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Introduction In patients with heart failure, the main cause of hospital admissions is due to episodes of decompensation, which are associated with an increase in the costs and resources needed for care; they have a negative impact on the quality of life and prognosis of the disease. Therefore, it is necessary to design, evaluate and implement alternatives to achieve efficient follow-up and monitoring, improving adherence to treatment and helping identify decompensation episodes that facilitate their early treatment, so new hospital admissions can be avoided. For this reason, the use of information and communication technologies (apps) is emerging as an excellent strategy for the possibility of improving coverage, real-time monitoring and timeliness of care. ControlVit® is an electronic application that allows permanent, real-time monitoring of biomedical measurements for early detection of complications. Objective To determine the efficacy of ControlVit® as a complementary strategy in reducing hospital admissions in patients in a heart failure program. Methodology A randomized, placebo-controlled, open-label clinical trial was conducted, (n=140), included patients with heart failure under controlled clinical follow-up in a structured heart failure program, into NYHA FC II–IV, capable of handling smartphones and with permanent internet connectivity. All patients were provided with educational elements, a scale and a blood pressure monitor to enter clinical data and a symptom questionnaire necessary for follow-up. The patients were randomized to 2 groups: intervention: use of ControlVit® vs. placebo, with a 6-month follow-up. The primary outcome was the difference in readmissions for heart failure between the 2 groups. Patients on the waiting list for heart transplantation or use of ventricular assist devices were excluded. All participants signed informed consent and the protocol was approved by the institutional ethics committee. Results A total of 140 patients were included in the study (intervention = 71, placebo = 69), with an average age of 66 years, 71% were men, the main etiology of heart failure was ischemic (60%), the main comorbidities were arterial hypertension (44%), dyslipidemia (42%), hypothyroidism (38%), chronic kidney disease (38%), and diabetes mellitus (27%). During follow-up, there were 6 deaths (3 in each group) and 17 readmissions (3 in the intervention group and 14 in the control group). After adjustment for comorbidities, HR 0.72 CI95 (0.52; 0.92), p=0.0325 was found. Conclusion In patients with heart failure, ControlVit® is a useful and complementary tool for follow-up, which reduces hospital admissions due to episodes of decompensation. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): German Saldarriega award.Javeriana University

BACKGROUND AND PURPOSE: There are no validated imaging criteria for the diagnosis of progressive multifocal leukoencephalopathy in the cerebellum. Here we introduce the MR imaging shrimp sign, a cerebellar white matter lesion identifiable in patients with cerebellar progressive multifocal leukoencephalopathy, and we evaluate its sensitivity and specificity. MATERIALS AND METHODS: We first identified patients with progressive multifocal leukoencephalopathy seen at Massachusetts General Hospital between 1998 and 2019 whose radiology reports included the term “cerebellum.” Drawing on a priori knowledge, 2 investigators developed preliminary diagnostic criteria for the shrimp sign. These criteria were revised and validated in 2 successive stages by 4 additional blinded investigators. After defining the MR imaging shrimp sign, we assessed its sensitivity, specificity, positive predictive value, and negative predictive value. RESULTS: We identified 20 patients with cerebellar progressive multifocal leukoencephalopathy: 16 with definite progressive multifocal leukoencephalopathy (mean, 46.4 [SD, 9.2] years of age; 5 women), and 4 with possible progressive multifocal leukoencephalopathy (mean, 45.8 [SD, 8.5] years of age; 1 woman). We studied 40 disease controls (mean, 43.6 [SD, 21.0] years of age; 16 women) with conditions known to affect the cerebellar white matter. We defined the MR imaging shrimp sign as a T2- and FLAIR-hyperintense, T1-hypointense, discrete cerebellar white matter lesion abutting-but-sparing the dentate nucleus. MR imaging shrimp sign sensitivity was 0.85; specificity, 1; positive predictive value, 1; and negative predictive value, 0.93. The shrimp sign was also seen in fragile X–associated tremor ataxia syndrome, but radiographic and clinical features distinguished it from progressive multifocal leukoencephalopathy. CONCLUSIONS: In the right clinical context, the MR imaging shrimp sign has excellent sensitivity and specificity for cerebellar progressive multifocal leukoencephalopathy, providing a new radiologic marker of the disease.

We evaluated the incidence, distribution, and histopathologic correlates of microvascular brain lesions in patients with severe COVID-19. Sixteen consecutive patients admitted to the intensive care unit with severe COVID-19 undergoing brain MRI for evaluation of coma or neurologic deficits were retrospectively identified. Eleven patients had punctate susceptibility-weighted imaging (SWI) lesions in the subcortical and deep white matter, eight patients had >10 SWI lesions, and four patients had lesions involving the corpus callosum. The distribution of SWI lesions was similar to that seen in patients with hypoxic respiratory failure, sepsis, and disseminated intravascular coagulation. Brain autopsy in one patient revealed that SWI lesions corresponded to widespread microvascular injury, characterized by perivascular and parenchymal petechial hemorrhages and microscopic ischemic lesions. Collectively, these radiologic and histopathologic findings add to growing evidence that patients with severe COVID-19 are at risk for multifocal microvascular hemorrhagic and ischemic lesions in the subcortical and deep white matter., National Institute of Neurological Disorders and Stroke (Grants R21NS109627, R21AG067562, RF1NS115268), NIH Director’s Office (Grant DP2HD101400), NIH National Institute of Mental Health (Grant K23MH115812), NIH National Institutes of Allergy and Infectious Diseases (Grant 2U19AI110818)

BACKGROUND AND PURPOSE: Patients infected with the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) can develop a spectrum of neurological disorders, including a leukoencephalopathy of variable severity. Our aim was to characterize imaging, lab, and clinical correlates of severe coronavirus disease 2019 (COVID-19) leukoencephalopathy, which may provide insight into the SARS-CoV-2 pathophysiology. MATERIALS AND METHODS: Twenty-seven consecutive patients positive for SARS-CoV-2 who had brain MR imaging following intensive care unit admission were included. Seven (7/27, 26%) developed an unusual pattern of “leukoencephalopathy with reduced diffusivity” on diffusion-weighted MR imaging. The remaining patients did not exhibit this pattern. Clinical and laboratory indices, as well as neuroimaging findings, were compared between groups. RESULTS: The reduced-diffusivity group had a significantly higher body mass index (36 versus 28 kg/m(2), P

Brain multivoxel MR spectroscopic imaging was performed in 3 consecutive patients with coronavirus disease 2019 (COVID-19). These included 1 patient with COVID-19-associated necrotizing leukoencephalopathy, another patient who had a recent pulseless electrical activity cardiac arrest with subtle white matter changes, and a patient without frank encephalopathy or a recent severe hypoxic episode. The MR spectroscopic imaging findings were compared with those of 2 patients with white matter pathology not related to Severe Acute Respiratory Syndrome coronavirus 2 infection and a healthy control subject. The NAA reduction, choline elevation, and glutamate/glutamine elevation found in the patient with COVID-19-associated necrotizing leukoencephalopathy and, to a lesser degree, the patient with COVID-19 postcardiac arrest, follow a similar pattern as seen with the patient with delayed posthypoxic leukoencephalopathy. Lactate elevation was most pronounced in the patient with COVID-19 necrotizing leukoencephalopathy.

BACKGROUND AND PURPOSE: Volumetric brain MR imaging typically has long acquisition times. We sought to evaluate an ultrafast MPRAGE sequence based on Wave-CAIPI (Wave-MPRAGE) compared with standard MPRAGE for evaluation of regional brain tissue volumes. MATERIALS AND METHODS: We performed scan-rescan experiments in 10 healthy volunteers to evaluate the intraindividual variability of the brain volumes measured using the standard and Wave-MPRAGE sequences. We then evaluated 43 consecutive patients undergoing brain MR imaging. Patients underwent 3T brain MR imaging, including a standard MPRAGE sequence (acceleration factor [R] = 2, acquisition time [TA] = 5.2 minutes) and an ultrafast Wave-MPRAGE sequence (R = 9, TA = 1.15 minutes for the 32-channel coil; R = 6, TA = 1.75 minutes for the 20-channel coil). Automated segmentation of regional brain volume was performed. Two radiologists evaluated regional brain atrophy using semiquantitative visual rating scales. RESULTS: The mean absolute symmetrized percent change in the healthy volunteers participating in the scan-rescan experiments was not statistically different in any brain region for both the standard and Wave-MPRAGE sequences. In the patients undergoing evaluation for neurodegenerative disease, the Dice coefficient of similarity between volumetric measurements obtained from standard and Wave-MPRAGE ranged from 0.86 to 0.95. Similarly, for all regions, the absolute symmetrized percent change for brain volume and cortical thickness showed

BACKGROUND AND PURPOSE: The development of new MR imaging scanners with stronger gradients and improvement in coil technology, allied with emerging fast imaging techniques, has allowed a substantial reduction in MR imaging scan times. Our goal was to develop a 10-minute gadolinium-enhanced brain MR imaging protocol with accelerated sequences and to evaluate its diagnostic performance compared with the standard clinical protocol. MATERIALS AND METHODS: Fifty-three patients referred for brain MR imaging with contrast were scanned with a 3T scanner. Each MR image consisted of 5 basic fast precontrast sequences plus standard and accelerated versions of the same postcontrast T1WI sequences. Two neuroradiologists assessed the image quality and the final diagnosis for each set of postcontrast sequences and compared their performances. RESULTS: The acquisition time of the combined accelerated pre- and postcontrast sequences was 10 minutes and 15 seconds; and of the fast postcontrast sequences, 3 minutes and 36 seconds, 46% of the standard sequences. The 10-minute postcontrast axial T1WI had fewer image artifacts (P < .001) and better overall diagnostic quality (P < .001). Although the 10-minute MPRAGE sequence showed a tendency to have more artifacts than the standard sequence (P = .08), the overall diagnostic quality was similar (P = .66). Moreover, there was no statistically significant difference in the diagnostic performance between the protocols. The sensitivity, specificity, and accuracy values for the 10-minute protocol were 100.0%, 88.9%, and 98.1%. CONCLUSIONS: The 10-minute brain MR imaging protocol with contrast is comparable in diagnostic performance with the standard protocol in an inpatient motion-prone population, with the additional benefits of reducing acquisition times and image artifacts.

BACKGROUND AND PURPOSE: SWI is valuable for characterization of intracranial hemorrhage and mineralization but has long acquisition times. We compared a highly accelerated wave–controlled aliasing in parallel imaging (CAIPI) SWI sequence with 2 commonly used alternatives, standard SWI and T2*-weighted gradient recalled-echo (T2*W GRE), for routine clinical brain imaging at 3T. MATERIALS AND METHODS: A total of 246 consecutive adult patients were prospectively evaluated using a conventional SWI or T2*W GRE sequence and an optimized wave–CAIPI SWI sequence, which was 3–5 times faster than the standard sequence. Two blinded radiologists scored each sequence for the presence of hemorrhage, the number of microhemorrhages, and severity of motion artifacts. Wave–CAIPI SWI was then evaluated in head-to-head comparison with the conventional sequences for visualization of pathology, artifacts, and overall diagnostic quality. Forced-choice comparisons were used for all scores. Wave–CAIPI SWI was tested for superiority relative to T2*W GRE and for noninferiority relative to standard SWI using a 15% noninferiority margin. RESULTS: Compared with T2*W GRE, wave–CAIPI SWI detected hemorrhages in more cases (P

BACKGROUND AND PURPOSE: Our aim was to investigate how often relevant diagnostic findings in an arch-to-vertex CTA scan, obtained specifically as part of the acute stroke CT protocol, are located in the head, neck, and upper chest regions. MATERIALS AND METHODS: Radiology reports were reviewed in 302 consecutive patients (170 men, 132 women; median ages, 66 and 73 years, respectively) who underwent emergency department investigation of suspected acute stroke between January and July 2010. Diagnostic CTA findings relevant to patient management were recorded for the head, neck, and chest regions individually. Additionally, the contributions to the total CTA scan effective dose were estimated from each of the 3 anatomic regions by using the ImPACT CT Dose Calculator. RESULTS: Of the 302 patients, 161 (54%) had relevant diagnostic findings in the head; 94 (31%), in the neck; and 4 (1%), in the chest. The estimated contributions to the total CTA scan dose from each body region, head, neck, and upper chest, were 14 ± 2%, 33 ± 5%, and 53 ± 6%, respectively. CONCLUSIONS: Most clinically relevant findings are in the head and neck, supporting inclusion of these regions in arch-to-vertex CTA performed specifically in patients with acute stroke in the emergency department. Further studies are required to investigate extending the scan to the upper chest because only 1% of patients in our study had clinically relevant findings in the mediastinum, yet half the CTA effective dose was due to scanning in this region.

Selecting acute ischemic stroke patients for reperfusion therapy on the basis of a diffusion-perfusion mismatch has not been uniformly proved to predict a beneficial treatment response. In a prior study, we have shown that combining clinical with MR imaging thresholds can predict clinical outcome with high positive predictive value. In this study, we sought to validate this predictive model in a larger patient cohort and evaluate the effects of reperfusion therapy and stroke side.One hundred twenty-three consecutive patients with anterior circulation acute ischemic stroke underwent MR imaging within 6 hours of stroke onset. DWI and PWI volumes were measured. Lesion volume and NIHSS score thresholds were used in models predicting good 3-month clinical outcome (mRS 0-2). Patients were stratified by treatment and stroke side.Receiver operating characteristic analysis demonstrated 95.6% and 100% specificity for DWI70 mL and NIHSS score20 to predict poor outcome, and 92.7% and 91.3% specificity for PWI (mean transit time)50 mL and NIHSS score8 to predict good outcome. Combining clinical and imaging thresholds led to an 88.8% (71/80) positive predictive value with a 65.0% (80/123) prognostic yield. One hundred percent specific thresholds for DWI (103 versus 31 mL) and NIHSS score (20 versus 17) to predict poor outcome were significantly higher in treated (intravenous and/or intra-arterial) versus untreated patients. Prognostic yield was lower in right- versus left-sided strokes for all thresholds (10.4%-20.7% versus 16.9%-40.0%). Patients with right-sided strokes had higher 100% specific DWI (103.1 versus 74.8 mL) thresholds for poor outcome, and the positive predictive value was lower.Our predictive model is validated in a much larger patient cohort. Outcome may be predicted in up to two-thirds of patients, and thresholds are affected by stroke side and reperfusion therapy.

Infection with human immunodeficiency virus (HIV) commonly results in neurologic disease called the AIDS dementia complex. Neuronal loss and injury have been found in the HIV brain, but the underlying mechanisms are not understood. The simian immunodeficiency virus (SIV)-infected macaque is an excellent animal model for HIV infection, but neuronal loss has not been demonstrated. To determine whether neuronal damage occurs in the SIV brain, we quantified the neuronal marker N-acetylaspartate (NAA) using proton magnetic resonance spectroscopy (1H-MRS) in brain extracts of control and SIV-infected macaques and correlated these findings with histologic analyses. We found reduced NAA in the SIV-infected animals compared with controls (2.94 +/- 1.37 versus 6.21 +/- 1.73 micromol/g of wet weight; p = 0.004). A significant decrease in NAA was also found in SIV-infected animals sacrificed in the acute stages of infection 9 or 10 days after inoculation with SIVmacYnef. We conclude that SIV infection of rhesus macaques results in neuronal damage that is demonstrable shortly after infection and that 1H-MRS may be used to measure such injury. The results further support the SIV macaque as a useful model to study the mechanisms of neuropathogenesis by HIV.

Atucha-2 is a Siemens-designed pressurized heavy water reactor located in Argentina. Its geometrical complexity and peculiarity [e.g., oblique control rods (CRs) and positive void coefficient] requ...

While the previous review of CNS-IRIS in the HIV-infected patient on highly active antiretroviral therapy (Part 1) dealt with an overview of the biology, pathology, and neurologic presentation of this condition and a discussion of the atypical imaging findings in PML-IRIS and cryptococcal meningitis-IRIS due to the robust inflammatory response, the current review (Part 2) discusses the imaging findings in other commonly encountered organisms seen in association with CNS-IRIS, namely, VZV, CMV, HIV, Candida organisms, Mycobacterium tuberculosis, and Toxoplasma gondii. Also described is the imaging appearance of CNS-IRIS when not associated with a particular organism. Recognition of these imaging findings will give credence to the diagnosis of CNS-IRIS and will allow the clinician to institute changes in medical management, if necessary, so that immune reconstitution and improved patient outcome can occur with time.

SUMMARY: While uncommon, CNS-IRIS developing after the initiation of HAART in the setting of HIV-related severe immunosuppression is characterized by an intense inflammatory reaction to dead or latent organisms or to self-antigens due to a heightened but dysregulated immune response. While this reaction can range from mild to fulminating, encompassing a very wide clinical spectrum, it is important to recognize because changes in medical management may be necessary to prevent neurologic decline and even death. Once contained, however, this inflammatory response can be associated with improved patient outcome as immune function is restored. Among the infectious organisms that are most commonly associated with CNS-IRIS are the JC virus and Cryptococcus organisms, which will be the subject of this review. CD8 cell infiltration in the leptomeninges, perivascular spaces, blood vessels, and even parenchyma seems to be the pathologic hallmark of CNS-IRIS. While recognition of CNS-IRIS may be difficult, the onset of new or progressive clinical symptoms, despite medical therapy and despite improved laboratory data, and the appearance on neuroimaging studies of contrast enhancement, interstitial edema, mass effect, and restricted diffusion in infections not typically characterized by these findings in the untreated HIV-infected patient should raise the strong suspicion for CNS-IRIS. While CNS-IRIS is a diagnosis of exclusion, the neuroradiologist can play a critical role in alerting the clinician to the possibility of this syndrome.

BACKGROUND AND PURPOSE: Early ischemic changes on pretreatment NCCT quantified using ASPECTS have been demonstrated to predict outcomes after IAT. We sought to determine the interobserver reliability of ASPECTS for patients with AIS with PAO and to determine whether pretreatment ASPECTS dichotomized at 7 would demonstrate at least substantial κ agreement. MATERIALS AND METHODS: From our prospective IAT data base, we identified consecutive patients with anterior circulation PAO who underwent IAT over a 6-year period. Only those with an evaluable pretreatment NCCT were included. ASPECTS was graded independently by 2 experienced readers. Interrater agreement was assessed for total ASPECTS, dichotomized ASPECTS (≤7 versus >7), and each ASPECTS region. Statistical analysis included determination of Cohen κ coefficients and concordance correlation coefficients. PABAK coefficients were also calculated. RESULTS: One hundred fifty-five patients met our study criteria. Median pretreatment ASPECTS was 8 (interquartile range 7–9). Interrater agreement for total ASPECTS was substantial (concordance correlation coefficient = 0.77). The mean ASPECTS difference between readers was 0.2 (95% confidence interval, −2.8 to 2.4). For dichotomized ASPECTS, there was a 76.8% (119/155) observed rate of agreement, with a moderate κ = 0.53 (PABAK = 0.54). By region, agreement was worst in the internal capsule and the cortical areas, ranging from fair to moderate. After adjusting for prevalence and bias, agreement improved to substantial or near perfect in most regions. CONCLUSIONS: Interobserver reliability is substantial for total ASPECTS but is only moderate for ASPECTS dichotomized at 7. This may limit the utility of dichotomized ASPECTS for IAT selection.

BACKGROUND AND PURPOSE: Various CTP parameters have been used to identify ischemic penumbra. The purpose of this study was to determine the optimal CTP parameter and threshold to distinguish true “at-risk” penumbra from benign oligemia in acute stroke patients without reperfusion. MATERIALS AND METHODS: Consecutive stroke patients were screened and 23 met the following criteria: 1) admission scanning within 9 hours of onset, 2) CTA confirmation of large vessel occlusion, 3) no late clinical or radiographic evidence of reperfusion, 4) no thrombolytic therapy, 5) DWI imaging within 3 hours of CTP, and 6) either CT or MR follow-up imaging. CTP was postprocessed with commercial software packages, using standard and delay-corrected deconvolution algorithms. Relative cerebral blood flow, volume, and mean transit time (rCBF, rCBV and rMTT) values were obtained by normalization to the uninvolved hemisphere. The admission DWI and final infarct were transposed onto the CTP maps and receiver operating characteristic curve analysis was performed to determine optimal thresholds for each perfusion parameter in defining penumbra destined to infarct. RESULTS: Relative and absolute MTT identified penumbra destined to infarct more accurately than CBF or CBV*CBF (P CONCLUSIONS: Appropriately thresholded absolute and relative MTT-CTP maps optimally distinguish “at-risk” penumbra from benign oligemia in acute stroke patients with large-vessel occlusion and no reperfusion. The precise threshold values may vary, however, depending on the postprocessing technique used for CTP map construction.

Migration of both uninfected and infected monocytes into the brain during acute HIV infection likely initiates metabolic changes that can be observed with magnetic resonance spectroscopy (MRS). Herein, we measured changes in brain metabolism during the first year of HIV infection and examined the relationship of these metabolite levels to CD16+ monocyte populations measured in the blood. MRS was performed on nine HIV+ subjects identified during acute HIV infection and nine seronegative control subjects. HIV+ subjects were examined within 90 days of an indeterminate Western blot, then again 2 and 6 months later, during early infection. Blood samples were collected for plasma viral RNA and monocyte subset quantification. HIV+ subjects were identified with acute viral ailment and did not display severe cognitive deficits such as dementia or minor cognitive motor disorder. Changes in lipid membrane metabolism (choline levels) in the frontal cortex and white matter were observed during the initial year of HIV infection. Greater numbers of CD16+ monocytes were associated with lower N-acetylaspartate levels and higher choline levels in the brain. These results suggest that HIV infection induces metabolic changes in the brain early during infection and that these changes may be related to monocyte dynamics in the periphery.

DVST is an important cause of ICH because its treatment may require anticoagulation or mechanical thrombectomy. We aimed to determine the frequency of adequate contrast opacification of the major intracranial venous structures in CTAs performed for ICH evaluation, which is an essential factor in excluding DVST as the ICH etiology.Two readers retrospectively reviewed CTAs performed in 170 consecutive patients with ICH who presented to our emergency department during a 1-year period to determine by consensus whether qualitatively, contrast opacification in each of the major intracranial venous structures was adequate to exclude DVST. "Adequate contrast opacification" was defined as homogeneous opacification of the venous structure examined. "Inadequate contrast opacification" was defined as either inhomogeneous opacification or nonopacification of the venous structure examined. Delayed scans, if obtained, were reviewed by the same readers blinded to the first-pass CTAs to determine the adequacy of contrast opacification in the venous structures according to the same criteria. In patients who did not have an arterial ICH etiology, the same readers determined if thrombosis of an inadequately opacified intracranial venous structure could have potentially explained the ICH by correlating the presumed venous drainage path of the ICH with the presence of inadequate contrast opacification within the venous structure draining the venous territory of the ICH. CTAs were performed in 16- or 64-section CT scanners with bolus-tracking, scanning from C1 to the vertex. Patients with a final diagnosis of DVST were excluded. We used the Pearson χ(2) test to determine the significance of the differences in the frequency of adequate contrast opacification within each of the major intracranial venous structures in scans obtained using either a 16- or 64-section MDCTA technique.Fifty-eight patients were evaluated with a 16-section MDCTA technique (34.1%) and 112 with a 64-section technique (65.9%). Adequate contrast opacification within all major noncavernous intracranial venous structures was significantly less frequent in first-pass CTAs performed with a 64-section technique (33%) than in those performed with a 16-section technique (60%, P value.0001). Delayed scans were obtained in 50 patients, all of which demonstrated adequate contrast opacification in the major noncavernous intracranial venous structures. In 142 patients with supratentorial or cerebellar ICH without an underlying arterial etiology, we found that thrombosis of an inadequately opacified major intracranial venous structure could have potentially explained the ICH in 38 patients (26.8%), most examined with a 64-section technique (86.8%).Inadequate contrast opacification of the major intracranial venous structures is common in first-pass CTAs performed for ICH evaluation, particularly if performed with a 64-section technique. Acquiring delayed scans appears necessary to confidently exclude DVST when there is strong clinical or radiologic suspicion.

BACKGROUND AND PURPOSE: An ICH patient9s risk of harboring an underlying vascular etiology varies according to baseline clinical and NCCT characteristics. Our aim was to develop a practical scoring system to stratify patients with ICH according to their risk of harboring a vascular etiology. MATERIALS AND METHODS: Using a data base of 623 patients with ICH evaluated with MDCTA during a 9-year period, we developed a scoring system based on baseline clinical characteristics (age group [0–2 points], sex [0–1 point], neither known HTN nor impaired coagulation [0–1 point]), and NCCT categorization (0–2 points) to predict the risk of harboring a vascular lesion as the ICH etiology (SICH score). We subsequently applied the SICH score to a prospective cohort of 222 patients with ICH who presented to our emergency department during a 13-month period. Using ROC analysis, we calculated the AUC and MOP for the SICH score in both the retrospective and prospective patient cohorts separately and the entire patient population. Patients with SAH in the basal cisterns were excluded. RESULTS: A vascular etiology was found in 120 of 845 patients with ICH evaluated with MDCTA (14.2%), most commonly AVMs (45.8%), aneurysms with purely intraparenchymal rupture (21.7%), and DVSTs (16.7%). The MOP was reached at a SICH score of >2, with the highest incidence of vascular ICH etiologies in patients with SICH scores of 3 (18.5%), 4 (39%), 5 (84.2%), and 6 (100%). There was no significant difference in the AUC between both patient cohorts (0.86–0.87). CONCLUSIONS: The SICH score successfully predicts a given ICH patient9s risk of harboring an underlying vascular etiology and could be used as a guide to select patients with ICH for neurovascular evaluation to exclude the presence of a vascular abnormality.

BACKGROUND AND PURPOSE: Routine axial CT images may not be ideally suited for detecting ICH in transversely oriented locations such as the floor of the anterior and middle cranial fossas and vertex. This study was performed to evaluate whether coronal reformations improve detection of ICH in NCCT performed for head trauma. MATERIALS AND METHODS: All patients undergoing a first NCCT in the ED for evaluation of head trauma were included prospectively during a 6-month interval. NCCT images were reconstructed into standard 5-mm axial datasets and were also reformatted into coronal datasets of 5-mm sections and 2.5-mm intervals. Thirty-two of 213 (15%) scans were interpreted as showing traumatic ICH. These cases were interspersed with 30 studies without ICH. Cases were reviewed for the presence and location of ICH by 2 staff neuroradiologists. RESULTS: Of 213 patients, 32 NCCTs demonstrated ICH (a total of 104 foci). Fifteen of 104 (14%) ICHs (8 patients) were detected solely on coronal images. Locations included the floor of the anterior and middle cranial fossas, vertex, corpus callosum, falx, tentorium, and occipital convexity. Coronal reformations allowed exclusion of suspicious findings on axial images in 14 instances (7 patients). Coronal images aided interpretation in 29/104 (28%) findings. CONCLUSIONS: Coronal reformations improve the detection of ICH over axial images alone, especially for lesions that lie in the axial plane immediately adjacent to bony surfaces. The use of coronal reformations should be considered in the routine interpretation of head CT examinations performed for the evaluation of head trauma.

BACKGROUND AND PURPOSE: Multidetector CT angiography (MDCTA) is emerging as the favored initial diagnostic examination in the evaluation of patients presenting with spontaneous intraparenchymal hemorrhage (IPH). This study aims to evaluate the diagnostic accuracy and yield of MDCTA for the detection of vascular etiologies in adult patients presenting to the emergency department with IPH. MATERIALS AND METHODS: We conducted a retrospective study of 623 consecutive adult patients presenting to the emergency department with IPH, who were evaluated with MDCTA during a 9-year period. CT angiograms were reviewed by 2 neuroradiologists to determine the IPH site and the presence of a vascular etiology. Patients with associated subarachnoid hemorrhage in the basal cisterns were excluded from the study. Medical records were reviewed for risk factors and correlation with final diagnosis. The diagnostic accuracy of MDCTA compared with conventional angiography, intraoperative evaluation, and pathologic findings was determined, when available. Multiple-variable logistic regression analysis was performed to determine clinical and radiologic factors that predict a higher yield of MDCTA. RESULTS: MDCTA demonstrated a vascular etiology in 91 patients (14.6%), with a sensitivity of 96%, specificity of 99%, and diagnostic accuracy of 98%. We found independent, statistically significant higher yields of MDCTA in patients with the following characteristics: 1) age younger than 46 years (47%); 2) lobar (20%) or infratentorial (16%) IPH, especially lobar IPH with associated intraventricular hemorrhage (25%); 3) female sex (18%); or 4) neither known hypertension nor impaired coagulation at presentation (33%). CONCLUSIONS: MDCTA is an accurate diagnostic examination in the evaluation of adult patients presenting with spontaneous IPH and should be performed in all patients with the aforementioned clinical and radiologic characteristics.

BACKGROUND AND PURPOSE: Internal carotid artery (ICA) atheromatous disease is an important cause of ischemic stroke, and endarterectomy or stent placement is typically indicated for symptomatic patients with ≥70% stenosis. Our purpose was to compare contrast-enhanced MR angiography (CE-MRA) with unenhanced 2D time-of-flight MR angiography (2D TOF MRA) in detecting hemodynamically significant ICA stenosis, by using CT angiography (CTA) as the reference standard. MATERIALS AND METHODS: This was an institutional review board−approved retrospective study. We identified 177 consecutive patients (354 ICAs) who received correlative CE-MRA, 2D TOF MRA, and CTA. Two neuroradiologists blinded to the CTA data graded the degree of ICA stenosis according to a 5-point scale. Additionally, luminal signal-intensity characteristics including 1) signal intensity drop-out, 2) distal-vessel narrowing, and 3) distal-vessel signal-intensity reduction were recorded. MRA results were correlated with those of CTA, and receiver-operating-characteristic (ROC) curves were constructed. RESULTS: On CTA, there were 55 ICAs with and 299 without ≥70% stenosis. CE-MRA was 84% sensitive and 96% specific for detecting ≥70% stenosis; 2D TOF MRA was 80% sensitive and 95% specific. The area under the ROC curve was 0.97 for CE-MRA and 0.95 for 2D TOF MRA (P = .51, not significant). For both MRA studies, each of the luminal signal-intensity characteristics had high specificity (>98%) but poor-to-mild sensitivity (35%–66%) in detecting ≥70% stenosis. CONCLUSIONS: Although it is established that CE-MRA more accurately delineates neurovascular anatomy than does unenhanced 2D TOF MRA, the administration of gadolinium did not offer a significant advantage in distinguishing surgically treatable ICA stenosis. This conclusion may be important in patients with contraindications to gadolinium.

BACKGROUND AND PURPOSE: Our aim was to determine the effects of intra-arterial (IA) nicardipine infusion on the cerebral hemodynamics of patients with aneurysmal subarachnoid hemorrhage (aSAH)–induced vasospasm by using first-pass quantitative cine CT perfusion (CTP). MATERIALS AND METHODS: Six patients post-aSAH with clinical and transcranial Doppler findings suggestive of vasospasm were evaluated by CT angiography and CTP immediately before angiography for possible vasospasm treatment. CTP was repeated immediately following IA nicardipine infusion. Maps of mean transit time (MTT), cerebral blood volume (CBV), and cerebral blood flow (CBF) were constructed and analyzed in a blinded manner. Corresponding regions of interest on these maps from the bilateral middle cerebral artery territories and, when appropriate, the bilateral anterior or posterior cerebral artery territories, were selected from the pre- and posttreatment scans. Normalized values were compared by repeated measures analysis of variance. RESULTS: Angiographic vasospasm was confirmed in all patients. In 5 of the 6 patients, both CBF and MTT improved significantly in affected regions in response to nicardipine therapy (mean increase in CBF, 41 ± 43%; range, −9%–162%, P = .0004; mean decrease in MTT, 26 ± 24%; range, 0%–70%, P = .0002). In 1 patient, we were unable to quantify improvement in flow parameters due to section-selection differences between the pre- and posttreatment examinations. CONCLUSIONS: IA nicardipine improves CBF and MTT in ischemic regions in patients with aSAH-induced vasospasm. Our data provide a tissue-level complement to the favorable effects of IA nicardipine reported on prior angiographic studies. CTP may provide a surrogate marker for monitoring the success of treatment strategies in patients with aSAH-induced vasospasm.

BACKGROUND AND PURPOSE: In acute middle cerebral artery (MCA) stroke, CT angiographic (CTA) source images (CTA-SI) identify tissue likely to infarct despite early recanalization. This pilot study evaluated the impact of recanalization status on clinical and radiologic predictors of patient outcomes. MATERIALS AND METHODS: Of 44 patients undergoing CT/CTA within 6 hours of developing symptoms of proximal MCA ischemia, 19 patients achieved complete proximal MCA (MCA M1) recanalization. Admission National Institutes of Health Stroke Scale (NIHSS) score, onset-to-imaging time, CTA-SI Alberta Stroke Program Early CT Score, MCA M1 occlusion, cerebrovascular collaterals score, and CTA-SI lesion volume were correlated with 3- to 6-month follow-up modified Rankin Scale (mRS). We developed 2 stepwise regression models: one for patients with complete MCA M1 recanalization and one for patients without complete recanalization. RESULTS: Complete and incomplete recanalization groups had similar median admission NIHSS scores (19 versus 19) and mean onset-to-imaging times (2.3 versus 1.9 hours) but different proportions of patients achieving mRS scores 0–2 (74% versus 40%; P = .04). The only independent predictors of clinical outcome in patients with complete recanalization were onset-to-imaging time and admission CTA-SI lesion volume (total model R 2 = 0.75; P = .01). The only independent predictors of outcome in patients with incomplete recanalization were admission CTA-SI lesion volume and NIHSS score (total model R 2 = 0.66; P = .007). CONCLUSION: Regardless of recanalization status, admission CTA-SI lesion volume was associated with clinical outcome. Recanalization status did, however, affect which variables in addition to CTA-SI volume significantly impacted clinical outcome: time with complete recanalization and NIHSS with incomplete recanalization. This finding may support the development of a model predicting the potential clinical benefit expected with early successful recanalization.

BACKGROUND AND PURPOSE: A simple classification instrument based on imaging that predicts outcomes in patients with actute ischemic stroke is lacking. We tested the hypotheses that the Boston Acute Stroke Imaging Scale (BASIS) classification instrument effectively predicts patient outcomes and is superior to the Alberta Stroke Program Early CT Score (ASPECTS) in predicting outcomes in acute ischemic stroke. MATERIALS AND METHODS: Of 230 prospectively screened, consecutive patients with acute ischemic stroke, 87 had noncontrast CT (NCCT)/CT angiography (CTA), and 118 had MR imaging/MR angiography (MRA) at admission and were classified as having major stroke by BASIS criteria if they had a proximal cerebral artery occlusion or, if no occlusion, imaging evidence of significant parenchymal ischemia; all of the others were classified as minor strokes. Outcomes included death, length of hospitalization, and discharge disposition. BASIS was compared with ASPECTS (dichotomized > or ≤7) in 87 patients who had NCCT/CTA. RESULTS: BASIS classification by NCCT/CTA was equivalent to MR imaging/MRA. Fifty-six of 205 patients were classified as having major strokes including all 6 of the deaths. A total of 71.4% and 15.4% of major and minor stroke survivors, respectively, were discharged to a rehabilitation facility, whereas 14.3% and 79.2% of patients with major and minor strokes were discharged to home. The mean length of hospitalization was 12.3 and 3.3 days for the major and minor stroke groups, respectively (all outcomes, P < .0001). In 87 NCCT/CTA patients, BASIS and ASPECTS agreed in 22 major and 44 minor strokes. BASIS classified 21 patients as having major strokes who were classified as having minor strokes by ASPECTS. The BASIS major/ASPECTS minor stroke group had outcomes similar to those classified as major strokes by both instruments. CONCLUSIONS: The BASIS classification instrument is effective and appears superior to ASPECTS in predicting outcomes in acute ischemic stroke.

Multiple Procedure Payment Reduction currently applies to multiple diagnostic imaging services administered to the same patient during the same day and entails a 50% decrease in the technical component and a 25% decrease in the professional component reimbursement. This might change with time due to further legislation, so it is important to be up-to-date on these health policy developments.

BACKGROUND AND PURPOSE: The durations of acute ischemic stroke patients9 CT or MR perfusion scans may be too short to fully sample the passage of the injected contrast agent through the brain. We tested the potential magnitude of hidden errors related to the truncation of data by short perfusion scans. MATERIALS AND METHODS: Fifty-seven patients with acute ischemic stroke underwent perfusion MR imaging within 12 hours of symptom onset, using a relatively long scan duration (110 seconds). Shorter scan durations (39.5–108.5 seconds) were simulated by progressively deleting the last-acquired images. CBV, CBF, MTT, and time to response function maximum (Tmax) were measured within DWI-identified acute infarcts, with commonly used postprocessing algorithms. All measurements except Tmax were normalized by dividing by the contralateral hemisphere values. The effects of the scan duration on these hemodynamic measurements and on the volumes of lesions with Tmax of >6 seconds were tested using regression. RESULTS: Decreasing scan duration from 110 seconds to 40 seconds falsely reduced perfusion estimates by 47.6%–64.2% of normal for CBV, 1.96%–4.10% for CBF, 133%–205% for MTT, and 6.2–8.0 seconds for Tmax, depending on the postprocessing method. This truncation falsely reduced estimated Tmax lesion volume by 71.5 or 93.8 mL, depending on the deconvolution method. “Lesion reversal” (ie, change from above-normal to apparently normal, or from >6 seconds to ≤6 seconds for the time to response function maximum) with increasing truncation occurred in 37%–46% of lesions for CBV, 2%–4% for CBF, 28%–54% for MTT, and 42%–44% for Tmax, depending on the postprocessing method. CONCLUSIONS: Hidden truncation-related errors in perfusion images may be large enough to alter patient management or affect outcomes of clinical trials.

Purpose: Final ASPECTS has been shown to predict patient outcomes after endovascular therapy in stroke. The goal of this study was to compare sequential ASPECTS imaging pre-treatment and post-treatment in predicting outcome. Methods: The PICS Study is a prospective registry of clinical and imaging data in proximal artery occlusion patients treated with the Penumbra System. In multivariate analysis, variables assessed for relationship to 90 day mRS included age, gender, time to reperfusion, occlusion location, ASPECTS, and NIHSS. ASPECTS scores were assessed by a central core laboratory, blinded except for stroke side. Results: In this study, 141 patients with mean age 67.9 ± 15.6 and median admission NIHSS score 16.0 (IQR 12.0-21.0) met study criteria. Univariate predictors of 90 day mRS included age, baseline NIHSS, 7 day/discharge NIHSS as well as post-treatment ASPECTS. After adjusting for age and baseline NIHSS, post procedure ASPECTS showed a stronger relationship with good outcome (p Conclusion: Sequential and post procedure ASPECTS are better predictors of clinical outcome following endovascular therapy than pre-ASPECTS. Final infarct volume quantified using ASPECTS serves as a surrogate biomarker for long-term functional outcome.

Purpose: To identify MR spectroscopic changes in the rat hippocampus following proton radiosurgery. Methods and Materials: A group of 12 rats were treated with Bragg peak proton beam irradiation involving the right hippocampus. Single doses of 30 CGE, 50 CGE, 70 CGE, 90 CGE were delivered to groups of 3 animals using single fraction technique. Animals were imaged using a standard 3 T GE Signa MRI at 4 months following treatment. An untreated animal was also studied. A 3″ surface coil was employed to obtain T1 weighted coronal pre- and post-gadolinium images (TR 600 and TE 30) and dual echo T2 weighted coronal images (TR 3000, TE 30/90). Volumetric analysis with custom software was done to evaluate areas of increased signal on T2 weighted images and the development of hydrocephalus was examined. Animals were sacrificed and specimens of the treated hippocampus were harvested for High Resolution Magic Angle Spinning MR Spectroscopy (HRMAS) followed by histopathology of the tissue samples. Peak values of choline, creatine, N-acetyl aspartate and lipids were evaluated and compared. Results: Peak tissue injury occurred in the surviving 90 CGE animal by both T2 weighted and post-gadolinium imaging. Gadolinium enhancement was seen in decreasing volumes of tissue at dosage levels from 90 to 50 CGE. Hydrocephalus was seen on the untreated side in the 90 CGE animal likely because of mass effect, while it was seen in small degrees in the side of treatment in the 70 and 50 CGE animals. Histopathology showed changes at 90 and 70 CGE, but not at 50 or 30 CGE at this time point using H and E stains. HRMAS showed spectroscopic changes in the surviving 90 and 70 CGE animals but not in the 50 and 30 CGE animals. Statistical significance was not reached because of the small sample size. Conclusions: Following single dose proton radiosurgery of rat hippocampus, HRMAS is able to identify metabolic changes induced by radiation. Studies built on these principles may help develop non-invasive MR spectroscopic methods to distinguish radiation changes from tumor recurrence.

Background: Patients with a newly detected brain mass and no history of cancer often undergo extensive diagnostic testing in search of a systemic primary neoplasm prior to selection of a biopsy site, potentially leading to unnecessary expense and delay. We sought patterns in the evaluation of these patients to allow rapid selection of a biopsy site. Methods: We compared the diagnostic evaluation of 176 patients with newly detected brain masses who were ultimately determined to have a metastatic or primary lesion. Results: In 88 patients presenting with brain metastasis, lung cancer was markedly overrepresented as a primary tumor, occurring in 82% of patients. Brain MRI and chest CT together identified the site for diagnostic biopsy in all except for two of the 176 patients. One-half of the patients with metastasis had brain biopsy as the primary diagnostic procedure, with 80% undergoing a craniotomy rather than needle biopsy. The initial management decision in the majority of metastasis patients was whether to perform a craniotomy for resection of tumor. Whereas patients with single and cerebellar lesions were most likely to undergo craniotomy, the extent of systemic disease did not affect the decision to recommend a neurosurgical procedure. The average time to biopsy for patients with metastatic and primary tumors was 4.7 days and 6.0 days. In this retrospective population, we estimated that evaluation with brain MRI and chest CT, followed by an early neurosurgical decision, could reduce the time to diagnosis by at least 10%. Conclusions: Chest CT and brain MRI, if used together as initial diagnostic studies, would have identified a biopsy site in 97% of patients with a newly detected brain mass.

The aims of this study were to assess the effects of a μ-opioid antagonist, naloxone, on endogenous opioid systems and to evaluate the effect of naloxone on the CNS response to mild noxious heat. Doubled-blinded experiments were performed in a cross-over design in 10 healthy male volunteers. Functional magnetic resonance imaging (fMRI) data were collected before and during the infusion and also during thermal stimuli. Increased signal was observed in a number of cortical and subcortical brain regions for naloxone versus saline infusion. Cortical activation was induced in regions including cingulate, prefrontal cortex, and insula. Subcortical regions showing increased signal change included hippocampus and entorhinal cortex. A 46°C stimulus delivered to the back of the hand induced an overall increase in activation in a number of regions in the naloxone group that were not seen in the saline group (e.g., insula, orbitofrontal cortex, thalamus, and hippocampus). These results show that naloxone, even in the absence of psychophysical effects, produces activation in several brain regions that are known to have high levels of μ-opioid receptors and may be involved in endogenous analgesia. Our study is an example of how fMRI can measure subtle changes in brain activation induced by pharmacological agents without cognitive effects.

Introduction/purpose We present a consecutive retrospective cohort of patients treated at an academic stroke center for acute ischemic stroke from large vessel occlusion of the vertebrobasilar circulation. We describe prognostic factors and outcomes for patients receiving medical and/or intra-arterial therapy (IAT) over a 12 year period. Materials and methods We treated 87 patients (medical therapy N = 44 and IAT = 43) between 2004–2015 for acute posterior circulation infarct with vertebrobasilar occlusion at our institution. Patients were dichotomized by modified Rankin Score (mRS) to good outcome defined as mRS 0–2 or poor outcome defined as mRS 3–6. Multiple characteristics were compared including age, gender, NIHSS, infarct volume, posterior ASPECTS, thrombus location, hconversion and treatment modality (medical therapy or IAT). Categorical variables were compared using Chi-square statistic, and continuous variables were compared using t-test and Mann-Whitney statistics. The study was conducted with IRB approval. Results Major etiologies of acute basilar occlusion included atrial fibrillation, PFO, vertebral artery dissection with distal embolus, and intracranial atherosclerosis (ICAD). Poor outcomes were associated with higher NIHSS, lower ASPECTS and extensive brainstem involvement on DWI. IAT patients presented with more severe deficit (NIHSS 21) compared to patients treated medically (NIHSS 14). Rates of good outcomes (mRS 0–2) were equivalent between the IAT (21/43, 49%) and medically treated cohort (21/44, 48%). When ICAD patients were excluded from analysis, results were similar with 50% of the IAT patients (18/36) and 43% of medically treated patients (15/35) having a good outcome. This time period spans major changes in endovascular techniques ranging from urokinase and wire manipulation to current devices. ADAPT or stentrievers were only uin ten cases. Conclusion Compared to medical trials in 2015, which demonstrate clinical benefit for IAT over medical therapy for acute ischemic stroke of the anterior circulation, the posterior circulation is less well studied. Important prognostic factors for stroke due to large vessel occlusion of posterior circulation include posterior ASPECTS score and infarct volume in the brainstem. In this small retrospective study, patients treated with IAT had greater stroke severity than the medical cohort, yet they had similar rates of good functional outcome. Parameters of this retrospective analysis may be used to improve triage and treatment of patients with acute vertebrobasilar occlusion for thrombectomy using current technology. References 1 Singer OC, Berkefeld L, Nolte CH, et al . Mechanical recanalization in basilar artery occlusion: The ENDOSTROKE Study. Ann Neurol 2015 Mar; 77 (3):415–24. 2 Strbian D, Sairanen T, Silvennoinen H, et al . Thrombolysis of basilar artery occlusion: impact of baseline ischemia and time. Ann Neurol 2013 Jun; 73 (6):688–94 Disclosures S. Raymond: None. T. Leslie-Mazwi: None. N. Rost: None. P. Schaefer: None. J. Hirsch: 2; C; Medtronic. R. Gonzalez: None. J. Rabinov: None.

The purpose of our study was to demonstrate the feasibility of using in vivo proton Magnetic Resonance Spectroscopy (MRS) to monitor the brain manifestations of SIV infection in the macaque model of AIDS. Previous spectroscopy work on macaque brain tissue and in vivo work in humans is reviewed to provide the motivation and context for this study. We collected 34 MRS data sets on 14 uninfected rhesus macaques. From this data, we demonstrate that we are capable of detecting changes similar to those observed in human MRS studies for most metabolites using less than 10 animals. The juvenile macaques utilized in this study demonstrate age-related changes in the levels of N-acetyl aspartate (NAA), a neuronal marker. The quantity and distribution of neurochemicals in the macaque are found to be slightly, but significantly, different than in the human.

The goal of this study was to identify and describe the different types and patterns of tissue injury which are encountered by diffusion-weighted imaging (DWI) in diffuse axonal injury (DAI) of the brain. The DWI data sets of 98 patients who suffered from a closed-head injury were retrospectively evaluated. Medical records were reviewed to rule out pre-existing neurological diseases. Lesions were studied for their DWI signal characteristics and lesion size or extension. Traumatic lesions were classified into three categories depending on their signal characteristica on DWI and apparent diffusion coefficient (ADC) maps: type 1, DWI- and ADC-hyperintense most likely representing lesions with vasogenic edema; type 2, DWI-hyperintense, ADC-hypointense indicating cytotoxic edema; type 3, central hemorrhagic lesion surrounded by an area of increased diffusion. According to the size and extent of lesions, injury was classified into three groups: group A, focal injury; group B, regional/confluent injury; and group C, extensive/diffuse injury. Our study showed that diffusion-weighted imaging differentiates between lesions with decreased and increased diffusion in patients with DAI. Different degrees of tissue injury extent were noticed. Future prospective studies should study if this additional information can be used as a predictor of injury reversibility, final outcome and prognosis.

As ∼40% of HIV-infected individuals experience neurocognitive decline, we investigated whether proton magnetic resonance spectroscopic imaging ((1) H-MRSI) detects early metabolic abnormalities in the cerebral cortex of a simian immunodeficiency virus (SIV)-infected rhesus monkey model of neuroAIDS.The brains of five rhesus monkeys before and 4 or 6 weeks after SIV infection (with CD8(+) T-cell depletion) were assessed with T2 -weighted quantitative magnetic resonance imaging (MRI) and 16×16×4 multivoxel (1) H-MRSI (echo time/repetition time = 33/1440 ms). Grey matter and white matter masks were segmented from the animal MRIs and used to produce cortical masks co-registered to (1) H-MRSI data to yield cortical metabolite concentrations of the glial markers myo-inositol (mI), creatine (Cr) and choline (Cho), and of the neuronal marker N-acetylaspartate (NAA). The cortex volume within the large, 28 cm(3) (∼35% of total monkey brain) volume of interest was also calculated for each animal pre- and post-infection. Mean metabolite concentrations and cortex volumes were compared pre- and post-infection using paired sample t-tests.The mean (± standard deviation) pre-infection concentrations of the glial markers mI, Cr and Cho were 5.8 ± 0.9, 7.2 ± 0.4 and 0.9 ± 0.1 mM, respectively; these concentrations increased 28% (p ≈ 0.06), 15% and 10% (both p 0.05), respectively, post-infection. The mean concentration of neuronal marker NAA remained unchanged (7.0 ± 0.6 mM pre-infection vs. 7.3 ± 0.8 mM post-infection; p ≈ 0.37). The mean cortex volume was also unchanged (8.1 ± 1.1 cm(3) pre-infection vs. 8.3 ± 0.5 cm(3) post-infection; p ≈ 0.76).These results support the hypothesis that early cortical glial activation occurs after SIV infection prior to the onset of neurodegeneration. This suggests HIV therapeutic interventions should potentially target early glial activation in the cerebral cortex.

Introduction: The knowledge of the outcome in patients with multiple intra-cranial aneurysms is crucial in the management of these patients. We compared the outcome between patients with single aneurysm and those with multiple aneurysms in a large single referral center. Hypothesis: We assessed the hypothesis that the risk of rupture and mortality is higher in patients with multiple aneurysms compared to patients with a single aneurysm. Methods: In an IRB-approved study, we evaluated 32.100 head CT angiogram examination reports, (from Dec-2001 to Aug-2010) 2.624 patients had n intracranial aneurysm. Patients were classified into a single aneurysm (SA) or a multiple aneurysms (MA)group. The rupture and mortality rate was calculated per total number of patients and aneurysm for each group. Statistical analysis was performed with Student's t-test and chi-square. Results: There was a significant differences in the occurrence of SAH (SA: 22.7% vs. MA: 11%), IVH (SA: 16.4% vs. MA: 6.9%) and IPH (SA: 7.3% vs. MA: 2.1%) when the comparison was made based on aneurysm occurrence. (p0.05). Conclusion: Patients with SA have as individuals a higher incidence of rupture than patients with MA. When rupture rate per aneurysm was calculated, again the SA (0.28) had a higher rate than MA (0.12) in this population. Prospective studies in patients with multiple aneurysms should be initiated.

To determine the probability that regions of decreased apparent diffusion coefficient (ADC) return to normal without persistent symptoms or T2 change and the settings in which these ADC reversals occur.Three hundred magnetic resonance (MR) imaging studies were selected at random from a database of 7,147 examinations to determine the probability of a pathologically decreased ADC. In cases with decreased ADC, the clinical history was recorded and, if available, follow-up MR imaging findings were evaluated. Five cases of ADC reversal became known during the same period and were evaluated to determine the initial ADC decrease, clinical outcome, and findings at follow-up imaging.Findings in 116 of 300 MR imaging studies revealed regions of decreased ADC. In 49 of 116 studies, follow-up MR imaging examinations were performed at least 4 weeks after the onset of symptoms; ADC did not reverse. Five cases of ADC reversal were identified in the same period, giving an estimated 0.2%-0.4% probability of ADC reversal. Clinical settings were venous sinus thrombosis and seizure (n = 3), hemiplegic migraine (n = 1), and hyperacute arterial infarction (n = 1). Both white matter (n = 3) and gray matter (n = 3) regions were involved.Reversal of ADC lesions is rare, occurs in complicated clinical settings, and can involve white or gray matter.

Background and Purpose — The goal of this study was to evaluate the utility of perfusion-weighted CT (PWCT) in predicting final infarct volume and clinical outcome in patients with acute middle cerebral artery (MCA) stroke. Methods — Twenty-two consecutive patients with MCA stem occlusion who underwent intra-arterial thrombolysis within 6 hours of stroke onset had noncontrast CT and CT angiography with whole-brain PWCT imaging before treatment. Infarct volumes were computed from the initial PWCT and follow-up scans; clinical outcome was measured with the modified Rankin scale. Results — Initial PWCT lesion volumes correlated significantly with final infarct volume ( P =0.0002) and clinical outcome ( P =0.01). For the 10 patients with complete recanalization, the relationship between initial and final lesion volume was especially strong ( R 2 =0.94, P R 2 =0.50, P =0.01, slope of regression line=1.61). All patients with either initial PWCT lesion volumes >100 mL or no recanalization had poor outcomes (Rankin scores, 4 to 6). Mean admission NIH Stroke Scale scores and mean lesion volumes in the poor outcome group were significantly different compared with the good or fair outcome (Rankin scores, 0 to 3) group (21±4 versus 17±5, P =0.05, and 106±79 versus 29±37 mL, P =0.01). Patients with initial volumes Conclusions — Lesion volumes on admission PWCT images approximate final infarct volume for patients with early complete recanalization of MCA stem occlusion. For those without complete recanalization, there is subsequent enlargement of lesion volume on follow-up. Initial PWCT lesion volumes also have predictive value; volumes >100 mL are associated with a poor clinical outcome. In these highly selected patients, initial PWCT lesion volume was a stronger predictor of clinical outcome than was initial NIH Stroke Scale score.

We used functional magnetic resonance imaging (fMRI) to determine whether similar brain regions activate during noxious hot and cold stimulation. Six male subjects underwent whole brain fMRI during phasic delivery of noxious hot (46 degrees C) and noxious cold (5 degrees C) stimulation to the dorsum of the left hand. Mid-brain regions activated included thalamus, basal ganglia and insula. Cortical areas activated included cingulate, somatosensory, premotor and motor cortices, as well as prefrontal and inferior parietal cortex. Most regions activated bilaterally but with stronger activation contralateral to the stimulus. Noxious cold stimulation produced significantly increased volumes of activation compared to noxious heat in prefrontal areas only. Our results suggest a similar network of regions activate common to the perception of pain produced by either noxious hot or cold stimulation.

To assess the use of nonstandard, variable window width and level review settings in computed tomography (CT) without contrast material administration in the detection of acute stroke.Nonenhanced CT was performed in 21 patients with acute (6 hours) middle cerebral arterial stroke and nine control patients. Two blinded neuroradiologists rated all scans for presence of parenchymal hypoattenuation. Images were reviewed at a picture archiving and communication system (PACS) workstation, with standard, locally determined center level and window width settings of 20 and 80 HU and with variable soft-copy settings initially centered at a level of 32 HU with a width of 8 HU. Reviewers altered settings to accentuate gray and white matter contrast.With standard viewing parameters, sensitivity and specificity for stroke detection were 57% and 100%. Sensitivity increased to 71% with variable window width and center level settings, without loss of specificity. Receiver operating characteristic analysis revealed a significant improvement in accuracy with nonstandard, soft-copy review settings (P = .03, one-tailed z test).In nonehanced CT of the head, detection of ischemic brain parenchyma is facilitated by soft-copy review with variable window width and center level settings to accentuate the contrast between normal and edematous tissue.

To (a) determine the optimal choice of a scalar metric of anisotropy and (b) determine by means of magnetic resonance imaging if changes in diffusion anisotropy occurred in acute human ischemic stroke.The full diffusion tensor over the entire brain was measured. To optimize the choice of a scalar anisotropy metric, the performances of scalar indices in simulated models and in a healthy volunteer were analyzed. The anisotropy, trace apparent diffusion coefficient (ADC), and eigenvalues of the diffusion tensor in lesions and contralateral normal brain were compared in 50 patients with stroke.Changes in anisotropy in patients were quantified by using fractional anisotropy because it provided the best performance in terms of contrast-to-noise ratio as a function of signal-to-noise ratio in simulations. The anisotropy of ischemic white matter decreased (P = .01). Changes in anisotropy in ischemic gray matter were not significant (P = .63). The trace ADC decreased for ischemic gray matter and white matter (P.001). The first and second eigenvalues decreased in both ischemic gray and ischemic white matter (P.001). The third eigenvalue decreased in ischemic gray (P = .001) and white matter (P = .03).Gray matter is mildly anisotropic in normal and early ischemic states. However, early white matter ischemia is associated with not only changes in trace ADC values but also significant changes in the anisotropy, or shape, of the water self-diffusion tensor.

A novel method of chemical shift imaging utilizing echoplanar imaging (EPI) has been developed for the purpose of improving the spatial resolution of metabolite images for the specific goal of high spatial resolution mapping of neuronal content. An EPI sequence was modified to allow temporal offsets of the 180 degree refocusing pulse that encode the chemical shift information into the phase of the signal. Implementation of this method on 1.5 and 3 T human imagers has resulted in images of N-acetyl aspartate in humans with spatial resolution of 360 microl and signal-to-noise ratio approximately 7:1 in less than 13 min.

To evaluate the diagnostic accuracy of diffusion-weighted magnetic resonance (MR) imaging performed within 6 hours of the onset of stroke symptoms.The authors reviewed the patient records and images from all patients hospitalized in a 10-month period in whom diffusion-weighted imaging was performed within 6 hours of the onset of strokelike symptoms (n = 22). Analyses included comparison of the initial interpretation of the diffusion-weighted images with the final clinical diagnosis; blinded reviews of computed tomographic (CT) scans and conventional and diffusion-weighted images; and determination of lesion contrast-to-noise ratios (CNRs).Diffusion-weighted images indicated stroke in 14 patients, all of whom had a final diagnosis of acute stroke. Diffusion-weighted images were negative in eight patients, all of whom had a final clinical diagnosis other than stroke (100% sensitivity, 100% specificity, chi 2 = 23.00, P.0001). Blinded reviews yielded 100% sensitivity and 86% specificity for diffusion-weighted MR imaging (chi 2 = 15.43, P.0005); 18% sensitivity and 100% specificity for conventional MR imaging (chi 2 = 2.85, P.2); and 45% sensitivity and 100% specificity for CT (chi 2 = 4.40, P.10). Lesion percentage CNRs were 77% for diffusion-weighted imaging, 5.5% for CT, 9.8% for T2-weighted MR imaging, and 3.1% for proton-density-weighted MR imaging (P.002 for diffusion-weighted imaging vs others).Diffusion-weighted MR imaging is highly accurate for diagnosing stroke within 6 hours of symptom onset and is superior to CT and conventional MR imaging.

The effective treatment of major strokes due to major cerebral artery occlusion is a great opportunity for diagnostic and interventional neuroradiology. These represent approximately one-third of all strokes and result in the most deaths and poor outcomes. The relevant physiology (occlusion site

Background and Purpose —We sought to characterize the evolution of acute ischemic stroke by MRI and its relationship to patients’ neurological outcome. Methods —Fourteen patients with acute ischemic stroke underwent MRI within 13 hours of symptom onset (mean, 7.4±3 hours) and underwent repeated imaging and concurrent neurological examination at 8, 24, 36, and 48 hours and 7 days and >42 days after first imaging. Results —Diffusion-weighted imaging (DWI) lesion volumes increased between the first and second scans in 10 of 14 patients; scans with maximum DWI lesion volume occurred at a mean of 70.4 hours. Initial DWI lesion volume correlated with the largest T2 lesion volume ( r =0.97; P r =0.67; P =0.01) and maximum T2 lesion volume ( r =0.77; P r =−0.64; P P Conclusions —Serial MRI demonstrates the dynamic nature of progressive ischemic injury in acute stroke patients developing over hours to days, and it suggests that both primary and secondary pathophysiological processes can be valuable targets for neuroprotective interventions.

We report the results of a study of human breast ductal carcinomas, conducted by using high resolution magic angle spinning proton magnetic resonance spectroscopy (HRMAS 1HMRS). This recently developed spectroscopic technique can measure tissue metabolism from intact pathological specimens and identify tissue biochemical changes, which closely correspond to tumor in vivo state. This procedure objectively indicates diagnostic parameters, independent of the skill and experience of the investigator, and has the potential to reduce the sampling errors inherently associated with procedures of conventional histopathology. In this study, we measured 19 cases of female ductal carcinomas. Our results demonstrate that: (1) highly resolved spectra of intact specimens of human breast ductal carcinomas can be obtained; (2) carcinoma-free tissues and carcinomas are distinguishable by alterations in the intensities and the spin-spin relaxation time T2 of cellular metabolites; and (3) tumor metabolic markers, such as phosphocholine, lactate, and lipids, may correlate with the histopathological grade determined from evaluation of the adjacent specimen. Our results suggest that biochemical markers thus measured may function as a valuable adjunct to histopathology to improve the accuracy of and reduce the time frame required for the diagnosis of human breast cancer.

We compared the sensitivity of diffusion MRI to T2SI for early detection of Wallerian degeneration secondary to cerebral infarction. Serial full tensor DWI of 15 acute stroke patients with B=1221. ROI analysis of ADC, T2, DWI, eigenvalues, and anisotropy indices in bilateral intracerebral corticospinal tracts. 5/16 patients developed DWI hyperintensity and/or ADC/FA reduction, prior to T2 prolongation, during initial two weeks in ipsilateral corticospinal tracts. Mean FA and ADC reductions were 12% and 24% respectively. All were subsequently confirmed to be Wallerian degeneration on follow up MRI.Another 6/15 patients without observable DWI signal changes demonstrated ipsilateral ADC and FA reductions at one or more levels in CS tracts without subsequent demonstration of Wallerian. Antegrade thalamic transneuronal degeneration was noted in 2/15. Changes in diffusion parameters precede T2 signal abnormalities in the evolution of Wallerian degeneration.

We studied a patient after amputation of an arm and found that in less than 24 h stimuli applied on the ipsilateral face were referred in a precise, topographically organized, modality-specific manner to distinct points on the phantom. Functional magnetic resonance imaging (fMRI) performed one month later showed that brush-evoked activity in the brain demonstrates objective signal changes which correlate with perceptual changes in the phantom hand. This finding in humans corresponds to the observations of immediate plasticity in cortical pathways described in animals, including primates. The results suggest that reorganization of sensory pathways occurs very soon after amputation in humans, potentially due to the unmasking of ordinarily silent inputs rather than sprouting of new axon terminals.

Focal areas of restricted diffusion adjacent to high-grade glioma resection cavities were detected in 70% of patients on immediate postoperative MRI studies. Follow-up studies demonstrated cystic encephalomalacia in 91% of these foci, suggesting the presence of infarction, and the infarcted tissue demonstrated enhancement in 43% of cases. New postoperative deficits correlated well with the anatomic region of infarction in six patients. Enhancement in perioperative infarcts can mimic tumor progression on follow-up imaging studies.