclusionsDiffusion-weighted imaging hypersensitivity and apparent diffusion coefficient values accurately assessed the activity of CD. No significant statistical difference in diagnostic accuracy was detected between 1.5 and 3 T.

Glibenclamide Prevents Water Diffusion Abnormality in the Brain After Cardiac Arrest in Rats.

Glibenclamide (GBC) improves neurological outcome after cardiac arrest (CA) in rats. In this study, we sought to elucidate the mechanism responsible for the neuroprotective effects of GBC by using a high-field MRI system. Male Sprague-Dawley rats were subjected to 10-min asphyxial CA followed by cardiopulmonary resuscitation (CPR). Diffusion-weighted imaging (DWI) as well as conventional T2-weighted imaging was conducted prior to CA and at 24, 48, and 72h after resuscitation. Afterward, histological examination was performed. Twelve rats were randomized to receive GBC (n=6) or vehicle (n=6) at 15min after return of spontaneous circulation, while four rats were set as sham control. Rats that underwent CA/CPR and received vehicle exhibited distinct neurological deficit, which was alleviated by GBC treatment. Marked water diffusion abnormality as demonstrated by hyperintense DWI in vulnerable regions of the brain was detected after CA/CPR, with the most prominent hyperintense DWI observed in the hippocampal CA1 region at 72h. Consistently, histological examination revealed neuronal swelling, dendritic injury, and activation of astrocytes and microglia in the hippocampal CA1 region in vehicle-treated rats. Correlation analysis revealed that the ADC values in the hippocampus were significantly correlated with the histological findings (all p<0.05). These results suggest that the neuroprotective effects of GBC after CA was exerted, as least in part, through prevention of water diffusion abnormality, namely brain edema.

Endometrial Stromal Sarcoma of the Uterus: Magnetic Resonance Imaging Findings Including Apparent Diffusion Coefficient Value and Its Correlation With Ki-67 Expression.

This study aimed to investigate the conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) features of endometrial stromal sarcoma (ESS) including a preliminary investigation of the correlation between the apparent diffusion coefficient (ADC) value and Ki-67 expression. The clinical and MRI data of 15 patients with ESS confirmed by surgery and pathology were analyzed retrospectively. The conventional MR morphological features, signal intensity on DWI, ADC value (n = 14), and clinicopathological marker Ki-67 (n = 13) were evaluated. Of 15 patients with ESS, 13 tumors were low-grade ESS (LGESS), and the remaining 2 were high-grade ESS (HGESS); 9 tumors were located in the myometrium, 5 were located in the endometrium and/or cervical canal, and 1 was located in extrauterine. Thirteen (87%) of 15 tumors showed a homo- or heterogeneous isointensity on T1-weighted imaging and a heterogeneous hyperintensity on T2-weighted imaging. The hypointense bands were observed in 11 tumors (73%) on T2-weighted imaging. The degenerations (cystic/necrosis/hemorrhage) were observed in 7 LGESS tumors and 2 HGESS tumors. The DWI hyperintensity was observed in 13 tumors (93%) and isointensity in remaining 1. The mean ADC value of the solid components in 14 ESSs was (1.05 ± 0.20) × 10mm/s. The contrast-enhanced MRI showed an obvious enhancement in 14 tumors (93%) (heterogeneous in 7 LGESSs and 2 HGESSs; homogeneous in 5 LGESSs). The ADC value was inversely correlated with the Ki-67 expression (r = -0.613, P = 0.026). Patients with ESS showed some characteristics on conventional MRI and DWI, and there was an inverse correlation between the ADC value and Ki-67 expression.

Severity of White Matter Lesions Correlates with Subcortical Diffusion-Weighted Imaging Abnormalities and Predicts Stroke Risk

The severity of white matter lesions (WMLs) has been strongly linked to small-vessel diseases or lacunar infarction. The present study aimed to investigate the correlation between severity of WMLs and distribution of diffusion-weighted imaging (DWI) hyperintensities, and to explore whether the severity of WMLs is an independent neuroimaging predictor of stroke risk after transient symptoms with infarction (TSI). We evaluated the presence and severity of WMLs on fluid-attenuated inversion recovery sequences using the age-related white matter changes scale and the location and size of hyperintensities on DWI sequences, respectively, in a prospective cohort study of TSI patients. The primary end point was recurrent stroke within 90 days. A total of 191 consecutive TSI patients were eligible for inclusion in the present analysis. The average age of the patients was 57.3 ± 12.8 years. DWI abnormalities occurred more often in the deep white matter with increasing severity of WMLs (P < .001). During 90-day follow-up, Kaplan-Meier analysis showed that recurrent stroke was correlated to the severity of WMLs (P = .01). The Cox proportional hazards model revealed that WMLs were predictive of recurrent stroke (hazard ratio, 1.748; 95% confidence interval, 1.16-2.634; P = .008). Severe WMLs were correlated with DWI hyperintensities in the deep white matter in TSI patients and contributed to an increased risk of recurrent stroke.

P.043 Presence of infiltrative glioblastoma cells in an isolated area of diffusion restriction

Background: Diffusion weighted imaging (DWI) has useful diagnostic and predictive value in the assessment of glial tumors. Most studies evaluating the use of DWI in glioblastomas have done so in regions that overlap with abnormal T2/fluid attenuation inversion recovery (FLAIR) signal or contrast enhancement. Isolated DWI abnormalities, which do not overlap with contrast enhancing lesions, are less commonly described. Their relationship with the tumour, and implications for prognosis, are not well understood, though it has been speculated that these lesions may represent infiltrative tumour cells. To our knowledge, this is the first reported case where the presence of infiltrative tumour cells in an area of diffusion restriction has been confirmed via biopsy. Methods: A ring enhancing lesion and isolated DWI hyperintensity from a newly diagnosed patient were biopsied separately. Results: Pathological specimens from both targets were identified as glioblastoma (WHO Grade IV), negative for IDH-1 R132H mutation, with methylated MGMT promoter. Conclusions: In patients with glioblastoma, DWI hyperintensities distant from areas of abnormal T2/FLAIR or contrast enhancement can contain infiltrative tumour cells. The presence of isolated diffusion restriction may be a useful predictor of disease progression and prognosis but further investigation into the nature and behavior of isolated DWI lesions is required.

Non-Hypervascular Hypointense Nodules at Gadoxetic Acid MRI: Hepatocellular Carcinoma Risk Assessment with Emphasis on the Role of Diffusion-Weighted Imaging.

In cirrhotic patients, the characterization of hypovascular nodules, hypointense on hepatobiliary phase gadoxetic acid disodium-enhanced magnetic resonance images (Gd-EOB-DTPA-enhanced MRI), is essential to look for the proper approach strategy. Our objective was to evaluate the imaging features and risk assessment of hypovascular nodules, hypointense on Gd-EOB-DTPA-enhanced MRI, focusing on the diagnostic value of diffusion-weighted imaging (DWI). This prospective study includes 35 patients with 50 hypovascular hypointense nodules. Signal intensity on T2-weighted images and DWI, vascular pattern on dynamic contrast-enhanced MRI and on hepatobiliary phase, and volume doubling time were analyzed for each nodule as well as patient's clinical features. Univariate and multivariate analyses were made to determine the variables associated with the development of hypervascular pattern. On 24months follow-up period, 40% of the hypointense nodules (mean size 14mm±6.1) became hypervascular hepatocellular carcinoma (HCC) with 6 and 12months cumulative risk of 45 and 55%. Nine/12 (75%, mean size 15.50mm±7.2) that appeared hyperintense in DWI at first exam show malignant transformation (p value=0.007). Univariate and multivariate analyses identified hyperintensity at initial DWI (OR 6.49; 95% CI 1.28-32.80; p value=0.009) and size ≥10mm (OR 6.22; 95% CI 1.57-24.63; p value=0.024) as independent factors with the development of HCC. In conclusion, hypovascular lesions ≥10mm and those hyperintense in DWI were associated with progression to hypervascular HCC. A close follow-up or histological characterization is recommended to improve patients outcome and to develop effective treatment.

Clinical feasibility of simultaneous multi-slice imaging with blipped-CAIPI for diffusion-weighted imaging and diffusion-tensor imaging of the brain

Background Simultaneous multi-slice (SMS) imaging is starting to be used in clinical situation, although evidence of clinical feasibility is scanty. Purpose To prospectively assess the clinical feasibility of SMS diffusion-weighted imaging (DWI) and diffusion-tensor imaging (DTI) with blipped-controlled aliasing in parallel imaging for brain lesions. Material and Methods The institutional review board approved this study. This study included 156 hyperintense lesions on DWI from 32 patients. A slice acceleration factor of 2 was applied for SMS scans, which allowed shortening of the scan time by 41.3%. The signal-to-noise ratio (SNR) was calculated for brain tissue of a selected slice. The contrast-to-noise ratio (CNR), apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were calculated in 36 hyperintense lesions with a diameter of three pixels or more. Visual assessment was performed for all 156 lesions. Tractography of the corticospinal tract of 29 patients was evaluated. The number of tracts and averaged tract length were used for quantitative analysis, and visual assessment was evaluated by grading. Results The SMS scan showed no bias and acceptable 95% limits of agreement compared to conventional scans in SNR, CNR, and ADC on Bland-Altman analyses. Only FA of the lesions was higher in the SMS scan by 9% ( P = 0.016), whereas FA of the surrounding tissues was similar. Quantitative analysis of tractography showed similar values. Visual assessment of DWI hyperintense lesions and tractography also resulted in comparable evaluation. Conclusion SMS imaging was clinically feasible for imaging quality and quantitative values compared with conventional DWI and DTI.

Voxel-Based Lesion Mapping of Cryptogenic Stroke in Patients with Advanced Cancer: A Detailed Magnetic Resonance Imaging Analysis of Distribution Pattern

Ischemic stroke is one form of cancer-associated thrombosis that can greatly worsen a patient's performance status. The present investigation aimed to elucidate the characteristic distribution pattern(s) of cryptogenic stroke lesions using a voxel-based lesion-mapping technique and examine the differences in clinical manifestations between cryptogenic and conventional strokes in patients with advanced cancer. Data from 43 patients with advanced cancer who developed acute ischemic stroke were retrospectively collected. Stroke etiology was grouped into either cryptogenic or conventional stroke etiology according to the ASCO stroke score. Clinical data were reviewed, and voxel-based lesion mapping using diffusion-weighted imaging (DWI) was performed to visualize the cross-patient spatial distribution of the lesions. Of the 43 patients, 25 were classified as having cryptogenic stroke etiology and 18 were classified as having conventional stroke etiology. Median survival time of patients from stroke onset was 96 days for cryptogenic stroke etiology and 570 days for conventional stroke etiology (P = .01). D-dimer of patients was significantly higher in cryptogenic stoke etiology than in conventional stroke etiology (P = .006). Voxel-based lesion mapping showed that DWI hyperintense lesions accumulated at cortical and internal watershed areas of the cerebrum and at the vascular border zone of the superior cerebellar and posterior inferior cerebellar arteries at the cerebellum. Voxel-based lesion mapping for cryptogenic stroke in patients with advanced cancer showed that lesions accumulated at vascular border zones within the brain both at the cerebrum and at the cerebellum, but not at perforating arterial territories.

Magnetic resonance enterography has good inter-rater agreement and diagnostic accuracy for detecting inflammation in pediatric Crohn disease.

Magnetic resonance enterography (MRE) is increasingly relied upon for noninvasive assessment of intestinal inflammation in Crohn disease. However very few studies have examined the diagnostic accuracy of individual MRE signs in children. We have created an MR-based multi-item measure of intestinal inflammation in children with Crohn disease - the Pediatric Inflammatory Crohn's MRE Index (PICMI). To inform item selection for this instrument, we explored the inter-rater agreement and diagnostic accuracy of individual MRE signs of inflammation in pediatric Crohn disease and compared our findings with the reference standards of the weighted Pediatric Crohn's Disease Activity Index (wPCDAI) and C-reactive protein (CRP). In this cross-sectional single-center study, MRE studies in 48 children with diagnosed Crohn disease (66% male, median age 15.5years) were reviewed by two independent radiologists for the presence of 15 MRE signs of inflammation. Using kappa statistics we explored inter-rater agreement for each MRE sign across 10 anatomical segments of the gastrointestinal tract. We correlated MRE signs with the reference standards using correlation coefficients. Radiologists measured the length of inflamed bowel in each segment of the gastrointestinal tract. In each segment, MRE signs were scored as either binary (0-absent, 1-present), or ordinal (0-absent, 1-mild, 2-marked). These segmental scores were weighted by the length of involved bowel and were summed to produce a weighted score per patient for each MRE sign. Using a combination of wPCDAI≥12.5 and CRP≥5 to define active inflammation, we calculated area under the receiver operating characteristic curve (AUC) for each weighted MRE sign. Bowel wall enhancement, wall T2 hyperintensity, wall thickening and wall diffusion-weighted imaging (DWI) hyperintensity were most commonly identified. Inter-rater agreement was best for decreased motility and wall DWI hyperintensity (kappa≥0.64). Correlation between MRE signs and wPCDAI was higher than with CRP. AUC was highest (≥0.75) for ulcers, wall enhancement, wall thickening, wall T2 hyperintensity and wall DWI hyperintensity. Some MRE signs had good inter-rater agreement and AUC for detection of inflammation in children with Crohn disease.

Abstract WMP97: Acute Cerebral Ischemia After Aggressive Blood Pressure Reduction in Primary Intracerebral Hemorrhage: How Low Can You Go?

Introduction: Despite studies of aggressive blood pressure reduction in primary intracerebral hemorrhage (ICH), the potential for inducing ischemia remains a concern. The primary objective of this study is to determine the relationship between blood pressure and acute cerebral ischemia following ICH. Methods: We performed a retrospective chart review of patients with primary ICH admitted between January 2013 and December 2014 in whom MRI brain with diffusion-weighted imaging (DWI) was performed within 2 weeks of admission. Acute ischemia was defined as DWI hyperintensity with corresponding apparent diffusion coefficient hypointensity. Lesions adjacent to the ICH or after an invasive procedure were excluded and all MRIs were performed prior to digital subtraction angiography. Serial blood pressure measurements were collected from admission to 72h post ictus. Clinical deterioration was defined as any acute exam change not explained by seizure, hematoma expansion or other medical causes. Results: Among 119 patients with primary ICH (mean age 69.3 years, 58% males, 65% Caucasians), 28 (23.5%) had acute ischemia. Acute ischemia was associated with lower mean 24-hour SBP (132 mmHg in DWI+ versus 141 mmHg in DWI-, p&lt;0.001), greater mean change in SBP from admission to 24 hours (67 mmHg in DWI+ versus -42 mmHg in DWI-, p=0.002), lower mean minimum SBP at 72 hours (104 mmHg in DWI+ versus 111 mmHg in DWI-, p=0.008) and lobar ICH location (35% in DWI+ versus 14% in DWI-, p=0.009). Minimum SBP &lt;120 mmHg during the first 72 hour after ICH has a sensitivity of 96% in predicting DWI lesions in patients with ICH (p=0.014). Overall, patients with DWI+ lesions had a higher incidence of clinical deterioration (32% in DWI+ versus 6% in DWI-, p&lt;0.001) and longer length of stay compared to patients without DWI lesions (13 days in DWI+ versus 8 days in DWI-, p=0.006). Hematoma volume, initial NIH Stroke Scale and admission SBP were not significantly associated with DWI lesions in patients with primary ICH. Conclusions: Aggressive SBP reduction, particularly SBP&lt;120 mmHg within the first 72h of ICH, can be associated with acute cerebral ischemia. A third of acute ischemic lesions are associated with clinical deterioration.

Abstract TP328: Ischemic Stroke Following Prothrombin Complex Concentrates Administration for Intracerebral Hemorrhage

Intro: There have been case reports of ischemic infarcts after treatment with prothrombotics for anticoagulation reversal following spontaneous intracerebral hemorrhage (ICH), though there have been no systematic studies evaluating MRI infarction following prothrombin complex concentrate (PCC) or factor eight inhibitor bypassing activity (FEIBA) administration. We evaluated the prevalence of ischemic infarcts on diffusion-weighted imaging (DWI) in ICH patients who received prothrombotics compared to those who did not. Methods: We performed a retrospective review of patients admitted with ICH between January 2013 and April 2016 in whom MRI brain with DWI imaging was performed within 2 weeks of admission and prior to digital subtraction angiography. PCC (4-factor Kcentra, weight, and INR based dosing) was administered to patients on warfarin at the time of ictus with a INR≥1.4 and FEIBA (50 u/kg) was given to patients exposed to an oral Factor Xa inhibitor or direct thrombin inhibitor if ICH occurred within 3-5 half lives of the last dose. Acute ischemia was defined as DWI hyperintensity with corresponding apparent diffusion coefficient hypointensity. Perihematoma lesions, and procedure-related infarctions were excluded from analysis. Groups were compared using chi-square and Wilcoxon Rank Sum tests. Results: A total of 254 patients were enrolled. Of these, 41 (16%) received either 4-factor PCC (n=33) or FEIBA (n=8). Comparing those who received prothrombotics to those who did not, there was no difference in age (median 68 with prothrombotics and without; p=0.724), sex (44% female in both groups; p=0.977), initial NIH Stroke Scale (median 6 versus 8, p=0.838), or hematoma volume (median 15ml versus 10ml; p=0.207). Patients who received prothrombotics were more likely to have lobar ICH than deep ICH (71% versus 47%; p=0.005). DWI infarctions were found in 16% of patients who receive PCC or FEIBA compared with 22% who did not (p=0.404). Conclusions: Our data suggests prothrombotics do not increase the risk of acute ischemic infarcts within two weeks of administration.

Abstract TP313: Dual Antiplatelet Therapy Reduced Early Stroke Risk After Transient Ischemic Attack Patients with Acute Diffusion-weighted Imaging Hyperintensities: A Real-world Experience in Clinical Practice

Background: Transient Ischemic Attack (TIA) patients with acute Diffusion-Weighted Image (DWI) hyperintensities bear a high risk of a subsequent ischemic stroke. Few studies focused on the efficacy of dual antiplatelet therapy (DAPT), clopidogrel plus aspirin, in TIA patients with acute DWI hyperintensities. The study aimed to identify whether dual antiplatelet therapy could decrease early stroke risk after TIA with acute DWI lesion. Methods: Patients with a transient ischemic attack within 72 hours and acute DWI lesions, within the prospective TIA database from the First Affiliated Hospital of Zhengzhou University, were screened in the present study. Baseline characteristics including antiplatelet therapy during hospitalization were recorded. The relationship between DAPT and the 90-day stroke risk after the index TIA were analyzed in a Cox proportional hazards model to adjust confounding factors. Results: Overall, 270 TIA patients with acute DWI lesions were recruited in the present study.The 90-day stroke risk was 13.4% in patients with dual antiplatelet therapy compared with 23.6% in those with monotherapy (p=0.0491). Dual antiplatelet therapy was associated with reduced early stroke risk in TIA patients with DWI hyperintensities (HR, 0.53; 95% CI, 0.29-0.96) , after adjusting for confounding factors. Conclusions: Dual antiplatelet therapy reduced early stroke risk in TIA patients with acute DWI hyperintensities. Randomized controlled trials are needed to validate our results.

Abstract WMP101: The Evolution of Lesions on Diffusion-Weighted MR Imaging in Cerebral Amyloid Angiopathy

Introduction: Small hyperintense diffusion-weighted imaging (DWI) lesions are frequent neuroimaging findings in patients with cerebral amyloid angiopathy (CAA). Despite their high occurrence, little is known about the clinical impact of these lesions as well as their evolution over time and potential underlying etiology. Although it is believed that DWI-bright lesions represent acute microinfarcts, it has also been suggested that they are precursors of microbleeds. In this study we assessed DWI lesions in a cohort of CAA patients that underwent multiple imaging sessions. Specifically, we addressed the pathophysiologic nature of DWI lesions by evaluating their appearance on follow-up MRI. Methods: Patients (n=79) with probable CAA, as assessed by the Boston criteria, who underwent at least two DWI scans &gt;2 months apart (&gt;2 weeks post-ICH), were included in the study. One experienced neuroradiologist assessed presence and number of DWI lesions at each available time-point. Lesions had to be hyperintense on DWI, hypointense on ADC, and isointense on GRE. Next, on available follow-up images (FLAIR, T1, and GRE scans), lesion visibility and imaging characteristics were assessed by two experienced raters. All ratings were performed on 1.5 T MRI scans. Results: A total number of 221 DWI scans were assessed for DWI lesions (39 patients had 2 DWI scans; 40 had ≥3). In total, 57 DWI lesions were found in this dataset (37 in white matter; 16 in grey matter; 4 in cerebellum). For 36/57 lesions &gt;1 imaging sequence was available at follow-up to determine lesion appearance. Twenty-two/36 DWI lesions (61%) were visible on follow-up MRI. Five appeared as lacunar infarcts (of which 4 were located in white matter), 16 were visible as signal change on T1 or FLAIR sequences. Only a single DWI lesion showed evidence of hemosiderin deposition on follow-up, compatible with hemorrhagic transformation / microbleed. Conclusions: DWI lesions are common neuroimaging findings in patients with probable CAA. More than 60% of the observed DWI lesions evolve into chronic lesions, but the minority shows cavitation. Their neuroimaging signature strongly suggests that these lesions have an ischemic pathophysiologic nature. We found only one lesion that underwent hemorrhagic transformation.

Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) Correlation of Histopathology and MRI in Prion Disease.

Creutzfeldt-Jakob disease (CJD) and other prion diseases are rapidly progressive spongiform encephalopathies that are invariably fatal. Clinical features and magnetic resonance imaging, electroencephalogram, and cerebrospinal fluid abnormalities may suggest prion disease, but a definitive diagnosis can only be made by means of neuropathologic examination. Fluorodeoxyglucose positron emission tomography (FDG-PET) is not routinely used to evaluate patients with suspected prion disease. This study includes 11 cases of definite prion disease in which FDG-PET scans were obtained. There were 8 sporadic CJD cases, 2 genetic CJD cases, and 1 fatal familial insomnia case. Automated FDG-PET analysis revealed parietal region hypometabolism in all cases. Surprisingly, limbic and mesolimbic hypermetabolism were also present in the majority of cases. When FDG-PET hypometabolism was compared with neuropathologic changes (neuronal loss, astrocytosis, spongiosis), hypometabolism was predictive of neuropathology in 80.6% of cortical regions versus 17.6% of subcortical regions. The odds of neuropathologic changes were 2.1 times higher in cortical regions than subcortical regions (P=0.0265). A similar discordance between cortical and subcortical regions was observed between FDG-PET hypometabolism and magnetic resonance imaging diffusion weighted imaging hyperintensity. This study shows that there may be a relationship between FDG-PET hypometabolism and neuropathology in cortical regions in prion disease but it is unlikely to be helpful for diagnosis.

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.

A correlation study of preoperative imaging findings of central meningiomas and surgical cleavage and clinical efficacy

Objectives To investigate the correlation between preoperative imaging features of central meningiomas and surgical cleavage and to comparatively analyze the clinical efficacy of the different surgical cleavages. Methods From February 2006 to February 2014, the correlation between imaging features and surgical cleavage in 97 patients with center meningioma admitted to the Department of Neurosurgery, People's Hospital of Zhengzhou University were analyzed retrospectively. The relationship between imaging features and surgical cleavage of the tumors were tested by the univariate analysis. Kaplan-Meier survival analysis and multivariate logistic regression analysis were used to assess whether the imaging parameters predicted the surgical cleavage. Cox regression model was used to analyze the relationship between surgical cleavage or overall survival (OS) and progression free survival (PFS). Results The result of single factor analysis showed that the relationships between the peritumoral edema and the position of venous sinus, the cortical infiltration and diffusion weighted imaging (DWI) signal intensity and surgical cleavage had obvious relevance (all P 0.05). Multivariate logistic regression analysis showed that cortical infiltration was the most important independent predictor of surgical cleavage on central meningioma (P<0.01), others followed by DWI hyperintensity, parasagittal sinus, and peritumoral edema (P<0.01). The results of Kaplan-Meier analysis show that the median OS and median PFS in patients with the central grade Ⅱ meningioma. Cox regression model analysis showed that the age, WHO pathological grade, and surgical cleavage could be used as the independent predictive factors of influencing prognosis (P<0.05). Conclusions The peritumoral edema provided by preoperative imaging, the relationship with the position of venous sinus, cortical infiltration and DWI signal intensity may predict the surgical cleavage of meningioma, and the surgical cleavage is directly associated with the prognosis of patients. Key words: Meningioma; Magnetic resonance imaging; Surgical cleavage; Clinical effect

The Clinical Stages of Sporadic Creutzfeldt-Jakob Disease with Met/Met Genotype in Korean Patients

Background: Clinical diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) is currently based on changes occurring in the late disease stages, which limits early-stage detection. Therefore, we investigated the disease course from the vague symptomatic to the terminal phase. Methods: We retrospectively reviewed 36 sCJD patient records, classifying the disease progression into 4 stages based on clinical manifestations: vague symptomatic, possible CJD, probable CJD and chronic vegetative state. We analyzed findings from diffusion-weighted imaging (DWI), electroencephalography (EEG) and cerebrospinal fluid (CSF) 14-3-3 protein testing performed at each stage. Results: In stage 1, the most distinctive feature was DWI hyperintensities in the neocortex, even with negative CSF 14-3-3 protein and EEG results. In stage 2, DWI hyperintensities in the limbic cortex were more remarkable. CSF 14-3-3 protein testing yielded positive results in >80% of patients; EEG showed sensitivity in <30% of patients. With progression toward stage 3, DWI hyperintensities in the subcortical nucleus increased, with a sustained higher rate of hyperintensities in the limbic and neocortical regions. With gradual progression to stage 4, the sensitivity of CSF 14-3-3 protein testing and EEG decreased and increased, respectively within limited data. Conclusions: Understanding disease stage-dependent differences in clinical symptoms and laboratory test results will facilitate early and accurate diagnosis.