AJNR. American journal of neuroradiology最新文献

The ASNR Neuroradiology Division Chief Working Group's 2023 survey, with responses from 62 division chiefs, provides insights into turnaround times, faculty recruitment, moonlighting opportunities, and academic funds. In emergency cases, 61% aim for a turnaround time of less than 45-60 minutes, with two-thirds meeting this expectation more than 75% of the time. For inpatient CT and MR imaging scans, 54% achieve a turnaround time of 4-8 hours, with three-quarters meeting this expectation at least 50% of the time. Outpatient scans have an expected turnaround time of 24-48 hours, which is met in 50% of cases. Faculty recruitment strategies included 35% offering sign-on bonuses, with a median of $30,000. Additionally, 23% provided bonuses to fellows during fellowship to retain them in the practice upon completion of their fellowship. Internal moonlighting opportunities for faculty were offered by 70% of divisions, with a median pay of $250 per hour. The median annual academic fund for a full-time neuroradiology faculty member was $6000, typically excluding license fees but including American College of Radiology and American Board of Radiology membership, leaving $4000 for professional expenses. This survey calls for further dialogue on adapting and innovating academic institutions to meet evolving needs in neuroradiology.

Background and purpose: Intracranial epidermoid tumors, temporal bone cholesteatomas, and head and neck epidermoid inclusion cysts are typically slow-growing, benign conditions arising from ectodermal tissue. They exhibit increased signal on DWI. While much of the imaging literature describes these lesions as showing diffusion restriction, we aimed to investigate these qualitative signal intensities and interpretations of restricted diffusion with respect to normal brain structures. This study aimed to quantitatively evaluate the ADC values and histogram features of these lesions.

Materials and methods: This retrospective study included children with histologically confirmed diagnoses of intracranial epidermoid tumors, temporal bone cholesteatomas, or head and neck epidermoid inclusion cysts. Lesions were segmented, and voxelwise calculation of ADC values was performed along with histogram analysis. ADC calculations were validated with a second analysis software to ensure accuracy. Normal brain ROIs-including the cerebellum, white matter, and thalamus-served as normal comparators. Correlational analysis and Bland-Altman plots assessed agreement among software tools for ADC calculations. Differences in the distribution of values between the lesions and normal brain tissues were assessed using the Wilcoxon rank sum and Kruskal-Wallis tests.

Results: Forty-eight pathology-proved cases were included in this study. Among them, 13 (27.1%) patients had intracranial epidermoid tumors, 14 (29.2%) had head and neck epidermoid inclusion cysts, and 21 (43.7%) had temporal bone cholesteatomas. The mean age was 8.67 (SD, 5.30) years, and 27 (52.9%) were female. The intraclass correlation for absolute agreement for lesional ADC between the 2 software tools was 0.997 (95% CI, 0.995-0.998). The intracranial epidermoid tumor, head and neck epidermoid inclusion cyst, and temporal bone cholesteatoma median ADC values were not significantly different (973.7 versus 875.7 versus 933.2 ×10^-6 mm²/s, P = .265). However, the ADCs of the 3 types of lesions were higher than those of 3 normal brain tissue types (933 versus 766, × 10^-6 mm²/s, P < .0001).

Conclusions: The ADC values of intracranial epidermoid tumors, temporal bone cholesteatomas, and head and neck epidermoid inclusion cysts are higher than those of normal brain regions. It is not accurate to simply classify these lesions as exhibiting restricted diffusion or reduced diffusivity without considering the tissue used for comparison. The observed hyperintensity on DWI compared with the brain is likely attributable to a relatively higher contribution of the T2 shinethrough effect.

Background and purpose: Recently, artificial intelligence tools have been deployed with increasing speed in educational and clinical settings. However, the use of artificial intelligence by trainees across different levels of experience has not been well-studied. This study investigates the impact of artificial intelligence assistance on the diagnostic accuracy for intracranial hemorrhage and large-vessel occlusion by medical students and resident trainees.

Materials and methods: This prospective study was conducted between March 2023 and October 2023. Medical students and resident trainees were asked to identify intracranial hemorrhage and large-vessel occlusion in 100 noncontrast head CTs and 100 head CTAs, respectively. One group received diagnostic aid simulating artificial intelligence for intracranial hemorrhage only (n = 26); the other, for large-vessel occlusion only (n = 28). Primary outcomes included accuracy, sensitivity, and specificity for intracranial hemorrhage/large-vessel occlusion detection without and with aid. Study interpretation time was a secondary outcome. Individual responses were pooled and analyzed with the t test; differences in continuous variables were assessed with ANOVA.

Results: Forty-eight participants completed the study, generating 10,779 intracranial hemorrhage or large-vessel occlusion interpretations. With diagnostic aid, medical student accuracy improved 11.0 points (P < .001) and resident trainee accuracy showed no significant change. Intracranial hemorrhage interpretation time increased with diagnostic aid for both groups (P < .001), while large-vessel occlusion interpretation time decreased for medical students (P < .001). Despite worse performance in the detection of the smallest-versus-largest hemorrhages at baseline, medical students were not more likely to accept a true-positive artificial intelligence result for these more difficult tasks. Both groups were considerably less accurate when disagreeing with the artificial intelligence or when supplied with an incorrect artificial intelligence result.

Conclusions: This study demonstrated greater improvement in diagnostic accuracy with artificial intelligence for medical students compared with resident trainees. However, medical students were less likely than resident trainees to overrule incorrect artificial intelligence interpretations and were less accurate, even with diagnostic aid, than the artificial intelligence was by itself.

Background and purpose: Symptoms of normal pressure hydrocephalus (NPH) are sometimes refractory to shunt placement, with limited ability to predict improvement for individual patients. We evaluated an MRI-based artificial intelligence method to predict postshunt NPH symptom improvement.

Materials and methods: Patients with NPH who underwent MRI before shunt placement at a single center (2014-2021) were identified. Twelve-month postshunt improvement in mRS, incontinence, gait, and cognition were retrospectively abstracted from clinical documentation. 3D deep residual neural networks were built on skull-stripped T2-weighted and FLAIR images. Predictions based on both sequences were fused by additional network layers. Patients from 2014-2019 were used for parameter optimization, while those from 2020-2021 were used for testing. Models were validated on an external validation data set from a second institution (n = 33).

Results: Of 249 patients, n = 201 and n = 185 were included in the T2-based and FLAIR-based models according to imaging availability. The combination of T2-weighted and FLAIR sequences offered the best performance in mRS and gait improvement predictions relative to models trained on imaging acquired by using only 1 sequence, with area under the receiver operating characteristic (AUROC) values of 0.7395 [0.5765-0.9024] for mRS and 0.8816 [0.8030-0.9602] for gait. For urinary incontinence and cognition, combined model performances on predicting outcomes were similar to FLAIR-only performance, with AUROC values of 0.7874 [0.6845-0.8903] and 0.7230 [0.5600-0.8859].

Conclusions: Application of a combined algorithm by using both T2-weighted and FLAIR sequences offered the best image-based prediction of postshunt symptom improvement, particularly for gait and overall function in terms of mRS.

Background and purpose: The neuroradiology job market is constantly changing along with the skill sets needed by fellowship graduates to participate successfully in the job market. This study aimed to establish a baseline of employer requirements in the neuroradiology job market within the study timeframe.

Materials and methods: The American Society of Neuroradiology and American College of Radiology job boards were queried for neuroradiology positions between August 12, 2022, and December 31, 2022. The positions and requirements were categorized into academic versus private practice, general diagnostic radiology, full-subspecialized neuroradiology, hybrid remote/onsite, outpatient, inpatient/emergency, general interventional radiology procedures, and neuroradiology procedures. Exclusion criteria included neurointerventional only, remote-only, pediatric-only, no preference for neuroradiology, and duplicate posts within and between the job boards.

Results: Of 1777 total job posts, 179 were neuroradiology-specific and the remainder were general. Of the 179 neuroradiology-specific jobs, 55 neuroradiology jobs were academic and 124 jobs were private practice. A higher proportion of private practice jobs required general diagnostic interpretations (83% versus 26%), a higher proportion of academic jobs required neuroradiology procedures (56% versus 31%), and a higher proportion of private practice jobs required general interventional radiology procedures (22% versus 0%). Thirty-nine percent of all neuroradiology-specific onsite jobs required neuroradiology procedures, and 15% required general interventional radiology procedures.

Conclusions: Because there was a sizable difference between general radiology and procedure requirements between academic and private practice positions, tailoring fellowship training for career aspirations of neuroradiology fellows should be considered to adapt to the skills needed for the evolving job market. In the queried timeframe, 61% of neuroradiology-specific onsite jobs did not have a specific procedure skill requirement for job applicants. This article serves as a single snapshot of the job market and its requirements for neuroradiologists, to aid in planning training to meet the needs of employers.

Noninvasive tumor control of vestibular schwannomas through stereotactic radiosurgery allows high rates of long-term tumor control and has been used primarily for small- and medium-sized vestibular schwannomas. The posttreatment imaging appearance of the tumor, temporal patterns of growth and treatment response, as well as extratumoral complications can often be both subtle or confusing and should be appropriately recognized. Herein, the authors present an imaging-based review of expected changes as well as associated complications related to radiosurgery for vestibular schwannomas.

Background and purpose: In fetuses with lateral ventriculomegaly and normal posterior fossa cerebrospinal spaces, third ventricle distention is a compelling clue that supports a diagnosis of aqueductal stenosis. However, this association assumes normal ventricular anatomy. Structural constraints can impair pressure-induced compliance. We aimed to determine how thalamic massa intermedia size alterations may impact the size of the third ventricle in the setting of congenital aqueductal stenosis.

Materials and methods: This retrospective study was performed at a single academic pediatric hospital after institutional review board approval. We searched our brain MRI reports for all examinations describing aqueductal stenosis and included all the patients who had both fetal and postnatal examinations. Patients with interhypothalamic adhesions and hydrocephalus unrelated to congenital aqueductal stenosis were excluded from this study. We evaluated all the MRIs for the presence of thalamic massa intermedia and documented third ventricle diameters (supraoptic recess, central and suprapineal recesses) and the thalamic massa intermedia circumference. The Spearman correlation was used to identify the potential relationship between the thalamic massa intermedia circumference and third ventricle size in fetal and postnatal MRIs. Patients were also stratified into 2 groups based on the presence or absence of thalamic massa intermedia. Mann-Whitney U tests were used to compare third ventricle diameters between these groups.

Results: The study included both fetal and postnatal studies from 59 patients. The overall third ventricle diameter was inversely proportional to the circumference of the thalamic massa intermedia in both groups (fetal: P = .001, ρ = -0.422; [95% CI, -0.628 to -0.181]; postnatal: P < .001, ρ = -0.653; [95% CI, -0.782 to -0.479]). Nonetheless, dilation of anterior and posterior recesses still occurred when the mid third ventricle was nondilated or less severely dilated in patients with an enlarged thalamic massa intermedia. Third ventricle dilation was most severe in patients lacking a thalamic massa intermedia compared with patients with a thalamic massa intermedia (P < .001).

Conclusions: In patients with suspected congenital aqueductal stenosis, lack of marked third ventriculomegaly as conventionally measured can sometimes be explained by thickening of the thalamic massa intermedia. In this circumstance, it is important to evaluate the extreme recesses of the third ventricle for evidence of dilation on fetal MRI.

Background and purpose: Imaging stewardship in the emergency department (ED) is vital in ensuring patients receive optimized care. While suspected cord compression (CC) is a frequent indication for total spine MR imaging in the ED, the incidence of CC is low. Recently, our level 1 trauma center introduced a survey spine MR imaging protocol to evaluate for suspected CC while reducing examination time to avoid imaging overutilization. This study aims to evaluate the time savings, frequency of ordering patterns of the survey, and the symptoms and outcomes of patients undergoing the survey.

Materials and methods: This retrospective study examined patients who received a survey spine MR imaging in the ED at our institution between 2018 and 2022. All examinations were performed on a 1.5T GE Healthcare scanner by using our institutional CC survey protocol, which includes sagittal T2WI and STIR sequences through the cervical, thoracic, and lumbar spine. Examinations were read by a blinded, board-certified neuroradiologist.

Results: A total of 2002 patients received a survey spine MR imaging protocol during the study period. Of these patients, 845 (42.2%, mean age 57 ± 19 years, 45% women) received survey spine MR imaging examinations for the suspicion of CC, and 120 patients (14.2% positivity rate) had radiographic CC. The survey spine MR imaging averaged 5 minutes and 50 seconds (79% faster than routine MR imaging). On multivariate analysis, trauma, back pain, lower extremity weakness, urinary or bowel incontinence, numbness, ataxia, and hyperreflexia were each independently associated with CC. Of the 120 patients with CC, 71 underwent emergent surgery, 20 underwent nonemergent surgery, and 29 were managed medically.

Conclusions: The survey spine protocol was positive for CC in 14% of patients in our cohort and acquired at a 79% faster rate compared with routine total spine. Understanding the positivity rate of CC, the clinical symptoms that are most associated with CC, and the subsequent care management for patients presenting with suspected cord compression who received the survey spine MR imaging may better inform the broad adoption and subsequent utilization of survey imaging protocols in emergency settings to increase throughput, improve allocation of resources, and provide efficient care for patients with suspected CC.

Background and purpose: Myelin maturation occurs in late fetal life to early adulthood, with the most rapid changes observed in the first few years of infancy. To quantify the degree of myelination, a specific MR imaging sequence is required to measure the changes in tissue proton relaxivity (R1). R1 positively correlates with the degree of myelination maturation at a given age. Similar to head circumference charts, these data can be used to develop normal growth charts for specific white matter tracts to detect pathologies involving abnormal myelination.

Materials and methods: This is a cross-sectional study using normal clinical pediatric brain MR images with the MP2RAGE sequence to generate T1 maps. The T1 maps were segmented to 75 brain regions from a brain atlas (white matter and gyri). Statistical modeling for all subjects across regions and the age range was computed, and estimates of population-level percentile ranking were computed to describe the effective myelination rate as a function of age. Test-retest analysis was performed to assess reproducibility. Logistic trendline and regression were performed for selected white matter regions and plotted for growth charts.

Results: After exclusion for abnormal MR imaging or diseases affecting myelination from the electronic medical record, 103 subject MR images were included, ranging from birth to 17 years of age. Test-retest analysis resulted in a high correlation for white matter (r = 0.88) and gyri (r = 0.95). All white matter regions from the atlas had significant P values for logistic regression with R ² values ranging from 0.41 to 0.99.

Conclusions: These data can serve as a myelination growth chart to permit patient comparisons with normal levels with respect to age and brain regions, thus improving detection of developmental disorders affecting myelin.