Multi-Parametric Radiomic Model to Predict 1p/19q Co-Deletion in Patients with IDH-1 Mutant Glioma: Added Value to the T2-FLAIR Mismatch Sign.

PURPOSE: The T2-FLAIR mismatch sign has shown promise in determining IDH mutant 1p/19q non-co-deleted gliomas with a high specificity and modest sensitivity. To develop a multi-parametric radiomic model using MRI to predict 1p/19q co-deletion status in patients with newly diagnosed IDH1 mutant glioma and to perform a comparative analysis to T2-FLAIR mismatch sign+. METHODS: In this retrospective study, patients with diagnosis of IDH1 mutant gliomas with known 1p/19q status who had preoperative MRI were included. T2-FLAIR mismatch was evaluated independently by two board-certified neuroradiologists. Texture features were extracted from glioma segmentation of FLAIR images. eXtremeGradient Boosting (XGboost) classifiers were used for model development. Leave-one-out-cross-validation (LOOCV) and external validation performances were reported for both the training and external validation sets. RESULTS: A total of 103 patients were included for model development and 18 patients for external testing validation. The diagnostic performance (sensitivity/specificity/accuracy) in the determination of the 1p/19q co-deletion status was 59%/83%/67% (training) and 62.5%/70.0%/66.3% (testing) for the T2-FLAIR mismatch sign. This was significantly improved (p = 0.04) using the radiomics model to 77.9%/82.8%/80.3% (training) and 87.5%/89.9%/88.8% (testing), respectively. The addition of radiomics as a computer-assisted tool resulted in significant (p = 0.02) improvement in the performance of the neuroradiologist with 13 additional corrected cases in comparison to just using the T2-FLAIR mismatch sign. CONCLUSION: The proposed radiomic model provides much needed sensitivity to the highly specific T2-FLAIR mismatch sign in the determination of the 1p/19q non-co-deletion status and improves the overall diagnostic performance of neuroradiologists when used as an assistive tool.

Vessel wall imaging with advanced flow suppression in the characterization of intracranial aneurysms following flow diversion with Pipeline embolization device.

BACKGROUND: High-resolution vessel wall MRI (VWI) is increasingly used to characterize intramural disorders of the intracranial vasculature unseen by conventional arteriography. OBJECTIVE: To evaluate the use of VWI for surveillance of flow diverter (FD) treated aneurysms. MATERIALS AND METHODS: Retrospective study of 28 aneurysms (in 21 patients) treated with a FD (mean 57 years; 14 female). All examinations included VWI and a contemporaneously obtained digital subtraction angiogram. Multiplanar pre- and post-gadolinium 3D, variable flip-angle T1 black-blood VWI was obtained using delay alternating nutation for tailored excitation (DANTE) at 3T. 3D time-of-flight MR angiography (MRA) was also carried out. Images were assessed for in-stent stenosis, aneurysm occlusion, presence and pattern/distribution of aneurysmal or parent vessel gadolinium enhancement. RESULTS: The VWI-MRI was performed on average at 361±259 days after the intervention. Follow-up DSA was performed at 338±254 days postintervention. Good or excellent black-blood angiographic quality was recorded in 22/28 (79%) pre-contrast and 21/28 (75%) post-contrast VWI, with no cases excluded for image quality. Aneurysm enhancement was noted in 24/28 (85.7%) aneurysms, including in 79% of angiographically occluded aneurysms and 100% of angiographically non-occluded aneurysms. Enhancement of the stented parent-vessel wall occurred significantly more often when aneurysm enhancement was present (92% vs 33%, p=0.049). CONCLUSION: Advanced VWI produces excellent depiction of FD-treated aneurysms, with robust evaluation of the parent vessel and aneurysm wall to an extent not achievable with conventional MRI/MRA. Gadolinium enhancement may, however, continue even after enduring catheter angiographic occlusion, confounding interpretation, and requiring cognizance of this potentially prolonged effect in such patients.

On-call radiology 2020: Where trainees look for help in a high stakes and time sensitive environment.

BACKGROUND: The radiology trainee on-call experience has undergone many changes in the past decade. The development of numerous online information sources has changed the landscape of opportunities for trainees seeking information while on-call. In this study, we sought to understand the current on-call information seeking behaviors of radiology trainees. METHODS: We surveyed radiology fellows and residents at three major metropolitan area academic institutions. Survey topics included demographic information, on-call volumes, on-call resource seeking behaviors, preferred first and second line on-call resources and rationale for particular resource usage. RESULTS: A total of 78 responses from trainees were recorded, 30.5% of the entire surveyed population. 70.5% of trainees preferred Radiopaedia as their first line resource. 26.9% of trainees preferred StatDx as their second line resource. 75.6% of respondents preferred their first line resource because it was easiest and fastest to access. 70.3% of respondents assigned a rating of 4 out of 5 when asked how often information they look for is found while on-call. There was a statistically significant difference according to gender (p = 0.002) with a higher percentage of males listing Radiopaedia as their first line resource compared to females. DISCUSSION: The radiology trainee on-call experience is influenced by various factors. Over the past decade, online resources, particularly the open access resource Radiopaedia and the paid service StatDx, have overwhelmingly become the preferred first and second line options, as demonstrated by our study results.

Spontaneous, Intrasphenoidal Rupture of Ecchordosis Physaliphora with Pneumocephalus Captured During Serial Imaging and Clinical Follow-Up: Pathoanatomic Features and Management.

BACKGROUND: Ecchordosis physaliphora (EP) is a congenital, uniformly asymptomatic, hamartomatous lesion of the primitive notochord. Herein we report, to our knowledge, the first credible case report of unprovoked intrasphenoidal rupture resulting in recurrent pneumocephalus and cerebrospinal fluid leak, definitively captured over serial imaging during clinical and radiologic surveillance. CASE DESCRIPTION: A 68-year old woman with Marfan syndrome presented to the emergency department with the worst headache of her life. Imaging demonstrated extensive pneumocephalus and revealed a small, dorsal midline clival lesion consistent with EP and a transsphenoidal defect. Remote imaging encounters confirmed typical EP without pneumocephalus or cortical defect, and an uneventful clinical course years preceding presentation. Over the ensuing months during neurosurgical follow-up, the patient reported recurrent headaches, imbalance, and unprovoked clear rhinorrhea. Further imaging demonstrated an apparently enlarging transsphenoidal defect which was managed by endoscopic transnasal resection and nasoseptal flap. Pathologic evaluation confirmed the diagnosis of EP and chronic dural defect. CONCLUSIONS: This represents, to our knowledge, the first unambiguous example of spontaneous EP rupture and recurrent pneumocephalus captured over serial imaging. The case further underscores rare but potentially significant complications of EP and highlights management options.

Radiological Management of Angiographically Negative, Spontaneous Intracranial Subarachnoid Hemorrhage: A Multicenter Study of Utilization and Diagnostic Yield.

BACKGROUND: The optimal diagnostic evaluation for patients with angiographically negative subarachnoid hemorrhage (AN-SAH) remains controversial. OBJECTIVE: To assess the utilization rate and diagnostic yield of imaging tests routinely obtained in identifying a structural cause for AN-SAH. METHODS: In this retrospective multicenter study, consecutive adult patients admitted with nontraumatic, AN-SAH between 01/2010 and 12/2015 were included. Patients with intraparenchymal, subdural, or epidural hematomas in addition to SAH were excluded. Outcomes studied included utilization rate, diagnostic yield, and median time from admission for the following imaging tests: initial computed tomography angiography (CTA) and digital subtraction angiography (DSA), brain and cervical spine magnetic resonance imaging (MRI), and any repeat DSA or CTA performed either during initial admission or at long-term follow-up. RESULTS: A total of 752 patients were included (mean age, 53 yr; 54% male). Initial CTA and DSA were performed in 89% and 100% of patients, respectively. Brain MRI was performed in 75% of patients and was positive in 0.7% of cases. Cervical spine MRI was performed in 61% of patients and was positive in 0.2% of cases. Repeat, same-admission follow-up DSA and CTA were performed in 48% and 51% of patients and were positive in 3.3% and 1% of cases, respectively. Delayed follow-up DSA and CTA after discharge were performed in 26% and 7% of patients and were positive in 2% and 3.7% of cases, respectively, all with negative prior imaging studies. CONCLUSION: Cervical spine and brain MRI have extremely low diagnostic yield, both are commonly utilized in patients with AN-SAH; while repeat DSA and CTA are utilized less commonly and have slightly higher diagnostic yield.