Atlas-Based Labeling of Resting-State fMRI.

Background: Functional magnetic resonance imaging (fMRI) has the potential to provide noninvasive functional mapping of the brain with high spatial and temporal resolution. However, fMRI independent components (ICs) must be manually inspected, selected, and interpreted, requiring time and expertise. We propose a novel approach for automated labeling of fMRI ICs by establishing their characteristic spatio-functional relationship. Methods: The approach identifies 9 resting-state networks and 45 ICs and generates a functional activation feature map that quantifies the spatial distribution, relative to an anatomical labeled atlas, of the z-scores of each IC across a cohort of 176 subjects. The cosine-similarity metric was used to classify unlabeled ICs based on the similarity to the spatial distribution of activation with the pregenerated feature map. The approach was tested on three fMRI datasets from the 1000 functional connectome projects, consisting of 280 subjects, that were not included in feature map generation. Results: The results demonstrate the effectiveness of the approach in classifying ICs based on their spatial features with an accuracy of better than 95%. Conclusions: The approach significantly reduces expert time and computation time required for labeling ICs, while improving reliability and accuracy. The spatio-functional relationship also provides an explainable relationship between the functional activation and the anatomically defined regions.

Evaluating the Robustness of a Deep Learning Bone Age Algorithm to Clinical Image Variation Using Computational Stress Testing.

Purpose To evaluate the robustness of an award-winning bone age deep learning (DL) model to extensive variations in image appearance. Materials and Methods In December 2021, the DL bone age model that won the 2017 RSNA Pediatric Bone Age Challenge was retrospectively evaluated using the RSNA validation set (1425 pediatric hand radiographs; internal test set in this study) and the Digital Hand Atlas (DHA) (1202 pediatric hand radiographs; external test set). Each test image underwent seven types of transformations (rotations, flips, brightness, contrast, inversion, laterality marker, and resolution) to represent a range of image appearances, many of which simulate real-world variations. Computational "stress tests" were performed by comparing the model's predictions on baseline and transformed images. Mean absolute differences (MADs) of predicted bone ages compared with radiologist-determined ground truth on baseline versus transformed images were compared using Wilcoxon signed rank tests. The proportion of clinically significant errors (CSEs) was compared using McNemar tests. Results There was no evidence of a difference in MAD of the model on the two baseline test sets (RSNA = 6.8 months, DHA = 6.9 months; P = .05), indicating good model generalization to external data. Except for the RSNA dataset images with an appended radiologic laterality marker (P = .86), there were significant differences in MAD for both the DHA and RSNA datasets among other transformation groups (rotations, flips, brightness, contrast, inversion, and resolution). There were significant differences in proportion of CSEs for 57% of the image transformations (19 of 33) performed on the DHA dataset. Conclusion Although an award-winning pediatric bone age DL model generalized well to curated external images, it had inconsistent predictions on images that had undergone simple transformations reflective of several real-world variations in image appearance. Keywords: Pediatrics, Hand, Convolutional Neural Network, Radiography Supplemental material is available for this article. © RSNA, 2024 See also commentary by Faghani and Erickson in this issue.

Generalizability and Bias in a Deep Learning Pediatric Bone Age Prediction Model Using Hand Radiographs.

Background Although deep learning (DL) models have demonstrated expert-level ability for pediatric bone age prediction, they have shown poor generalizability and bias in other use cases. Purpose To quantify generalizability and bias in a bone age DL model measured by performance on external versus internal test sets and performance differences between different demographic groups, respectively. Materials and Methods The winning DL model of the 2017 RSNA Pediatric Bone Age Challenge was retrospectively evaluated and trained on 12 611 pediatric hand radiographs from two U.S. hospitals. The DL model was tested from September 2021 to December 2021 on an internal validation set and an external test set of pediatric hand radiographs with diverse demographic representation. Images reporting ground-truth bone age were included for study. Mean absolute difference (MAD) between ground-truth bone age and the model prediction bone age was calculated for each set. Generalizability was evaluated by comparing MAD between internal and external evaluation sets with use of t tests. Bias was evaluated by comparing MAD and clinically significant error rate (rate of errors changing the clinical diagnosis) between demographic groups with use of t tests or analysis of variance and χ2 tests, respectively (statistically significant difference defined as P < .05). Results The internal validation set had images from 1425 individuals (773 boys), and the external test set had images from 1202 individuals (mean age, 133 months ± 60 [SD]; 614 boys). The bone age model generalized well to the external test set, with no difference in MAD (6.8 months in the validation set vs 6.9 months in the external set; P = .64). Model predictions would have led to clinically significant errors in 194 of 1202 images (16%) in the external test set. The MAD was greater for girls than boys in the internal validation set (P = .01) and in the subcategories of age and Tanner stage in the external test set (P < .001 for both). Conclusion A deep learning (DL) bone age model generalized well to an external test set, although clinically significant sex-, age-, and sexual maturity-based biases in DL bone age were identified. © RSNA, 2022 Online supplemental material is available for this article See also the editorial by Larson in this issue.

Improving Radiology Trainees' Perception Using Where's Waldo?

RATIONALE AND OBJECTIVES: Perception is an essential skill leading to expertise in diagnostic radiology. We determined if practicing "Where's Waldo?" images improves accuracy and speed with which first and second year radiology residents detect abnormalities on chest radiographs (CXRs). MATERIALS AND METHODS: Residents at three institutions were pretested using 50 CXRs, identifying locations of potential abnormalities. They were then split into trained (examining 7 "Where's Waldo?" images over three weeks) and control groups (no "Where's Waldo?"). They were then re-tested on the 50 CXRs. At one site, visual search parameters were acquired. Data were analyzed with repeated measures ANOVAs. RESULTS: There was no significant difference in performance for trained vs control (F = 0.622, p = 0.436), with both improving significantly on post-test (F = 4.72, p = 0.037). Session time decreased significantly for both groups from pre to post-test (F = 81.47, p < 0.0001) and the decrease was significantly more (F = 31.59, p < 0.0001) for the trained group than the control group as well as for PGY with PGY3 having a larger average decrease in session time than PGY2. Eye-tracking data also showed significant increases in per image search efficiency with training. CONCLUSION: Practicing "Where's Waldo?" or similar nonradiology search tasks may facilitate the acquisition of radiology image search but not detection skills, impacting reading efficiency more than detection accuracy.

Identification of the Somatomotor Network from Language Task-based fMRI Compared with Resting-State fMRI in Patients with Brain Lesions.

Background Resting-state functional MRI (rs-fMRI) is a potential alternative to task-based functional MRI (tb-fMRI) for somatomotor network (SMN) identification. Brain networks can also be generated from tb-fMRI by using independent component analysis (ICA). Purpose To investigate whether the SMN can be identified by using ICA from a language task without a motor component, the sentence completion functional MRI (sc-fMRI) task, compared with rs-fMRI. Materials and Methods The sc-fMRI and rs-fMRI scans in patients who underwent presurgical brain mapping between 2012 and 2016 were analyzed, using the same imaging parameters (other than scanning time) on a 3.0-T MRI scanner. ICA was performed on rs-fMRI and sc-fMRI scans with use of a tool to separate data sets into their spatial and temporal components. Two neuroradiologists independently determined the presence of the dorsal SMN (dSMN) and ventral SMN (vSMN) on each study. Groups were compared by using t tests, and logistic regression was performed to identify predictors of the presence of SMNs. Results One hundred patients (mean age, 40.9 years ± 14.8 [standard deviation]; 61 men) were evaluated. The dSMN and vSMN were identified in 86% (86 of 100) and 76% (76 of 100) of rs-fMRI scans and 85% (85 of 100) and 69% (69 of 100) of sc-fMRI scans, respectively. The concordance between rs-fMRI and sc-fMRI for presence of dSMN and vSMN was 75% (75 of 100 patients) and 53% (53 of 100 patients), respectively. In 10 of 14 patients (71%) where rs-fMRI did not show the dSMN, sc-fMRI demonstrated it. This rate was 67% for the vSMN (16 of 24 patients). Conclusion In the majority of patients, independent component analysis of sentence completion task functional MRI scans reliably demonstrated the somatomotor network compared with resting-state functional MRI scans. Identifying target networks with a single sentence completion scan could reduce overall functional MRI scanning times by eliminating the need for separate motor tasks. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Field and Birn in this issue.

Role of Functional Magnetic Resonance Imaging in the Presurgical Mapping of Brain Tumors.

When planning for brain tumor resection, a balance between maximizing resection and minimizing injury to eloquent brain parenchyma is paramount. The advent of blood oxygenation level-dependent functional magnetic resonance (fMR) imaging has allowed researchers and clinicians to reliably measure physiologic fluctuations in brain oxygenation related to neuronal activity with good spatial resolution. fMR imaging can offer a unique insight into preoperative planning for brain tumors by identifying eloquent areas of the brain affected or spared by the neoplasm. This article discusses the fMR imaging techniques and their applications in neurosurgical planning.

Dynamic Brain Connectivity in Resting State Functional MR Imaging.

Dynamic functional connectivity adds another dimension to resting-state functional MR imaging analysis. In recent years, dynamic functional connectivity has been increasingly used in resting-state functional MR imaging, and several studies have demonstrated that dynamic functional connectivity patterns correlate with different physiologic and pathologic brain states. In fact, evidence suggests that dynamic functional connectivity is a more sensitive marker than static functional connectivity; therefore, it might be a promising tool to add to clinical functional neuroimaging. This article provides a broad overview of dynamic functional connectivity and reviews its general principles, techniques, and potential clinical applications.

Are Women Disadvantaged in Academic Radiology?

RATIONALE AND OBJECTIVES: Women remain underrepresented in leadership positions in radiology. We sought to determine if 1) women are equitably represented in the senior author positions in radiology journals and 2) if women's contributions to the radiology literature and their individual productivity are proportional to their representation at senior academic rank. MATERIALS AND METHODS: The gender of 3,702 first and last authors listed for manuscripts published in nine high-impact American radiology journals was assessed between 2002-2017. For the same years, the gender composition of academic faculty and ranks based on AAMC data was queried. Statistical tests were employed to detect discrepancies and changes over time. RESULTS: First authorship by women grew from 26.9% to 37.4% and from 15.7% to 23.9% as senior author between 2002-2017 (P<.0001). Although the index of manuscript productivity rate was nearly equal for men and women over the 16-year study period, women remained under-represented in senior radiology faculty rank over the same period. CONCLUSIONS: Although women have proportionally increased their contribution to the radiology literature over the years, commensurate increased representation of women in senior authorship and faculty positions was not observed. Despite increased involvement of women in research over time, they remain disproportionately at junior faculty positions.

Vascular imaging in the initial evaluation of embolic stroke source.

PURPOSE: During acute ischemic stroke evaluations, neurovascular imaging is commonly performed to localize the source of a thromboembolus and to identify vascular stenoses. In this study, we aimed to analyze 1) the usefulness of intracranial and/or cervical CTA and MRA and carotid doppler ultrasound (DUS) for identifying the stroke source and 2) the incidence of vascular stenoses across stroke etiologies. METHODS: We retrospectively reviewed intracranial and/or cervical CTA, DUS and MRA studies to identify the source of the acute stroke by Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria for 200 consecutive patients admitted with a stroke to our tertiary hospital. Stroke etiologies were ascertained and the rates of intracranial and cervical vascular stenoses were stratified by stroke type. RESULTS: Of 200 patients, the most probable sources of stroke were small vessel disease (29%), cardioembolic (26.0%) and atheroembolic (23.5%). Across all groups, 27.5% of patients had ≥70% stenosis on neurovascular imaging. The rate of ≥70% vascular stenosis in the neck was 6.9% and 5.8% in the small vessel and cardioembolic categories, respectively. CONCLUSIONS: The TOAST etiologies of strokes were nearly equally distributed. Neurovascular imaging was of high utility for identifying large vessel intracranial stenoses in patients presenting with acute stroke across all etiologies, although neck CTA/MRA had a lower rate of positive studies with cardiogenic and small vessel strokes. These findings have implications on the use of CTA/MRA in acute stroke work-up.

Intravenous Tissue Plasminogen Activator in Combination With Mechanical Thrombectomy: Clot Migration, Intracranial Bleeding, and the Impact of "Drip and Ship" on Effectiveness and Outcomes.

Purpose: Intravenous tissue plasminogen activator (tPA) is indicated prior to mechanical thrombectomy (MT) to treat large vessel occlusion (LVO). However, administration takes time, and rates of clot migration complicating successful retrieval and hemorrhagic transformation may be higher. Given time-to-effectiveness, the benefit of tPA may vary significantly based on whether administration occurs at a thrombectomy-capable center or transferring hospital. Methods: We prospectively evaluated 170 individuals with LVO involving the anterior circulation who underwent MT at our Comprehensive Stroke Center over a 3.5 year period. Two thirds (n = 114) of patients were admitted through our Emergency Department (ED). The other 33% were transferred from outside hospitals (OSH). Patients meeting criteria were bridged with IV tPA; the others were treated with MT alone. Clot migration, recanalization times, TICI scores, and hemorrhage rates were compared for those bridged vs. treated with MT alone, along with modified Rankin scores (mRS) at discharge and 90-day follow-up. Multivariable regression was used to determine the relationship between site of presentation and effect of tPA on outcomes. Results: Patients presenting to an OSH had longer mean discovery to puncture/recanalization times, but were actually more likely to receive IV tPA prior to MT (70 vs. 42%). The rate of clot migration was low (11%) and similar between groups, though slightly higher for those receiving IV tPA. There was no difference in symptomatic ICH rate after tPA. TICI scores were also not significantly different; however, more patients achieved TICI 2b or higher reperfusion (83 vs. 67%, p = 0.027) after tPA, and TICI 0 reperfusion was seen almost exclusively in patients who were not treated with tPA. Those bridged at an OSH required fewer passes before successful recanalization (2.4 vs. 1.6, p = 0.037). Overall, mean mRS scores on discharge and at 90 days were significantly better for those receiving IV tPA (3.9 vs. 4.6, 3.4 vs. 4.4 respectively, p ~ 0.01) and differences persisted when comparing only patients recanalized in under 6 h. Conclusion: Independent of site of presentation, IV tPA before MT appears to lead to better radiographic outcomes, without increased rates of clot migration or higher intracranial hemorrhage risk, and overall better functional outcomes.

Fellowship Candidate Factors Considered by Program Directors.

OBJECTIVE: The neuroradiology fellowship match has been in existence for about 20 years. However, the elements by which neuroradiology fellowship program directors evaluate candidates have not been clearly elucidated. We sought to identify the factors that program directors use to rank neuroradiology fellowship applicants. METHODS: An anonymous Qualtrics online five-question survey about educational credentials, personal traits, extracurricular activities, and demographic characteristics was sent to 72 neuroradiology program directors in April 2019. Each question required ranking of 10 factors based on different characteristics of fellowship candidates. Items included gender, nationality, US Medical Licensing Examination scores, internal applicants, work and research experience, recommendation letters, residency program, medical school attended, and visa status. Program directors had the ability to list any new characteristics that were not included in the survey. RESULTS: In all, 68 of 72 (94.4%) neuroradiology programs responded to the survey. The most important criteria by which candidates were assessed were (1) residency program attended for educational credential, (2) personality as assessed by faculty at interviews for candidate personal traits, (3) research performed for candidate's extracurricular activities, and (4) likelihood of coming to or previous experience in the fellowship geographic area. Neuroradiology program directors independently stressed residency program attended, personality assessed during the interview by faculty, internal candidate status, letters of recommendation, and research activities as their top five criteria in ranking the candidates. CONCLUSION: Multiple factors are weighed by neuroradiology fellowship program directors in selecting fellows, but recent experiences in residency, research, and faculty interactions are prioritized. Internal candidates have an advantage for remaining as fellows within their residency programs.

Musculoskeletal Radiology Reports: Overlooked or Valuable?

The electronic medical record (EMR) can reveal preferences of clinicians regarding imaging services. We sought to evaluate viewing habits for reports and images of musculoskeletal (MSK) studies by ordering clinicians. We hypothesized that MSK reports are important to clinical management, especially for advanced imaging modalities. We tracked the image and report access of all MSK studies ordered in September 2016 over 8 months using logs of the EMR (Epic Systems, Verona, WI), and by an independent analysis of the institutional PACS (Picture Archiving and Communication Systems) (Carestream Health, Rochester, NY). The time stamps were extracted for when images and reports were viewed. We categorized MSK studies by modality and provider department. We also compared the rates of viewing reports and images among different modalities and departments using the chi-square test. Of the 8143 viewed MSK studies, 7842 (96.3%) reports (with/without images) and 3916 (48.1%) imaging data (with/without reports) were viewed. Viewing reports alone occurred in 4227 (51.9%) studies. CT and MRI reports alone views occurred more often in comparison to radiographs ([482/706; 68.3%] for CT and [981/1713; 57.3%] for MRI vs. [2764/5724; 48.3%] for radiography, p < 0.001). Orthopedists ordered the highest number of MSK studies and viewed reports 99.2% (3216/3242) of the time, including a 54.6% (1770/3242) rate of viewing reports alone and a 44.6% (1446/3242) rate of viewing both reports and images. They viewed images without reports in 0.8% (27/3242) of cases. MSK reports were viewed significantly more frequently than the images across all modalities and all relevant specialties.

Functional Connectivity in Neurodegenerative Disorders: Alzheimer's Disease and Frontotemporal Dementia.

Neurodegenerative disorders are a growing cause of morbidity and mortality worldwide. Onset is typically insidious and clinical symptoms of behavioral change, memory loss, or cognitive dysfunction may not be evident early in the disease process. Efforts have been made to discover biomarkers that allow for earlier diagnosis of neurodegenerative disorders, to initiate treatment that may slow the course of clinical deterioration. Neuronal dysfunction occurs earlier than clinical symptoms manifest. Thus, assessment of neuronal function using functional brain imaging has been examined as a potential biomarker. While most early studies used task-functional magnetic resonance imaging (fMRI), with the more recent technique of resting-state fMRI, "intrinsic" relationships between brain regions or brain networks have been studied in greater detail in neurodegenerative disorders. In Alzheimer's disease, the most common neurodegenerative disorder, and frontotemporal dementia, another of the common dementias, specific brain networks may be particularly susceptible to dysfunction. In this review, we highlight the major findings of functional connectivity assessed by resting state fMRI in Alzheimer's disease and frontotemporal dementia.

Magnetic resonance imaging findings in Parinaud's syndrome: comparing pineal mass findings to other etiologies.

PURPOSE: In a recent study, it was found that, although intrinsic midbrain signal abnormality (IMSA) on MRI is associated with Parinaud's syndrome (PS) in patients with pineal gland masses (PM), it had no predictive value with respect to resolution of PS. We sought to compare the PM and non-pineal etiologies (NPE) of PS by reviewing imaging features of PS and whether or not they are predictive of resolution of symptoms. METHODS: We reviewed electronic medical records from 1980 to 2017 and identified 71 patients with PS from any etiology who had MR imaging: 26 with PM and 45 with NPE. We subdivided the 45 NPE patients into those with intrinsic midbrain lesions (IMBL) (n = 23) and those with extrinsic midbrain lesions (EMBL) (n = 22). PS resolution and hydrocephalus data were collected. Imaging studies were reviewed for the presence of IMSA and hydrocephalus. RESULTS: PS patients with EMBL were less likely to have IMSA than those with PM or IMBL (p ≤0.001). PS resolution occurred more commonly with PM than IMBL and NPE (p = 0.03, p = 0.01). For all NPE patients, resolution of PS occurred with equal frequency in patients with and without IMSA (p = 1.00). Hydrocephalus occurred more frequently in patients with PM and EMBL than IMBL (p = 0.01, p = 0.03). CONCLUSIONS: IMSA is present more often in patients with PS from PM or IMBL than in patients with EMBL. EMBL, including PM, have an increased likelihood for PS resolution. There is no predictive value of IMSA with respect to resolution of PS in NPE as well as PM.

The Policy of Co-First Authorship and Co-Senior Authorship in Radiology Journals.

OBJECTIVE: Increasingly, medical journals are recognizing "equally credited authors" (ECA) in the primary and senior authorship of articles. The aim of this study was to assess the policies of co-first authorship, co-senior authorship, and designation of a corresponding author in the radiology literature. METHODS: We identified 29 radiology journals based on impact factor ranking. Journal offices were contacted by phone and e-mail to ascertain their practices on first and senior authorship ECA designations. We surveyed the March, June, and December 2018 issues of each journal (when available) to assess the utilization of the co-designations in articles. RESULTS: Twenty-five of 29 journals responded to our survey (response rate: 86.2%). Of 25 journals, 20 (80%) allowed co-first authorship. Among these, 4 of 25 journals (16%) allowed more than two co-first authors. Among the 25 responses, 14 journals (56%) allowed co-senior authorship. Among the 24 journals who responded to this specific question, 23 (96%) approved designation of a corresponding author, different from the first or senior author. The review of March, June, December 2018 editions found co-first authorship and co-senior authorship ECA rates of 8.6% (range 0.0%-22.7%) and 1.8% (range 0.0%-13.3%), respectively. A corresponding author other than first or senior author was noted in 13.3% (range 0.0%-34.7%). DISCUSSION: There has been widespread acceptance of the concept of ECA in the policies of the top cited imaging journals particularly for first authors (80%). However, the utilization of these designations is uncommon for first authorship (8.6%) and rare (1.8%) for senior authorship based on our 2018 sampling.

Combination of Hydroquinone and Fractional CO2 Laser versus Hydroquinone Monotherapy in Melasma Treatment: A Randomized, Single-blinded, Split-face Clinical Trial.

BACKGROUND: Melasma is a chronic hyperpigmentation skin disorder mainly affecting women in the reproductive age. Available treatments for melasma do not lead to long-term satisfactory results. AIMS: This study aimed to compare the efficacy of fractional CO2 laser in combination with topical therapy to topical therapy alone. MATERIALS AND METHODS: Forty women with bilateral melasma were studied in this randomized single-blinded clinical trial. Each side of the face was randomly allotted to either topical hydroquinone 4% or combination of topical hydroquinone 4% and fractional CO2 laser. Patients received three sessions of laser therapy at 3-week intervals. Hydroquinone 4% application on both sides maintained for 3 months after the last laser session. The clinical improvement (darkness [D] and homogeneity [H] of hyperpigmentation) was measured by a blinded main investigator and an outcome assessor. Furthermore, improvement was assessed by physician's global assessment (PGA) and patient satisfaction (visual analog scale [VAS] score). RESULTS: Significant reduction in D observed 3 weeks after combination therapy (P<0.001) and 6 weeks after monotherapy (P<0.001). Reduction in H became significant after 6 weeks in both groups (P<0.001). However, the two methods were not considerably different in any session (P>0.05). Furthermore, control and experiment sides were not significantly different considering VAS score and PGA (P>0.05). CONCLUSION: Considering the short-term outcome of laser and hydroquinone therapy, we can apply it to obtain earlier positive results. However, because of the lack of significant difference between the two methods and also the high cost of laser therapy, it seems better not to recommend fractional CO2 laser to patients as adjunctive therapy for long-term treatment of melasma.

Missed Opportunity: Neuroradiology Training Programs and Social Media.

OBJECTIVE. The purpose of this study was to ascertain the degree to which the academic neuroradiology community is embracing social media in its messaging. The hypothesis was that, compared with peer neurosurgery and neurology programs, a majority of neuroradiology programs would actively engage through Facebook and Twitter accounts. MATERIALS AND METHODS. An Internet search was conducted for Facebook, Twitter, LinkedIn, and Instagram accounts for the 75 National Resident Matching Program-registered U.S. neuroradiology fellowship programs and their division chiefs and for the neurosurgery and neurology social media accounts of the same institutions. The content and audience responses of the neuroradiology accounts were categorized. RESULTS. Only 8 of 75 neuroradiology programs had one or more social media accounts. Neurosurgery (odds ratio, 5.9; 95% CI, 2.5-14.0) and neurology (odds ratio, 3.2; 95% CI, 1.3-7.9) had a significantly greater social media presence than neuroradiology did. Larger neuroradiology programs (five or more fellowship positions) had significantly greater likelihood (odds ratio, 7.6,; 95% CI, 1.6-36.4) of having social media accounts compared with those with fewer than five positions. Division chiefs had accounts on LinkedIn more than other media. Few neuroradiology chiefs actively engaged professionally on Facebook and Twitter. Most neuroradiology programs used social media more for recruitment and program information than for education, research, or patient information. CONCLUSION. Most neuroradiology training programs do not have social media accounts and do not use social media for education, engagement, recruitment, or research promulgation. Neurosurgery and neurology programs have more but still limited World Wide Web representation. There is an opportunity for neuroradiology programs to have greater impact in this arena.

MRI findings in Parinaud's syndrome: a closer look at pineal masses.

PURPOSE: The association between MRI findings in patients with pineal lesions and the presence or absence of Parinaud's syndrome (PS) remains poorly described. We sought to better understand what MRI characteristics of a pineal lesion make PS more likely. Can these features predict prognosis for clinical resolution? Based on the anatomical relationship of the pineal gland and midbrain, we hypothesized that the degree of midbrain injury by a pineal mass as assessed by abutment, displacement, or intrinsic midbrain signal abnormality (IMSA) may predict PS. METHODS: We reviewed our institution's databases to find patients with MRI evidence of an intrinsic lesion of the pineal gland. Seventy-seven patients with intrinsic pineal gland lesions, 26 with PS and 51 without PS (NPS), were identified. Data regarding clinical history were collected, and an experienced neuroradiologist reviewed all MRI studies and recorded mass size, midbrain abutment, displacement by the pineal lesion, and presence or absence of IMSA. RESULTS: IMSA occurred with increased frequency in pineal lesions with PS (85%) when compared with NPS (39.2%) (p = 0.0001). Midbrain abutment, compression, and displacement occurred with similar frequencies in both groups, with no statistically significant difference. Hydrocephalus was present in 80.8% of patients with PS and 84% without PS (p = 0.75). CONCLUSION: IMSA in a patient with an intrinsic pineal gland mass is associated with PS. Other findings such as hydrocephalus and midbrain displacement are common in patients with pineal masses both with and without PS and do not have any predictive value.

"Worst Headache of Life" in a Migraineur: Marginal Value of Emergency Department CT Scanning.

PURPOSE: The ACR Appropriateness Criteria recommend performing noncontrast head CT (NCCT) for patients with sudden severe headache ("worst headache of life" [WHOL] or "thunderclap headache" [TCH]). The aim of this study was to assess the value of NCCT scanning in patients with known migraine histories and WHOL or TCH. The hypothesis was that there would be little utility in performing emergency department (ED) NCCT scans in migraineurs without other red flags, even if they had WHOL or TCH. METHODS: The ED NCCT scans of all patients reporting WHOL or TCH who had established diagnoses of migraine were retrospectively reviewed over a 5-year period. Patients without known intracranial pathology, cancer, or immunocompromising disease or recent head trauma were included as the main study group. For comparison, patients with any of those factors were included as the comparison group. Scans were graded as (1) normal, (2) minor unimportant findings, (3) findings requiring intervention or follow-up, or (4) critical. RESULTS: Two hundred twenty-four patients with the chief symptom of WHOL or TCH and a history of migraine who underwent ED NCCT were studied. In the main study group, no patients had grade 4 imaging findings (0%), one had a false-positive grade 3 finding (0.8%), and there were no cases of subarachnoid hemorrhage (0%). In the comparison group, six patients had grade 4 imaging findings (6.5%) and three had grade 3 findings (3.3%). CONCLUSIONS: NCCT in known migraineurs with WHOL or TCH who do not have intracranial pathology, cancer, immunocompromising disease, or recent head trauma yielded no critical findings. Therefore, the value of scanning these patients is questionable.