Mechanical disorders of the cervicocerebral circulation in children and young adults.

Mechanical disorders of the cervicocerebral circulation (MDCC) are conditions in which neurological symptoms result from a disturbance of cerebral blood flow attributable to external mechanical forces exerted on extracranial blood vessels by adjacent musculoskeletal structures during head movement that is presumably within a physiological range. The disease spectrum includes bow hunter's syndrome, carotid-type Eagle syndrome, and various dynamic venous compression syndromes. These conditions have distinct phenotypes in children which differ from those expressed in older adults. In contemporary practice, recognition and diagnostic evaluation is the domain of the neuroendovascular specialist. The diagnostic evaluation of MDCC involves significant technical nuance that can be critical to directing appropriate management, particularly in children. This report aims to provide a comprehensive overview of the pathophysiology, anatomical patterns, diagnosis, and treatment for the full spectrum of MDCC that is commonly encountered in clinical practice.

SuperDyna: Unlocking the Potential of Post-Treatment Device Evaluation.

BACKGROUND: Current imaging algorithms for post-device evaluation are limited by either poor representation of the device or poor delineation of the treated vessel. Combining the high-resolution images from a traditional three-dimensional digital subtraction angiography (3D-DSA) protocol with the longer cone-beam computed tomography (CBCT) protocol may provide simultaneous visualization of both the device and the vessel content in a single volume, improving the accuracy and detail of the assessment. We aim here to review our use of this technique which we termed "SuperDyna". METHODS: In this retrospective study, patients who underwent an endovascular procedure between February 2022 and January 2023 were identified. We analyzed patients who had both non-contrast CBCT and 3D-DSA post-treatment and collected information on pre-/post-blood urea nitrogen, creatinine, radiation dose, and the intervention type. RESULTS: In 1 year, SuperDyna was performed in 52 (of 1935, 2.6%) patients, of which 72% were women, median age 60 years. The most common reason for the addition of the SuperDyna was for post-flow diversion assessment (n=39). Renal function tests showed no changes. The average total procedure radiation dose was 2.8 Gy, with 4% dose and ~20 mL of contrast attributed to the additional 3D-DSA needed to generate the SuperDyna. CONCLUSIONS: The SuperDyna is a fusion imaging method that combines high-resolution CBCT and contrasted 3D-DSA to evaluate intracranial vasculature post-treatment. It allows for more comprehensive evaluation of the device position and apposition, aiding in treatment planning and patient education.

Establishing a Departmental Symposium for Resident Scholarly Activity: How We Did It.

Many radiology departments have successfully increased trainee research involvement by providing protected academic time for research, offering travel funding for conferences, and developing research-focused curriculum via resident research tracks and other mechanisms. A departmental platform for trainees to share their scholarly projects can foster intradepartmental awareness and collaborations, supplement the existing resident research curriculum, encourage peer learning amongst trainees, and allow departmental celebration of their trainees' accomplishments. The authors describe the development of a departmental symposium for resident scholarly activity at their institution and detail a practical framework for implementation and lessons learned, which may serve as a guide for other radiology departments interested in establishing a similar event.

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.

Improving Billing Accuracy Through Enterprise-Wide Standardized Structured Reporting With Cross-Divisional Shared Templates.

OBJECTIVE: We describe our experience in implementing enterprise-wide standardized structured reporting for chest radiographs (CXRs) via change management strategies and assess the economic impact of structured template adoption. METHODS: Enterprise-wide standardized structured CXR reporting was implemented in a large urban health care enterprise in two phases from September 2016 to March 2019: initial implementation of division-specific structured templates followed by introduction of auto launching cross-divisional consensus structured templates. Usage was tracked over time, and potential radiologist time savings were estimated. Correct-to-bill (CTB) rates were collected between January 2018 and May 2019 for radiography. RESULTS: CXR structured template adoption increased from 46% to 92% in phase 1 and to 96.2% in phase 2, resulting in an estimated 8.5 hours per month of radiologist time saved. CTB rates for both radiographs and all radiology reports showed a linearly increasing trend postintervention with radiography CTB rate showing greater absolute values with an average difference of 20% throughout the sampling period. The CTB rate for all modalities increased by 12%, and the rate for radiography increased by 8%. DISCUSSION: Change management strategies prompted adoption of division-specific structured templates, and exposure via auto launching enforced widespread adoption of consensus templates. Standardized structured reporting resulted in both economic gains and projected radiologist time saved.

Predictors for venous sinus stent retreatment in patients with idiopathic intracranial hypertension.

BACKGROUND: Venous sinus stenting for dural sinus stenoses is an emerging alternative to cerebrospinal fluid diversion in cases of medically refractory idiopathic intracranial hypertension. Juxta-stent 're-stenoses' have been reported and managed alternatively with ventricular shunting or stent revision. Identification of factors that might predispose patients to recurrent narrowing may help to select or exclude patients with idiopathic intracranial hypertension for venous sinus stenting. METHODS: We retrospectively reviewed a prospectively maintained database spanning December 2011 to May 2015 of all patients with idiopathic intracranial hypertension who were screened for possible venous sinus stenting, including only patients who received a stent, noting symptomatic improvements, changes in opening lumbar puncture pressure, demographic characteristics, and any subsequent intervention after stent placement. Fisher's exact test and logistic regression were used to test each of seven potential predictors for retreatment. RESULTS: There were eight revisions in 31 patients (25.8%). Among Caucasians, 8.0% required a revision compared with 100% of African-Americans (p<0.001). The c-index for race was 0.857. Body mass index (BMI) was also a significant predictor of revision (p=0.031): among class III obese patients the revision rate was 46.2% compared with 16.7% among class I and II obese patients and 0% among overweight to normal weight patients. CONCLUSIONS: BMI was a significant predictor of revision, suggesting that higher BMI may have a higher risk of revision. The small number of African-Americans in the study makes interpretation of the practical significance of the revision rate in these patients uncertain. None of the other studied factors was statistically significant.

Thoracic exophytic ependymoma masquerading as a benign extra-axial tumor.

Spinal tumors are conventionally differentiated based on location in relation to the spinal cord. Benign spinal tumors such as schwannomas and meningiomas are typically extra-axial (intradural extramedullary) lesions, whereas more aggressive primary spinal tumors such as ependymomas are typically intramedullary masses. Rarely, ependymomas can have both intramedullary and extramedullary components (typically referred to as exophytic ependymomas). We report a case of a spinal exophytic ependymoma that radiographically masqueraded as a benign intradural extramedullary lesion causing cord compression and neurologic deficit in a 47-year-old man. The diagnosis of exophytic ependymoma was made intra-operatively, with resultant gross total resection of the extramedullary portion and subtotal resection of the intramedullary portion. Histopathological examination confirmed ependymoma with World Health Organization grade II/IV. Pre-operative suspicion of an exophytic ependymoma influences operative planning and clinical management. We review the literature and discuss clinical management strategies for these interesting spinal tumors.

Reduction in Syrinx Size and Severity After Venous Sinus Stenting in a Patient With Pseudotumor Cerebri and Chiari Malformation: Technical Case Report.

BACKGROUND AND IMPORTANCE: Pseudotumor cerebri and Chiari I malformation are found to coexist in a subset of patients. Surgical cranial decompression has been the mainstay of Chiari malformation management, whereas venous sinus stenting has emerged as an effective treatment modality for pseudotumor cerebri. Gaps in our current understanding of cerebrospinal fluid (CSF) circulation and the pathophysiology behind CSF-related disorders present difficulties in the simultaneous management of these conditions. A case is presented of the successful management of both conditions with venous sinus stenting, with sustained improvement in symptoms and structural abnormalities of the Chiari malformation and associated syrinxes. CLINICAL PRESENTATION: An obese woman in her 20s with a history of occipital headaches who presented with progressively worsening intermittent visual obscurations was diagnosed with pseudotumor cerebri, Chiari I malformation, and associated spinal syrinxes. Magnetic resonance venography demonstrated right transverse sinus narrowing with an elevated pressure gradient. Successful endovascular intervention with venous sinus stenting achieved normalization of the venous sinus pressure gradient and symptomatic improvement. After stenting, the cervical syrinx was observed to have decreased in size, with a decrease in the extent of cerebellar tonsillar herniation and an increase in CSF signal around the cerebellar tonsils. CONCLUSION: Venous sinus stenting for treatment of concomitant pseudotumor cerebri and Chiari I malformation can be effective in patients demonstrating transverse sinus stenosis.

Progressive proximal-to-distal reduction in expression of the tight junction complex in colonic epithelium of virally-suppressed HIV+ individuals.

Effective antiretroviral therapy (ART) dramatically reduces AIDS-related complications, yet the life expectancy of long-term ART-treated HIV-infected patients remains shortened compared to that of uninfected controls, due to increased risk of non-AIDS related morbidities. Many propose that these complications result from translocated microbial products from the gut that stimulate systemic inflammation--a consequence of increased intestinal paracellular permeability that persists in this population. Concurrent intestinal immunodeficiency and structural barrier deterioration are postulated to drive microbial translocation, and direct evidence of intestinal epithelial breakdown has been reported in untreated pathogenic SIV infection of rhesus macaques. To assess and characterize the extent of epithelial cell damage in virally-suppressed HIV-infected patients, we analyzed intestinal biopsy tissues for changes in the epithelium at the cellular and molecular level. The intestinal epithelium in the HIV gut is grossly intact, exhibiting no decreases in the relative abundance and packing of intestinal epithelial cells. We found no evidence for structural and subcellular localization changes in intestinal epithelial tight junctions (TJ), but observed significant decreases in the colonic, but not terminal ileal, transcript levels of TJ components in the HIV+ cohort. This result is confirmed by a reduction in TJ proteins in the descending colon of HIV+ patients. In the HIV+ cohort, colonic TJ transcript levels progressively decreased along the proximal-to-distal axis. In contrast, expression levels of the same TJ transcripts stayed unchanged, or progressively increased, from the proximal-to-distal gut in the healthy controls. Non-TJ intestinal epithelial cell-specific mRNAs reveal differing patterns of HIV-associated transcriptional alteration, arguing for an overall change in intestinal epithelial transcriptional regulation in the HIV colon. These findings suggest that persistent intestinal epithelial dysregulation involving a reduction in TJ expression is a mechanism driving increases in colonic permeability and microbial translocation in the ART-treated HIV-infected patient, and a possible immunopathogenic factor for non-AIDS related complications.