Neuroimaging Pearls from the MDS Congress Video Challenge. Part 1: Genetic Disorders.

We selected several "imaging pearls" presented during the Movement Disorder Society (MDS) Video Challenge for this review. While the event, as implicated by its name, was video-centered, we would like to emphasize the important role of imaging in making the correct diagnosis. We divided this anthology into two parts: genetic and acquired disorders. Genetic cases described herein were organized by the inheritance pattern and the focus was put on the imaging findings and differential diagnoses. Despite the overlapping phenotypes, certain described disorders have pathognomonic MRI brain findings that would provide either the "spot" diagnosis or result in further investigations leading to the diagnosis. Despite this, the diagnosis is often challenging with a broad differential diagnosis, and hallmark findings may be present for only a limited time.

Neuroimaging Pearls from the MDS Congress Video Challenge. Part 2: Acquired Disorders.

The MDS Video Challenge continues to be the one of most widely attended sessions at the International Congress. Although the primary focus of this event is the presentation of complex and challenging cases through videos, a number of cases over the years have also presented an unusual or important neuroimaging finding related to the case. We reviewed the previous Video Challenge cases and present here a selection of those cases which incorporated such imaging findings. We have compiled these "imaging pearls" into two anthologies. The first focuses on pearls where the underlying diagnosis was a genetic condition. This second anthology focuses on imaging pearls in cases where the underlying condition was acquired. For each case we present brief clinical details along with neuroimaging findings, the characteristic imaging findings of that disorder and, finally, the differential diagnosis for the imaging findings seen.

Gender Differences in Diagnostic Radiology Practice: An Observational Study.

PURPOSE: To investigate gender differences in diagnostic radiology practice, specifically, the differences in scope of practice, the frequency of consultations to other colleagues, and the error rates. MATERIAL AND METHODS: A retrospective observational study was performed including radiologists working for a European teleradiology provider between 2013 and 2019. Main outcome measures included the adjusted odds ratio of female gender for reporting cases in more than one subspecialty, the adjusted incidence rate ratio (IRR) of female gender for the count of second opinion requests to other colleagues, and the adjusted IRR of female gender for the count of radiologic errors. Multivariable adjustment was performed for covariates associated with experience, type of cases reported, part- or full-time employment, and reporting speed. RESULTS: A total of 213 radiologists (36% female) were included in the analysis of gender differences in scope of practice. Female gender was associated with a lower odds of reporting cases in more than one subspecialty with an odds ratio of 0.46 (95% confidence interval, 0.22-0.96). A total of 204 radiologists (36% female) were included in the analysis of gender differences in the count of second opinion requests to colleagues. There was a trend toward an association between female gender and higher odds of requesting a second opinion with an adjusted IRR of 1.6 compared with male gender, but it was not statistically significant (P = .08). A total of 199 radiologists were included (37% female) in the analysis of gender differences in the number of radiologic errors. Female gender was associated with a decrease in the odds of error with an IRR of 0.8 (95% confidence interval, 0.64-0.995). CONCLUSIONS: Female radiologists tend to have a narrower scope of practice and make fewer mistakes than their male counterparts, even after detailed adjustment for factors that might explain gender differences in scope of practice and errors.

External Validation and Modification of Nationwide Inpatient Sample Subarachnoid Hemorrhage Severity Score.

BACKGROUND: The Nationwide Inpatient Sample Subarachnoid Hemorrhage (SAH) Severity Score (NIS-SSS) was developed as a measure of SAH severity for use in administrative databases. The NIS-SSS consists of International Classification of Diseases Ninth Revision (ICD-9) diagnostic and procedure codes derived from the SAH inpatient course and has been validated against the Hunt-Hess score (HH). OBJECTIVE: To externally validate both the NIS-SSS and a modified version of the NIS-SSS (m-NIS-SSS) consisting of codes present only on admission, against the HH in a Canadian province-wide registry and administrative database of SAH patients. METHODS: A total of 1467 SAH patients admitted to Ontario stroke centers between 2003 and 2013 with recorded HH were included. The NIS-SSS and m-NIS-SSS were validated against the HH by testing correlation between the NIS-SSS/m-NIS-SSS and HH, comparing discriminative ability of the NIS-SSS/m-NIS-SSS vs HH for poor outcome by calculating area under the curve (AUC), and comparing calibration of the NIS-SSS, m-NIS-SSS, and HH by plotting predicted vs observed outcome. RESULTS: Correlation with HH was 0.417 (P ≤ .001) for NIS-SSS, and 0.403 (P ≤ .001) for m-NIS-SSS. AUC for prediction of poor outcome was 0.786 (0.764-0.808) for HH, 0.771 (0.748-0.793) for NIS-SSS, and 0.744 (0.721-0.767) for m-NIS-SSS. Calibration plots demonstrated that HH had the most accurate prediction of outcome, whereas the NIS-SSS and m-NIS-SSS did not accurately predict low risk of poor outcome. CONCLUSION: The NIS-SSS and m-NIS-SSS have good external validity, and therefore, may be suitable to approximate traditional clinical scores of disease severity in SAH research using administrative data.

Seizures and early onset dementia: D2HGA1 inborn error of metabolism in adults.

D-2-hydroxyglutaric aciduria type 1 (D2HGA1) is a rare inherited metabolic disorder usually manifesting in infancy/early childhood with seizures and significant central nervous system involvement. We report two siblings with D2HGA1 presenting with mild intellectual disability, and the onset of seizures in adulthood. One of them was misdiagnosed as tuberous sclerosis due to her presentation and the presence of subependymal nodules on brain imaging. Both further developed early onset dementia. This report expands the phenotype of D2HGA1 to include late-onset seizures and early onset dementia in adults.

Cerebrovascular Imaging: Which Test is Best?

Optimal diagnosis and characterization of cerebrovascular disease requires selection of the appropriate imaging exam for each clinical situation. In this review, we focus on intracranial arterial disease and discuss the techniques in current clinical use for imaging the blood vessel lumen and blood vessel wall, and for mapping cerebral hemodynamic impairment at the tissue level. We then discuss specific strategies for imaging intracranial aneurysms, arteriovenous malformations, dural arterial venous fistulas, and arterial steno-occlusive disease.

Meta-analysis of timing of endovascular aneurysm treatment in subarachnoid haemorrhage: inconsistent results of early treatment within 1 day.

BACKGROUND AND PURPOSE: To systematically review and meta-analyse the data on impact of timing of endovascular treatment in aneurysmal subarachnoid haemorrhage (SAH) to determine if earlier treatment is associated with improved clinical outcomes and reduced case fatality. METHODS: We searched MEDLINE, Cochrane database, EMBASE and Web of Science to identify studies for inclusion. The measures of effect utilised were unadjusted/adjusted ORs. Effect estimates were combined using random effects models for each outcome (poor outcome, case fatality); heterogeneity was assessed using the I2 index. Subgroup and sensitivity analyses were performed to account for heterogeneity and risk of bias. RESULTS: 16 studies met the inclusion criteria. Treatment <1 day was associated with a reduced odds of poor outcome compared with treatment >1 day (OR=0.40 (95% CI 0.28 to 0.56; I2=0%)) but not when compared with treatment at 1-3 days (OR=1.16 (95% CI 0.47 to 2.90; I2=81%)). Treatment at <2 days and at <3 days were associated with similar odds of poor outcome compared with later treatment (OR=1.20 (95% CI 0.70 to 2.05; I2=73%; OR=0.71 (95% CI 0.36 to 1.37; I2=71%)). Early treatment was associated with similar odds of case fatality compared with later treatment, regardless of how early/late treatment were defined (OR=1.80 (95% CI 0.88 to 3.67; I2=34%) for treatment <1 day vs days 1-3; OR=1.71 (95% CI 0.72 to 4.03; I2=54%) for treatment <2 days vs later; OR=0.90 (95% CI 0.31 to 2.68; I2=48%) for treatment <3 days vs later). CONCLUSIONS: In only 1 of the analyses was there a statistically significant result, which favoured treatment <1 day. The inconsistent results and heterogeneity within most analyses highlight the lack of evidence for best timing of endovascular treatment in SAH patients.

Natural history and management of basilar trunk artery aneurysms.

BACKGROUND AND PURPOSE: Basilar trunk aneurysms (BTAs), defined as aneurysms distal to the basilar origin and proximal to the origin of the superior cerebellar artery, are rare and challenging to manage. We describe the natural history and management in a consecutive series of BTAs. METHODS: Between 2000 and 2013, 2522 patients with 3238 aneurysms were referred to our institution for aneurysm management. A retrospective review of this database was conducted to identify all patients with BTAs. RESULTS: In total, 52 patients had a BTA. Mean age was 56 (SD±18) years. Median clinical follow-up was 33 (interquartile range, 8-86) months, and imaging follow-up was 26 (interquartile range, 2-80.5) months. BTAs were classified into 4 causal subtypes: acute dissecting aneurysms, segmental fusiform ectasia, mural bleeding ectasia, and saccular aneurysms. Multiple aneurysms were more frequently noticed among the 13 saccular aneurysms when compared with overall population (P=0.021). There was preponderance of segmental ectasia or mural bleeding ectasia (P=0.045) in patients presenting with transit ischemic attack/stroke or mass effect. Six patients with segmental and 4 with mural bleeding ectasia demonstrated increasing size of their aneurysm, with 2 having subarachnoid hemorrhage caused by aneurysm rupture. None of the fusiform aneurysms that remained stable bled. CONCLUSIONS: BTAs natural histories may differ depending on subtype of aneurysm. Saccular aneurysms likely represent an underlying predisposition to aneurysm development because more than half of these cases were associated with multiple intracranial aneurysms. Intervention should be considered in segmental ectasia and chronic dissecting aneurysms, which demonstrate increase in size over time as there is an increased risk of subarachnoid hemorrhage.

Effectiveness of diagnostic strategies in suspected delayed cerebral ischemia: a decision analysis.

BACKGROUND AND PURPOSE: Delayed cerebral ischemia (DCI) is a serious complication after aneurysmal subarachnoid hemorrhage. If DCI is suspected clinically, imaging methods designed to detect angiographic vasospasm or regional hypoperfusion are often used before instituting therapy. Uncertainty in the strength of the relationship between imaged vasospasm or perfusion deficits and DCI-related outcomes raises the question of whether imaging to select patients for therapy improves outcomes in clinical DCI. METHODS: Decision analysis was performed using Markov models. Strategies were either to treat all patients immediately or to first undergo diagnostic testing by digital subtraction angiography or computed tomography angiography to assess for angiographic vasospasm, or computed tomography perfusion to assess for perfusion deficits. According to current practice guidelines, treatment consisted of induced hypertension. Outcomes were survival in terms of life-years and quality-adjusted life-years. RESULTS: When treatment was assumed to be ineffective in nonvasospasm patients, Treat All and digital subtraction angiography were equivalent strategies; when a moderate treatment effect was assumed in nonvasospasm patients, Treat All became the superior strategy. Treating all patients was also superior to selecting patients for treatment via computed tomography perfusion. One-way sensitivity analyses demonstrated that the models were robust; 2- and 3-way sensitivity analyses with variation of disease and treatment parameters reinforced dominance of the Treat All strategy. CONCLUSIONS: Imaging studies to test for the presence of angiographic vasospasm or perfusion deficits in patients with clinical DCI do not seem helpful in selecting which patients should undergo treatment and may not improve outcomes. Future directions include validating these results in prospective cohort studies.

Magnetic resonance evolution of de novo formation of a cavernoma in a thrombosed developmental venous anomaly: a case report.

BACKGROUND AND IMPORTANCE: Mechanisms that lead to de novo formations of nonfamilial-type cavernomas are not well understood. One of the interesting hypotheses is the causative relationship between developmental venous anomaly (DVA) and cavernoma formation. We report a unique case in which serial imaging demonstrated the evolution of de novo formation of a cavernoma in association with a thrombosed DVA. A detailed review of the causal hypothesis between a DVA and cavernoma is also provided. CLINICAL PRESENTATION: We report a 37-year-old female patient in whom a cavernoma-like lesion arose 1 year after the progressive thrombosis of a medullary (or caput medusa) vein of a DVA. The presence of an acute angulation in the draining vein may have prompted an intrinsic outflow restriction. Possible worsening of venous disequilibrium led to subsequent thrombus progression, venous congestion, and occlusion of the vein with venous dilation and signs of stasis on follow-up magnetic resonance imaging. Finally, this developed into a lobulated lesion with salt-and-pepper appearance at the converging region of medullary tributaries, which typified the classic features of a cavernoma. CONCLUSION: Compared with other published cases of de novo cavernoma formation in relation to a DVA, our case, for the first time, allows us to witness the temporal evolution from a thrombosed DVA to the birth of a cavernoma around it. This supports the hypothesis that the cavernoma can be an acquired disease that arises from a DVA.

Transitioning from 16-slice to 64-slice multidetector computed tomography for the assessment of coronary artery disease: are we really making progress?

BACKGROUND: Multidetector computed tomography (MDCT) has demonstrated promise in the noninvasive evaluation of coronary artery disease. OBJECTIVE: To systematically review the literature regarding the improved diagnostic accuracy of 64-slice MDCT. METHODS: An EMBASE, OVID, PubMed and Cochrane Library database search was performed using the key words 'computed tomography' matched with the terms 'coronary artery' or 'coronary angiography' to identify English-language articles examining MDCT cardiac imaging. Studies that compared 16-slice or 64-slice MDCT with catheter-based coronary angiography for the detection of coronary artery disease in nonrevascularized, poststent and post-coronary artery bypass graft patients were included. Data were pooled to obtain a weighted sensitivity, specificity and diagnostic accuracy for MDCT. Negative and positive predictive values, and likelihood ratios were calculated based on sensitivity and specificity. RESULTS: Currently, 15 studies involving 1008 patients have examined the efficacy of 64-slice MDCT in the assessment of coronary artery stenosis (more than 50% luminal narrowing). In these studies, 64-slice MDCT has demonstrated a sensitivity (89%), specificity (96%) and diagnostic accuracy (95%) similar to that of 16-slice MDCT. However, 64-slice MDCT was able to assess 5% more coronary artery segments than 16-slice MDCT. In revascularized patients, MDCT can accurately assess both bypass graft occlusion and stenosis. The 64-slice MDCT is also capable of adequately detecting in-stent restenosis. Improvements in spatial and temporal resolution with 64-slice technology have decreased the occurrence of high attenuation and motion artefacts that plagued the previous generation of MDCT scanners. CONCLUSION: MDCT offers an accurate assessment of the coronary arteries, stented arteries and bypass grafts. The improved accuracy and safety of MDCT may reduce the need for catheter-based coronary angiography.

The role of abdominal radiography in the evaluation of the nontrauma emergency patient.

PURPOSE: To characterize the utility of abdominal radiography for nontrauma emergency patients in a single-institution setting. MATERIALS AND METHODS: Following approval from the Director of Professional Services, a retrospective review of radiography and of patient records was conducted for patients who presented to a nontrauma emergency department over a period of 6 months and who were imaged by using abdominal radiography. Only the first radiograph per patient was used for analysis. The interpretations were sorted as normal, nonspecific, or abnormal. The patients' medical records were reviewed to determine whether further imaging was performed (computed tomography, ultrasonography, or upper gastrointestinal imaging) and results were compared with abdominal radiography. Chart reviews were conducted to identify patients in whom abdominal radiography alone influenced treatment. RESULTS: In 874 patients, interpretation of abdominal radiography was normal in 34% (n = 300), nonspecific in 46% (n = 406), and abnormal in 19% (n = 168). Further imaging was performed for 50% (436) of all patients. Of 300 patients whose abdominal radiography results were normal, 42% (n = 125) had follow-up imaging; 72% (n = 90) of these showed abnormal, 78% (165 of 212) showed nonspecific, and 87% (86 of 99) showed abnormal findings. Of 438 patients who did not undergo follow-up imaging, 75% (n = 327) were discharged. For all indications other than catheter placement, abdominal radiography helped confirm the suspected diagnosis in 2%-8% of cases. In 37 (4%) of 874 patients, abdominal radiography was possibly helpful in changing patient treatment without a follow-up study. CONCLUSION: Abdominal radiography is often requested; however, its results contribute to patient treatment in a small percentage of cases. With the exception of catheter placement, if a patient requires investigation beyond clinical history, physical examination, and lab results, the emergency physician should be encouraged to request more definitive imaging.