MRI Studies Research Articles

Practice Patterns in Asymmetric Sensorineural Hearing Loss: Survey Data.

Although screening protocols for patients who present with asymmetric sensorineural hearing loss (ASNHL) exist, there are no clear guidelines to direct practitioners. In particular, various thresholds have been proposed for the degree of hearing loss that should prompt MRI studies, but the topic remains understudied. This project aims to compare protocols followed by practitioners to guide their imaging practices. Web-based survey. Otolaryngology faculty at academic medical centers. A list of 530 otolaryngologists (276 otology/neurotology specialists, 254 general otolaryngologists) was compiled. A survey consisting of three parts: demographics, general practice patterns, and simulated patient cases was distributed. A total of 468 surveys were successfully distributed, resulting in 88 (18.8%) responses. The majority of respondents (63.8%) self-reported their definition of ASNHL as ">30 dB hearing asymmetry at one frequency OR >20 dB hearing asymmetry at two continuous frequencies OR >10 dB hearing asymmetry at three contiguous frequencies." Overall, general otolaryngologists were more likely to observe asymmetric findings with serial audiogram alone, whereas otology/neurotology specialists were more likely to obtain imaging. There is significant variability between providers with regard to managing patients with ASNHL and evidence-based guidelines would be useful in guiding imaging practices. NA Laryngoscope, 134:4745-4753, 2024.

Cerebral damage after malignant hypertensive crisis: cerebral MRI follow-up data

Abstract Background Malignant hypertension (MHT) crisis is characterized by acute and diffuse microvascular damages, and the brain is a primary target organ. While a recent MRI study has revealed extensive and frequent cerebral injuries during the acute phase of MHT crisis (1), there is a scarcity of follow-up data. Purpose This study aims to investigate the evolution of MRI markers of cerebral injury following the management of the acute phase of MHT. Methods In this retrospective analysis, we examined brain MRI data from patients admitted for acute MHT between 2008 and 2022 at our center. Eligible patients had at least one follow-up brain MRI available. A skilled operator conducted a comprehensive analysis of each brain MRI, searching for posterior reversible encephalopathy syndrome (PRES), acute stroke or cerebral hemorrhage and microangiopathy markers, blinded for clinical and demographical data. Results Among 149 patients enrolled, 104 had a brain MRI at inclusion, 47 individuals had at least one follow-up brain MRI and were included in the analysis. 72,3% were male, mean age was 48,2 ± 10.8 years and 45,7% presented blood pressure control at the time of the follow-up brain MRI. Median interval between initial and follow-up brain MRI was 228 (84 – 726) days. Five (10,6%) new recent strokes, 2 (4,3 %) cerebral hemorrhage and 0 PRES were recorded during follow-up. On the follow-up brain MRI, more patients presented chronic lacunar infarct and/or microbleeds, in higher numbers. On the contrary, overall Fazekas score was stable in 31 patients (66,0%), improved in 15 patients (31,9 %) and worsened in 1 patients (2,1%). Comparison of subgroups dichotomized according to blood pressure control or follow up duration showed no difference in brain MRI markers. Conclusion This study offers valuable insights into the risk of new cerebrovascular events and the evolution of brain MRI markers after managing the acute phase of MHT. Our findings emphasize the dynamic nature of cerebral microvascular burden and the potential for regression of white matter hyperintensities. A better understanding of these phenomena might contribute to improved diagnosis, tailored treatment, and proactive patient care in the context of MHT.

Long-term volume retention of breast augmentation with fat grafting depends on weight changes: a three-year prospective MRI study.

Fat grafting is increasingly used for breast augmentation. However, long-term volume retention, time to reach steady state, and the effect of postoperative weight changes on these outcomes are not fully understood. In this prospective study, we included patients undergoing breast augmentation with fat grafting and examined them with MRI preoperatively and up to three years postoperatively. We modeled fat graft retention over time and calculated the time to volumetric steady state of the fat graft. Secondly, we used our model to assess the effect of postoperative weight changes on fat graft retention and to determine the association between the graft/recipient volume ratio and the percentage breast augmentation at steady state. Finally, we assessed patient satisfaction using the BREAST-Q questionnaire. The study included 28 patients (46 breasts). The time to steady state was 253 days (95%CI 185-283) postoperatively, with a volume retention of 46% (95%CI 35-58). Patients with a weight loss of one BMI point after surgery had a volume retention of 22% (95%CI 4.7-38) while those increasing one and two BMI points had retention rates of 57% (95%CI 45-69) and 85% (95%CI 72-98), respectively. Increasing graft/recipient volume ratio was associated with higher percentage augmentation with no plateau in this relationship even up to ratios of 2:1. Postoperative satisfaction with breasts and sexual well-being increased substantially. Breast augmentation with fat grafting reached volumetric steady state after 8 months with a volume retention of 46%. Weight loss following fat grafting leads to significantly lower volume retention.

Pharmacological manipulation of neurotransmitter activity induces disparate effects on cerebral blood flow and resting-state fluctuations

Abstract Functional MRI methods can assess aspects of drug-induced brain response. Resting blood oxygenation level dependent (BOLD) fMRI and arterial spin labeling (ASL) perfusion MRI indirectly measure brain function through the coupling of activity to cerebral blood flow (CBF) and oxygenation but their relative sensitivity has not been directly compared. We assessed changes in resting measures of BOLD and ASL MRI in response to two neurotransmitter modulators: citalopram, a selective serotonin reuptake inhibitor, and alprazolam, a positive allosteric modulator of GABA type A receptor. Thirty healthy subjects were imaged in a placebo-controlled study, with N=20 subjects receiving each treatment as part of an incomplete block design. Time-averaged CBF images from ASL and measures of resting-state fluctuations of BOLD and ASL images were assessed for significant effects. Following acute citalopram administration, analysis of the ASL data showed a reduction in time-averaged regional CBF in regions associated with high levels of 5-HT1A receptor density. In contrast, following alprazolam administration, BOLD amplitude of low frequency fluctuations showed a highly significant and cortically widespread increase, consistent with the distribution of GABA-A receptors. Only a marginal decrease in ASL CBF was detected after alprazolam intake. BOLD and ASL are each sensitive to drugs targeting neurotransmitter systems, but appear to reflect different aspects of neural metabolism and the balance between excitatory and inhibitory activity. Accordingly, their combination may best capture the effects of neurotransmitter modulations, and thus be advantageous for pharmacological MRI studies.

Assessing the Diagnostic Value of Brain White Matter Hyperintensities and Clinical Symptoms in Predicting the Detection of CSF Venous Fistula in Patients with Suspected Spontaneous Intracranial Hypotension.

Spontaneous intracranial hypotension (SIH) due to CSF venous fistula (CVF) is increasingly recognized as a secondary cause of headaches, with symptoms often overlapping with primary headache syndromes such as migraine. While brain MRI studies have focused on features indicative of SIH, findings that support an alternate headache etiology, such as the bifrontal white matter hyperintensities (WMH) often seen in migraines, have not been explored in this context. This study assesses 1) the quantity and distribution of WMH and 2) the presenting clinical features in patients with and without CVF found on dynamic decubitus CT myelography (dCTM). 72 consecutive patients underwent clinical workup for SIH due to suspected CVF, including pre-procedural brain and spine MRI followed by dCTM. Brain imaging features were analyzed, including Bern score, quantitative WMH burden, and WMH distribution. Demographics and clinical symptoms present at the time of presentation were recorded. Imaging features were compared between groups with and without CVF using parametric or nonparametric comparisons according to variable normality. Multivariate logistic regression explored the relationships between imaging features, clinical symptoms, and the presence of CVF. The cohort included 40 patients with (CVF+) and 32 patients without (CVF-), with no significant age or sex differences. CVF+ patients had significantly higher Bern scores and significantly fewer WMH. There were significant differences in the frequencies of WMH patterns between groups, with a migrainous pattern observed most frequently in CVF-patients. Logistic regression combining Bern score, WMH burden, and WMH pattern demonstrated a better fit for predicting CVF than using Bern score or WMH features alone. Fourteen clinical symptoms showed the greatest differences between CVF+ and CVF-groups. Logistic regression demonstrated a positive association between CVF detection and a pressure/throbbing headache quality, and negative associations for neck pain, facial pain, phonophobia, and anhedonia/depression. These findings suggest a negative association between CVF detection, increased burden of WMH, and a migrainous WMH pattern. Symptom analysis describes distinct clinical phenotypes, challenging orthostatic headache as a defining characteristic. These results support a comprehensive assessment of imaging and clinical presentations in the workup of suspected SIH. SIH = spontaneous intracranial hypotension; CVF = CSF venous fistula; WMH = white matter hyperintensities; dCTM = dynamic CT myelography; dDSM = dynamic digital subtraction myelography; PPV = positive predictive value; NPV = negative predictive value Received month day, year; accepted after revision month day, year.

Left Atrial Low-Voltage Extent Predicts the Recurrence of Supraventricular Arrhythmias.

The incidence of left atrial (LA) supraventricular arrhythmias is increasing. Even after LA ablation, recurrence of these tachycardias is common. MRI studies show that LA cardiomyopathy is a significant risk factor for recurrence and correlates with low voltage areas detected via 3D electroanatomic mapping (EAM). There are limited data on the impact of low voltage extent detected by EAM on recurrence-free survival. Voltage thresholds defining low voltage vary across different studies. This study aims to investigate the impact of the extent of low voltage areas in the LA on recurrence-free survival and to assess whether defining low voltage areas using thresholds of 0.5, 0.4, or 0.3 mV offers better predictive performance. Patients with atrial arrhythmia who underwent LA EAM at Ulm University Heart Center between September 2018 and September 2022 were included from the ATRIUM registry. ROC analysis determined the voltage threshold for predicting recurrence-free survival. Kaplan-Meier and logistic regression models adjusted for patient variables were used to analyze recurrence-free survival. Of 1089 screened patients, 108 met the inclusion criteria. ROC analysis indicated that a 0.4 mV threshold for low voltage provided the best predictive performance. Logistic regression showed a 1.039-fold increase in recurrence risk per percent increase in LA low voltage area (odds ratio = 1.039, 95% CI 1.014-1.064). Low voltage extent in EAM correlates with 1-year recurrence rate after ablation of left atrial supraventricular arrhythmias. The threshold of 0.4 mV is the most suitable for predicting recurrences of those examined.

Neurological and Systemic Pitfalls in the Diagnosis of Cluster Headaches: A Case-Based Review.

To describe different pitfalls in the diagnosis of primary cluster headaches (CHs) with the guidance of seven case vignettes. The question of whether primary CHs and migraines are totally different entities has been long debated. Autonomic features can be detected in as many as 60% of migraine patients. Although some genetic similarities have been found, CACNA1A mutations have not been detected among CH patients with hemimotor aura in contrast to hemiplegic migraine. Recently, functional MRI studies have shown that the left thalamic network was the most discriminative MRI feature in distinguishing migraine from CH patients. Compared to migraine, CH patients showed decreased functional interaction between the left thalamus and cortical areas mediating interception and sensory integration. However, clinically the most significant feature had been the restlessness and agitation seen during headache attacks patients with CHs. This feature is also important in distinguishing cluster patients from other patients having other trigeminal autonomic cephalalgias except for a subset of patients with hemicrania continua. CH is an important member of the group of headache disorders characterized by their association with one or more autonomic features in the trigeminal nerve distribution and termed Trigeminal Autonomic Cephalalgias (TACs). Although CH is a relatively rare condition, judged by the distress it generally causes to the affected individual, early diagnosis and institution of appropriate therapy seem mandatory. Correct diagnosis of CHs needs avoidance of pitfalls. Such pitfalls generally include differentiation from migraine, differentiation from other side locked headache disorders, from other trigeminal autonomic cephalalgias (TACs), and lastly, recognition of rare presentations of cluster-like manifestations with hemiplegic aura and simulating trigeminal and glossopharyngeal neuralgias. Differentiation between primary and symptomatic CHs related to sellar pathologies and systemic medical conditions is of equal importance. In the present review such issues are discussed with the assistance of seven case vignettes.

Exploring the links among brain iron accumulation, cognitive performance, and dietary intake in older adults: A longitudinal MRI study

This study evaluated longitudinal brain iron accumulation in older adults, its association with cognition, and the role of specific nutrients in mitigating iron accumulation. MRI-based, quantitative susceptibility mapping estimates of brain iron concentration were acquired from seventy-two healthy older adults (47 women, ages 60–86) at a baseline timepoint (TP1) and a follow-up timepoint (TP2) 2.5–3.0 years later. Dietary intake was evaluated at baseline using a validated questionnaire. Cognitive performance was assessed at TP2 using the uniform data set (Version 3) neuropsychological tests of episodic memory (MEM) and executive function (EF). Voxel-wise, linear mixed-effects models, adjusted for longitudinal gray matter volume alterations, age, and several non-dietary lifestyle factors revealed brain iron accumulation in multiple subcortical and cortical brain regions, which was negatively associated with both MEM and EF performance at T2. However, consumption of specific dietary nutrients at TP1 was associated with reduced brain iron accumulation. Our study provides a map of brain regions showing iron accumulation in older adults over a short 2.5-year follow-up and indicates that certain dietary nutrients may slow brain iron accumulation.

P11.05.B LONGITUDINAL MODIFICATIONS OF GRADIENTS AND GRAPH-THEORY MEASURES OF FUNCTIONAL MRI CONNECTIVITY IN GLIOMA PATIENTS AS POTENTIAL MARKERS OF POST-SURGICAL LONG-TERM COGNITIVE OUTCOME

Abstract BACKGROUND Integrating connectomics and functional brain activity into the study of brain tumors is among neuro-oncology’s challenges. Functional MRI (fMRI) studies showed that gliomas are integrated with brain networks’ activity, exerting effects beyond their margins. We investigated longitudinal modifications of fMRI gradients and graph-theory parameters in glioma patients, assessing their role in cognitive prognostication. MATERIAL AND METHODS Diffuse non-enhancing glioma patients underwent fMRI and cognitive assessments (OCS-Bridge) before, within 72h after, 3 and 12 months after surgery. Cognitive data were normalized and averaged into a global score. Differences between the last and preoperative scores were computed (“cognitive difference”). fMRI data underwent preprocessing, cortical parcellation, computation of timeseries, connectivity matrices, gradients and graph-theory measures. To quantify gradient dispersion, we computed a circularity metric (“CM”) of the hull perimeter of the first two gradients’ distribution. T-tests, partial correlations (correcting for volume and surgery radicality) and linear regression (regressors: age, volume, preoperative cognition, surgery radicality) were used to investigate associations with cognitive difference. RESULTS 17 patients (22-56 years, 8 females) were included, 4 had long-term cognitive worsening. Postoperative circularity metric, especially of the healthy intra- and inter-hemispheric connectivity (“HIIHC”), was higher than the preoperative (0.43 vs 0.32, t=2.4, p=0.03). Month3-postoperative and month3-preoperative differences in HIIHC CM were higher in patients with compared to those without cognitive worsening (0.33 vs -0.06, t=6.9, p<0.0001 and 0.27 vs 0.009, t=4.3, p=0.001). Both were negative predictors of the cognitive difference (the first: R=-0.94 with p=0.0002; β=-1.1 with p=0.001 and regression model’s p=0.003; the second: R=-0.76 with p=0.006; β=-1.1 with p=0.02 and model’s p=0.05). Month3-preoperative network modularity difference correlated with the second metric (R=-0.72, p=0.01) and the cognitive difference (R=0.67, p=0.02), while the preoperative modularity with the first metric (R=0.77, p=0.014). Similar results were obtained using a predetermined number of modules (Yeo’s 7 networks). Month12-preoperative difference in healthy intra-hemispheric connectivity CM also correlated with cognitive difference (R=-0.91, p=0.002). CONCLUSION Functional gradients seem dispersed after glioma surgery. Their recovery or worsening at month 3 could predict opposite long-term cognitive outcomes, putatively due to connectivity changes mainly involving the healthy hemisphere. Low preoperative network modularity and its increase at month 3 are associated with such gradient dispersion. Cognitive rehabilitation might be beneficial in the early post-surgical phase.

Reduced neurovascular coupling of the visual network in migraine patients with aura as revealed with arterial spin labeling MRI: is there a demand-supply mismatch behind the scenes?

BackgroundAlthough neuroimaging investigations have consistently demonstrated that “hyperresponsive” and “hyperconnected” visual cortices may represent the functional substrate of cortical spreading depolarization in patients with migraine with aura, the mechanisms which underpin the brain “tendency” to ignite the cortical spreading depolarization and, consequently, aura phenomenon are still matter of debate. Considering that triggers able to induce aura phenomenon constrain brain to increase global (such as physical activity, stressors and sleep abnormalities) or local (such as bright light visual stimulations) energy demand, a vascular supply unable to satisfy the increased energy requirement could be hypothesized in these patients.MethodsTwenty-three patients with migraine with aura, 25 patients with migraine without aura and 20 healthy controls underwent a 3-Tesla MRI study. Cerebral blood flow and local functional connectivity (regional homogeneity) maps were obtained and registered to the MNI space where 100 cortical regions were derived using a functional local-global normative parcellation. A surrogate estimate of the regional neurovascular coupling for each subject was obtained at each parcel from the correlation coefficient between the z-scored ReHo map and the z-scored cerebral blood flow maps.ResultsA significantly higher regional cerebral blood flow across the visual cortex of both hemispheres (i.e. fusiform and lingual gyri) was detected in migraine with aura patients when compared to patients with migraine without aura (p < 0.05, corrected for multiple comparisons). Concomitantly, a significantly reduced neurovascular coupling (p < 0.05, false discovery rate corrected) in the primary visual cortex parcel (VIS-4) of the large-scale visual network was observed in the left hemisphere of patients with migraine with aura (0.23±0.03), compared to both patients with migraine without aura (0.32±0.05) and healthy controls (0.29±0.05).ConclusionsVisual cortex neurovascular “decoupling” might represent the “link” between the exposure to trigger factors and aura phenomenon ignition. While physiological vascular oversupply may compensate neurovascular demand-supply at rest, it becomes inadequate in case of increased energy demand (e.g. when patients face with trigger factors) paving the way to the aura phenomenon ignition in patients with migraine with aura. Whether preventive treatments may exert their therapeutic activity on migraine with aura restoring the energy demands and cerebral blood flow trade-off within the visual network should be further investigated.

MENINGIOMA SIZE IS POSITIVELY CORRELATED WITH TUMOR WHO GRADE

Abstract AIMS It is well established that the surgical outcome is poorer in larger meningiomas. Vascular/ neural encasement and bone/dural/vascular invasion complicate surgical resection. Nevertheless, it is also likely that meningiomas will become biologically more aggressive with increasing size and tumor cell burden. To prove this hypothesis we studied radiological features of 316 meningiomas and correlated these features with tumor WHO-grade. METHOD 316 meningioma patients who were operated on and who received pathological diagnoses at one single institution were analyzed. Pathological grading was revised by one single neuropathologist according to WHO 2021 criteria. 123 high-grade (WHO grade 2 and 3) patients were initially selected and later substituted with a further 193 age and anatomical-location-matched individuals. Preoperative MRI studies were analyzed for size, hyperostosis, intratumoral calcification, mass effect, peritumoral edema, shape (globular/en-plaque), lobulation, cystic component, intratumoral heterogeneity, dural tail, and necrosis/hemorrhage. Univariate analysis as well as logistic regression were performed. RESULTS High-grade meningiomas were significantly more common to have lobulation (p: 7.111 x 10-8), necrosis/hemorrhage (p: 1.176 x 10-6), peritumoral edema (p: 3.421 x 10-6), intratumoral heterogeneity (p: 1.201 x 10-5), mass effect (p: 0.0002408), and cystic component (p: 0.003519) compared to WHO grade 1 meningiomas. Logistic regression indicated that tumor volume was an independent and significant parameter. High-grade tumors were significantly larger (40.83 cm3 vs 22.18 cm3, p: 3.518 x 10-6). Skull base meningiomas were of significantly lower grade (p: 0.001318). Mean volume was significantly higher in high-grade meningiomas. Mean tumor volume varied significantly among histopathological subtypes but was highest in anaplastic and atypical subtypes. Tumor volume was strongly correlated with mitosis (p: 2.353 x 10-6), hypercellularity (p: 1.22 x 10-4), spontaneous necrosis (p: 3.273 x 10-4), brain invasion (p: 0.02491), macronucleus (p: 0.05327), small cell (p: 0.09425), and ki-67 levels (p: 2x10-16). CONCLUSION Tumor size is strongly correlated with WHO grade in meningiomas.

Chronic ankle instability: a cadaveric anatomical and 3D high-resolution MRI study for surgical reconstruction procedures

ObjectivesTo quantitatively investigate the anatomy of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) for surgical reconstruction procedures in chronic ankle instability (CAI).Methods3D MRI was performed on five fresh-frozen cadaveric ankles using six different spatial resolutions (0.3 × 0.3 × 0.3 mm3, 0.45 × 0.45 × 0.45 mm3, 0.6 × 0.6 × 0.6 mm3, 0.75 × 0.75 × 0.75 mm3, 0.9 × 0.9 × 0.9 mm3, 1.05 × 1.05 × 1.05 mm3). After comparing the MRI results with cadaver dissection, a resolution of 0.45 × 0.45 × 0.45 mm³ was selected for bilateral ankles MRI on 24 volunteers. Classification of the ATFL and four distances of surgically relevant bony landmarkers were analyzed (distance 1 and 3, the fibular origin of the ATFL and CFL to the tip of fibula, respectively; distance 2, the talar insertion of the ATFL to the bare zone of talus; distance 4, the calcaneal insertion of the CFL to the peroneal tubercle).ResultsIn subjective evaluation, the interobserver ICC was 0.95 (95% confidence interval (CI): 0.94–0.97) between two readers. The spatial resolution of 0.3 × 0.3 × 0.3 mm3 and 0.45 × 0.45 × 0.45 mm3 received highest subjective score on average and demonstrated highest consistency with autopsy measurements in objective evaluation. Measurements on the 48 volunteer ankles, distance 1 in type I and II were 12.65 ± 2.08 mm, 13.43 ± 2.06 mm (superior-banded in Type II) and 7.69 ± 2.56 mm (inferior-banded in Type II) (means ± SD), respectively. Distance 2 in type I and II were 10.90 ± 2.24 mm, 11.07 ± 2.66 mm (superior-banded in Type II), and 18.44 ± 3.28 mm (inferior-banded in Type II), respectively. Distance 3 and 4 were 4.71 ± 1.04 mm and 14.35 ± 2.22 mm, respectively.ConclusionWe demonstrated the feasibility of quantifying the distances between bony landmarkers for surgical reconstruction surgery in CAI using high-resolution 3D MRI.Critical relevance statementHigh-resolution 3D MRI examination may have a guiding effect on the preoperative evaluation of chronic ankle instability patients.Key PointsSpatial resolutions of 0.3 × 0.3 × 0.3 mm3 and 0.45 × 0.45 × 0.45 mm3 demonstrated highest consistency with autopsy measurements.The spatial resolution of 0.45 × 0.45 × 0.45 mm3 was conformed more to clinical needs.3D MRI can assist surgeons in developing preoperative plans for chronic ankle instability.Graphical

Unveiling connections between venous disruption and cerebral small vessel disease using diffusion tensor image analysis along perivascular space (DTI-ALPS): A 7T MRI study.

Cerebral venous disruption is one of the characteristic findings in cerebral small vessel disease (CSVD), and its disruption may impede perivascular glymphatic drainage. And lower diffusivity along perivascular space (DTI-ALPS) index has been suggested to be with the presence and severity of CSVD. However, the relationships between venous disruption, DTI-ALPS index, and CSVD neuroimaging features remain unclear. To investigate the association between venous integrity and perivascular diffusion activity, and explore the mediating role of DTI-ALPS index between venous disruption and CSVD imaging features. In this cross-sectional study, 31 patients (mean age, 59.0 ± 9.9 years) were prospectively enrolled and underwent 7T MR imaging. DTI-ALPS index was measured to quantify the perivascular diffusivity. The visibility and continuity of deep medullary veins (DMVs) were evaluated based on a brain region-based visual score on high-resolution susceptibility weighted imaging. White matter hyperintensity (WMH) and perivascular space (PVS) were assessed using qualitative and quantitative methods. Linear regression and mediation analysis were performed to analyze the relationships among DMV scores, DTI-ALPS index, and CSVD features. The DTI-ALPS index was significantly associated with the parietal DMV score [β = -0.573, p-corrected = 0.004]. Parietal DMV score was associated with WMH volume [β = 0.463, p-corrected = 0.013] and PVS volume in basal ganglia (β = 0.415, p-corrected = 0.028]. Mediation analyses showed that DTI-ALPS index manifested a full mediating effect on the association between parietal DMV score and WMH (indirect effect = 0.115, Pm=43.1%), as well as between parietal DMV score and PVS volume in basal ganglia (indirect effect = 0.161, Pm=42.8%). Cerebral venous disruption is associated with glymphatic activity, and with WMH and PVS volumes. Our results suggest cerebral venous integrity may play a critical role in preserving perivascular glymphatic activity; while disruption of small veins may impair the perivascular diffusivity, thereby contributing to the development of WMH and PVS enlargement.

Predictors of Abnormal MRI Findings in Patients with Asymmetrical Sensorineural Hearing Loss.

This study aimed to determine the predictive factors of abnormal MRI findings in patients with asymmetrical sensorineural hearing loss (ASNHL). A retrospective review of medical records. A tertiary care hospital. Patients with asymmetries of ≥10 dB in at least 1 frequency, who underwent an MRI study of the temporal bone or brain during 2019-2021, were included. Age, sex, clinical symptoms, past medical history, and audiometric parameters, including pure tone thresholds, speech reception thresholds, and speech discrimination scores, were retrieved from the electronic database. The MRI findings reported by radiologists were reviewed and extracted. Of 390 patients, 50 (12.8%) patients had relevant abnormal MRI findings that could explain ASNHL. The most prevalent abnormal MRI finding was an internal acoustic canal (IAC) or cerebellopontine angle (CPA) tumor (n = 38; 76.0%), with other notable abnormalities including labyrinthitis, stroke, mucocele, and epidermoid. Multiple logistic regression analysis highlighted that hearing asymmetry of 15 dB at 1000 Hz (OR = 4.8; 95% CI 2.2-10.5) was a significant variable. The proposed predictor demonstrated 84% sensitivity and 48% specificity in detecting abnormal MRI findings. A hearing asymmetry of 15 dB at 1000 Hz was an important clinical predictor of abnormal MRI findings in patients with ASNHL. This finding has the potential to serve as a referral guide for further MRI investigations. Level 3 Laryngoscope, 2024.

Radiomics in the differential diagnosis of focal brain lesions: a retrospective study

INTRODUCTION: Glioblastoma and solitary metastases are the most common malignant neoplasms of the brain, characterized by high mortality and severe disability in patients. The method of choice for neuroimaging glioblastomas and metastases is contrast-enhanced magnetic resonance imaging. However, differentiation between the two is often difficult due to similar radiological features on MRI. Radiomics and machine learning can differentiate the primary origin of brain metastases and identify pathological tumor types noninvasively.OBJECTIVE: Application of texture analysis for differential diagnosis of glioblastomas and metastases of different etiologies.MATERIALS AND METHODS: 169 MRI studies from the RSCRR database were used in the study, 11 of which visualized morphologically differentiated glioblastoma of the brain, 55 lung cancer metastases and 103 breast cancer metastases. Segmentation of the regions of interest was performed semi-automatically in the free 3D-Slicer software with the ability to upload radiomic features from the regions of interest. For each lesion, 107 radiomic features were calculated from T1 and T2 sequences. Statistics: The calculation of statistical indicators was performed in a computer program for statistical data processing IBMSPSS Statistics 23. In statistical data processing, the Mann-Whitney statistical criterion for quantitative indicators and correlation analysis using the Pearson criterion were used to reduce the feature space. The reduction of the feature space and the selection of predictors by the feature_importances measure based on decision forests were carried out. Machine learning models were built in Python 3.10 using specialized libraries.RESULTS: For the model based on radiomic features extracted from T1 sequence, random forest showed the most efficient result, ROC-AUC=0.815 [0.749; 0.874]. For the model based on the radiomic features extracted from the T2 sequence, random forest showed the most effective result, ROC-AUC=0.817 [0.743; 0.873]. For the complex model based on radiomic features extracted from T1 and T2 sequences, random forest showed the most efficient result, ROC-AUC=0.855 [0.789; 0.906].DISCUSSION: The classification models and their metrics obtained by us indicate that the radiomic features extracted from T2 weighted MR images make it possible to differentiate breast cancer metastases from lung cancer metastases with higher sensitivity than the features extracted from T1 weighted MR images. We also identified a large number of significantly different indicators in the construction of models for the differentiation of glioblastomas from metastases, which demonstrates the prospects of this direction. It is planned to continue the study with the expansion of samples. Our conclusions are also confirmed by the research results of our foreign colleagues.CONCLUSION: The models we have obtained are highly accurate and sensitive to the differentiation of metastases of various etiologies and demonstrate significant potential in continuing this study with an expansion of samples.

Sex Differences in Fat Distribution and Muscle Fat Infiltration in the Lower Extremity: A Retrospective Diverse-Ethnicity 7T MRI Study in a Research Institute Setting in the USA.

Background: Fat infiltration in skeletal muscle is related to declining muscle strength, whereas excess subcutaneous fat is implicated in the development of metabolic diseases. Methods: Using multi-slice axial T2-weighted (T2w) MR images, this retrospective study characterized muscle fat infiltration (MFI) and fat distribution in the lower extremity of 107 subjects (64M/43F, age 11-79 years) with diverse ethnicities (including White, Black, Latino, and Asian subjects). Results: MRI data analysis shows that MFI, evaluated by the relative intensities of the pixel histogram profile in the calf muscle, tends to increase with both age and BMI. However, statistical significance was found only for the age correlation in women (p < 0.002), and the BMI correlation in men (p = 0.04). Sex disparities were also seen in the fat distribution, which was assessed according to subcutaneous fat thickness (SFT) and the fibula bone marrow cross-sectional area (BMA). SFT tends to decrease with age in men (p < 0.01), whereas SFT tends to increase with BMI only in women (p < 0.01). In contrast, BMA tends to increase with age in women (p < 0.01) and with BMI in men (p = 0.04). Additionally, MFI is positively correlated with BMA but not with SFT, suggesting that compromised bone structure may contribute to fat infiltration in the surrounding skeletal muscle. Conclusions: The findings of this study highlight a sex factor affecting MFI and fat distribution, which may offer valuable insights into effective strategies to prevent and treat MFI in women versus men.

Microstructural correlates of olfactory dysfunction in Parkinson's Disease: a systematic review of diffusion MRI studies.

Olfactory dysfunction (OD) is a non-motor symptom of Parkinson's Disease, affecting 75-95% of the patients. This symptom usually emerges before the clinical diagnosis, and patients with OD present with more severe forms of PD and need higher doses of therapy. It remains unknown whether OD is just a mere non-motor symptom or if it is a part of a series of pathological changes in different brain regions of the affected patients. We performed a systematic review to find the microstructural correlates of OD in people with PD. The systematic search in PubMed, Scopus, Embase, and Web of Science yielded ten eligible studies. Assessments in most included studies were inconclusive. However, we found variable brain regions and tracts associated with OD. The most repeated areas included the primary olfactory cortex, gyrus rectus, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, corticospinal tract, uncinate fasciculus, cingulum, and cerebellar peduncle. Despite some limitations, we pointed out the microstructural correlates of OD, which were also present in areas other than the olfactory system. These findings imply that OD might be a manifestation of an unknown, greater pathology in the brain of patients with PD.

Is there enough evidence supporting the clinical adoption of clear cell likelihood score (ccLS)? An updated systematic review and meta-analysis

ObjectiveTo review the evidence for clinical adoption of clear cell likelihood score (ccLS) for identifying clear cell renal cell carcinoma (ccRCC) from small renal masses (SRMs).MethodsWe distinguished the literature on ccLS for identifying ccRCC via systematic search using PubMed, Embase, Web of Science, China National Knowledge Infrastructure, and Wanfang Data until 31 March, 2024. The risk of bias and concern on application was assessed using the modified quality assessment of diagnostic accuracy studies (QUADAS-2) tool. The level of evidence supporting the clinical adoption of ccLS for identifying ccRCC was determined based on meta-analyses.ResultsEight MRI studies and three CT studies were included. The risk of bias and application were mainly related to the index test and flow and timing, due to incomplete imaging protocol, unclear rating process, and inappropriate interval between imaging and surgery. The diagnostic odds ratios (95% confidence intervals) of MRI and CT ccLS were 14.69 (9.71–22.22; 6 studies, 1429 SRM, 869 ccRCC), and 5.64 (3.34–9.54; 3 studies, 296 SRM, 147 ccRCC), respectively, for identifying ccRCC from SRM. The evidence level for clinical adoption of MRI and CT ccLS were both rated as weak. MRI ccLS version 2.0 potentially has better diagnostic performance than version 1.0 (1 study, 700 SRM, 509 ccRCC). Both T2-weighted-imaging with or without fat suppression might be suitable for MRI ccLS version 2.0 (1 study, 111 SRM, 82 ccRCC).ConclusionccLS shows promising diagnostic performance for identifying ccRCC from SRM, but the evidence for its adoption in clinical routine remains weak.Critical relevance statementAlthough clear cell likelihood score (ccLS) demonstrates promising performance for detecting clear cell renal cell carcinoma, additional evidence is crucial to support its routine use as a tool for both initial diagnosis and active surveillance of small renal masses.Key PointsClear cell likelihood score is designed for the evaluation of small renal masses.Both CT and MRI clear cell likelihood scores are accurate and efficient.More evidence is necessary for the clinical adoption of a clear cell likelihood score.Graphical

Clinical and Video-Oculographic Characteristics of Spinocerebellar Ataxia Type 27B (GAA-FGF14 Ataxia): A Single-Center Retrospective Study

An intronic GAA repeat expansion in the FGF14 gene was recently identified as a common cause of autosomal dominant GAA-FGF14 ataxia (SCA27B). We aimed to characterize in detail the clinical and video-oculographic features in our cohort of SCA27B patients. We genotyped the FGF14 GAA repeat expansion in 52 patients with unsolved late-onset cerebellar ataxia. Brain MRI and nerve conduction study, as well as video-oculographic (VOG) assessment, were performed. Eight patients (15.4%) with pathogenic GAA repeat expansion in the FGF14 gene were found. The median age at onset was 51 years (range—23–63 years). Sensory axonal neuropathy was found in 5/8 patients. Cerebellar atrophy was observed in 5/8 patients, and in one case, pontocerebellar atrophy was found. All tested patients had impaired smooth pursuit, 5/6 patients had impaired vestibulo-ocular reflex suppression, nystagmus, and an increased number of square wave jerks, 4/6 patients had horizontal gaze-evoked nystagmus, 3/6 had spontaneous downbeat nystagmus, and 1/6 had an upbeat one. Video head impulse test gain was lower than 0.8 on both sides in 2/4 patients, along with the presence of overt saccades. Further studies in different cohorts are needed to complete the phenotype of the FGF14-related disorders.

The prevalence of intervertebral disc degeneration in the cervical, thoracic, and lumbar spine in asymptomatic cats.

To investigate the prevalence and severity of intervertebral disc (IVD) degeneration (IVDD) throughout the spine of young, middle-aged, and old asymptomatic cats; identify differences between the cervical, thoracic, and lumbar spine; and investigate the influence of sex and neuter status on the prevalence of feline IVDD. 60 cadavers were collected from asymptomatic cats and subdivided into 3 age groups: young (≥ 1 to < 6 years), middle aged (≥ 6 to < 12 years), and old (≥ 12 years). T2 weighted sagittal MRI studies of the spine were obtained. Each IVD was graded according to the modified Pfirrmann grading for feline IVDD. Cumulative link mixed models were used to analyze the significance of spinal region, age, sex, and neuter status on the degenerative state of the IVDs. A total of 1,544 IVDs were evaluated; 884 (57.3%), 425 (27.5%), 147 (9.5%), 82 (5.3%), and 6 (0.4%) were graded Pfirrmann 1, 2, 3, 4, and 5, respectively. Irrespective of spinal region, middle-aged cats (OR, 4.03; P < .01) and old cats (OR, 12.5; P < .01) had significantly higher odds for IVDD compared to young cats. For old cats, thoracic (OR, 4.44; P < .01) and cervical IVDs (OR, 2.76; P < .01) had significantly higher odds of degenerating compared to lumbar IVDs. No significant effect of sex (P = .81) and neuter status (P = .61) was found. The prevalence of feline IVDD significantly increases with progressive age, with the thoracic and cervical IVDs showing the highest odds for degeneration. However, extreme stages of IVDD were only occasionally observed.