Fully automated 3D machine learning model for HPV status characterization in oropharyngeal squamous cell carcinomas based on CT images.

BACKGROUND: Human papillomavirus (HPV) status plays a major role in predicting oropharyngeal squamous cell carcinoma (OPSCC) survival. This study assesses the accuracy of a fully automated 3D convolutional neural network (CNN) in predicting HPV status using CT images. METHODS: Pretreatment CT images from OPSCC patients were used to train a 3D DenseNet-121 model to predict HPV-p16 status. Performance was evaluated by the ROC Curve (AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and F1 score. RESULTS: The network achieved a mean AUC of 0.80 ± 0.06. The best-preforming fold had a sensitivity of 0.86 and specificity of 0.92 at the Youden's index. The PPV, NPV, and F1 scores are 0.97, 0.71, and 0.82, respectively. CONCLUSIONS: A fully automated CNN can characterize the HPV status of OPSCC patients with high sensitivity and specificity. Further refinement of this algorithm has the potential to provide a non-invasive tool to guide clinical management.

Emergence of the natural history of Myhre syndrome: 47 patients evaluated in the Massachusetts General Hospital Myhre Syndrome Clinic (2016-2023).

Myhre syndrome is an increasingly diagnosed ultrarare condition caused by recurrent germline autosomal dominant de novo variants in SMAD4. Detailed multispecialty evaluations performed at the Massachusetts General Hospital (MGH) Myhre Syndrome Clinic (2016-2023) and by collaborating specialists have facilitated deep phenotyping, genotyping and natural history analysis. Of 47 patients (four previously reported), most (81%) patients returned to MGH at least once. For patients followed for at least 5 years, symptom progression was observed in all. 55% were female and 9% were older than 18 years at diagnosis. Pathogenic variants in SMAD4 involved protein residues p.Ile500Val (49%), p.Ile500Thr (11%), p.Ile500Leu (2%), and p.Arg496Cys (38%). Individuals with the SMAD4 variant p.Arg496Cys were less likely to have hearing loss, growth restriction, and aortic hypoplasia than the other variant groups. Those with the p.Ile500Thr variant had moderate/severe aortic hypoplasia in three patients (60%), however, the small number (n = 5) prevented statistical comparison with the other variants. Two deaths reported in this cohort involved complex cardiovascular disease and airway stenosis, respectively. We provide a foundation for ongoing natural history studies and emphasize the need for evidence-based guidelines in anticipation of disease-specific therapies.

Multisystem factors contributing to redundant intracranial vascular imaging in the ED.

PURPOSE: To evaluate the multisystem factors contributing to redundant neurovascular orders in the ED. METHODS: This was an IRB-approved, retrospective study, performed at a single institution examining a 5-year history of redundant CTA/MRA head and neck (HN) exams performed in the ED for patients with no documented clinical change in mental status/neurological exam necessitating additional imaging. Factors contributing to redundant ordering including provider experience, synchronous order placement, and radiologist recommendations were examined. Additionally, the impact of duplicative imaging in terms of medical cost and ED length of stay was evaluated. RESULTS: 250 patients met inclusion criteria with both CTA/MRA of the HN performed during a single ED encounter (total 500 exams). 190 (76%) redundant exams were not recommended by a radiologist and contributed to an added ED length of stay of 3.6 h on average. Provider experience was not a significant contributing factor. 60 (24%) of redundant exams were recommended by a radiologist and were most frequently CTAs needed to clarify an area of artifact/high-grade stenosis/occlusion on a primary MRA exam. CONCLUSION: Evaluation of contributing factors to redundant CTA/MRA HN exams ordering has highlighted multiple associated factors including provider experience, recommendations by radiologists for clarification of MRA findings, as well as systems processes related to synchronous CTA/MRA order placement.

Implementation of a Survey Spine Magnetic Resonance Imaging Protocol for Cord Compression in the Emergency Department: Experience at a Level-1 Trauma Center.

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 MRI in the ED, the incidence of CC is low. Recently, our level-I trauma center introduced a survey spine MRI protocol to evaluate for suspected CC while reducing exam 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 MRI in the ED at our institution between 2018 and 2022. All exams were performed on a 1.5T GE scanner using our institutional CC survey protocol, which includes sagittal T2 and STIR sequences through the cervical, thoracic, and lumbar spine. Exams were read by a blinded, board-certified neuroradiologist. RESULTS: A total of 2,002 patients received a survey spine MRI protocol during the study period. Of these patients, 845 (42.2%, mean age 57 ± 19 years, 45% female) received survey spine MRI exams for the suspicion of CC, and 120 patients (14.2% positivity rate) had radiographic CC. The survey spine MRI averaged 5 minutes and 50 seconds (79% faster than routine MRI). 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 non-emergent 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 to 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 MRI 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.ABBREVIATIONS: CC, cord compression; ED, emergency department; MRI, magnetic resonance imaging; T2; T2-weighted imaging sequence; STIR, short TI inversion recovery.

Coronal Diffusion-Weighted Imaging Does Not Improve Detection of Posterior Fossa Infarcts Compared With Conventional Axial Diffusion-Weighted Imaging.

PURPOSE: Recent publications have suggested incorporating coronal diffusion-weighted imaging (DWI) sequences and axial DWI sequences to enhance the detection of posterior fossa infarcts (PFIs). This study evaluated the utility of coronal DWIs compared with axial DWIs for assessing PFIs in the emergency department (ED). METHODS: A retrospective, institutional review board-approved study was conducted at a level I stroke center, including 118 patients who presented to the ED between 2016 and 2023 with suspected PFI. Inclusion criteria involved patients who underwent emergent 1.5 T magnetic resonance imaging (MRI) and had axial and coronal DWI sequences. Two neuroradiologists independently evaluated the DWI sequences for PFI detection in 2 rounds, with a 4-week interval between rounds. The neuroradiologists assessed the quality of axial and coronal DWIs using a 5-point Likert scale. Descriptive statistics, interrater reliability, and marginal homogeneity tests were performed. RESULTS: Among the 118 MRI scans, 23 (19%) showed PFI on axial and coronal DWI sequences. All 23 cases were identified on axial DWI, whereas 8 cases of PFI (35%) were not detected on coronal DWI (P value = 0.013). No PFIs were observed on coronal DWI that was not identified on axial DWI. The quality scores for both raters were significantly higher for axial DWIs than coronal DWIs (P value <0.00001). CONCLUSION: Despite recent recommendations advocating for the inclusion of coronal DWI in PFI detection, this study's findings indicate no improvement in PFI detection or image quality using coronal DWI. Further research is necessary to validate these results and explore the potential benefits of incorporating coronal DWI in assessing posterior fossa strokes.

Correlating Evans Index, Callosal Angle, and Lateral Ventricle Volume With Gait Response Outcomes in Idiopathic Normal Pressure Hydrocephalus Diagnosis.

OBJECTIVE: Radiological imaging is pivotal in diagnosing idiopathic normal pressure hydrocephalus (iNPH), given the similarity of its symptoms to other neurodegenerative diseases. We aimed to correlate the Evans index (EI), callosal angle (CA), and the volume of the lateral ventricles measured before cerebrospinal fluid removal with the resultant outcomes in gait response. METHODS: In our retrospective study, we identified 42 patients with a diagnosis of iNPH. These patients underwent gait analysis, imaging, and lumbar puncture. Radiological assessments included measurements of CA EI and lateral ventricular volume. Clinically, we assessed the following 4 gait parameters: cadence, gait speed, stride length, and timed up and go. Change in the 4 gait parameters was calculated, normalized, and compiled into a composite score, following which the group was divided into 'responders' and 'nonresponders' based on z score of 0.5. Our dependent variable was clinical improvement in gait, and our independent variables included lateral ventricular volume, EI, and CA. We performed a Wilcoxon rank-sum test to compare significant responder status using CA, EI, and lateral ventricle volume. A receiver operating characteristic analysis was employed to determine which volume measurement exhibited the strongest correlation with responder status. Determining the significant variables, a chi-square analysis was subsequently conducted.A significance threshold was set at P < 0.05. All our statistical evaluations were conducted in the Spyder environment, which is compatible with Python 3.10. RESULTS: There was a significant difference for responder status in EI and lateral ventricle volume. Evan index showing a statistic of 2.202 (P value = 0.02) and lateral ventricle volume demonstrating a statistic of 2.086 (P value = 0.03). Subsequent exploration using receiver operating characteristic analysis, with area under the curve of 0.71, identified 105.40 cm3 as the most robustly correlated volume threshold with responder status. CONCLUSIONS: The lateral ventricular volume demonstrates a stronger correlation with gait improvement compared to the CA or EI. These observations indicate that evaluating the lateral ventricle volume before lumbar puncture could serve as a predictor for gait response after lumbar puncture in individuals with normal pressure hydrocephalus.

Trends in non-focal neurological chief complaints and CT angiography utilization among adults in the emergency department.

Prudent imaging use is essential for cost reduction and efficient patient triage. Recent efforts have focused on head and neck CTA in patients with emergent concerns for non-focal neurological complaints, but have failed to demonstrate whether increases in utilization have resulted in better care. The objective of this study was to examine trends in head and neck CTA ordering and determine whether a correlation exists between imaging utilization and positivity rates. This is a single-center retrospective observational study at a quaternary referral center. This study includes patients presenting with headache and/or dizziness to the emergency department between January 2017 and December 2021. Patients who received a head and neck CTA were compared to those who did not. The main outcomes included annual head and neck CTA utilization and positivity rates, defined as the percent of scans with attributable acute pathologies. Among 24,892 emergency department visits, 2264 (9.1%) underwent head and neck CTA imaging. The percentage of patients who received a scan over the study period increased from 7.89% (422/5351) in 2017 to 13.24% (662/5001) in 2021, representing a 67.4% increase from baseline (OR, 1.14; 95% CI 1.11-1.18; P < .001). The positivity rate, or the percentage of scans ordered that revealed attributable acute pathology, dropped from 16.8% (71/422) in 2017 to 10.4% (69/662) in 2021 (OR, 0.86; 95% CI 0.79-0.94; P = .001), a 38% reduction in positive examinations. Throughout the study period, there was a 67.4% increase in head and neck CTA ordering with a concomitant 38.1% decrease in positivity rate.

Using Texture Analysis of Neck Computed Tomography Images to Differentiate Primary Hyperparathyroidism From Normal Controls.

OBJECTIVE: To investigate the utility of texture analysis in detecting osseous changes associated with hyperparathyroidism on neck CT examinations compared with control patients and to explore the best regions in the head and neck to evaluate changes in the trabecular architecture secondary to hyperparathyroidism. METHODS: Patients with hyperparathyroidism who underwent a 4D CT of the neck with contrast were included in this study. Age-matched control patients with no history of hyperparathyroidism who underwent a contrast-enhanced neck CT were also included. Mandibular condyles, bilateral mandibular bodies, the body of the C4 vertebra, the manubrium of the sternum, and bilateral clavicular heads were selected for analysis, and oval-shaped regions of interest were manually placed. These segmented areas were imported into an in-house developed texture analysis program, and 41 texture analysis features were extracted. A mixed linear regression model was used to compare differences in the texture analysis features contoured at each of the osseous structures between patients with hyperparathyroidism and age-matched control patients. RESULTS: A total of 30 patients with hyperparathyroidism and 30 age-matched control patients were included in this study. Statistically significant differences in texture features between patients with hyperparathyroidism and control patients in all 8 investigated osseous regions. The sternum showed the greatest number of texture features with statistically significant differences between these groups. CONCLUSIONS: Some CT texture features demonstrated statistically significant differences between patients with hyperparathyroidism and control patients. The results suggest that texture features may discriminate changes in the osseous architecture of the head and neck in patients with hyperparathyroidism.

No Surprises Act: Legal Challenges and Implications for Radiology.

When the word "surprise" is used as a noun, it generally describes an unexpected event. When "surprise" is used in conjunction with "billing", it conjures up images with which even the most hardened backroom medical administrator can empathize. One's first reaction is likely patient based, that a person received medical services from a health care provider or facility that are larger than anticipated in-network charges. As a result, the bill for services incorporates that, no-doubt unpleasant, surprise. The whole truth is understandably more complex. Radiology groups contract with insurance companies who for their own reasons, might have historically preferred progressively narrower networks. Nonetheless, these contracts allow providers the opportunity to negotiate reasonable payments for services rendered. Events have changed the historic dynamic between providers and insurance companies.

An imaging review of the hippocampus and its common pathologies.

The hippocampus is a complex structure located in the mesial temporal lobe that plays a critical role in cognitive and memory-related processes. The hippocampal formation consists of the dentate gyrus, hippocampus proper, and subiculum, and its importance in the neural circuitry makes it a key anatomic structure to evaluate in neuroimaging studies. Advancements in imaging techniques now allow detailed assessment of hippocampus internal architecture and signal features that has improved identification and characterization of hippocampal abnormalities. This review aims to summarize the neuroimaging features of the hippocampus and its common pathologies. It provides an overview of the hippocampal anatomy on magnetic resonance imaging and discusses how various imaging techniques can be used to assess the hippocampus. The review explores neuroimaging findings related to hippocampal variants (incomplete hippocampal inversion, sulcal remnant and choroidal fissure cysts), and pathologies of neoplastic (astrocytoma and glioma, ganglioglioma, dysembryoplastic neuroepithelial tumor, multinodular and vacuolating neuronal tumor, and metastasis), epileptic (mesial temporal sclerosis and focal cortical dysplasia), neurodegenerative (Alzheimer's disease, progressive primary aphasia, and frontotemporal dementia), infectious (Herpes simplex virus and limbic encephalitis), vascular (ischemic stroke, arteriovenous malformation, and cerebral cavernous malformations), and toxic-metabolic (transient global amnesia and opioid-associated amnestic syndrome) etiologies.

Christianson Syndrome across the Lifespan: An International Longitudinal Study in Children, Adolescents, and Adults.

Mutations in the X-linked endosomal Na+/H+ Exchanger 6 (NHE6) causes Christianson Syndrome (CS). In the largest study to date, we examine genetic diversity and clinical progression, including cerebellar degeneration, in CS into adulthood. Data were collected as part of the International Christianson Syndrome and NHE6 (SLC9A6) Gene Network Study. Forty-four individuals with 31 unique NHE6 mutations, age 2 to 32 years, were followed prospectively, herein reporting baseline, 1-year follow-up, and retrospective natural history. We present data on the CS phenotype with regard to physical growth, adaptive and motor regression, and across the lifespan, including information on mortality. Longitudinal data on body weight and height were examined using a linear mixed model: the rate of growth across development was slow and resulted in prominently decreased age-normed height and weight by adulthood. Adaptive functioning was longitudinally examined: a majority of adult (18+ years) participants lost gross and fine motor skills over a 1-year follow-up. Previously defined core diagnostic criteria for CS (present in >85%) - namely nonverbal status, intellectual disability, epilepsy, postnatal microcephaly, ataxia, hyperkinesia - were universally present in age 6 to 16; however, an additional core feature of high pain tolerance was added (present in 91%), and furthermore, evolution of symptoms were noted across the lifespan, such that postnatal microcephaly, ataxia and high pain threshold were often not apparent prior to age 6, and hyperkinesis decreased after age 16. While neurologic exams were consistent with cerebellar dysfunction, importantly, a majority of individuals (>50% older than 10) also had corticospinal tract abnormalities. Three participants died during the period of the study. In this large and longitudinal study of CS, we begin to define the trajectory of symptoms and the adult phenotype, thereby identifying critical targets for treatment.

Effect of Provider Type on Overutilization of CT Angiograms of the Head and Neck for Patients Presenting to the Emergency Department with Nonfocal Neurologic Symptoms.

PURPOSE: Overutilization of neuroimaging in the emergency department (ED), especially CT angiogram of the head and neck (CTAHN) examinations, contributes to rising health care expenditures, exposes patients to radiation, and may result in delays in care. We evaluated the rate of CTAHN overutilization for patients with nonfocal neurologic complaints in the ED and its potential association with patient clinical data, demographic data, and ED provider type. METHODS: This study was retrospective, was approved by an institutional review board, and was performed at a single institution, spanning a 6-year period. ED patients with nonfocal neurologic complaints who had a CTAHN examination with no history of trauma, recent surgery, or intracranial malignancy were included. Each CTAHN examination was categorized into one of four groups (0 = negative, 1 = chronic findings not related to presentation, 2 = nonacute and/or nonemergent findings or findings that may account for the presentation, and 3 = acute and/or emergent findings that may account for the presentation). Basic demographic data including patient age, patient sex, ordering ED provider type (attending, resident, nonphysician practitioner [(NPP]) were collected and analyzed using a multiple logistic regression analysis. RESULTS: A total of 960 CTAHN examinations were reviewed. The mean age of patients was 50 years (SD = 18 years), with 63% female patients and 37% male patients. Headache was the most frequent presentation (76%). A total of 75% of cases were negative, and 7% had chronic imaging findings not related to their ED presentation. A total of 12.5% of cases had nonacute and/or nonemergent findings possibly related to the presentation, and only 5.5% had acute and/or emergent findings related to ED presentation. A significantly greater proportion of CTAHN examinations ordered by NPPs, followed by the proportion ordered by ED residents, were negative or had no findings related to the patient presentation, and these patients were ultimately discharged to home. DISCUSSION: A total of 82% of ED CTAHN examinations performed for patients with nonfocal neurologic complaints had no actionable findings. These examinations are significantly more likely to be ordered by NPPs and ED residents.

Atlantoaxial instability associated with ALDH18A1 mutation.

We report a 10-year-old boy with a de novo pathogenic variant in ALDH18A1, a rare form of metabolic cutis laxa, which was complicated by atlantoaxial instability and spinal cord compression following a fall from standing height. The patient required emergent cervical spine fusion and decompression followed by a 2-month hospitalization and rehabilitation. In addition to the core clinical features of joint and skin laxity, hypotonia, and developmental delays, we expand the connective tissue phenotype by adding a new potential feature of cervical spine instability. Patients with pathogenic variants in ALDH18A1 may warrant cervical spine screening to minimize possible morbidity. Neurosurgeons, geneticists, primary care providers, and families should be aware of the increased risk of severe cervical injury from minor trauma.

Surgery and proton radiation therapy for pediatric base of skull chordomas: Long-term clinical outcomes for 204 patients.

BACKGROUND: Data on clinical outcomes for base of skull (BOS) chordomas in the pediatric population is limited. We report patient outcomes after surgery and proton radiotherapy (PRT). METHODS: Pediatric patients with BOS chordomas were treated with PRT or combined proton/photon approach (proton-based; for most, 80% proton/20% photon) at the Massachusetts General Hospital from 1981 to 2021. Endpoints of interest were overall survival (OS), disease-specific survival, progression-free survival (PFS), freedom from local recurrence (LC), and freedom from distant failure (DC). RESULTS: Of 204 patients, median age at diagnosis was 11.1 years (range, 1-21). Chordoma location included 59% upper and/or middle clivus, 36% lower clivus, 4% craniocervical junction, and 1% nasal cavity. Fifteen (7%) received pre-RT chemotherapy. Forty-seven (23%) received PRT, and 157 (77%) received comboRT. Median total dose was 76.7 Gy (RBE) (range, 59.3-83.3). At a median follow-up of 10 years (interquartile range, 5-16 years), 56 recurred. Median OS and PFS were 26 and 25 years, with 5-, 10-, and 20-year OS and PFS rates of 84% and 74%, 78% and 69%, and 64% and 64%, respectively. Multivariable actuarial analyses showed poorly differentiated subtype, radiographical progression prior to RT, larger treatment volume, and lower clivus location to be prognostic factors for worse OS, PFS, and LC. RT was well tolerated at a median follow-up of 9 years (interquartile range, 4-16 years). Side effects included 166 patients (80%) with mild/moderate acute toxicities, 24 (12%) patients with late toxicities, and 4 (2%) who developed secondary radiation-related malignancies. CONCLUSION: This is the largest cohort of BOS chordomas in the literature, pediatric and/or adult. High-dose PRT following surgical resection is effective with low rates of late toxicity.

An ultrafast brain MRI technique for evaluating acute neurologic deficits in the emergency department.

Herein we share our preliminary experience with an ultrafast brain MRI technique for use in the ED consisting of axial T1-weighted (40 s), axial T2-weighted (62 s), axial diffusion-weighted (80 s), axial FLAIR (96 s), axial T2* (6 s), and axial susceptibility-weighted (108 s) imaging for a total scan time of 6 min and 53 s. Utilization of this ultrafast technique yields an efficient assessment of the brain, decreases ED length of stay and inpatient observation admissions, and may obviate the need for vascular imaging with either CTA or MRA in the ED.

The "Crossing Collection Sign": A Diagnostic Tool on Spine Magnetic Resonance Imaging For Localizing Cerebrospinal Fluid Leak.

OBJECTIVE: The aim of the study is to determine whether the site of "cross" between ventral and dorsal spinal longitudinal extradural CSF collections (SLECs) seen on magnetic resonance imaging during initial workup of patients with suspected CSF leaks can predict the subsequently confirmed leakage site on computed tomography myelography or surgical repair. METHODS: This was an institutional review board-approved, retrospective study performed from 2006 to 2021. Patients with SLECs who underwent total spine magnetic resonance imaging at our institution, followed by myelography and/or surgical repair for CSF leak, were included. Patients with incomplete workup including lack of computed tomography myelography and/or surgical repair and patients severely motion degraded imaging were excluded from our study. The site of cross between ventral and dorsal SLECs was defined as the "crossing collection sign" and was compared with the anatomically confirmed site of leak on myelography and/or at surgical repair. RESULTS: Thirthy-eight patients met inclusion criteria with 18 females and 11 males ranging in age from 27 to 60 years (median, 40 years; interquartile range, 14 years). The crossing collection sign was seen in 76% of patients (n = 29). The distributions of confirmed CSF leak were as follows: cervical (n = 9), thoracic (n = 17), and lumbar spine (n = 3). The crossing collection sign predicted the site of CSF leak in 14 of 29 patients (48%) and was within 3-vertebral segments in 26 of 29 cases (90%). CONCLUSIONS: The crossing collection sign can help prospectively identify spinal regions with highest likelihood for CSF leak in patients with SLECs. This can potentially help optimize the more invasive subsequent steps in the workup for these patients, including dynamic myelography and surgical exploration for repair.

Incorporating algorithmic uncertainty into a clinical machine deep learning algorithm for urgent head CTs.

Machine learning (ML) algorithms to detect critical findings on head CTs may expedite patient management. Most ML algorithms for diagnostic imaging analysis utilize dichotomous classifications to determine whether a specific abnormality is present. However, imaging findings may be indeterminate, and algorithmic inferences may have substantial uncertainty. We incorporated awareness of uncertainty into an ML algorithm that detects intracranial hemorrhage or other urgent intracranial abnormalities and evaluated prospectively identified, 1000 consecutive noncontrast head CTs assigned to Emergency Department Neuroradiology for interpretation. The algorithm classified the scans into high (IC+) and low (IC-) probabilities for intracranial hemorrhage or other urgent abnormalities. All other cases were designated as No Prediction (NP) by the algorithm. The positive predictive value for IC+ cases (N = 103) was 0.91 (CI: 0.84-0.96), and the negative predictive value for IC- cases (N = 729) was 0.94 (0.91-0.96). Admission, neurosurgical intervention, and 30-day mortality rates for IC+ was 75% (63-84), 35% (24-47), and 10% (4-20), compared to 43% (40-47), 4% (3-6), and 3% (2-5) for IC-. There were 168 NP cases, of which 32% had intracranial hemorrhage or other urgent abnormalities, 31% had artifacts and postoperative changes, and 29% had no abnormalities. An ML algorithm incorporating uncertainty classified most head CTs into clinically relevant groups with high predictive values and may help accelerate the management of patients with intracranial hemorrhage or other urgent intracranial abnormalities.

Labyrinthine Fluid Signal Intensity on T2-Weighted MR Imaging in Patients With Vestibular Schwannomas Undergoing Proton Radiotherapy: A Longitudinal Assessment.

OBJECTIVE: In vestibular schwannoma patients, a loss of signal intensity (SI) on T2-weighted magnetic resonance imaging (MRI) has been reported within the ipsilateral labyrinth. The purpose of this study was to quantitatively evaluate the occurrence and course of this intensity loss in relation to proton radiotherapy and its possible association with hearing loss. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Patients who received proton therapy for a vestibular schwannoma and underwent at least two high-resolution T2-weighted cisternographic sequence (constructive interference in steady state/fast imaging employing steady-state acquisition/DRIVE) MRIs and audiometry assessments. MAIN OUTCOME MEASURES: Relative T2 SIs from the vestibules and basal/apical cochlear turns of the labyrinth, bilaterally. RESULTS: Ninety-five MRI scans from 34 patients were included. The apical turn of the ipsilateral cochlea showed a lower mean cochlear SI than on the contralateral side (±3.5 versus 5.0). The mean relative cochlear SI did not significantly change after proton radiotherapy. The ipsilateral vestibule showed a higher SI than the cochlea. The relative mean cochlear SI was not directly correlated to (the degree of) hearing loss before or after proton radiotherapy, nor did it predict future hearing loss. CONCLUSION: The relative mean cochlear SI on cisternographic T2-MRI in vestibular schwannoma patients is diminished on the treated side, when compared with the ipsilateral vestibule and the contralateral cochlea/vestibule. The SI of the ipsilateral cochlea does not further decrease after proton radiotherapy and seems to be related to the tumor rather than the therapy. The diminished cochlear SI does not correlate with subsequent loss of hearing.

Imaging, Clinical, and Demographic Differences in Patients With Type III Spinal Cerebrospinal Fluid Leak (Cerebrospinal Venous Fistulas) Compared With Patients With Types I and II Spinal Cerebrospinal Fluid Leak.

OBJECTIVE: Spinal cerebrospinal fluid (CSF) leaks are an underdiagnosed cause of neurologic symptoms. The most common types of spinal CSF leaks are from dural tears (type I) and meningeal diverticula (type II). Cerebrospinal fluid-venous fistulas (type III) are less common and underrecognized. The purpose of this study was to evaluate the intracranial and spinal imaging findings in patients with types I/II versus type III leaks. MATERIALS AND METHODS: This was a retrospective, institutional review board-approved study performed on adult patients between January 2020 to September 2021 with surgically confirmed type I/II/III spinal CSF leak. Patients had preoperative brain magnetic resonance imaging (MRI) with contrast and medical records detailing symptoms and clinical diagnoses. Patients were excluded for nondiagnostic brain MRIs. Demographic and clinical information were recorded. The presence of extra-axial collections, pachymeningeal thickening, brain sagging, and decreased pontomamillary distance were evaluated on MRI. RESULTS: Seven patients had type III leaks, and 16 had type I/II leaks. Patients with type III leaks were older ( P = 0.0003) and had higher rates of initial misdiagnosis (100% vs 31%) and longer times to correct diagnosis ( P = 0.03) compared with type I/II leaks. Intracranial extra-axial collections were never seen with type III leaks but were seen in 50% of type I/II leaks. Pachymeningeal thickening and brainstem sagging occurred in nearly equal frequency between groups. Smaller pontomamillary distances were seen in type III leaks versus type I/II leaks ( P = 0.047). CONCLUSIONS: When evaluating patients with suspected spinal CSF leak, findings of older age, absence of intracranial extra-axial collections, and small pontomamillary distances may raise suspicion for type III versus type I/II leak.