Arterial spin labeling as an ancillary assessment to postoperative conventional angiogram in pediatric moyamoya disease.

OBJECTIVE: Digital subtraction angiography (DSA) is commonly performed after pial synangiosis surgery for pediatric moyamoya disease to assess the degree of neovascularization. However, angiography is invasive, and the risk of ionizing radiation is a concern in children. In this study, the authors aimed to identify whether arterial spin labeling (ASL) can predict postoperative angiogram grading. In addition, they sought to determine whether patients who underwent ASL imaging without DSA had similar postoperative outcomes when compared with patients who received ASL imaging and postoperative DSA. METHODS: The medical records of pediatric patients who underwent pial synangiosis for moyamoya disease at a quaternary children's hospital were reviewed during a 10-year period. ASL-only and ASL+DSA cohorts were analyzed. The frequency of preoperative and postoperative symptoms was analyzed within each cohort. Three neuroradiologists assigned a visual ASL grade for each patient indicating the change from the preoperative to postoperative ASL perfusion sequences. A postoperative neovascularization grade was also assigned for patients who underwent DSA. RESULTS: Overall, 21 hemispheres of 14 patients with ASL only and 14 hemispheres of 8 patients with ASL+DSA were analyzed. The groups had similar rates of MRI evidence of acute or chronic stroke preoperatively (61.9% in the ASL-only group and 64.3% in the ASL+DSA group). In the entire cohort, transient ischemic attack (TIA) (p = 0.027), TIA composite (TIA or unexplained neurological symptoms; p = 0.0006), chronic headaches (p = 0.035), aphasia (p = 0.019), and weakness (p = 0.001) all had decreased frequency after intervention. The authors found a positive association between revascularization observed on DSA and the visual ASL grading (p = 0.048). The visual ASL grades in patients with an angiogram indicating robust neovascularization demonstrated improved perfusion when compared with the ASL grades of patients with a poor neovascularization. CONCLUSIONS: Noninvasive ASL perfusion imaging had an association with postoperative DSA neoangiogenesis following pial synangiosis surgery in children. There were no significant postoperative stroke differences between the ASL-only and ASL+DSA cohorts. Both cohorts demonstrated significant improvement in preoperative symptoms after surgery. Further study in larger cohorts is necessary to determine whether the results of this study are validated in order to circumvent the invasive catheter angiogram.

Tentorial Dural Arteriovenous Fistulas as a Cause of Thalamic Edema: 2 Cases of an Important Differential Diagnosis to Consider.

The differential diagnosis for bilateral thalamic edema is extensive and includes vascular, neoplastic, metabolic, and infectious causes. Of the vascular causes of thalamic edema, arterial and venous infarctions are well-documented, but dural arteriovenous fistulas (dAVFs) are a relatively uncommon and widely underrecognized cause of thalamic edema. Dural AVFs are notoriously difficult to diagnose clinically, especially in the absence of hemorrhage, and cross-sectional imaging findings can be subtle. This can result in a delayed diagnosis, and occasionally, an invasive biopsy for further clarification of a purely vascular disease. In this review, we detail our experience with the imaging diagnosis of dAVF as a cause of thalamic edema and present a short differential of other vascular causes.

Neuroendovascular Treatment of Acute Stroke During COVID-19: A Guide From the Frontlines.

Since the initial reports surfaced of a novel coronavirus causing illness and loss of life in Wuhan, China, COVID-19 has rapidly spread across the globe, infecting millions and leaving hundreds and thousands dead. As hospitals cope with the influx of patients with COVID-19, new challenges have arisen as health-care systems care for patients with COVID-19 while still providing essential emergency care for patients with acute strokes and acute myocardial infarction. Adding to this complex scenario are new reports that patients with COVID-19 are at increased risk of thromboembolic complications including strokes. In this article, we detail our experience caring for acute stroke patients and provide some insight into neurointerventional workflow modifications that have helped us adapt to the COVID-19 era.

Vascular imaging of the spine in the US Medicare population: Catheter and MR angiography volumes from 2004 to 2016.

AIMS: The purpose of our study was to analyze utilization trends and physician specialty distribution in spinal catheter angiography and magnetic resonance angiography in the Medicare fee-for-service population. METHODS: Data from the CMS Physician/Supplier Procedure Summary Master Files for 2004 to 2016 were used for this study. The Current Procedural Terminology version 4 codes for spinal magnetic resonance angiography (72159) and spinal catheter angiography (75705) were used to analyze the volumes of these procedures. Using Medicare's 108 specialty code, we compared procedure volumes among physician specialties. Data analysis was performed using SAS version 9.3 for Windows. RESULTS: The volume of spinal catheter angiography performed was 4758 in 2004, peaked at 6869 in 2012, and dropped to 6656 in 2016. Overall, the volume of spinal catheter angiography increased by 40% from 2004 to 2016. Radiologists performed the majority of these procedures (3736 or 56.1%) in 2016, followed by neurosurgeons (2456 or 36.9%), and neurologists (346 or 5.2%). The spinal magnetic resonance angiography volume fluctuated between 0 and 1 from 2004 to 2009, then precipitously increased to 40 in 2010, peaked at 133 in 2011, and declined to 81 in 2016. The volume of spinal magnetic resonance angiography procedures increased by 8000% from 2004 to 2016, with radiologists performing the majority of them. CONCLUSION: Our results show that spinal catheter angiography volumes continue to rise in the Medicare fee-for-service population, and are largely performed by radiologists, neurosurgeons, and neurologists. Although spinal magnetic resonance angiography volumes have started to increase, they comprise only a small fraction of studies performed for vascular evaluation of the spine.

Salivary gland disease in the era of COVID-19 pandemic.

Coronavirus disease 2019 (COVID-19) pandemic forced significant changes in current approach to outpatient evaluation of common otolaryngology complaints as hospitals around the world are trying to limit the spread of the virus and to preserve health care resources. These changes raise a lot of questions regarding patient triage and treatment decisions in clinical situations when it is unclear if the workup and management can be postponed. In this communication, we present our approach to evaluation and triage of new patients with complaints concerning for salivary gland disease.

Type V Dural Arteriovenous Fistula Supplied by the Artery of Wollschlaeger and Wollschlaeger Causing Cervical Myelopathy and Quadriparesis.

BACKGROUND: The artery of Wollschlaeger and Wollschlaeger is a tentorial branch of the superior cerebellar artery that is usually not visualized on conventional cerebral angiography, unless it is pathologically enlarged. It can be recruited as part of the blood supply to tentorial dural arteriovenous fistulas (AVFs), although this occurs infrequently. CASE DESCRIPTION: Here we report the clinico-radiologic evaluation and treatment of a 48-year-old man referred to our institution for hitherto workup negative progressive, relapsing quadriparesis. This represents the first reported case of cervical myelopathy caused by venous congestion from a type V dural AVF supplied by the artery of Wollschlaeger and Wollschlaeger. CONCLUSIONS: The anatomic discrepancy between the symptomatic spinal cord lesion and the etiologic intracranial fistula frequently results in delayed care in cases of myelopathy due to intracranial dural AVFs. Familiarity with these disorders and of their pathophysiologic mechanisms is important to avoid unnecessary diagnostic delays.

Subarachnoid Hemorrhage as Result of Retrocorporeal Artery Aneurysm Rupture: Rare Sequel of Subclavian Steal Syndrome.

BACKGROUND: Subclavian steal phenomenon can cause retrograde flow in the vertebral artery as a result of ipsilateral occlusion of the subclavian artery. This phenomenon has various clinical presentations, such as claudication of the affected extremity or intermittent vertebrobasilar ischemia. Aneurysm formation in the spinal cord circulation is exceptionally rare but may occur secondary to collateral formation in subclavian steal syndrome. CASE DESCRIPTION: The case presented herein is a 53-year-old male who presented with headache and severe neck pain. Imaging studies revealed that the patient had subarachnoid hemorrhage in the perimedullary and cervicomedullary cisterns and extending to C3-C7 ventrally. Computed tomography angiography reconstruction demonstrated an aneurysmally dilated vessel dorsal to the C6 vertebral body within the spinal canal. Catheter-based angiography of the right subclavian artery demonstrated retrograde flow within the left vertebral artery and confirmed proximal left subclavian artery occlusion, findings diagnostic of subclavian steal. Further, a branch of the right thyrocervical trunk supplied a retrocorporeal artery collateral to the left vertebral artery, which also contributed to the anterior spinal artery. CONCLUSIONS: After endovascular coiling of the aneurysm, the patient had no neurologic deficits or postoperative complications. Postoperative angiography revealed complete obliteration with no residual aneurysm. Imaging further demonstrated patency of the radiculomedullary (anterior spinal) artery.

Lymphoma Metastasis to Vertebral Body Hemangioma: Collision Tumor Causing Cord Compression.

BACKGROUND: Collision tumors of the spine are extremely uncommon. Prior reports have detailed intracranial collision tumors comprising meningiomas and astrocytomas, as well as metastases to meningiomas. Spinal collision tumors are even rarer, with only 5 cases in the literature, none involving the osseous spine. In this report, we highlight the salient features of a case of lymphoma metastasis to a preexisting benign osseous hemangioma, resulting in cord compression. CASE DESCRIPTION: An 81-year-old woman with a known typical T8 vertebral body hemangioma stable for over 6 years was evaluated for increasing back pain, new gait instability, and urinary retention. Magnetic resonance imaging showed a change in the appearance of the T8 hemangioma, with marrow replacement and new associated epidural soft tissue causing cord compression. A biopsy was performed, which showed diffuse large B-cell lymphoma within blood elements, consistent with lymphoma metastasis to a vertebral body hemangioma. The patient was treated with intravenous steroids and radiation therapy. CONCLUSIONS: Collision tumors of the spine are extremely rare. New or increasingly aggressive appearance of a previously benign spinal osseous lesion should prompt consideration for a collision tumor or malignant transformation of the benign tumor. Biopsy of the lesion should be strongly pursued whenever feasible, as the treatment strategy may vary depending on the histology of the tumor.

Transcranial Optical Monitoring of Cerebral Hemodynamics in Acute Stroke Patients during Mechanical Thrombectomy.

INTRODUCTION: Mechanical thrombectomy is revolutionizing treatment of acute stroke due to large vessel occlusion (LVO). Unfortunately, use of the modified Thrombolysis in Cerebral Infarction score (mTICI) to characterize recanalization of the cerebral vasculature does not address microvascular perfusion of the distal parenchyma, nor provide more than a vascular "snapshot." Thus, little is known about tissue-level hemodynamic consequences of LVO recanalization. Diffuse correlation spectroscopy (DCS) and diffuse optical spectroscopy (DOS) are promising methods for continuous, noninvasive, contrast-free transcranial monitoring of cerebral microvasculature. METHODS: Here, we use a combined DCS/DOS system to monitor frontal lobe hemodynamic changes during endovascular treatment of 2 patients with ischemic stroke due to internal carotid artery (ICA) occlusions. RESULTS AND DISCUSSION: The monitoring instrument identified a recanalization-induced increase in ipsilateral cerebral blood flow (CBF) with little or no concurrent change in contralateral CBF and extracerebral blood flow. The results suggest that diffuse optical monitoring is sensitive to intracerebral hemodynamics in patients with ICA occlusion and can measure microvascular responses to mechanical thrombectomy.

Neurointerventional Radiology for the Aspiring Radiology Resident: Current State of the Field and Future Directions.

OBJECTIVE: The purposes of this study were to document recent trends in stroke intervention at a tertiary-care facility with a comprehensive stroke center and to analyze current procedure volumes and the employment of specialty providers in neurointerventional radiology (NIR). MATERIALS AND METHODS: Institutional trends in the volume of mechanical thrombectomy were analyzed on the basis of the number of patients who underwent mechanical thrombectomy from 2013 to 2017. To evaluate the current status of mechanical thrombectomy volumes in the United States, the number of patients in the Medicare fee-for-service database who underwent mechanical thrombectomy in 2016 was assessed. The specialty backgrounds of the various providers who performed mechanical thrombectomy were analyzed. Procedure volumes for intracranial stenting, embolization, and vertebral augmentation procedures were assessed. RESULTS: From 2013 to 2017, the total numbers of mechanical thrombectomy procedures for acute ischemic stroke were 19 in 2013 and 111 in 2017. The total volume of mechanical thrombectomy procedures in the Medicare fee-for-service population in 2016 was 7479. For intracranial endovascular procedures, 20,850 were performed in the U.S. Medicare population in 2015 and 22,511 in 2016. Radiologists performed 45% of procedures in 2016; neurosurgeons, 41%; and neurologists, 11%. When the total numbers of percutaneous brain and spine procedures were combined, radiologists performed 41%; neurosurgeons, 23%; and neurologists, 3%. In 2016, there were a total of 220 active NIR staff at the NIR programs with rotating residents or fellows. In these programs, 49% of staff members were neuroradiologists, 41% were neurosurgeons, and 10% were neurologists. Of the 72 NIR departments with confirmed rotating fellows or residents, 14 had only neuroradiologists on staff, six had only neurosurgeons, and one had only neurologists. CONCLUSION: Increasing radiology resident interest and participation in NIR should ensure a steady influx of radiologists into the field, continuing the strong tradition of radiology participation, leadership, and innovation in NIR.

Muslin Granuloma Mimicking Parenchymal Hematoma in Patient with Seizures 30 Years After Aneurysm Wrapping.

Muslin foreign body granulomas are a known complication of muslin aneurysm wrapping and have been associated with vision loss from optochiasmatic arachnoiditis. Muslin granulomas have also been confused with abscesses due to surrounding inflammatory changes. In this clinical image, we present a unique case of a muslin granuloma mimicking an intraparenchymal hematoma.

Anomalous Origin of the Right Vertebral Artery from the Right Common Carotid Artery.

The anomalous origin of the right vertebral artery (VA) from the right common carotid artery (CCA) is a rare vascular anomaly, which is usually clinically asymptomatic and found incidentally during angiographic examinations. This anomaly is invariably associated with an aberrant right subclavian artery (RSCA). Approximately 31 cases have been reported in the literature. We present a case of a right VA originating from the right CCA in a patient with Down syndrome and discuss the imaging findings, embryological etiology of the anomaly, as well as its implications for endovascular/surgical treatment.

Proposed biopsy performance benchmarks for MRI based on an audit of a large academic center.

Performance benchmarks exist for mammography (MG); however, performance benchmarks for magnetic resonance imaging (MRI) are not yet fully developed. The purpose of our study was to perform an MRI audit based on established MG and screening MRI benchmarks and to review whether these benchmarks can be applied to an MRI practice. An IRB approved retrospective review of breast MRIs was performed at our center from 1/1/2011 through 12/31/13. For patients with biopsy recommendation, core biopsy and surgical pathology results were reviewed. The data were used to derive mean performance parameter values, including abnormal interpretation rate (AIR), positive predictive value (PPV), cancer detection rate (CDR), percentage of minimal cancers and axillary node negative cancers and compared with MG and screening MRI benchmarks. MRIs were also divided by screening and diagnostic indications to assess for differences in performance benchmarks amongst these two groups. Of the 2455 MRIs performed over 3-years, 1563 were performed for screening indications and 892 for diagnostic indications. With the exception of PPV2 for screening breast MRIs from 2011 to 2013, PPVs were met for our screening and diagnostic populations when compared to the MRI screening benchmarks established by the Breast Imaging Reporting and Data System (BI-RADS) 5 Atlas® . AIR and CDR were lower for screening indications as compared to diagnostic indications. New MRI screening benchmarks can be used for screening MRI audits while the American College of Radiology (ACR) desirable goals for diagnostic MG can be used for diagnostic MRI audits. Our study corroborates established findings regarding differences in AIR and CDR amongst screening versus diagnostic indications.

Loading and elution characteristics of quadrasphere microspheres loaded with bevacizumab.

AIM: Super absorbent polyvinyl alcohol-sodium acrylate copolymer microspheres, Quadrasphere microspheres (QSM), are commonly used for drug-eluting bead therapy, however, the literature only reports its use with small molecule chemotherapeutics. This study evaluates the loading and elution characteristics of bevacizumab-loaded QSM. METHODS & RESULTS: A single vial of QSM was reconstituted with 200 mg of bevacizumab. Drug concentration was determined by ELISA immunoassay. At approximately 90 min, there was maximal loading at 59% of the starting dose. In vitro elution demonstrated 52% of bound bevacizumab was released within the first hour and 68% by 16 h. CONCLUSION: Bevacizumab can load onto QSM and elute over time. This targeted delivery vehicle may potentially result in more effective treatment and fewer complications related to systemic toxicity.

Radiology Abroad: A Global Health Initiative in Guyana.

OBJECTIVE: The purpose of this article is to share our experience conducting a global health outreach initiative in the Radiology Department of the Georgetown Public Hospital in Guyana alongside RAD-AID, a nonprofit organization whose mission is to increase the availability of medical imaging services in developing countries. CONCLUSION: The collaboration between RAD-AID and the Guyanese Ministry of Health has resulted in significant strides for radiology, including the introduction of new resources such as updated sonography and, for the first time, computed tomography for the public sector. In addition, collaboration with the Georgetown Public Hospital has strengthened the clinical management of patients and radiological education of health-care workers in Guyana.

Migration Phenotype of Brain-Cancer Cells Predicts Patient Outcomes.

Glioblastoma multiforme is a heterogeneous and infiltrative cancer with dismal prognosis. Studying the migratory behavior of tumor-derived cell populations can be informative, but it places a high premium on the precision of in vitro methods and the relevance of in vivo conditions. In particular, the analysis of 2D cell migration may not reflect invasion into 3D extracellular matrices in vivo. Here, we describe a method that allows time-resolved studies of primary cell migration with single-cell resolution on a fibrillar surface that closely mimics in vivo 3D migration. We used this platform to screen 14 patient-derived glioblastoma samples. We observed that the migratory phenotype of a subset of cells in response to platelet-derived growth factor was highly predictive of tumor location and recurrence in the clinic. Therefore, migratory phenotypic classifiers analyzed at the single-cell level in a patient-specific way can provide high diagnostic and prognostic value for invasive cancers.

Intra-arterial Onyx Embolization of Vertebral Body Lesions.

While Onyx embolization of cerebrospinal arteriovenous shunts is well-established, clinical researchers continue to broaden applications to other vascular lesions of the neuraxis. This report illustrates the application of Onyx (eV3, Plymouth, MN) embolization to vertebral body lesions, specifically, a vertebral hemangioma and renal cell carcinoma vertebral body metastatic lesion.

Generation of chordoma cell line JHC7 and the identification of Brachyury as a novel molecular target.

OBJECT: Chordoma is a malignant bone neoplasm hypothesized to arise from notochordal remnants along the length of the neuraxis. Recent genomic investigation of chordomas has identified T (Brachyury) gene duplication as a major susceptibility mutation in familial chordomas. Brachyury plays a vital role during embryonic development of the notochord and has recently been shown to regulate epithelial-to-mesenchymal transition in epithelial-derived cancers. However, current understanding of the role of this transcription factor in chordoma is limited due to the lack of availability of a fully characterized chordoma cell line expressing Brachyury. Thus, the objective of this study was to establish the first fully characterized primary chordoma cell line expressing gain of the T gene locus that readily recapitulates the original parental tumor phenotype in vitro and in vivo. METHODS: Using an intraoperatively obtained tumor sample from a 61-year-old woman with primary sacral chordoma, a chordoma cell line (JHC7, or Johns Hopkins Chordoma Line 7) was established. Molecular characterization of the primary tumor and cell line was conducted using standard immunostaining and Western blotting. Chromosomal aberrations and genomic amplification of the T gene in this cell line were determined. Using this cell line, a xenograft model was established and the histopathological analysis of the tumor was performed. Silencing of Brachyury and changes in gene expression were assessed. RESULTS: The authors report, for the first time, the successful establishment of a chordoma cell line (JHC7) from a patient with pathologically confirmed sacral chordoma. This cell line readily forms tumors in immunodeficient mice that recapitulate the parental tumor phenotype with conserved histological features consistent with the parental tumor. Furthermore, it is demonstrated for the first time that silencing of Brachyury using short hairpin RNA renders the morphology of chordoma cells to a more differentiated-like state and leads to complete growth arrest and senescence with an inability to be passaged serially in vitro. CONCLUSIONS: This report represents the first xenograft model of a sacral chordoma line described in the literature and the first cell line established with stable Brachyury expression. The authors propose that Brachyury is an attractive therapeutic target in chordoma and that JHC7 will serve as a clinically relevant model for the study of this disease.

Harvey Cushing's early experience with pediatric gliomas.

PURPOSE: Diagnosing and operating pediatric patients with intracranial lesions posed a greater diagnostic challenge for physicians during the early twentieth century. At the time, an intracranial neoplasm was indistinctively diagnosed as a glioma, encompassing a broad category of brain tumor pathologies. The treatment and surgical interventions followed for children diagnosed with gliomas is not well-described in the literature from this time. METHODS: Following IRB approval, and through the courtesy of the Alan Mason Chesney Archives, we reviewed the Johns Hopkins Hospital surgical files from 1896-1912. Patients 18 years or younger, who underwent surgical intervention by Cushing for suspected intracranial tumors, were selected. RESULTS: Of the eight pediatric cases diagnosed with gliomas by Cushing, four cases were later diagnosed as medulloblastomas by Dr. Cushing in 1925. Of the remaining four pediatric cases, one was diagnosed as a brainstem glioma and another as a ventricular glioma. We describe the remaining two cases. CONCLUSION: These examples illustrate Cushing's approach to treating brain tumors diagnosed as gliomas in pediatric patients, focusing on an initial decompression and followed by a thorough surgical exploration for tumor. Furthermore, these cases demonstrate Cushing's early attempts to manage such lesions in children and highlight the challenges faced in diagnosing and localizing intracranial lesions within this group of patients.