MR perfusion characteristics of pseudoprogression in brain tumors treated with immunotherapy - a comparative study with chemo-radiation induced pseudoprogression and radiation necrosis.

Purpose: Pseudoprogression is an atypical imaging pattern of response to immunotherapy in patients with brain tumors. MR perfusion studies in this field are limited. The purpose of our study is to compare the perfusion features between pseudoprogression lesions in malignant gliomas and brain metastases treated with immunotherapy (iPsP) and the pseudoprogression after chemo-radiation therapy and radiation necrosis after radiation treatment (ChR-PsP & RN).

A comprehensive neuroimaging review of the primary and metastatic brain tumors treated with immunotherapy: current status, and the application of advanced imaging approaches and artificial intelligence.

Cancer immunotherapy has emerged as a novel clinical therapeutic option for a variety of solid tumors over the past decades. The application of immunotherapy in primary and metastatic brain tumors continues to grow despite limitations due to the physiological characteristics of the immune system within the central nervous system (CNS) and distinct pathological barriers of malignant brain tumors. The post-immunotherapy treatment imaging is more complex.

Non-classical monocyte levels correlate negatively with HIV-associated cerebral small vessel disease and cognitive performance.

Background: Despite antiretroviral treatment (cART), aging people living with HIV (PWH) are more susceptible to neurocognitive impairment (NCI) probably due to synergistic/additive contribution of traditional cerebrovascular risk factors. Specifically, transmigration of inflammatory CD16+ monocytes through the altered blood brain barrier (BBB) may exacerbate cerebral small vessel disease (CSVD), a known cause of vascular cognitive impairment.

Methods: PWH on cART (n=108) and age, sex, and Reynold's cardiovascular risk score-matched uninfected individuals (PWoH, n=111) were enrolled.

Gadolinium during human pregnancy following administration of gadolinium chelate before pregnancy.

Gadolinium (Gd), a toxic rare earth element, has been shown to dissociate from chelating agents and bioaccumulate within tissues, raising concerns about the possibility of their remobilization during pregnancy with subsequent free Gd exposures to developing fetuses. Gd chelates are among the most commonly used magnetic resonance imaging (MRI) contrast agents. This investigation was undertaken after the detection of elevated Gd (800-1000× higher than the usual rare earth element levels) in preliminary unpublished studies from the placentae of subjects in the NIH ECHO/UPSIDE Rochester Cohort Study and unpublished studies from placentae analyzed in formalin-fixed placental specimens from Surgical Pathology at the University of Rochester.

A case of spontaneous basal ganglia hemorrhage with contralateral extension utilizing the canal of Gratiolet.

Background: Intracranial hemorrhage accounts for 10-20% of stroke etiologies annually. Basal ganglia is the most common site for intracranial hemorrhage accounting for 50% of all cases. Bilateral spontaneous basal ganglia hemorrhages (BGH) are rare with few reported cases.

Role of non-classical monocytes in HIV-associated vascular cognitive impairment.

Despite antiretroviral treatment (cART), people living with HIV (PLWH) are more susceptible to neurocognitive impairment (NCI), probably due to synergistic/additive contribution of traditional cerebrovascular risk factors. Specifically, altered blood brain barrier (BBB) and transmigration of inflammatory monocytes are risk factors for developing cerebral small vessel disease (CSVD). In order to investigate if inflammatory monocytes exacerbate CSVD and cognitive impairment, 110 PLWH on cART and 110 age-, sex- and Reynold’s cardiovascular risk score-matched uninfected individuals were enrolled.

Brain lesions disrupting addiction map to a common human brain circuit.

Drug addiction is a public health crisis for which new treatments are urgently needed. In rare cases, regional brain damage can lead to addiction remission. These cases may be used to identify therapeutic targets for neuromodulation.

Increased risk for cerebral small vessel disease is associated with quantitative susceptibility mapping in HIV infected and uninfected individuals.

The aim of this study was to assess, in the context of cerebral small vessel disease (CSVD), whether cardiovascular risk factors and white matter hyperintensities (WMHs) were associated with brain tissue susceptibility as measured by quantitative susceptibility mapping (QSM). Given that CSVD is diagnosed by the presence of lacunar strokes, periventricular and deep WMHs, increased perivascular spaces, and microbleeds, we expected that QSM could capture changes in brain tissue due to underlying CSVD pathology. We compared a cohort of 101 HIV-infected individuals (mean age ± SD = 53.

Pathomechanisms of HIV-Associated Cerebral Small Vessel Disease: A Comprehensive Clinical and Neuroimaging Protocol and Analysis Pipeline.

We provide an in-depth description of a comprehensive clinical, immunological, and neuroimaging study that includes a full image processing pipeline. This approach, although implemented in HIV infected individuals, can be used in the general population to assess cerebrovascular health. In this longitudinal study, we seek to determine the effects of neuroinflammation due to HIV-1 infection on the pathomechanisms of cerebral small vessel disease (CSVD).

The correlation of fractional anisotropy parameters with Ki-67 index, and the clinical implication in grading of non-enhancing gliomas and neuronal-glial tumors.

Purpose: To investigate the correlation between the FA parameters and Ki-67 labeling index, and their diagnostic performance in grading supratentorial non-enhancing gliomas and neuronal-glial tumors (GNGT).

Methods: This institutional review board-approved, Health Insurance Portability and Accountability (HIPAA) compliant retrospective study enrolled 35 patients, including 19 with low grade GNGT and 16 with high grade GNGT. The mean FA, maximal FA and mean maximal FA values derived from diffusion tensor imaging were measured.

Advanced Neuroimaging in the Evaluation of Spinal Cord Tumors and Tumor Mimics: Diffusion Tensor and Perfusion-Weighted Imaging.

Spinal cord tumors are an important component of pathologic diseases involving the spinal cord. Conventional magnetic resonance (MR) imaging only provides anatomical information. MR diffusion tensor imaging (DTI) and MR perfusion-weighted imaging (PWI) may detect microstructure diffusion and hemodynamic changes in these tumors.

Immediate and Sustained Decrease in Smoking Urges After Acute Insular Cortex Damage.

Introduction: Smoking urges are fundamental aspects of nicotine dependence that contribute significantly to drug use and postquit relapse. Recent evidence has indicated that damage to the insular cortex disrupts smoking behaviors and claims to reduce urges associated with nicotine use, although tools that assess urge have yet to be used to validate these findings. We examined the effect of insular versus non-insular damage on urge using a well-accepted urge scale.

Damage to the insula leads to decreased nicotine withdrawal during abstinence.

Background And Aims: Current pharmacotherapies for tobacco dependence are generally well tolerated, but have relatively high rates of relapse. They target primarily the brains' mesocorticolimbic 'reward' pathway. However, recent evidence suggests that the insular cortex, a central cerebral hemispheric region historically overlooked in addiction models, may also play an important role in cognitive and emotional processes that facilitate drug use.

Smoking cessation behaviors three months following acute insular damage from stroke.

Background: Recent evidence suggests that the insular cortex may play an important role in cognitive and emotional processes that facilitate drug use but it is unclear whether changes to the insula would result in sustained abstinence. To better understand the role of the insula in maintaining abstinence, we examined quitting patterns in smokers with acute damage to their insula relative to other regions.

Design: Prospective cohort study with 3month follow-up, beginning June 2013 and ending May 2014.

64-detector CT angiography within 24 hours after carotid endarterectomy and correlation with postoperative stroke.

Object: Carotid endarterectomy (CEA) carries a small but not insignificant risk of stroke/transient ischemic attack (TIA), most frequently observed within 24 hours of surgery, which can lead to the need for urgent vascular imaging in the immediate postoperative period. However, distinguishing expected versus pathological postoperative changes may not be straightforward on imaging studies of the carotid artery early after CEA. The authors aimed to describe routine versus pathological anatomical findings on CTA performed within 24 hours of CEA, and to evaluate associations between these CTA findings and postoperative stroke/TIA.

Subependymal giant cell astrocytoma: diagnosis, screening, and treatment. Recommendations from the International Tuberous Sclerosis Complex Consensus Conference 2012.

Background: Tuberous sclerosis complex is an autosomal dominant disorder predisposing to the development of benign lesions in different body organs, mainly in the brain, kidney, liver, skin, heart, and lung. Subependymal giant cell astrocytomas are characteristic brain tumors that occur in 10% to 20% of tuberous sclerosis complex patients and are almost exclusively related to tuberous sclerosis complex. Subependymal giant cell astrocytomas usually grow slowly, but their progression ultimately leads to the occlusion of the foramen of Monro, with subsequent increased intracranial pressure and hydrocephalus, thus necessitating intervention.

Coup de sabre presenting with worsening diplopia and enophthalmos.

A middle-aged woman with a diagnosis of linear scleroderma and systemic sclerosis presented with an atrophic skin lesion of the forehead extending in the right orbit and progressive diplopia in the right gaze. On exam, she had enophthalmos with a small, manifest esotropia in the right gaze. Orbital MRI revealed fat atrophy of the right upper eyelid and orbit not previously described.

Correlation analysis of quantitative diffusion parameters in ipsilateral cerebral peduncle during Wallerian degeneration with motor function outcome after cerebral ischemic stroke.

Background And Purpose: To evaluate the time periods of Wallerian degeneration (WD) in which the diffusion parameters of ipsilateral corticalspinal tract (CST) can be used to predict the motor function outcome after brain infarction.

Methods: This retrospective study classified 48 diffusion tensor imaging patients with WD along CST into four groups based on the following time points after stroke onset, Group 1: within the first 2 weeks; Group 2: from 3 to 4 weeks; Group 3: from 5 to 14 weeks; Group 4: after 14 weeks. The apparent diffusion coefficient (ADC), fractional anisotropy (FA), and their ratios (=ipsilateral diffusion value/contralateral value) of cerebral peduncle were evaluated.

Correlation of diffusion and perfusion MRI with Ki-67 in high-grade meningiomas.

Objective: Atypical and anaplastic meningiomas have a greater likelihood of recurrence than benign meningiomas. The risk for recurrence is often estimated using the Ki-67 labeling index. The purpose of this study was to determine the correlation between Ki-67 and regional cerebral blood volume (rCBV) and between Ki-67 and apparent diffusion coefficient (ADC) in atypical and anaplastic meningiomas.

Dual-energy CT angiography in the evaluation of intracranial aneurysms: image quality, radiation dose, and comparison with 3D rotational digital subtraction angiography.

Objective: The purpose of this study was to evaluate the image quality, radiation dose, and diagnostic accuracy of dual-energy CT angiography (CTA) compared with 3D rotational digital subtraction angiography (DSA) in the detection of intracranial aneurysms.

Subjects And Methods: Forty-six patients with clinically suspected intracranial aneurysms underwent dual-source dual-energy CTA and 3D DSA. For the analysis of the image quality and radiation dose of dual-energy CTA, 46 patients who underwent digital subtraction CTA were recruited as a control group.

Conspicuity of diffuse axonal injury lesions on diffusion-weighted MR imaging.

Objective: (1) To detect diffuse axonal injury (DAI) lesions by diffusion-weighted imaging (DWI), as compared with fluid-attenuated inversion recovery (FLAIR) imaging and (2) to evaluate hemorrhagic DAI lesions by b0 images obtained from DWI, as compared with gradient-echo (GRE) imaging.

Methods: We reviewed MR images of 36 patients with a diagnosis of DAI. MR imaging was performed 20 h to 14 days (mean, 3.

Secondary degeneration of the substantia nigra and corticospinal tract after hemorrhagic middle cerebral artery infarction: diffusion-weighted MR findings.

Middle cerebral artery (MCA) infarction involving the striatum can cause secondary degeneration of the substantia nigra and corticospinal tract. We present a patient with subacute hemorrhagic MCA infarction in whom diffusion-weighted MR images showed high signal intensity in the ipsilateral substantia nigra and corticospinal tract. A corresponding apparent diffusion coefficient map revealed a uniformly decreased signal in the same area.

Clinically silent choroid plexus cyst: evaluation by diffusion-weighted MRI.

We retrospectively reviewed diffusion-weighted magnetic resonance images of 57 patients with a choroid plexus cyst diagnosed by contrast-enhanced T1-weighted imaging. All the cysts appeared to represent incidental findings. Thirty-eight of 57 patients had bilateral cysts and 19 had unilateral ones.