Author: jross

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.

Quantifying Intracranial Plaque Permeability with Dynamic Contrast-Enhanced MRI: A Pilot Study

Editor’s Choice

The purpose of this study was to use DCE MR imaging to quantify the contrast permeability of intracranial atherosclerotic disease plaques in 10 symptomatic patients and to compare these parameters against existing markers of plaque volatility using black-blood MR imaging pulse sequences. Ktrans and fractional plasma volume (Vp) measurements were higher in plaques versus healthy white matter and similar or less than values in the choroid plexus. Only Ktrans correlated significantly with time from symptom onset. Dynamic contrast-enhanced MR imaging parameters were not found to correlate significantly with intraplaque enhancement or hyperintensity. The authors suggest that Ktrans may be an independent imaging biomarker of acute and symptom-associated pathologic changes in intracranial atherosclerotic disease plaques.

Journal Scan – This Month in Other Journals, February 2017

Domino JS, Baek J, Meurer WJ, et al. Emerging temporal trends in tissue plasminogen activator use. Neurology. 2016;87(21):2184-2191. doi:10.1212/WNL.0000000000003349.

Mexican Americans (MA) have an increased stroke burden when compared to their non-Hispanic white (NHW) counterparts, including increased stroke incidence and poorer neurologic, functional, and cognitive outcomes.

The authors explored the temporal trends in tissue plasminogen activator (tPA) administration for acute ischemic stroke (AIS) in a biethnic community without an academic medical center. Cases of AIS were identified from 7 hospitals in the Brain Attack Surveillance in Corpus Christi (BASIC) project, a population-based surveillance study from 2000-2012. There were 5,277 AIS cases identified from 4,589 individuals. tPA use was steady at 2% and began increasing in 2006, reaching 11% in subsequent years. Although ethnicity did not modify the temporal trend, Mexican Americans were less likely to receive tPA than non- Hispanic whites due to emerging ethnic differences in later years. The results suggest that increases in tPA use were greater in higher severity patients compared to lower severity patients, and a gap between MAs and NHWs in tPA administration may be emerging.  The authors conclude that as physician experience with tPA and its use in community settings increases, follow-up studies should continue to explore temporal trends in tPA as well as identify possible strategies to improve tPA use in MAs.

2 Figures (graphs), 2 Tables

Goldstein LB. IV tPA for acute ischemic stroke. Neurology. 2016;87(21):2178-2179. doi:10.1212/WNL.0000000000003366.

In this editorial on the Domino et al. paper, Dr. Goldstein notes that there were considerable barriers that slowed IV tPA adoption after it was approved by the FDA in 1996.  Eight years after FDA approval, IV tPA was being given to only 1%–2% of stroke patients. Transformation of the structure and organization of stroke care delivery were needed, and in part led …

White Matter Injury and General Movements in High-Risk Preterm Infants

Fellows’ Journal Club

Cerebral palsy has been predicted by analysis of spontaneous movements in the infant termed “General Movement Assessment.” The authors evaluated the utility of General Movement Assessment in predicting adverse cognitive, language, and motor outcomes in very preterm infants and attempted to identify brain imaging markers associated with both adverse outcomes and aberrant general movements in 47 preterm infants using MRI volumetric analysis and DTI. Nine infants had aberrant general movements and were more likely to have adverse neurodevelopmental outcomes, compared with infants with normal movements. In infants with aberrant movements, Tract-Based Spatial Statistics analysis identified significantly lower fractional anisotropy in widespread WM tracts. They conclude that aberrant general movements at 10–15 weeks’ postterm are associated with adverse neurodevelopmental outcomes and specific white matter microstructure abnormalities for cognitive, language, and motor delays.

Abstract

Figure 1 from paper
Differences in white matter at term-equivalent age between infants with normal and aberrant fidgety movements at 10–15 weeks. Mean FA skeleton, in green, is overlaid on the mean FA map. Superimposed are pseudocolored voxels having significantly greater anisotropy in infants with normal than in infants with aberrant fidgety movements. Color bar shows the range of P values represented by the pseudocolors. Significantly higher regions of FA can be observed in the splenium (ccs) and genu (ccg) of the corpus callosum, inferior (ilf) and superior longitudinal fasciculus (slf), fronto-occipital fasciculus (fof), anterior (alic) and posterior (plic) internal capsule, corona radiata (cr), cerebellar peduncles (cp), and fornix/stria terminalis (fx/st). Z represents the MR imaging axial section coordinates (zero is the center of the anterior commissure).

BACKGROUND AND PURPOSE

Very preterm infants (birth weight, <1500 g) are at increased risk of cognitive and motor impairment, including cerebral palsy. These adverse neurodevelopmental outcomes are associated with white matter abnormalities on MR imaging at term-equivalent age. Cerebral palsy has been

Limited Dorsal Myeloschisis and Congenital Dermal Sinus: Comparison of Clinical and MR Imaging Features

Editor’s Choice

These investigators retrospectively reviewed the clinical and MR imaging findings of 12 patients with limited dorsal myeloschisis and 10 patients with congenital dermal sinus. A crater covered with pale epithelium was the most common skin lesion in limited dorsal myeloschisis (83%). Infectious complications were common in congenital dermal sinus (60%), but not found in limited dorsal myeloschisis. They show that limited dorsal myeloschisis has distinct MR imaging features including a visible intrathecal tract with dorsal tenting of the cord at the tract-cord union.

Endovascular Therapy of M2 Occlusion in IMS III: Role of M2 Segment Definition and Location on Clinical and Revascularization Outcomes

Fellows’ Journal Club

The authors reviewed the impact of revascularization on clinical outcomes in 83 patients with M2 occlusions in the Interventional Management of Stroke III trial according to specific M1–M2 segment anatomic features. AnmRS 0–2 outcome was associated with reperfusion for M2 trunk (n = 9) or M2 division (n = 42) occlusions, but not for M2 branch occlusions (n = 28). Of the 83 participants with M2 occlusion who underwent endovascular therapy, 41.0% achieved mRS 0–2 at 90 days, including 46.6% with modified TICI 2–3 reperfusion compared with 26.1% with modified TICI 0–1 reperfusion. They conclude that mRS 0–2 at 90 days was dependent on reperfusion for M2 trunk but not for M2 branch occlusions in IMS III.

Abstract

Figure 1 from paper
A, Right M1 trunk gives rise to the ATA with the posterior temporal branch filling on microcatheter injection. B, Lateral view baseline common carotid arteriogram confirms mid- and posterior temporal lobe cortical supply from the patent posterior temporal artery.

BACKGROUND AND PURPOSE

Uncertainty persists regarding the safety and efficacy of endovascular therapy of M2 occlusions following IV tPA. We reviewed the impact of revascularization on clinical outcomes in 83 patients with M2 occlusions in the Interventional Management of Stroke III trial according to specific M1-M2 segment anatomic features.

MATERIALS AND METHODS

Perfusion of any M2 branch distinguished M2-versus-M1 occlusion. Prespecified modified TICI and arterial occlusive lesion revascularization and clinical mRS 0–2 end points at 90 days for endovascular therapy–treated M2 occlusions were analyzed. Post hoc analyses of the relationship of outcomes to multiple baseline angiographic M2 and M1 subgroup characteristics were performed.

RESULTS

Of 83 participants with M2 occlusion who underwent endovascular therapy, 41.0% achieved mRS 0–2 at 90 days, including 46.6% with modified TICI 2–3 reperfusion compared with 26.1% with modified TICI 0–1 reperfusion (risk

Emergent Endovascular Management of Long-Segment and Flow-Limiting Carotid Artery Dissections in Acute Ischemic Stroke Intervention with Multiple Tandem Stents

Editor’s Choice

The authors investigated the role of emergent endovascular stenting of long-segment carotid dissections in the acute ischemic stroke setting in 15 patients. They specifically evaluated long-segment carotid dissections requiring stent reconstruction with multiple tandem stents (≥ 3 stents) and presenting with acute (<12 hours) ischemic stroke symptoms (NIHSS score, ≥ 4). Carotid stent reconstruction was successful in all patients with no residual stenosis or flow limitation. Nine patients (60%) harbored intracranial occlusions, and 6 patients (40%) required intra-arterial thrombolysis/thrombectomy, achieving 100% TICI 2b–3 reperfusion. They conclude that emergent stent reconstruction of long-segment and flow-limiting carotid dissections in acute ischemic stroke intervention is safe and effective, with favorable clinical outcomes.

Intracranial Arteriovenous Shunting: Detection with Arterial Spin-Labeling and Susceptibility-Weighted Imaging Combined

Fellows’ Journal Club

Ninety-two consecutive patients with a known (n = 24) or suspected arteriovenous shunting (n = 68) underwent DSA and brain MR imaging, including arterial spin-labeling/SWI and conventional angiographic MR imaging. DSA showed arteriovenous shunting in 63 of the 92 patients. Interobserver agreement was excellent. In 5 patients, arterial spin-labeling/SWI correctly detected arteriovenous shunting, while the conventional angiographic MR imaging did not. The authors conclude that the combined use of arterial spin-labeling and SWI may be an alternative to contrast-enhanced MRA for the detection of intracranial arteriovenous shunting.

Abstract

Figure 3 from paper
A 60-year-old patient with a right paracentral AVM. ASL raw data (A) demonstrates a strong hypersignal at the anterior part of the right paracentral region (A, arrow). The slight venous hypersignal related to AVS was initially missed by the blinded readers by using SWI alone (B, arrowhead) but was correctly identified by using ASL and SWI combined (C, ASL/SWI merged image, arrow). Findings of time-resolved 4D contrast-enhanced MRA (D) were considered negative by the blinded readers. DSA reveals a small pial AVM in the right paracentral region (E, arrow).

BACKGROUND AND PURPOSE

Arterial spin-labeling and susceptibility-weighted imaging are 2 MR imaging techniques that do not require gadolinium. The study aimed to assess the accuracy of arterial spin-labeling and SWI combined for detecting intracranial arteriovenous shunting in comparison with conventional MR imaging.

MATERIALS AND METHODS

Ninety-two consecutive patients with a known (n = 24) or suspected arteriovenous shunting (n = 68) underwent digital subtraction angiography and brain MR imaging, including arterial spin-labeling/SWI and conventional angiographic MR imaging (3D TOF, 4D time-resolved, and 3D contrast-enhanced MRA). Arterial spin-labeling/SWI and conventional MR imaging were reviewed separately in a randomized order by 2 blinded radiologists who judged the presence or absence of arteriovenous shunting. The accuracy of arterial spin-labeling/SWI for the detection of

Journal Scan – This Month in Other Journals, January 2017

Akoudad S, Wolters FJ, Viswanathan A, et al. Association of Cerebral Microbleeds With Cognitive Decline and Dementia. JAMA Neurol. 2016;73(8):934. doi:10.1001/jamaneurol.2016.1017.

The authors wanted to determine whether microbleed count and location were associated with an increased risk for cognitive impairment and dementia. They evaluated a prospective population-based study set in the general community, and assessed the presence, number, and location of microbleeds at baseline (August 2005 to December 2011) on brain MRI in 4841 participants 45 years or older. Trained research physicians, blinded to clinical data, reviewed the MRs. Cerebral microbleeds were defined as small, round to ovoid areas of focal signal loss on T2- weighted images. Participants underwent neuropsychological testing at 2 time points approximately 6 years apart, and were also followed up for incident dementia. 3257 participants underwent baseline and follow-up cognitive testing. Microbleed prevalence was 15.3%. The presence of more than 4 microbleeds was associated with cognitive decline. The presence of microbleeds was associated with an increased risk for dementia after adjustment for age, sex, and educational level, including Alzheimer dementia.

The strengths of this study, according to the authors, is the longitudinal population based design with a large sample size, the use of an extensive neuropsychological test battery, and the virtually complete screening for incident dementia. Limitations include multiple statistical tests, increasing the chance of type I errors. Second, selection bias may have influenced the results, because healthier people without subjective memory complaints were more likely to receive follow-up cognitive testing. Most importantly perhaps, the microbleed number may not reflect the true biological number because microbleed detection strongly depends on technical imaging methods used. T2W images were used, and as we know, SWI is far superior for the detection of these lesions.

4 Tables

Manoso MW, Moore TA, Agel J, Bellabarba C, Bransford RJ. Floating

CT and MR Imaging in the Diagnosis of Scleritis

Fellows’ Journal Club

Scleritis is a rare vision-threatening condition that can occur isolated or in association with other orbital abnormalities and whose etiology is typically inflammatory/noninfectious, either idiopathic or in the context of systemic disease. The authors analyzed 11 cases of scleritis in which CT and/or MR imaging were performed during the active phase of disease and assessed the diagnostic utility of these techniques. The most important imaging findings of scleritis were scleral enhancement, scleral thickening, and focal periscleral cellulitis. MR imaging is the recommended imaging technique.

Summary

Figure 1 from paper
Asynchronous IOID with scleritis. A, CECT depicts outward, eccentric thickening and enhancement of the right globe wall with focal periscleral cellulitis (black arrow), compatible with posterior scleritis. There is associated pre- and postseptal cellulitis (white arrow) and proptosis. B, CECT 18 months after examination (A) shows almost identical findings in the left orbit. Black and white arrows point to the scleritis and cellulitis, respectively. Notice the complete resolution of the alterations of the right orbit. Also, notice involvement of the tendon of the lateral rectus anteriorly (dashed arrow).

Scleritis is a rare, underdiagnosed vision-threatening condition that can occur isolated or in association with other orbital abnormalities. The etiology of scleritis is mainly inflammatory noninfectious, either idiopathic or in the context of systemic disease. Ultrasonography remains the criterion standard in diagnostic imaging of this condition but might prove insufficient, and studies on the diagnostic value of CT and MR imaging are lacking. We retrospectively analyzed 11 cases of scleritis in which CT and/or MR imaging were performed during the active phase of disease and assessed the diagnostic utility of these techniques. The most important imaging findings of scleritis were scleral enhancement, scleral thickening, and focal periscleral cellulitis. MR imaging is the recommended imaging technique, though posterior scleritis also can be accurately diagnosed on

Metabolic Abnormalities in the Hippocampus of Patients with Schizophrenia: A 3D Multivoxel MR Spectroscopic Imaging Study at 3T

Editor’s Choice

Nineteen patients with schizophrenia and 11 matched healthy controls underwent MR imaging and multivoxel point-resolved 1H-MRS at 3T to obtain their hippocampal gray matter absolute NAA, Cr, and Cho concentrations. Patients’ average hippocampal GM Cr concentrations were 19% higher than those of controls. NAA and Cho showed no differences. The authors conclude that the findings suggest the hippocampal volume deficit in schizophrenia is not due to net loss of neurons, which is in agreement with histopathology studies but not with prior 1H-MR spectroscopy reports. Elevated Cr would be consistent with hippocampal hypermetabolism.