Initial testing of pegfilgrastim (Neulasta Onpro) on-body injector in multiple radiological imaging environments.

PURPOSE: An increasing number of implantable or external devices can impact whether patients can receive radiological imaging examinations. This study examines and tests the Neulasta (pegfilgrastim) Onpro on-body injector in multiple imaging environments. METHODS: The injector was analyzed for four imaging modalities with testing protocols and strategies developed for each modality. In x-ray and computed tomography (CT), scans with much higher exposure than clinical protocols were performed with the device attached to an anthropomorphic phantom. The device was monitored until the completion of drug delivery. For magnetic resonance imaging (MRI), the device was assessed using a hand-held magnet and underwent the magnetically induced displacement testing in a 1.5T clinical MRI scanner room. For ultrasound, magnetic field changes were measured around an ultrasound scanner system with three transducers. RESULTS: For x-ray and CT no sign of device error was identified during or after the high radiation exposure scans. Drug delivery was completed at expected timing with expected volume. For MRI the device showed significant attractive force towards the hand-held magnet and a 50-degree deflection angle at 50 cm from the opening of the scanner bore. No further assessment from the gradient or radiofrequency field was deemed necessary. For ultrasound the maximum magnetic field change from baseline was measured to be +11.7 µT in comparison to +74.2 µT at 4 inches from a working microwave. CONCLUSIONS: No device performance issue was identified under the extreme test conditions in x-ray or CT. The device was found to be MR Unsafe. Magnetic field changes around an ultrasound system met the limitation set by manufacture. Patient ultrasound scanning is considered safe as long as the transducers do not inadvertently loosen the device.

Updated Imaging Features of Dysplastic Cerebellar Gangliocytoma.

OBJECTIVE: The aim of this study was to perform an updated review of the imaging features of dysplastic cerebellar gangliocytoma (DCG). METHODS: Imaging findings were retrospectively reviewed in 14 patients with DCG. The analysis included size, location, cyst formation, calcification, intralesional hemorrhage, enhancement pattern, and apparent diffusion coefficient (ADC). RESULTS: In addition to revisiting many well-established imaging features of DCG, enhancement was much more common (64.3%) than previously reported, and small enhancing veins were also frequently encountered within or along the periphery of the lesions (50%). Dysplastic cerebellar gangliocytomas had an elevated ADC compared with normal cerebellum (967.8 ± 115.7 vs 770.4 ± 47.3 × 10 mm/s; P < 0.0001). CONCLUSIONS: Enhancement on magnetic resonance imaging within DCG should be an accepted imaging finding rather than being viewed as uncommon or atypical. Dysplastic cerebellar gangliocytomas typically have an elevated ADC compared with normal cerebellum, which may assist in differentiation from other posterior fossa neoplasms.

Computed Tomography-Based Texture Analysis to Determine Human Papillomavirus Status of Oropharyngeal Squamous Cell Carcinoma.

OBJECTIVE: To determine whether machine learning can accurately classify human papillomavirus (HPV) status of oropharyngeal squamous cell carcinoma (OPSCC) using computed tomography (CT)-based texture analysis. METHODS: Texture analyses were retrospectively applied to regions of interest from OPSCC primary tumors on contrast-enhanced neck CT, and machine learning was used to create a model that classified HPV status with the highest accuracy. Results were compared against the blinded review of 2 neuroradiologists. RESULTS: The HPV-positive (n = 92) and -negative (n = 15) cohorts were well matched clinically. Neuroradiologist classification accuracies for HPV status (44.9%, 55.1%) were not significantly different (P = 0.13), and there was a lack of agreement between the 2 neuroradiologists (κ = -0.145). The best machine learning model had an accuracy of 75.7%, which was greater than either neuroradiologist (P < 0.001, P = 0.002). CONCLUSIONS: Useful diagnostic information regarding HPV infection can be extracted from the CT appearance of OPSCC beyond what is apparent to the trained human eye.

Pulmonary Arteriovenous Malformations Are Associated with Silent Brain Infarcts in Hereditary Hemorrhagic Telangiectasia Patients.

BACKGROUND AND PURPOSE: There is a high prevalence of right-to-left shunting pulmonary arteriovenous malformations (PAVMs), which are stroke risk factors, in hereditary hemorrhagic telangiectasia (HHT) patients. While the prevalence of ischemic complications in HHT patients is known, the prevalence of silent brain infarcts (SBI) remains unknown. The purpose of this study was to determine the prevalence and risk factors for SBI in HHT patients. MATERIALS AND METHODS: Our institutional HHT database was queried to identify HHT patients who received a baseline screening brain MRI from January 2000 to February 2017. This study group was further refined by excluding patients who had a history of clinical ischemic disease as defined by having a stroke or transient ischemic attack (TIA). Brain MRIs were reviewed for SBI. Baseline data on demographics, Curacao criteria, presence of PAVMs, and cardiovascular risk factors were collected. The primary outcome was SBI prevalence. We also examined which baseline patient characteristics were associated with SBI through univariate chi-square and Student t tests and multivariate logistic regression analyses. RESULTS: Three hundred fifty three consecutive HHT patients from January 2000 to February 2017 with a screening brain MRI and no prior history of stroke/TIA were included. SBI prevalence was 9.9% (35/353). SBI patients were more likely to have PAVMs than non-SBI patients (80.6 vs. 53.1%, p = 0.005). The median age was 66 in the SBI group and 52 in the non-SBI group (p = 0.006). SBI patients had higher prevalence of hyperlipidemia (34.3 vs. 9.8%, p < 0.0001), hypertension (48.6 vs. 22.0%, p = 0.005), and tobacco use (25.7 vs. 9.8%, p = 0.005). No patients under 30 had SBI. In the 60-69 age group, the prevalence of SBI was 18.8% with rates of 28.6% in the PAVM group and 10.5% in the non-PAVM group. For patients ≥70 years old, the prevalence of SBI was 21.4% overall and 27.6% in the PAVM group and 10.5% in the non-PAVM group. On multivariate analysis, PAVMs (OR 3.62, 95% CI 1.46-10.40) and increasing age (OR 1.04, 95% CI 1.01-1.07) were independently associated with SBI. CONCLUSIONS: Overall, a similar 10% SBI prevalence in the HHT cohort was noted as compared to the general population. However, the prevalence of SBI was higher in HHT patients with PAVMs when compared to that of the general population, particularly among patients than 60 years old. These findings highlight the need to accurately identify, and when appropriate, treat PAVMs in the HHT population especially given the multiple significant, clinical consequences of SBI.

Hypoglossal Canal Lesions: Distinctive Imaging Features and Simple Diagnostic Algorithm.

OBJECTIVE: The objective of this study is to compare the prevalence of hypoglossal canal lesions and identify differentiating imaging features. MATERIALS AND METHODS: A 15-year retrospective review of lesions of the hypoglossal nerve and hypoglossal canal, excluding those in patients with metastasis or prior head and neck cancer and those treated with radiation or surgery, was performed. Clinical findings and lesion imaging features were documented. The contrast-enhanced T1-weighted nonenhancing cystic component of hypoglossal schwannomas was compared with size-matched pathologically proven vestibular schwannomas. RESULTS: Our review identified 40 lesions encroaching on the hypoglossal canal, located within the hypoglossal canal, or found in both locations: 16 hypoglossal schwannomas, 15 juxtaarticular cysts, and nine purely cystic hypoglossal canal lesions. Hypoglossal schwannomas, which were intradural when involving the premedullary cistern, most commonly enhanced heterogeneously, with a thick peripheral enhancing component, a central enhancing component, or both enhancing components. Juxtaarticular cysts encroaching on the hypoglossal canal were extradural, were contiguous with a craniocervical junction synovial joint, and showed thin rim enhancement. Hypoglossal canal nonenhancing cystic lesions were confined to the hypoglossal canal, had signal intensity equivalent to CSF, and lacked any contrast enhancement. CONCLUSION: Although hypoglossal schwannomas, juxtaarticular cysts, and hypoglossal canal nonenhancing cystic lesions may all encroach on or lie within the hypoglossal canal, purely cystic lesions are unlikely to be schwannomas. A diagnostic algorithm applying key imaging and clinical findings allows differentiation of these lesions, which have vastly different treatment regimens.

Nomenclature in Abdominal Wall Hernias: Is It Time for Consensus?

Abdominal wall reconstruction is a rapidly evolving area of surgical interest. Due to the increase in prevalence and size of ventral hernias and the high recurrence rates, the academic community has become motivated to find the best reconstruction techniques. Whilst interrogating the abdominal wall reconstruction literature, we discovered an inconsistency in hernia nomenclature that must be addressed. The terms used to describe the anatomical planes of mesh implantation 'inlay', 'sublay' and 'underlay' are misinterpreted throughout. We describe the misinterpretation of these terms and give evidence of where it exists in the literature. We give three critical arguments of why these misinterpretations hinder advances in abdominal wall reconstruction research. The correct definitions of the anatomical planes, and their respective terms, are described and illustrated. Clearly defined nomenclature is required as academic surgeons strive to improve abdominal wall reconstruction outcomes and lower complication rates.

Hypothalamic hamartoma with neurofibrillary tangles.

Hypothalamic hamartomas are rare tumors that typically present in childhood, often with gelastic seizures, precocious puberty, or as a manifestation of Pallister-Hall syndrome. Neurofibrillary tangles are cytoplasmic aggregates of hyperphosphorylated tau that are best recognized in Alzheimer disease, other tau-associated neurodegenerative diseases, or as part of aging, but occasionally may be seen in low-grade neoplasms with a ganglion cell component as gangliocytoma or ganglioglioma. Herein, we report a case of hypothalamic hamartoma with neurofibrillary tangles.

Neuroimaging Findings in Cardiac Myxoma Patients: A Single-Center Case Series of 47 Patients.

BACKGROUND AND PURPOSE: Cardiac myxomas can present with a myriad of neurological complications including stroke, cerebral aneurysm formation and metastatic disease. Our study had two objectives: (1) to describe the neuroimaging findings of patients with cardiac myxomas and (2) to examine the relationship between a history of embolic complications secondary to myxoma and intracranial aneurysm formation, hemorrhage and metastatic disease. We hypothesized that patients who present with embolic complications related to myxoma would be more likely to have such complications. MATERIALS AND METHODS: We searched our institutional database for all patients with pathologically proven cardiac myxomas from 1995 to 2014 who received neuroimaging. Neuroimaging findings were categorized as acute ischemic stroke, intracerebral hemorrhage, oncotic aneurysm, and cerebral metastasis. Cardiac myxoma patients were divided into those presenting with embolic complications (i.e. lower extremity emboli or cerebral emboli) and those presenting with non-embolic complications prior to surgical resection of the myxoma. The prevalence of intracranial hemorrhage, myxomatous aneurysm formation, and cerebral metastases was compared in myxoma patients presenting with and without embolic complications using a Chi-squared test. RESULTS: Forty-seven consecutive patients were included in this study. Sixteen patients (34.0%) had imaging evidence of acute ischemic stroke. Of these, 13 had acute ischemic strokes directly attributed to the cardiac myxoma (27.7%) and 3 had acute ischemic strokes secondary to causes other than myxoma (6.4%). Seven patients (14.9%) had aneurysms. Two patients (4.3%) had parenchymal metastatic disease on long-term imaging. Fourteen patients (29.8%) presented with ischemic symptoms that were attributed to cardiac myxoma (1 with lower extremity ischemia, 1 with lower extremity ischemia and ischemic stroke, and 12 with ischemic stroke). Patients presenting with embolic complications related to the myxoma (ischemic stroke or lower extremity ischemia) were more likely to have imaging evidence of intracranial hemorrhage (21.4 vs. 3.0%, p = 0.09), oncotic aneurysm (35.7 vs. 6.1%, p = 0.03), and cerebral metastasis (14.3 vs. 0.0%, p = 0.07) on follow-up imaging. CONCLUSIONS: Ischemic stroke and intracranial oncotic aneurysm were found in a substantial proportion of cardiac myxoma patients undergoing neuroimaging. Patients presenting with embolic complications of cardiac myxoma are more likely to have intracranial hemorrhage, intracranial oncotic aneurysms, and cerebral metastatic disease.

Safety and outcomes of magnetic resonance imaging in patients with abandoned pacemaker and defibrillator leads.

INTRODUCTION: Abandoned cardiovascular implantable electronic device (CIED) leads remain a contraindication to magnetic resonance imaging (MRI) studies, largely due to in vitro data showing endocardial heating secondary to the radiofrequency field. We tested the hypothesis that abandoned CIED leads do not pose an increased risk of clinical harm for patients undergoing MRI. METHODS: This single-center retrospective study examined the outcomes of patients who had device generators removed before MRI, rendering the device leads abandoned. Information was gathered through chart review. Data collected included lead model, pacing threshold before MRI, anatomic region examined, threshold data after generator reimplantation, and clinical patient outcome. RESULTS: Patients (n = 19, 11 men and eight women) ranged in age from 19 to 85 at the time of MRI. There was a mean of 1.63 abandoned leads at the time of imaging; none of the leads were MRI conditional. Of the three implantable cardioverter defibrillator (ICD) leads, two of three were dual coil. Most (31/35) of the scans performed were of the central nervous system, including head and spinal imaging. There were no adverse events associated with MRI in any of these patients with abandoned leads within 7 days of the scan. No lead malfunctions or clinically significant change in pacing thresholds were noted with generator reimplantation. CONCLUSION: The use of MRI in patients with abandoned cardiac device leads appears feasible when performed under careful monitoring, with no adverse events, although the experience is small. MRI did not affect the function of leads that were subsequently reconnected to a cardiac device.

Emerging trends in the volume and format of outside examinations submitted for secondary interpretation.

OBJECTIVE: The purpose of this article is to describe the trends of secondary interpretations, including the total volume and format of cases. MATERIALS AND METHODS: This retrospective study involved all outside neuroradiology examinations submitted for secondary interpretation from November 2006 through December 2010. This practice utilizes consistent criteria and includes all images that cover the brain, neck, and spine. For each month, the total number of outside examinations and their format (i.e., hard-copy film, DICOM CD-ROM, or non-DICOM CD-ROM) were recorded. RESULTS: There was no significant change in the volume of cases (1043 ± 131 cases/month; p = 0.46, two-sided Student t test). There was a significant decrease in the volume of hard-copy films submitted, with the mean number of examinations submitted per month on hard-copy film declining from 297 in 2007 to 57 in 2010 (p < 0.0001, Student t test). This decrease was mirrored by an increase in the mean number of cases submitted on CD-ROM (753 cases/month in 2007 and 1036 cases/month in 2010; p < 0.0001). Although most were submitted in DICOM format, there was almost a doubling of the volume of cases submitted on non-DICOM CD-ROM (mean number of non-DICOM CD-ROMs, nine cases/month in 2007 and 17 cases/month in 2010; p < 0.001). CONCLUSION: There has been a significant decrease in the number of hard-copy films submitted for secondary interpretation. There has been almost a doubling of the volume of cases submitted in non-DICOM formats, which is unfortunate, given the many advantages of the internationally derived DICOM standard, including ease of archiving, standardized display, efficient review, improved interpretation, and quality of patient care.

Acute epidural spinal hemorrhage from vasculitis: resolution with immunosuppression.

BACKGROUND: Angiographic vasculitis affecting the spine has been rarely described. The use of immunosuppression as a primary treatment and a review of the literature is presented. METHODS: Case report. RESULTS: A 61-year-old female presented with sudden onset back pain and headache. The patient was found to have acute spinal epidural hemorrhage and subsequent work-up demonstrated angiographic spinal vasculitis. Immunosuppression with cyclophosphamide resulted in clinical and radiographic improvement. CONCLUSIONS: Immunomodulating therapy should be considered in the management of select patients with spinal vasculitis which may lead to improved clinical outcome and potentially disease resolution.

Superficial siderosis associated with an iatrogenic posterior fossa dural leak identified on CT cisternography.

Superficial siderosis refers to hemosiderin deposition along the pial surface of the brain and spinal cord. It results from chronic and repetitive low-grade bleeding into the subarachnoid space. Dural tears are a common cause of superficial siderosis. Although such tears typically occur in the spine, dural tears can also occur in the posterior fossa. In many cases, posterior fossa dural tears are iatrogenic, and patients may present with neuroimaging evidence of postoperative pseudomeningoceles. We present a case of superficial siderosis caused by a persistent posterior fossa dural leak. The patient presented with superficial siderosis 30 years after a Chiari I malformation repair. A pinhole-sized dural tear was identified preoperatively using computed tomography cisternography. The dural defect was successfully repaired. An additional small tear that was not seen on imaging was also identified at surgery and successfully repaired.

Clinical safety of magnetic resonance imaging in patients with implanted SynchroMed EL infusion pumps.

INTRODUCTION: Patients with implanted SynchroMed spinal infusion pumps (Medtronic, Inc., Minneapolis, MN) routinely undergo magnetic resonance imaging at our institution. In August 2008, Medtronic issued an urgent medical device correction report regarding several pumps. Because of the rare potential "for a delay in the return of proper drug infusion" and "for a delay in the logging of motor stall events," "a patient's pump must be interrogated after MRI exposure in order to confirm proper pump functionality." This is particularly important in patients receiving intrathecal baclofen, for whom a delay in return of proper pump infusion could lead to life-threatening baclofen withdrawal syndrome. The objective of this report is to present our experience and protocol of performing magnetic resonance imaging in patients with implanted SynchroMed EL pumps. METHODS: We retrospectively reviewed records of 86 patients with implanted SynchroMed EL spinal infusion pumps who underwent 112 examinations on 1.5-T magnetic resonance imaging scanners from September 1, 1998 to July 7, 2004. RESULTS: No SynchroMed EL pumps were damaged by magnetic resonance imaging, and the programmable settings remained unchanged in all patients. CONCLUSIONS: Our data suggest that SynchroMed EL pump malfunction is indeed rare after routine clinical 1.5-T magnetic resonance imaging examinations. However, based on the Medtronic correction report, we perform pump interrogation before and after imaging.

Preparing for the next pandemic: It is more than just about numbers.

The COVID-19 pandemic has brought enormous hardships to our country and healthcare system. We present our experience navigating through this pandemic with emphasis on reactivating our practice while keeping patients and staff safe. It is hoped that the methods and thought processes provided in this manuscript will help those who are in various stages of managing their practice or provide lessons learned as our country eventually moves beyond this pandemic. Lastly, we aspire to provide a guide for those who are in a position to prepare for the next pandemic.

e-ASPECTS software improves interobserver agreement and accuracy of interpretation of aspects score.

INTRODUCTION: There is increased interest in the use of artificial intelligence-based (AI) software packages in the evaluation of neuroimaging studies for acute ischemic stroke. We studied whether, compared to standard image interpretation without AI, Brainomix e-ASPECTS software improved interobserver agreement and accuracy in detecting ASPECTS regions affected in anterior circulation LVO. METHODS: We included 60 consecutive patients with anterior circulation LVO who had TICI 3 revascularization within 60 minutes of their baseline CT. A total of 16 readers, including senior neuroradiologists, junior neuroradiologists and vascular neurologists participated. Readers interpreted CT scans on independent workstations and assessed final ASPECTS and evaluated whether each individual ASPECTS region was affected. Two months later, readers again evaluated the CT scans, but with assistance of e-ASPECTS software. We assessed interclass correlation coefficient for total ASPECTS and interobserver agreement with Fleiss' Kappa for each ASPECTS region with and without assistance of the e-ASPECTS. We also assessed accuracy for the readers with and without e-ASPECTS assistance. In our assessment of accuracy, ground truth was the 24 hour CT in this cohort of patients who had prompt and complete revascularization. RESULTS: Interclass correlation coefficient for total ASPECTS without e-ASPECTS assistance was 0.395, indicating fair agreement compared, to 0.574 with e-ASPECTS assistance, indicating good agreement (P < 0.01). There was significant improvement in inter-rater agreement with e-ASPECTS assistance for each individual region with the exception of M6 and caudate. The e-ASPECTS software had higher accuracy than the overall cohort of readers (with and without e-ASPECTS assistance) for every region except the caudate. CONCLUSIONS: Use of Brainomix e-ASPECTS software resulted in significant improvements in inter-rater agreement and accuracy of ASPECTS score evaluation in a large group of neuroradiologists and neurologists. e-ASPECTS software was more predictive of final infarct/ASPECTS than the overall group interpreting the CT scans with and without e-ASPECTS assistance.

Profound intellectual disability caused by homozygous TRAPPC9 pathogenic variant in a man from Malta.

BACKGROUND: Intellectual disability is a complex multi-faceted condition with diverse underlying etiologies. One rare form of intellectual disability is secondary to the loss of TRAPPC9, an activator of NF-κB and a mediator of intracellular protein processing and trafficking. TRAPPC9 deficiency has been described in 48 patients with more than 15 pathologic variants. METHOD: Clinical evaluation, magnetic resonance imaging, and whole-exome sequencing were used to characterize the underlying cause of absent speech, restricted/repetitive behaviors, and worsening behavioral outbursts in 27-year-old man from Malta. RESULTS: Magnetic Resonance Imaging showed morphologic abnormalities, including global cerebral and cerebellar hypoplasia. Genetic analysis through Whole Exome Sequencing identified a homozygous deletion (c.568_574del) in TRAPPC9 resulting in a frameshift, premature stop codon, and ultimately a truncated protein (p.Trp190Argfs*95). In this case, the pathogenic variant was homozygous, identified in both of the parents without known consanguinity. CONCLUSION: Given the phenotype and genotype consistent with a deficiency in TRAPPC9, it is likely that this patient represents a novel case of this rare genetic syndrome. Specifically, this case, in the context of 48 total reported patients, raises questions as to the geographic origin of the pathologic variant and optimal detection and therapeutic intervention for this condition.