Author: jross

Jeffrey Ross • Mayo Clinic, Phoenix

Dr. Jeffrey S. Ross is a Professor of Radiology at the Mayo Clinic College of Medicine, and practices neuroradiology at the Mayo Clinic in Phoenix, Arizona. His publications include over 100 peer-reviewed articles, nearly 60 non-refereed articles, 33 book chapters, and 10 books. He was an AJNR Senior Editor from 2006-2015, is a member of the editorial board for 3 other journals, and a manuscript reviewer for 10 journals. He became Editor-in-Chief of the AJNR in July 2015. He received the Gold Medal Award from the ASSR in 2013.

Diagnostic Performance of a 10-Minute Gadolinium-Enhanced Brain MRI Protocol Compared with the Standard Clinical Protocol for Detection of Intracranial Enhancing Lesions

Fellows’ Journal Club

A total of 53 patients underwent MR imaging consisting 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. The 10-minute brain MR imaging protocol with contrast was 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.

Relationship between Glioblastoma Heterogeneity and Survival Time: An MR Imaging Texture Analysis

Editor’s Choice

A group of 133 patients with primary glioblastoma who underwent postcontrast T1-weighted imaging (acquired before treatment) and whose data were filed with the survival times were selected from the Cancer Genome Atlas. On the basis of overall survival, the patients were divided into 2 groups: long-term (≥12 months, n = 67) and short-term (<12 months, n = 66) survival. To measure heterogeneity, the authors extracted 3 types of textures, co-occurrence matrix, run-length matrix, and histogram, reflecting local, regional, and global spatial variations, respectively. Then the support vector machine classification was used to determine how different texture types perform in differentiating the 2 groups. The results suggest that local and regional heterogeneity may play an important role in the survival stratification of patients with glioblastoma.

Journal Scan – This Month in Other Journals, September 2017

McKeith IG, Boeve BF, Dickson DW, et al. Diagnosis and management of dementia with Lewy bodies: Fourth consensus report of the DLB Consortium. Neurology. 2017;65(12):1863-1872. doi:10.1212/WNL.0000000000004058

The Dementia with Lewy Bodies (DLB) Consortium last reported on diagnosis and management in December 2005, and its recommendations have been widely cited for both clinical and research use. The revised DLB criteria which are presented incorporate new developments and result from a review process that combined the reports of 4 multidisciplinary, expert working groups with a meeting that included patient and care partner participation. Dementia, defined as a progressive cognitive decline of sufficient magnitude to interfere with normal social or occupational functions, or with usual daily activities, is an essential requirement for DLB diagnosis. Disproportionate attentional, executive function, and visual processing deficits relative to memory and naming are typical. DLB consciousness fluctuations are typically delirium-like, occurring as spontaneous alterations in cognition, attention, and arousal. They include waxing and waning episodes of behavioral inconsistency, incoherent speech, variable attention, or altered consciousness that involves staring or zoning out.

Recurrent, complex visual hallucinations occur in up to 80% of patients with DLB and are a frequent clinical signpost to diagnosis. They are typically well-formed, featuring people, children, or animals, sometimes accompanied by related phenomena including passage hallucinations (transient visual hallucinations consisting of people or animals that pass sideways out of the visual field), sense of presence, and visual illusions.

Spontaneous parkinsonian features, not due to antidopaminergic medications or stroke, are common in DLB, eventually occurring in over 85%. Parkinsonism in Parkinson disease (PD) is defined as bradykinesia in combination with rest tremor, rigidity, or both. Many DLB patients’ parkinsonism falls short of this, so documentation of only one of these cardinal features is required.

REM sleep behavior disorder is a parasomnia manifested by recurrent …

Functional Connectivity in Virally Suppressed Patients with HIV-Associated Neurocognitive Disorder: A Resting-State Analysis

Fellows’ Journal Club

Eighteen patients with active HIV-associated neurocognitive disorder (recent diagnosis with progressing symptoms) on combination antiretroviral therapy with viral suppression in both blood and CSF and 9 demographically matched control subjects underwent resting-state functional MR imaging. The connectivity in the 6 known neural networks was assessed. There were significant group differences between the control and HIV-associated neurocognitive disorder groups in the salience and executive networks. The authors conclude that active HIV-associated neurocognitive disorder in virally suppressed patients is associated with significantly decreased connectivity in the salience and executive networks, thereby making it potentially useful as a biomarker.

The Impact of Conscious Sedation versus General Anesthesia for Stroke Thrombectomy on the Predictive Value of Collateral Status: A Post Hoc Analysis of the SIESTA Trial

Editor’s Choice

Using imaging data from the Sedation versus Intubation for Endovascular Stroke TreAtment (SIESTA) trial, the authors assessed collateral status with the score of Tan et al and graded it from absent to good collaterals (0–3). They examined the association of collateral status with 24-hour improvement of the NIHSS score, infarct volume, and mRS at 3 months according to the sedation regimen in a cohort of 104 patients. The sedation mode, conscious sedation or general anesthesia, did not influence the predictive value of collaterals in patients with large-vessel occlusion anterior circulation stroke undergoing thrombectomy in the SIESTA trial.

Acute Basilar Artery Occlusion: Differences in Characteristics and Outcomes after Endovascular Therapy between Patients with and without Underlying Severe Atherosclerotic Stenosis

Fellows’ Journal Club

Sixty-two patients with acute basilar artery occlusion underwent multimodal endovascular therapy with stent-retriever thrombectomy as a first-line endovascular therapy. Patients with underlying intracranial atherosclerotic stenosis underwent additional intracranial angioplasty and stent placement. Underlying intracranial atherosclerotic stenosis was identified at the occlusion site in 15 patients (24.1%). Occlusion in the proximal segment of the basilar artery was more common in patients with intracranial atherosclerotic stenosis (60% versus 6.4%), whereas occlusion in the distal segment was more common in those without it. Patients with and without underlying intracranial atherosclerotic stenosis who underwent endovascular therapy had similar outcomes.

Temporal and Spatial Variances in Arterial Spin-Labeling Are Inversely Related to Large-Artery Blood Velocity

Editor’s Choice

The authors performed consecutive pseudocontinuous arterial spin-labeling and phase-contrast MR imaging on 82 individuals (healthy young adults, healthy older adults, and older adults with cerebral small vessel disease or chronic stroke infarcts) and examined associations between extracranial phase-contrast hemodynamics and intracranial arterial spin-labeling characteristics, which were defined by labeling efficiency, temporal signal-to-noise ratio, and spatial coefficient of variation. Large-artery blood velocity was inversely associated with labeling efficiency, temporal SNR, and spatial coefficient of variation of arterial spin-labeling. They conclude that choosing arterial spin-labeling timing parameters with on-line knowledge of blood velocity may improve CBF quantification.

Journal Scan – This Month in Other Journals, August 2017

Charidimou A, Boulouis G, Xiong L, et al. Cortical superficial siderosis and first-ever cerebral hemorrhage in cerebral amyloid angiopathy. Neurology. 2017;88(17):1607-1614. doi:10.1212/WNL.0000000000003866.

Cortical superficial siderosis (cSS) on T2*-GRE or SWI is a strong hemorrhagic signature of cerebral amyloid angiopathy (CAA)—a common small vessel disease characterized by cerebrovascular amyloid deposition affecting superficial cortical microvascular networks, leading to spontaneous lobar intracerebral hemorrhage (ICH). Cortical superficial siderosis results from bleeding episodes within or adjacent to cortical sulci, presumably from amyloid-laden superficial cortical and leptomeningeal arterioles. Cortical superficial siderosis is a common manifestation of cerebral amyloid angiopathy, being found in 40%–60% of patients.

In this study, consecutive patients meeting modified Boston criteria for probable CAA in the absence of ICH from a single-center cohort were analyzed. Cortical superficial siderosis and other small vessel disease MRI markers were assessed according to recent consensus recommendations. Patients were followed prospectively for future incident symptomatic lobar ICH.

The cohort included 236 patients with probable CAA without lobar ICH at baseline. Cortical superficial siderosis prevalence was 34%. During a median follow-up of 3.26 years, 27 of 236 patients (11.4%) experienced a first-ever symptomatic lobar ICH. Cortical superficial siderosis was a predictor of time until first ICH. The risk of symptomatic ICH at 5 years of follow-up was 19% for patients with cortical superficial siderosis at baseline vs 6% for patients without cortical superficial siderosis. In multivariable Cox regression models, cortical superficial siderosis presence was the only independent predictor of increased symptomatic ICH risk during follow-up.

The authors found that cortical superficial siderosis on T2*-GRE/SWI MRI is associated with an increased risk of future first-ever symptomatic lobar ICH. The prognostic value of cSS in this setting was strong and independent of age and other neuroimaging markers of CAA severity, including lobar cerebral microbleed burden and WMH. Hence, cortical superficial …

Volumetric Analysis from a Harmonized Multisite Brain MRI Study of a Single Subject with Multiple Sclerosis

Fellows’ Journal Club

The North American Imaging in Multiple Sclerosis Cooperative steering committee developed a uniform high-resolution 3T MR imaging protocol relevant to the quantification of cerebral lesions and atrophy and implemented it at 7 sites across the United States. They assessed intersite variability in scan data, by imaging a volunteer with relapsing-remitting MS with a scan-rescan at each site. In multicenter studies with consistent scanner field strength and manufacturer after protocol harmonization, systematic differences can lead to severe biases in volumetric analyses.

Differentiation between Treatment-Induced Necrosis and Recurrent Tumors in Patients with Metastatic Brain Tumors: Comparison among 11C-Methionine-PET, FDG-PET, MR Permeability Imaging, and MRI-ADC—Preliminary Results

Editor’s Choice

The authors evaluated the feasibility of MR permeability imaging by comparison with 11C-methionine-PET, FDG-PET, and DWI for differentiating radiation necrosis from recurrent tumors in 15 patients with 18 lesions following gamma knife radiosurgery. The area under the ROC curve for differentiating radiation necrosis from recurrent tumors was the best for the 11C-methionine ratio (0.90) followed by the contrast-enhancement ratio (0.81), maximum slope of increase (millimole/second) (0.80), and the initial area under the signal intensity–time curve (0.78). They conclude that PET using 11C-methionine may be superior to MR permeability imaging, ADC, and FDG-PET for differentiating radiation necrosis from recurrent tumors after gamma knife radiosurgery for metastatic brain tumors.