Imaging Intracranial Aneurysms in the Endovascular Era: Surveillance and Posttreatment Follow-up.

While most intracranial aneurysms (IAs) remain asymptomatic over a patient's lifetime, those that rupture can cause devastating outcomes. The increased usage and quality of neuroimaging has increased detection of unruptured IAs and driven an increase in surveillance and treatment of these lesions. Standard practice is to treat incidentally discovered unruptured IAs that confer high rupture risk as well as ruptured IAs to prevent rehemorrhage. IAs are increasingly treated with coil embolization instead of microsurgical clipping; more recently, flow diversion and intrasaccular flow disruption have further expanded the versatility and utility of endovascular IA treatment. Imaging is increasingly used for posttreatment IA follow-up in the endovascular era. While cerebral angiography remains the standard for IA characterization and treatment planning, advances in CT and CT angiography and MR angiography have improved the diagnostic accuracy of noninvasive imaging for initial diagnosis and surveillance. IA features including size, dome-to-neck ratio, location, and orientation allow rupture risk stratification and determination of optimal treatment strategy and timing. The radiologist should be familiar with the imaging appearance of common IA treatment devices and the expected imaging findings following treatment. In distinction to clipping and coil embolization, flow diversion and intrasaccular flow disruption induce progressive aneurysm obliteration over months to years. Careful assessment of the device; the treated IA; adjacent brain, bone, meninges; and involved extracranial and intracranial vasculature is crucial at posttreatment follow-up imaging to confirm aneurysm obliteration and identify short-term and long-term posttreatment complications. An invited commentary by Chatterjee is available online. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. ©RSNA, 2022.

Automated Processing of Head CT Perfusion Imaging for Ischemic Stroke Triage: A Practical Guide to Quality Assurance and Interpretation.

Recent successful trials of thrombectomy launched a shift to imaging-based patient selection for stroke intervention. Many centers have adopted CT perfusion imaging (CTP) as a routine part of stroke workflow, and the demand for emergent CTP interpretation is growing. Fully automated CTP postprocessing software that rapidly generates standardized color-coded CTP summary maps with minimal user input and with easy accessibility of the software output is increasingly being adopted. Such automated postprocessing greatly streamlines clinical workflow and CTP interpretation for radiologists and other frontline physicians. However, the straightforward interface overshadows the computational complexity of the underlying postprocessing workflow, which, if not carefully examined, predisposes the interpreting physician to diagnostic errors. Using case examples, this article aims to familiarize the general radiologist with interpreting automated CTP software data output in the context of contemporary stroke management, providing a discussion of CTP acquisition and postprocessing, a stepwise guide for CTP quality assurance and troubleshooting, and a framework for avoiding clinically significant pitfalls of CTP interpretation in commonly encountered clinical scenarios. Interpreting radiologists should apply the outlined approach for quality assurance and develop a comprehensive search pattern for the identified pitfalls, to ensure accurate CTP interpretation and optimize patient selection for reperfusion.

Ischemic Infarction in Young Adults: A Review for Radiologists.

Ischemic strokes in young adults are devastatingly debilitating and increasingly frequent. Stroke remains the leading cause of serious disability in the United States. The consequences of this familiar disease in this atypical age group are especially detrimental and long lasting. Ischemic stroke in young adults is now emerging as a public health issue, one in which radiologists can play a key role. The incidence of ischemic infarction in young adults has risen over the past couple of decades. Increased public awareness, increased use of MRI and angiography, and more accurate diagnosis may in part explain the increased detection of stroke in young adults. The increased prevalence of stroke risk factors in young adults (especially sedentary lifestyle and hypertension) may also contribute. However, compared with older adults, young adults have fewer ischemic infarcts related to the standard cardiovascular risk factors and large- or small-vessel disease. Instead, their infarcts most commonly result from cardioembolic disease and other demonstrated causes (ie, dissection). Thus, radiologists must expand their differential diagnoses to appropriately diagnose ischemic strokes and identify their causes in the young adult population. From the more frequent cardioembolism and dissection to the less common vasculitis, drug-related, CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy), moyamoya, and hypercoagulable state-related infarcts, this article covers a wide breadth of causes and imaging findings of ischemic stroke in young adults. ©RSNA, 2019.

Skull Base-related Lesions at Routine Head CT from the Emergency Department: Pearls, Pitfalls, and Lessons Learned.

Routine non-contrast material-enhanced head CT is one of the most frequently ordered studies in the emergency department. Skull base-related pathologic entities, often depicted on the first or last images of a routine head CT study, can be easily overlooked in the emergency setting if not incorporated in the interpreting radiologist's search pattern, as the findings can be incompletely imaged. Delayed diagnosis, misdiagnosis, or lack of recognition of skull base pathologic entities can negatively impact patient care. This article reviews and illustrates the essential skull base anatomy and common blind spots that are important to radiologists who interpret nonenhanced head CT images in the acute setting. The imaging characteristics of important "do not miss" lesions are emphasized and categorized by their cause and location within the skull base, and the potential differential diagnoses are discussed. An interpretation checklist to improve diagnostic accuracy is provided. ©RSNA, 2019.

Streaming Success: Harnessing Social Media for Dynamic Radiology Education.

Social media are increasingly used as tools in radiologists education. This article describes features that aid with the selection of SM platforms, and how to emulate educator roles in the digital world. In addition, we summarize best practices regarding curating and delivering stellar content, building a SM brand, and rules of professionalism when using SM in radiology education.

Training the New Radiologists: Approaches for Education.

The field of Radiology is continually changing, requiring corresponding evolution in both medical student and resident training to adequately prepare the next generation of radiologists. With advancements in adult education theory and a deeper understanding of perception in imaging interpretation, expert educators are reshaping the training landscape by introducing innovative teaching methods to align with increased workload demands and emerging technologies. These include the use of peer and interdisciplinary teaching, gamification, case repositories, flipped-classroom models, social media, and drawing and comics. This publication aims to investigate these novel approaches and offer persuasive evidence supporting their incorporation into the updated Radiology curriculum.

Conquering Educational Mountains: Maintaining a Radiology Clinical Education Track.

Establishing a clinical education track as part of a radiology residency is essential in shaping future radiology educators. Many obstacles will be encountered while starting, maintaining, and improving these educational pathways. Hurdles may include recruiting suitable residents for the track, recruiting and supporting faculty advisors, sustaining long-term resident engagement, counteracting educational exclusivity, and providing adequate time and financial support. Although every program and institution may face individualized "mountains" to overcome, they are not insurmountable. The goal of this review is to address different conflicts we have encountered while maintaining the clinical education tract at our institution and to provide tips for overcoming them.

Developing a Resident-led First-year Radiology Resident Lecture Series.

The first year of radiology residency presents many unique challenges, from transitioning into a completely new, specialized field to preparing for call. Implementation of a longitudinal lecture series dedicated towards the clinical demands of being a first-year radiology resident may improve their knowledge and comfort level, as well as benefit the entire program. In this article, we outline our experience with the development of a resident-led dedicated first-year radiology resident lecture series providing targeted, high-yield instruction on rotation logistics, basic physics and artifacts, examination protocolling, and common and "don't miss" pathology.

Evolving Radiology Trainee Neuroimaging Workloads: A National Medicare Claims-based Analysis.

RATIONALE AND OBJECTIVES: While radiology training programs aim to prepare trainees for clinical practice, the relationship between trainee, and national radiology workforce demands is unclear. This study assesses changing radiology trainee neuroimaging workloads nationwide for neuroimaging studies. MATERIALS AND METHODS: Using aggregate Medicare claims files from 2002 to 2018, we identified all computed tomography (CT) and magnetic resonance (MR) examinations of the brain, head and neck, and spine (hereafter "neuroimaging") in Medicare fee-for-service beneficiaries nationwide. Using separate Medicare files, we calculated population utilization rates, and work relative value unit (wRVU) weights of all diagnostic neuroradiology services. Using claims modifiers, we identified services rendered by radiology trainees. Using separate national trainee enrollment files, we calculated mean annual per trainee wRVUs. RESULTS: Between 2002 and 2018, total Medicare neuroimaging claims increased for both radiologists overall (86.1%) and trainees (162.5%), including increases in both CT (102.9% vs 196.8%), and MR (59.9% vs 106.6%). The national percentage of all radiologist neuroimaging wRVUs rendered by trainees increased 46.1% (3.8% of all wRVUs nationally in 2002 to 5.6% in 2018). National trainee increases were present across all neuroimaging services but greatest for head and neck CT (+86.5%). Mean annual per radiology trainee neuroimaging Medicare wRVUs increased +174.9% (42.1 per trainee in 2002 to 115.70 in 2018). Mean per trainee wRVU increases were greatest for spine CT (+394.2%) but present across all neuroimaging services. CONCLUSION: As neuroimaging utilization in Medicare beneficiaries has grown, radiology trainee neuroimaging workloads have increased disproportionately.

Factors Influential in the Selection of Radiology Residents in the Post-Step 1 World: A Discrete Choice Experiment.

OBJECTIVES: Reporting of United States Medical Licensing Examination Step 1 results will transition from a numerical score to a pass or fail result. We sought an objective analysis to determine changes in the relative importance of resident application attributes when numerical Step 1 results are replaced. METHODS: A discrete choice experiment was designed to model radiology resident selection and determine the relative weights of various application factors when paired with a numerical or pass or fail Step 1 result. Faculty involved in resident selection at 14 US radiology programs chose between hypothetical pairs of applicant profiles between August and November 2020. A conditional logistic regression model assessed the relative weights of the attributes, and odds ratios (ORs) were calculated. RESULTS: There were 212 participants. When a numerical Step 1 score was provided, the most influential attributes were medical school (OR: 2.35, 95% confidence interval [CI]: 2.07-2.67), Black or Hispanic race or ethnicity (OR: 2.04, 95% CI: 1.79-2.38), and Step 1 score (OR: 1.8, 95% CI: 1.69-1.95). When Step 1 was reported as pass, the applicant's medical school grew in influence (OR: 2.78, 95% CI: 2.42-3.18), and there was a significant increase in influence of Step 2 scores (OR: 1.31, 95% CI: 1.23-1.40 versus OR 1.57, 95% CI: 1.46-1.69). There was little change in the relative influence of race or ethnicity, gender, class rank, or clerkship honors. DISCUSSION: When Step 1 reporting transitions to pass or fail, medical school prestige gains outsized influence and Step 2 scores partly fill the gap left by Step 1 examination as a single metric of decisive importance in application decisions.

PET and SPECT Imaging of Epilepsy: Technical Considerations, Pathologies, and Pitfalls.

Epilepsy is generated by a plethora of varying pathologies, structural lesions, and pathways and may significantly impact a patient's livelihood. The combination of clinical semiology, electroencephalogram, and magnetic resonance imaging often fails to identify a structural seizure focus. The addition of functional radionuclide imaging is complementary to structural imaging and essential when structural imaging is discordant or inconclusive. The understanding of the key radiopharmaceuticals, imaging techniques, spectrum of disease processes, and potential pitfalls is necessary for diagnosis and surgical planning in epilepsy.

Dural Arteriovenous Fistula Presenting as Trigeminal Neuralgia: 2 Case Reports and Review of the Literature.

BACKGROUND: Dural arteriovenous fistulae (dAVFs) can sporadically compress the root entry zone of the trigeminal nerve or the Gasserian ganglion and therefore be a rare cause of isolated or complicated trigeminal neuralgia (TN). CASE DESCRIPTION: We describe 2 cases of TN related to dAVF treated similarly with transarterial embolization but with divergent outcomes. Further, we completed a comprehensive literature review of previously reported cases to date. A sparse but growing literature with regards to this specific and rare but salient cause of TN was noted. The type of dAVF most commonly found to cause TN was that of a tentorial nidus, a lesion generally accepted to be at high risk of hemorrhage and in need of urgent treatment. This warrants imaging for new TN presentations to ensure that a dangerous lesion does not represent the underlying cause, especially when the TN symptoms are comorbid with other symptoms such as a bruit. Treatments pursued span the range of open surgery, endovascular treatment, and radiosurgery with great success in treating both the TN symptoms, as well as the rupture risk of the dAVF itself in most cases. Indeed, endovascular approaches are becoming more widely employed for these cases over time, often resolving the abnormality on first treatment attempt. Other cases reach resolution after employing a combination of treatment modalities. CONCLUSIONS: This work highlights that dAVFs, particularly the tentorial type, are capable of causing TN symptomatically identical to that of other etiologies and that treatment of the dAVF itself is often sufficient.

Internal auditory canal meningocele-perilabyrinthine/translabyrinthine fistula: Case report and imaging.

The case of a 17-year-old patient with progressive unilateral sensorineural hearing loss and temporal bone malformations concerning for internal auditory canal meningocele with translabyrinthine/perilabyrinthine cerebrospinal fluid fistula is presented with associated computed tomography and magnetic resonance imaging. As the second reported case of an unruptured internal auditory canal meningocele with translabyrinthine/perilabyrinthine fistula, the case presents several clinically relevant points for otologists, neurotologists, and neuroradiologists. Although rare, it is an additional entity to consider as a cause of unilateral sensorineural hearing loss and may pose a risk for developing meningitis and possible "gushing" of cerebrospinal fluid should surgical intervention be attempted. Laryngoscope, 126:1931-1934, 2016.