Vestibular schwannoma-related increased labyrinthine post-gadolinium 3D-FLAIR signal intensity and association with hearing impairment.

BACKGROUND AND PURPOSE: Vestibular schwannomas (VSs) are benign neurogenic tumors commonly associated with progressive unilateral hearing loss, tinnitus, and vestibular symptoms. Growing evidence links signal changes in the VS-adjacent labyrinth with sensorineural hearing loss. This study seeks to quantify the association of labyrinthine signal on post-gadolinium 3D-FLAIR imaging correlates with hearing loss and to evaluate potential longitudinal changes over time. MATERIALS AND METHODS: Selected patients were identified from a prospectively maintained VS registry. Mean signal intensity ratios of the bilateral labyrinth and pons were measured on 3D-FLAIR post-gadolinium MRI. Correlations with paired audiometric data including pure tone average (PTA), word recognition score (WRS), and AAO-HNS hearing class within one year were evaluated. RESULTS: 125 studies obtained from 2015 to 2022 among 66 patients undergoing observational management for sporadic VS were analyzed. Increased signal intensity was noted of the VS-affected labyrinth/contralateral labyrinth (mean ratio 1.56, SD 0.58). Increased signal intensity was associated with increased PTA on both labyrinthine (correlation coefficient [CC] 0.20, p=0.03) and pontine comparisons (CC 0.24, p=0.006), and with decreased WRS on pontine comparisons (CC -0.18, p=0.04). Increased signal intensity was significantly associated with non-serviceable AAO-HNS C/D hearing when intensities were compared to the pons (p=0.01) but not the contralateral labyrinth (p=0.1). Among 44 patients with available follow-up, no statistically significant associations were identified between audiometric data and signal changes over the same interval. CONCLUSIONS: Increased 3D-FLAIR post-gadolinium labyrinthine signal is associated with sensorineural hearing loss; however, its relationship with hearing trajectory remains unclear. Overall findings suggest that while post-gadolinium 3D-FLAIR techniques are sensitive to inner ear involvement associated with VS, the driving mechanism and their temporal relationships with labyrinthine signal intensity and hearing impairment remain unknown. ABBREVIATIONS: AAO-HNS =American Academy of Otolaryngology -Head and Neck Surgery. BLB =blood-labyrinth barrier. CPA = cerebellopontine angle. IAC = internal auditory canal. PTA = pure tone average; SIR = signal intensity ratio. VS = vestibular schwannoma. WRS = word recognition score.

Results of a Prospective Randomized Multicenter Study Comparing Indocyanine Green (ICG) Fluorescence Combined with a Standard Tracer Versus ICG Alone for Sentinel Lymph Node Biopsy in Early Breast Cancer: The INFLUENCE Trial.

BACKGROUND: For clinically node-negative early breast cancer patients, sentinel lymph node biopsy (SLNB) using dual localization with blue dye and radioisotope (RI) is currently standard of care. Documented disadvantages with these tracers have prompted exploration of alternative agents such as fluorescent indocyanine green (ICG), which demonstrates high detection rates combined with other tracers. Results of a randomized study evaluating ICG as a single tracer for SLN identification are presented. METHODS: Overall, 100 patients with unilateral, clinically node-negative, biopsy-proven invasive breast cancer (≤5 cm) scheduled for SLNB were recruited in two separate randomized cohorts, with 50 patients receiving ICG alone. Cohort 1 received ICG alone (n = 25) or combined with RI [Technetium99] (n = 25), while Cohort 2 received ICG alone (n = 25) or combined with blue dye (n = 25). The primary outcome was sensitivity for SLN identification. RESULTS: Among evaluable patients (n = 97), the overall SLN identification rate was 96.9% (ICG alone = 97.9%; ICG + RI = 100%; ICG + blue dye = 92%). Node positivity rates were 14.9% for ICG alone, 16% for ICG combined with RI, and 20% for ICG combined with blue dye. There were no significant differences (p < 0.05) in performance parameters, with ICG alone being non-inferior to tracer combinations for procedural node positivity rates when adjusted for specific factors. CONCLUSION: These results support potential use of ICG as a sole tracer agent for routine SLNB, thereby avoiding disadvantages of RI and/or blue dye. The latter can be safely withheld as a co-tracer without compromising detection of positive nodes in primary surgical patients.

High-Resolution Head CTA: A Prospective Patient Study Comparing Image Quality of Photon-Counting Detector CT and Energy-Integrating Detector CT.

BACKGROUND AND PURPOSE: Photon-counting detector CT (PCD-CT) is now clinically available and offers ultra-high-resolution (UHR) imaging. Our purpose was to prospectively evaluate the relative image quality and impact on diagnostic confidence of head CTA images acquired by using a PCD-CT compared with an energy-integrating detector CT (EID-CT). MATERIALS AND METHODS: Adult patients undergoing head CTA on EID-CT also underwent a PCD-CT research examination. For both CT examinations, images were reconstructed at 0.6 mm by using a matched standard resolution (SR) kernel. Additionally, PCD-CT images were reconstructed at the thinnest section thickness of 0.2 mm (UHR) with the sharpest kernel, and denoised with a deep convolutional neural network (CNN) algorithm (PCD-UHR-CNN). Two readers (R1, R2) independently evaluated image quality in randomized, blinded fashion in 2 sessions, PCD-SR versus EID-SR and PCD-UHR-CNN versus EID-SR. The readers rated overall image quality (1 [worst] to 5 [best]) and provided a Likert comparison score (-2 [significantly inferior] to 2 [significantly superior]) for the 2 series when compared side-by-side for several image quality features, including visualization of specific arterial segments. Diagnostic confidence (0-100) was rated for PCD versus EID for specific arterial findings, if present. RESULTS: Twenty-eight adult patients were enrolled. The volume CT dose index was similar (EID: 37.1 ± 4.7 mGy; PCD: 36.1 ± 4.0 mGy). Overall image quality for PCD-SR and PCD-UHR-CNN was higher than EID-SR (eg, PCD-UHR-CNN versus EID-SR: 4.0 ± 0.0 versus 3.0 ± 0.0 (R1), 4.9 ± 0.3 versus 3.0 ± 0.0 (R2); all P values < .001). For depiction of arterial segments, PCD-SR was preferred over EID-SR (R1: 1.0-1.3; R2: 1.0-1.8), and PCD-UHR-CNN over EID-SR (R1: 0.9-1.4; R2: 1.9-2.0). Diagnostic confidence of arterial findings for PCD-SR and PCD-UHR-CNN was significantly higher than EID-SR: eg, PCD-UHR-CNN versus EID-SR: 93.0 ± 5.8 versus 78.2 ± 9.3 (R1), 88.6 ± 5.9 versus 70.4 ± 5.0 (R2); all P values < .001. CONCLUSIONS: PCD-CT provides improved image quality for head CTA images compared with EID-CT, both when PCD and EID reconstructions are matched, and to an even greater extent when PCD-UHR reconstruction is combined with a CNN denoising algorithm.

Spinal CSF Leaks: The Neuroradiologist Transforming Care.

SUMMARY: Spinal CSF leak care has considerably evolved over the past several years due to pivotal advances in its diagnosis and treatment. To the reader of the AJNR, it has been impossible to miss the exponential increase in groundbreaking research on spinal CSF leaks and spontaneous intracranial hypotension (SIH). While many clinical specialties have contributed to these successes, the neuroradiologist has been instrumental in driving this transformation due to innovations in non-invasive imaging, novel myelographic techniques, and imageguided therapies. In this editorial, we will delve into the exciting advancements in spinal CSF leak diagnosis and treatment and celebrate the vital role of the neuroradiologist at the forefront of this revolution, with particular attention to CSF leak related work published in the AJNR.ABBREVIATIONS: SIH = spontaneous intracranial hypotension; CVF = CSF-venous fistula; CTM = CT myelography; DSM = digital subtraction myelography; CB-CTM = conebeam CT myelography; PCD-CT = photon counting detector CT.

Beta Trace Protein as a Potential Biomarker for CSF-Venous Fistulas.

BACKGROUND AND PURPOSE: Accurately identifying patients with CSF-venous fistulas (CVF), one cause of spontaneous intracranial hypotension (SIH), is a diagnostic dilemma. This conundrum underscores the need for a CVF biomarker to help select who should undergo an invasive myelogram for further diagnostic workup. Beta trace protein (BTP) is the most abundant CNS derived protein in the CSF and therefore is a potential venous biomarker for CVF detection. The purpose of our study was to measure venous BTP levels as a potential CVF biomarker. MATERIALS AND METHODS: We prospectively enrolled 14 patients with CVF and measured BTP in venous blood samples from the paraspinal veins near the CVF and compared those levels to the peripheral blood. Myelograms used initially to identify the CVF were evaluated for modality, CVF laterality, CVF level, and venous drainage pattern. Patient sex, patient age, and symptom duration were also collected. Brain MR images were reviewed for Bern scores. We also measured the peripheral blood BTP levels in 20 normal controls. RESULTS: In patients with CVF, the mean BTP level near the CVF was 54.5% higher (0.760 [SD 0.673] vs 0.492 [SD 0.095] mg/L; p = 0.069) compared to peripheral blood. Nine (64.3%) patients with CVF had a higher paraspinal BTP level than peripheral BTP level. The 20 control patients had a higher the mean peripheral BTP level 0.720 (SD 0.191) mg/L compared to patients with CVF (p<0.001). CONCLUSIONS: We found that venous blood at the site of CVF had higher BTP values compared to peripheral blood in the majority, but not all patients with CVF. This may reflect the intermittent leaking nature of CVF. Additionally, we found that patients with CVF had a lower peripheral blood BTP level compared to normal controls. BTP requires further evaluation as a potential CVF biomarker. ABBREVIATIONS: SIH = Spontaneous Intracranial Hypotension; CVF = CSF-Venous Fistula; CTM = CT myelogram; DSM = Digital Subtraction Myelography; BTP = Beta Trace Protein.

CT-Guided Epidural Contrast Injection for the Identification of Dural Defects.

Post-dural puncture headache (PDPH) is an increasingly recognized cause of chronic headache. Outside of clinical history and myelography that requires an additional dural puncture, there is no reliable diagnostic test to evaluate for persistent dural defects. We describe the injection of iodinated contrast into the dorsal epidural space under CT guidance in five patients as a potential tool to visualize persistent dural defects.ABBREVIATIONS: PDPH = post-dural puncture headache; SIH = spontaneous intracranial hypotension; DSM = digital subtraction myelography; CTM = CT myelography.

Myelographic Techniques for the Localization of CSF-Venous Fistulas: Updates in 2024.

CSF-venous fistulas (CVFs) are a common cause of spontaneous intracranial hypotension. Despite their relatively frequent occurrence, they can be exceedingly difficult to detect on imaging. Since the initial description of CVFs in 2014, the recognition and diagnosis of this type of CSF leak has continually increased. As a result of multi-institutional efforts, a wide spectrum of imaging modalities and specialized techniques for CVF detection is now available. It is important for radiologists to be familiar with the multitude of available techniques, because each has unique advantages and drawbacks. In this article, we review the spectrum of imaging modalities available for the detection of CVFs, explain the advantages and disadvantages of each, provide typical imaging examples, and discuss provocative maneuvers that may improve the conspicuity of CVFs. Discussed modalities include conventional CT myelography, dynamic myelography, digital subtraction myelography, conebeam CT myelography, decubitus CT myelography by using conventional energy-integrating detector scanners, decubitus photon counting CT myelography, and intrathecal gadolinium MR myelography. Additional topics to be discussed include optimal patient positioning, respiratory techniques, and intrathecal pressure augmentation.

Soft tissue aneurysmal bone cyst presenting as an enlarging neck mass: Case report and review of the head and neck literature.

Soft tissue aneurysmal bone cysts (STABCs) are rare neoplasms histopathologically identical to aneurysmal bone cysts. These benign lesions are characterized by thin, peripheral ossification and no skeletal continuity. STABC may be difficult to distinguish from myositis ossificans (MO) and malignant entities from imaging and fine needle aspiration, due to rarity and overlapping features. We present a case of a STABC occurring in the paraspinal cervical muscles. The imaging, histopathology, molecular analysis, and treatment are discussed. Four other published cases of STABC of the head and neck are reviewed.

Visual acuity and optic nerve size assessed by magnetic resonance imaging in optic nerve hypoplasia.

We investigated the relationship between optic nerve (ON) size and visual acuity in children with optic nerve hypoplasia (ONH). The medical records of patients <19 years with ONH who underwent brain magnetic resonance imaging (MRI) and visual acuity assessment were reviewed. ON diameter at orbital and cisternal segments was assessed independently by two neuroradiologists and compared with visual acuity. ON diameter <1.7 mm represented a cutoff, below which was significantly associated with visual acuity of 20/200 or worse (P = 0.04) and above which was significantly associated with visual acuity of 20/40 or better (P = 0.004). ON diameter measured with MRI may provide an early prognostic indication of visual potential for children with ONH.

Photon-Counting CT in the Head and Neck: Current Applications and Future Prospects.

Photon-counting detectors (PCDs) represent a major milestone in the evolution of CT imaging. CT scanners using PCD systems have already been shown to generate images with substantially greater spatial resolution, superior iodine contrast-to-noise ratio, and reduced artifact compared with conventional energy-integrating detector-based systems. These benefits can be achieved with considerably decreased radiation dose. Recent studies have focused on the advantages of PCD-CT scanners in numerous anatomic regions, particularly the coronary and cerebral vasculature, pulmonary structures, and musculoskeletal imaging. However, PCD-CT imaging is also anticipated to be a major advantage for head and neck imaging. In this paper, we review current clinical applications of PCD-CT in head and neck imaging, with a focus on the temporal bone, facial bones, and paranasal sinuses; minor arterial vasculature; and the spectral capabilities of PCD systems.

Prevalence of Tendon Rupture and Tendinopathies Among Patients with Atherosclerotic Cardiovascular Disease Derived From United States Administrative Claims Data.

INTRODUCTION: The prevalence of tendon rupture and tendinopathies (TRT) has not been determined in a large population of patients with atherosclerotic cardiovascular disease (ASCVD). We investigated TRT prevalence among patients with ASCVD and in the general population, using data from the Symphony Health Integrated Dataverse, a large US medical and pharmacy claims database. METHODS: This retrospective, observational study included patients aged ≥ 19 years from the claims database during the identification period (January 2019 to December 2020) and 12 months of continuous enrollment. The primary outcome was evidence of TRT in the 12 months following the index date (first ASCVD diagnosis in the ASCVD cohort; first claim in the claims database in the overall population). Diagnostic codes (ICD-10 and/or CPT) were used to define ASCVD and TRT diagnosis. RESULTS: The ASCVD cohort and overall population included 5,589,273 and 61,715,843 patients, respectively. In the ASCVD cohort, use of medications with a potential or known association with TRT was identified in 67.9% (statins), 17.7% (corticosteroids), and 16.7% (fluoroquinolones) of patients. Bempedoic acid use was reported in 1556 (< 0.1%) patients. TRT prevalence during 12-month follow-up was 3.4% (ASCVD cohort) and 1.9% (overall population). Among patients with ASCVD, 83.5% experienced TRT in only one region of the body. Factors most associated with TRT in the ASCVD cohort were increasing age, most notably in those aged 45-|64 years (odds ratio [OR] 2.19; 95% confidence interval [CI] 2.07-2.32), obesity (OR 1.51; 95% CI 1.50-1.53), and rheumatoid arthritis (OR 1.47; 95% CI 1.45-1.79). Use of statins or bempedoic acid was not associated with increased TRT risk. CONCLUSION: Patients with ASCVD may have greater risk of TRT than the general population, which may be driven by an increased prevalence of comorbidities and use of medications with a potential or known association with TRT.

Patients with atherosclerosis, the main cause of heart attacks, strokes, and peripheral vascular disease, typically require several drugs to control the disease. Some of the drugs used to treat atherosclerosis have been linked to a higher occurrence of tendon tears (or ruptures) or swelling/inflammation of the tendons (tendinopathies). However, there may be other factors present in these patients that increase the risk of tendon injuries that are not related to these drugs. This study used the medical records of over 5.5 million patients with atherosclerosis and over 63 million patients reflecting the general population in the United States to determine the prevalence of tendon injury. Additionally, the researchers looked at other factors that might be related to a higher risk of tendon injury in each group. Over a 12-month period, tendon injuries occurred in 3.4% of patients with atherosclerosis and 1.8% of patients in the general population. In patients with atherosclerosis, factors such as being obese, older (45­64 years), or having rheumatoid arthritis were also linked to an increased risk of tendon injuries. There was no association seen between statin or bempedoic acid use and tendon injuries. These results may help healthcare providers to determine the underlying risk of tendon injuries and guide treatment of this patient population.

Atherosclerotic carotid artery disease Radiomics: A systematic review with meta-analysis and radiomic quality score assessment.

BACKGROUND: Stroke, a leading global cause of mortality and neurological disability, is often associated with atherosclerotic carotid artery disease. Distinguishing between symptomatic and asymptomatic carotid artery disease is crucial for appropriate treatment decisions. Radiomics, a quantitative image analysis technique, and ML have emerged as promising tools in medical imaging, including neuroradiology. This systematic review and meta-analysis aimed to evaluate the methodological quality of studies employing radiomics for atherosclerotic carotid artery disease analysis and ML algorithms for culprit plaque identification using CT or MRI. MATERIALS AND METHODS: Pubmed, WoS and Scopus databases were searched for relevant studies published from January 2005 to May 2023. RQS assessed methodological quality of studies included in the review. QUADAS-2 assessed the risk of bias. A meta-analysis and three meta regressions were conducted on study performance based on model type, imaging modality and segmentation method. RESULTS: RQS assessed methodological quality, revealing an overall low score and consistent findings with other radiology domains. QUADAS-2 indicated an overall low risk, except for a single study with high bias. The meta-analysis demonstrated that radiomics-based ML models for predicting culprit plaques had a satisfactory performance, with an AUC of 0.85, surpassing clinical models. However, combining radiomics with clinical features yielded the highest AUC of 0.89. Meta-regression analyses confirmed these findings. MRI-based models slightly outperformed CT-based ones, but the difference was not significant. CONCLUSION: In conclusion, radiomics and ML hold promise for assessing carotid plaque vulnerability, aiding in early cerebrovascular event prediction. Combining radiomics with clinical data enhances predictive performance.

Machine Learning Detects Symptomatic Plaques in Patients With Carotid Atherosclerosis on CT Angiography.

BACKGROUND: This study aimed to develop and validate a computed tomography angiography based machine learning model that uses plaque composition data and degree of carotid stenosis to detect symptomatic carotid plaques in patients with carotid atherosclerosis. METHODS: The machine learning based model was trained using degree of stenosis and the volumes of 13 computed tomography angiography derived intracarotid plaque subcomponents (eg, lipid, intraplaque hemorrhage, calcium) to identify plaques associated with cerebrovascular events. The model was internally validated through repeated 10-fold cross-validation and tested on a dedicated testing cohort according to discrimination and calibration. RESULTS: This retrospective, single-center study evaluated computed tomography angiography scans of 268 patients with both symptomatic and asymptomatic carotid atherosclerosis (163 for the derivation set and 106 for the testing set) performed between March 2013 and October 2019. The area-under-receiver-operating characteristics curve by machine learning on the testing cohort (0.89) was significantly higher than the areas under the curve of traditional logit analysis based on the degree of stenosis (0.51, P<0.001), presence of intraplaque hemorrhage (0.69, P<0.001), and plaque composition (0.78, P<0.001), respectively. Comparable performance was obtained on internal validation. The identified plaque components and associated cutoff values that were significantly associated with a higher likelihood of symptomatic status after adjustment were the ratio of intraplaque hemorrhage to lipid volume (≥50%, 38.5 [10.1-205.1]; odds ratio, 95% CI) and percentage of intraplaque hemorrhage volume (≥10%, 18.5 [5.7-69.4]; odds ratio, 95% CI). CONCLUSIONS: This study presented an interpretable machine learning model that accurately identifies symptomatic carotid plaques using computed tomography angiography derived plaque composition features, aiding clinical decision-making.

Deep Learning-Based Reconstruction of 3D T1 SPACE Vessel Wall Imaging Provides Improved Image Quality with Reduced Scan Times: A Preliminary Study.

BACKGROUND AND PURPOSE: Intracranial vessel wall imaging is technically challenging to implement, given the simultaneous requirements of high spatial resolution, excellent blood and CSF signal suppression, and clinically acceptable gradient times. Herein, we present our preliminary findings on the evaluation of a deep learning-optimized sequence using T1-weighted imaging. MATERIALS AND METHODS: Clinical and optimized deep learning-based image reconstruction T1 3D Sampling Perfection with Application optimized Contrast using different flip angle Evolution (SPACE) were evaluated, comparing noncontrast sequences in 10 healthy controls and postcontrast sequences in 5 consecutive patients. Images were reviewed on a Likert-like scale by 4 fellowship-trained neuroradiologists. Scores (range, 1-4) were separately assigned for 11 vessel segments in terms of vessel wall and lumen delineation. Additionally, images were evaluated in terms of overall background noise, image sharpness, and homogeneous CSF signal. Segment-wise scores were compared using paired samples t tests. RESULTS: The scan time for the clinical and deep learning-based image reconstruction sequences were 7:26 minutes and 5:23 minutes respectively. Deep learning-based image reconstruction images showed consistently higher wall signal and lumen visualization scores, with the differences being statistically significant in most vessel segments on both pre- and postcontrast images. Deep learning-based image reconstruction had lower background noise, higher image sharpness, and uniform CSF signal. Depiction of intracranial pathologies was better or similar on the deep learning-based image reconstruction. CONCLUSIONS: Our preliminary findings suggest that deep learning-based image reconstruction-optimized intracranial vessel wall imaging sequences may be helpful in achieving shorter gradient times with improved vessel wall visualization and overall image quality. These improvements may help with wider adoption of intracranial vessel wall imaging in clinical practice and should be further validated on a larger cohort.

Carotid artery calcium score: Definition, classification, application, and limits.

INTRODUCTION: In the current paper, the "carotid artery calcium score" method is presented with the target to offer a metric method to quantify the amount of calcification in the carotid artery. MODEL AND DEFINITION: The Volume of Interest (VOI) should be extracted and those voxels, with a Hounsfield Unit (HU) value ≥130, should be considered. The total weight value is determined by calculating the sum of the HU attenuation values of all voxels with values ≥130 HU. This value should be multiplied by the conversion factor ("or voxel size") and divided by a weighting factor, the attenuation threshold to consider a voxel as calcified (and therefore 130 HU): this equation determines the Carotid Artery Calcium Score (CACS). RESULTS: In order to provide the demonstration of the potential feasibility of the model, the CACS was calculated in 131 subjects (94 males; mean age 72.7 years) for 235 carotid arteries (in 27 subjects, unilateral plaque was present) considered. The CACS value ranged from 0.67 to 11716. A statistically significant correlation was found (rho value = 0.663, p value = .0001) between the CACS in the right and left carotid plaques. Moreover, a statistically significant correlation between the age and the total CACS was present (rho value = 0.244, p value = .005), whereas no statistically significant difference was found in the distribution of CACS by gender (p = .148). The CACS was also tested at baseline and after contrast and no statistically significant difference was found. CONCLUSION: In conclusion, this method is of easy application, and it weights at the same time the volume and the degree of calcification in a unique parameter. This method needs to be tested to verify its potential utility, similar to the coronary artery calcium score, for the risk stratification of the occurrence of cerebrovascular events of the anterior circulation. Further studies using this new diagnostic tool to determine the prognostic value of carotid calcium quantification are needed.

The left atrial appendage: An enigmatic friend or foe and implications of closure.

The left atrial appendage (LAA) is often thought of as a vestigial organ serving as a nidus for clot formation in those with atrial fibrillation (A-fib). The LAA, however, has unique anatomy which allows it to serve special functions in the human body. Closing the LAA has been shown to decrease the risk of thromboembolic events in patients who cannot tolerate anticoagulation. Several methods of closure exist including percutaneous endocardial closure, epicardial closure, and surgical clipping. In addition to decreasing stroke risk, there appears to be physiologic changes that occur after LAA closure. This comprehensive review aims to describe the functions of the LAA, compare the different methods of closure, and propose a new method for identifying which patients may benefit from LAA closure versus anticoagulation based on each patients' individual comorbidities rather than their contraindications.