Computed tomography angiography findings predictive of post-intervention vasospasm in patients with aneurysmal subarachnoid hemorrhage.

OBJECTIVE: To evaluate the association of CT/CT angiography (CTA) findings and clinical characteristics with subsequent vasospasm in patients with aneurysmal subarachnoid hemorrhage (aSAH). METHODS-: Consecutive presentation CTA head exams in patients with aSAH between January 2005 and June 2015 were retrospectively evaluated for intracranial arterial calcification, undulation and non-calcified stenosis. Additional variables including modified Fisher Scale (mFS), Glasgow Coma Scale (GCS) and neurological exam status were reviewed. Associations of CTA findings with the incidence of angiographic vasospasm were assessed with multivariate logistic regression models using the least absolute shrinkage and selection operator machine-learning algorithm. Model performance was summarized using c-index with bootstrap optimism-adjustment. RESULTS: Intracranial arterial calcification, seen in 51.7% of 195 total patients, was protective against vasospasm (OR-0.6; 95% CI-0.52-0.67; p = 0.009), while arterial undulation (24%) was associated with subsequent vasospasm (OR-2.6; 95% CI-1.3-5.1; p = 0.007). Non-calcified intracranial arterial stenosis (5%) was associated with subsequent vasospasm, (OR-4.7; 95% CI-1.0-22.8; p = 0.054). Least absolute shrinkage and selection operator selected all three CTA findings as predictors in a multivariate model for vasospasm in addition to clinical factors, which demonstrated superior predictive performance (c-index-0.74; 95% CI-0.69-0.82) compared to a model based on mFS and clinical factors only (c-index-0.66; 95% CI-0.57-0.75; p = 0.010 for the difference). CONCLUSION: Presentation CTA findings combined with clinical factors may better predict the development of vasospasm in patients with aSAH compared to current prognostic models alone. ADVANCES IN KNOWLEDGE: The combination of initial CT/CTA and clinical findings better predict development of vasospasm after aSAH. This can lead to better markers for use in future clinical trials to develop vasospasm preventative treatments and potentially provide better targets for early aggressive treatment.

Comparison of time-of-flight MR angiography and intracranial vessel wall MRI for luminal measurements relative to CT angiography.

OBJECTIVE: To assess whether intracranial vessel wall (IVW) MRI luminal measurements are more accurate than non-contrast 3D-TOF-MRA measurements for intracranial atherosclerotic stenosis, relative to CTA. METHODS: Consecutive patients with non-calcified intracranial atherosclerotic stenosis seen on CTA, who had non-contrast 3D-TOF-MRA and IVW performed between 1 January 2013 and 20 April 2014 were selected, and images with stenosis were pre-selected by a single independent rater. The pre-selected CTA, MRA, and IVW (T1-weighted) images were then reviewed by two independent raters blinded to the other measurements in random order. Measurements were made in a plane perpendicular to the lumen on each modality. MRA and IVW measurements were compared to CTA, to determine which more accurately matched the degree of stenosis. RESULTS: 18 patients with 33 intracranial atherosclerotic stenoses were included. Relative to CTA, IVW had 40% less variance than MRA (p = .004). IVW had a significantly higher concordance correlation coefficient (CCC) relative to CTA than MRA (.87 vs .68, p = .002). IVW and MRA did not have significant bias relative to CTA, however, 8/33 lesions showed >20% overestimation of the degree of stenosis on MRA, compared to 1/33 for IVW. CCC between raters were 0.84 (95% CI 0.67-0.93) for CTA, 0.83 (0.67-0.93) for TOF-MRA, and 0.85 (0.71-0.94) for IVW. For stenosis >50% sensitivity was 82% for IVW and 64% for MRA, while specificity was 73% for both. CONCLUSION: IVW provides more accurate stenosis measurements than MRA when compared to CTA. ADVANCES IN KNOWLEDGE: Considering higher stenosis measurement accuracy of IVW, it can be more reliably used for quantitative evaluation relative to MRA.

Natural History of Blunt Cerebrovascular Injury: Experience Over a 10-year Period at a Level I Trauma Center.

Background Blunt cerebrovascular injury (BCVI) is associated with increased stroke and mortality risk. However, the most appropriate follow-up strategy remains uncertain. Purpose To better understand the natural history of BCVI and help define the most optimal timing and length of follow-up imaging. Materials and Methods In this retrospective HIPAA-compliant study, data from all patients treated for BCVI at a level I trauma center between April 1, 2005, and June 30, 2015, were reviewed. For patients with at least one follow-up study, time-to-event analysis was performed to assess the trend in injury evolution. Association of injury grade and injury evolution was also assessed. The Fisher exact test and multivariable logistic regression were used to evaluate association of the number of injured vessels, vessel grade, and vessel type (internal carotid artery, vertebral artery) with BCVI-associated stroke. Results A total of 1204 patients (800 men; mean age ± standard deviation, 45 years ± 22) with 1604 vessel injuries were evaluated. High-grade (grades 3-5) injuries were less likely to resolve (hazard ratio [HR], 0.2; P < .001) than low-grade injuries. High-grade injuries were more likely to progress than low-grade injuries (HR, 3.3; P = .005). Of the injuries that improved or resolved (343 of 419 [81.9%]), 76% (259 of 343) changed within 30 days after the initial injury, and the remaining 24% (84 of 343) changed between 30 and 90 days. Of the injuries that progressed (46 of 419 [11.0%]), 87% (40 of 46) changed within 90 days. Beyond 90 days, no improvement or resolution occurred, and only 1.4% (six of 419) of injuries progressed. Higher injury grade (adjusted odds ratio, 2.0 per one-grade increase [95% confidence interval {CI}: 1.6, 2.4]; P < .001), carotid injuries versus vertebral artery injuries (49 of 420 [11.7%] vs 35 of 667 [5.2%]; P < .001), and increasing number of vessels injured per patient (adjusted odds ratio, 1.6 per one-vessel increase [95% CI: 1.3, 2.2]; P < .001) were associated with increased risk for BCVI-related stroke. Conclusion Most blunt cerebrovascular injury-related changes occurred within 30 days; changes rarely occurred beyond 90 days. Follow-up imaging is therefore unlikely to be helpful beyond 90 days. © RSNA, 2020 See also the editorial by Talbott in this issue.

Updates in the Neuoroimaging and WHO Classification of Primary CNS Gliomas: A Review of Current Terminology, Diagnosis, and Clinical Relevance From a Radiologic Prospective.

As new advances in the genomics and imaging of CNS tumors continues to evolve, a standardized system for classification is increasingly essential to diagnosis and management. The molecular markers introduced in the 2016 WHO classification of CNS tumors bring both practical and conceptual advances to the characterization of gliomas, strengthening the prognostic and predictive value of terminology while shedding light on the underlying mechanisms that drive biologic behavior. The purpose of this article is to provide a succinct overview of primary intracranial gliomas from a neuroradiologic prospective and according to the 5th edition WHO classification that was revised in 2016. An update of the molecular markers pertinent to defining the major lineages of brain gliomas will be provided, followed by discussion of the terminology, grading and imaging features associated with individual entities. Neuroradiologists should be aware of the key genomic and radiomic features of common brain gliomas, and familiar with an integrated approach to their diagnosis and grading.

Emergent spinal MRI in IVDU patients presenting with back pain: do we need an MRI in every case?

PURPOSE: Spinal MRI is the exam of choice for the workup of patients with suspected spinal infection. In this retrospective study, we assess the value of obtaining contrast-enhanced spinal MRI for patients presenting to the emergency department (ED) with acute back pain and a history of intravenous drug use (IVDU). METHODS: A retrospective IRB-approved, HIPAA compliant review of the imaging findings, reports and electronic charts of 167 consecutive IV drug-using patients (M/F = 96:71, mean age = 40 years) that presented to the ED with acute back pain over a 55-month period and underwent contrast-enhanced spinal MRI within 24 h. Fisher's exact test was used to identify statistically significant (p < 0.05) associations with MRI findings. RESULTS: Evidence of infectious spondylitis was demonstrated on the spinal MRIs of 39.5% (n = 66) of 167 patients, all of whom were admitted, and nearly half (48.5%; 32/66) underwent surgical or percutaneous intervention. Statistically significant differences in the decision to admit, blood cultures, and the type of treatment was demonstrated in patients with findings of spinal infection on MRI (p < 0.05). CONCLUSION: Use of emergent spinal MRI in the workup of IVDU patients with acute back pain is justified despite the resultant pressure on MRI scanner, technologist, and interpretation time.

Extremity CTA for penetrating trauma: 10-year experience using a 64-detector row CT scanner.

PURPOSE: The purpose of this study is to assess the performance of CT angiography (CTA) in the evaluation of penetrating vascular trauma to the extremities in a large cohort of patients at our level I trauma center. METHODS: A retrospective, IRB-approved review of consecutive CTAs for the evaluation of penetrating trauma to the extremities in 446 patients (M/F = 396:50, mean age = 27 years) from 1/1/2005 to 5/1/2015 was performed. Medical records were reviewed to correlate diagnostic imaging findings with clinical history and subsequent interventions. Image quality was quantified by measurement of CT attenuation coefficients in the major arteries of the extremities. The Fisher's exact test was used to analyze the relationships between the presence and type of vascular injury and subsequent clinical management. RESULTS: One hundred and thirty-one (29.4 %) of 446 patients with penetrating trauma demonstrated major vascular injury on CTA, 35 (26.7 %) of whom underwent subsequent surgical repair. None of the patients without vascular injury on CTA underwent subsequent vascular intervention. Fisher's exact test demonstrated a statistically significant difference in management and requirement for vascular repair in those patients with a vascular injury on CTA when compared to those without a vascular injury (p < 0.0001). The mean attenuation values achieved in upper and lower extremity CTAs in this population exceeded 250 HU. CONCLUSION: Extremity CTA is found to be an accurate tool for surgical triage in patients having sustained penetrating vascular trauma.