A case of hydrocephalus confounded by suprasellar arachnoid cyst and concomitant reversible cerebral vasoconstriction syndrome.

Background: Obstructive hydrocephalus is a neurologic condition that has varied clinical and imaging presentations, as well as a multitude of congenital etiologies including aqueductal stenosis and less commonly arachnoid cysts. Aqueductal stenosis is a physical limitation to cerebrospinal fluid flow along the course of the aqueduct, which results in enlargement of the third and lateral ventricles. Arachnoid cysts are thin walled and fluid filled central nervous system lesions that can result in mass effect on adjacent structures. While arachnoid cysts are mostly asymptomatic, they may present with neurological symptoms that vary depending on the location of the lesion. Suprasellar cysts in particular may cause obstructive hydrocephalus as well as endocrine dysfunction. Reversible cerebral vasoconstriction syndrome (RCVS) is an unusual condition caused by cerebral arterial vasoconstriction that often presents initially with a thunderclap headache. Frequently, there is some environmental trigger associated with this condition. RCVS more commonly affects women and can induce stroke. Case Description: A 57-year-old female presented to the emergency department with progressive headache and visual changes. Initial workup suggested the patient's symptoms where related to RCVS but subsequent surgical management of what was presumed to be long standing, compensated hydrocephalus resulted in resolution of the patient's symptoms. Conclusion: We report, to the best of our knowledge, the first case of aquedutal stenosis and suprasellar arachnoid cyst with concomitant RCVS. The presence of multiple pathologies found on radiologic imaging illustrates the challenges presented by incidental findings and subsequent anchoring bias in medical diagnosis.

Virtual reality simulation of neuroendovascular intervention improves procedure speed in a cohort of trainees.

BACKGROUND: Realistic virtual reality (VR) simulators have greatly expanded the tools available for training surgeons and interventionalists. While this technology is effective in improving performance in many fields, it has never been evaluated for neuroendovascular procedures. This study aims to determine whether VR is an effective tool for improving neuroendovascular skill among trainees. METHODS: Trainees performed two VR revascularizations of a right-sided middle cerebral artery (MCA) thrombosis and their times to procedural benchmarks (time to enter internal carotid artery [ICA], traverse clot, and complete procedure) were compared. To determine whether the improvement was case specific, trainees with less procedural exposure were timed during VR left-sided ICA (LICA) aneurysm coiling before or after performing MCA thrombectomy simulations. To determine the value of observing simulations, medical students were timed during the right MCA revascularization simulations after watching other VR procedures. RESULTS: Trainees significantly improved their time to every procedural benchmark during their second MCA revascularization (mean decrease = 1.08, 1.57, and 2.24 min; P = 0.0072, 0.0466, and 0.0230). In addition, time required to access the LICA during aneurysm coiling was shortened by 0.77 min for each previous VR right MCA revascularization performed (P = 0.0176; r 2 = 0.71). Finally, medical students' MCA revascularization simulation times improved by 0.87 min for each prior simulation viewed (P < 0.0221; r 2 = 0.96). CONCLUSION: Both performance and viewing of simulated procedures produced significant decreases in time to reach neuroendovascular procedural benchmarks. These data show that VR simulation is a valuable tool for improving trainee skill in neuroendovascular procedures.

A radiologist's guide to the clinical scales used in the 2015 Endovascular Stroke Trials and the Revised American Heart Association/American Stroke Association Guidelines for Endovascular Stroke Treatment.

In 2015, five trials demonstrated the efficacy of endovascular treatment for acute stroke, culminating in the revised American Heart Association/American Stroke Association (AHA/ASA) recommendations for stroke management. The different clinical scales used in these trials may be unfamiliar to emergency and on-call radiologists. The modified Rankin Scale was used to describe patient disability for prestroke assessment in three of the trials and for the 90-day follow up in all five trials. The Barthel index was used in one trial to score prestroke ability to perform activities of daily living. The NIH Stroke Scale was used as part of eligibility criteria in four of the stroke trials to assess pre-existing neurological deficits. Also, the modified Rankin Scale and the NIH Stroke Scale are used in the revised AHA/ASA recommendations. By understanding these scales, emergency and on-call radiologists will better appreciate the stroke patient's condition and will be able to more actively collaborate in the care of acute stroke patients.

Current Clinical Applications and Future Potential of Diffusion Tensor Imaging in Traumatic Brain Injury.

In the setting of acute central nervous system (CNS) emergencies, computed tomography (CT) and conventional magnetic resonance imaging (MRI) play an important role in the identification of life-threatening intracranial injury. However, the full extent or even presence of brain damage frequently escapes detection by conventional CT and MRI. Advanced MRI techniques such as diffusion tensor imaging (DTI) are emerging as important adjuncts in the diagnosis of microstructural white matter injury in the acute and postacute brain-injured patient. Although DTI aids in detection of brain injury pathology, which has been repeatedly associated with typical adverse clinical outcomes, the evolution of acute changes and their long-term prognostic implications are less clear and the subject of much active research. A major aim of current research is to identify imaging-based biomarkers that can identify the subset of TBI patients who are at risk for adverse outcome and can therefore most benefit from ongoing care and rehabilitation as well as future therapeutic interventions.The aim of this study is to introduce the current methods used to obtain DTI in the clinical setting, describe a set of common interpretation strategies with their associated advantages and pitfalls, as well as illustrate the clinical utility of DTI through a set of specific patient scenarios. We conclude with a discussion of future potential for the management of TBI.

External validation of the New Orleans Criteria (NOC), the Canadian CT Head Rule (CCHR) and the National Emergency X-Radiography Utilization Study II (NEXUS II) for CT scanning in pediatric patients with minor head injury in a non-trauma center.

BACKGROUND: Head CT scans are considered the imaging modality of choice to screen patients with head trauma for neurocranial injuries; however, widespread CT imaging is not recommended and much research has been conducted to establish objective clinical predictors of intracranial injury (ICI) in order to optimize the use of neuroimaging in children with minor head trauma. OBJECTIVE: To evaluate whether a strict application of the New Orleans Criteria (NOC), Canadian CT Head Rule (CCHR) and National Emergency X-Radiography Utilization Study II (NEXUS II) in pediatric patients with head trauma presenting to a non-trauma center (level II) could reduce the number of cranial CT scans performed without missing clinically significant ICI. MATERIALS AND METHODS: We conducted an IRB-approved retrospective analysis of pediatric patients with head trauma who received a cranial CT scan between Jan. 1, 2001, and Sept. 1, 2008, and identified which patients would have required a scan based on the criteria of the above listed decision instruments. We then determined the sensitivities, specificities and negative predictive values of these aids. RESULTS: In our cohort of 2,101 patients, 92 (4.4%) had positive head CT findings. The sensitivities for the NOC, CCHR and NEXUS II were 96.7% (95%CI 93.1-100), 65.2% (95%CI 55.5-74.9) and 78.3% (95%CI 69.9-86.7), respectively, and their negative predictive values were 98.7%, 97.6% and 97.2%, respectively. In contrast, the specificities for these aids were 11.2% (95%CI 9.8-12.6), 64.2% (95%CI 62.1-66.3) and 34.2% (95%CI 32.1-36.3), respectively. Therefore, in our population it would have been possible to scan at least 10.9% fewer patients. CONCLUSIONS: The number of cranial CT scans conducted in our pediatric cohort with head trauma would have been reduced had any of the three clinical decision aids been applied. Therefore, we recommend that further validation and adoption of pediatric head CT decision aids in non-trauma centers be considered to ultimately increase patient safety while reducing medical expense.

Radiologic Evaluation of Mesenchymal Tumors of the Female Genital Tract.

Mesenchymal neoplasms of the female genital tract are a diverse group of tumors, of which the most common are smooth muscle tumors. There is a significant overlap in the imaging characteristics of benign and malignant tumors and final diagnosis often requires pathologic correlation. However, familiarity with typical radiologic features, common imaging pitfalls, and the utility of different imaging modalities can be valuable in the evaluation of mesenchymal tumors. This article highlights the imaging features of the most commonly encountered mesenchymal tumors in the female genital tract.