3D-FLAIR MRI Research Articles

Impairment of Internal Auditory Canal Barrier in Meniere'sDisease.

The aim of this investigation was to explore the potential correlation between the signal intensity ratio (SIR) at the internal auditory canal (IAC) fundus and hearing impairment in Meniere's disease (MD), thereby providing a foundation to further understand the mechanisms underlying hearing loss. Fifty patients diagnosed with unilateral definite MD were enrolled in the study. 3D-FLAIR MRI was conducted 4 h after intravenous administration of gadobutrol to determine the SIR of the bilateral IAC fundus. The difference in the SIR of the IAC fundus between the affected and unaffected sides was assessed, followed by an analysis of its correlation with low-, middle-, and high-tone hearing thresholds. Correlation analysis was also conducted between the degree of endolymphatic hydrops (EH) in the vestibule and cochlea and the SIR on the affected side. The degree of EH in MD can be clearly visualised using 3D-FLAIR MRI. The SIR on the affected side was significantly higher than that on the unaffected side (p = 0.000). Furthermore, a positive correlation was observed between the SIR at the affected and low (r = 0.692, p = 0.000), middle (r = 0.615, p = 0.000) and high-tone (r = 0.440, p = 0.001) hearing thresholds, while the SIR showed no significant correlation with cochlear (r = 0.315, p = 0.088) or vestibular hydrops (r = 0.215, p = 0.244). The IAC fundus barrier may be damaged in patients with MD, representing one of the factors affecting the level of hearing.

Deep learning for efficient reconstruction of highly accelerated 3D FLAIR MRI in neurological deficits.

To compare compressed sensing (CS) and the Cascades of Independently Recurrent Inference Machines (CIRIM) with respect to image quality and reconstruction times when 12-fold accelerated scans of patients with neurological deficits are reconstructed. Twelve-fold accelerated 3D T2-FLAIR images were obtained from a cohort of 62 patients with neurological deficits on 3T MRI. Images were reconstructed offline via CS and the CIRIM. Image quality was assessed in a blinded and randomized manner by two experienced interventional neuroradiologists and one experienced pediatric neuroradiologist on imaging artifacts, perceived spatial resolution (sharpness), anatomic conspicuity, diagnostic confidence, and contrast. The methods were also compared in terms of self-referenced quality metrics, image resolution, patient groups and reconstruction time. In ten scans, the contrast ratio (CR) was determined between lesions and white matter. The effect of acceleration factor was assessed in a publicly available fully sampled dataset, since ground truth data are not available in prospectively accelerated clinical scans. Specifically, 451 FLAIR scans, including scans with white matter lesions, were adopted from the FastMRI database to evaluate structural similarity (SSIM) and the CR of lesions and white matter on ranging acceleration factors from four-fold up to 12-fold. Interventional neuroradiologists significantly preferred the CIRIM for imaging artifacts, anatomic conspicuity, and contrast. One rater significantly preferred the CIRIM in terms of sharpness and diagnostic confidence. The pediatric neuroradiologist preferred CS for imaging artifacts and sharpness. Compared to CS, the CIRIM reconstructions significantly improved in terms of imaging artifacts and anatomic conspicuity (p < 0.01) for higher resolution scans while yielding a 28% higher SNR (p = 0.001) and a 5.8% lower CR (p = 0.04). There were no differences between patient groups. Additionally, CIRIM was five times faster than CS was. An increasing acceleration factor did not lead to changes in CR (p = 0.92), but led to lower SSIM (p = 0.002). Patients with neurological deficits can undergo MRI at a range of moderate to high acceleration. DL reconstruction outperforms CS in terms of image resolution, efficient denoising with a modest reduction in contrast and reduced reconstruction times.

The effect of delay time after injecting gadobutrol on the diagnosis of endolymphatic hydrops

ObjectivesThe aim of this study was to reduce the time delay between gadolinium injection and 3D-FLAIR (three-dimensional fluid-attenuated inversion recovery) MRI by using a single dose of intravenous gadobutrol in Menière's disease patients. Methods17 patients diagnosed with definite unilateral Meniere's disease underwent 3D-FLAIR MRI scans at 2, 4, and 6 h post-intravenous administration of a single-dose of gadobutrol. The signal intensity ratio of bilateral inner ear, cochlear and vestibular hydrops was measured at 2 h, 4 h and 6 h, while the differences in signal intensity ratio and endolymphatic hydrops were evaluated at three time points. ResultsThe cochlea, vestibule, and semicircular canal exhibit clear structural features with distinct perilymph-endolymph boundaries at 2 h, 4 h, and 6 h. The signal intensity ratio of the affected ear was significantly higher than that of the unaffected ear at 2 h, 4 h, and 6 h. The signal intensity ratio at 4 h and 6 h in both the affected and unaffected ears was significantly higher than that at 2 h, but there was no significant difference between 4 h and 6 h. Cochlear hydrops and vestibular hydrops show no significant differences at these time points, demonstrating excellent consistency. ConclusionsWe have demonstrated that 3D-FLAIR images acquired 2 h after intravenous administration of a single-dose gadobutrol are of high quality and equally effective as those obtained at the conventional 4-h time point for diagnosing endolymphatic hydrops in Menière's disease. In clinical practice, the delay time can be safely shortened to 2 h.

White Matter Hyperintensity Growth/Regression quantification: MarkVCID multi‐site Instrumental Validation

AbstractBackgroundWhite matter hyperintensities (WMH) are one of the main recognized biomarkers for the small vessel diseases related to the vascular contributions to cognitive impairment and dementia (VCID). WMH found to be dynamic, increasing in volume, but also stability or even decreasing in volume over time. The ability to measure and track such longitudinal change over periods of time, as short as one‐year, is critical for both mechanistic discoveries and for the informed future use of biomarkers to track disease modification in clinical trials of VCID. The NINDS‐funded MarkVCID Consortium engaged to test such a protocol for cross‐site inter‐rater and test‐retest reliability to establish instrumental validation of this candidate biomarker for VCID.MethodT1 and 3D FLAIR MRI acquisitions were collected longitudinally and analyzed across six independent sites, using a unique post‐acquisition processing protocol. The analytic platform was built within a Singularity Container to provide the necessary software tools for rigorous uniform co‐registration and intensity corrections that enabled precise measurement of WMH change in regard to growth, stability and regression over a one‐year interval. Baseline and 12‐month follow‐up scans were acquired across MarkVCID sites and pooled to generate the validation dataset used for cross‐site inter‐rater reliability (n = 30). To evaluate test‐retest reliability, two baseline scans (acquired approximately one‐week apart) were independently co‐registered to the 12‐month follow‐up scan (n = 18). Cross‐site inter‐rater and test‐retest reliability were assessed using intraclass correlational analyses (ICC).ResultICC values for test‐retest reliability of WMH growth and regression were 0.97 and 0.94 respectively. Mean ICC values for cross‐center WMH masks were 1.0 for both time points, see Fig. 1 and 2, and WMH growth and regression were 0.99 for both see Fig. 3 and 4.ConclusionThe present data demonstrate robust ICC validity of a WMH growth/regression protocol over a one‐year period as measured by cross‐site inter‐rater and test‐retest reliability. These data suggest that this approach may serve an important role in clinical trials of disease modifying agents for VCID that may preferentially affect WMH growth, stability, or regression.

Visualization and clinical relevance of the endolymphatic duct and sac in Ménière's disease.

Ménière's disease (MD) is a chronic inner ear disorder with a multifactorial etiology. Decreased visualization of the endolymphatic duct (ED) and sac (ES) is thought to be associated with MD, although controversy exists about whether this finding is specific to MD. Recent literature has revealed that two distinct ES pathologies, developmental hypoplasia and epithelial degeneration, can be distinguished in MD using the angular trajectory of the vestibular aqueduct (ATVA) or ED-ES system as a radiographic surrogate marker. It has been suggested that these two subtypes are associated with distinct phenotypical features. However, the clinical differences between the ATVA subtypes require further validation. The objective of this study is to investigate whether (1) non-visualization of the ED-ES system is a discriminative radiological feature for MD in a cohort of vertigo-associated pathologies (VAPs) and whether (2) different angular trajectories of the ED-ES system in MD are associated with distinguishable clinical features. The study was conducted in the Vertigo Referral Center (Haga Teaching Hospital, The Hague, the Netherlands). We retrospectively assessed 301 patients (187 definite MD and 114 other VAPs) that underwent 4h-delayed 3D FLAIR MRI. We evaluated (1) the visibility of the ED-ES system between MD and other VAP patients and (2) measured the angular trajectory of the ED-ES system. MD patients were stratified based on the angular measurements into αexit ≤ 120° (MD-120), αexit 120°-140° (MD-intermediate), or αexit ≥ 140° (MD-140). Correlations between ATVA subgroups and clinical parameters were evaluated. Non-visualization of the ED-ES system was more common in definite MD patients compared with other VAPs (P < 0.001). Among definite MD patients, the MD-140 subtype demonstrated a longer history of vertigo (P = 0.006), a higher prevalence of bilateral clinical disease (P = 0.005), and a trend toward a male preponderance (p = 0.053). No significant differences were found between ATVA subgroups regarding the presence or severity of auditory symptoms, or the frequency of vertigo attacks. Non-visualization of the ED-ES system is significantly associated with MD. Among MD patients with a visible ED-ES system, we demonstrated that the MD-140 subtype is associated with a longer disease duration, a higher prevalence of bilateral MD, and a trend toward a male preponderance.

The value of postcontrast delayed 3D fluid-attenuated inversion recovery MRI in the diagnosis of unilateral peripheral vestibular dysfunction.

Clinically, unilateral peripheral vestibular dysfunction (UPVD) with dizziness or vertigo as the chief complaint is quite common. This study aimed to investigate the correlations between 3-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI) findings and cochleovestibular function test results in patients with UPVD and to explore the possible etiologies of UPVD. This retrospective study enrolled 76 patients with UPVD. Endolymphatic hydrops (EH) and perilymphatic enhancement (PE) in the vestibule and cochlea on 3D-FLAIR images, their correlations with the parameters of the cochleovestibular function test and vascular risk factors, and the immunological findings of patients with EH and PE were assessed. Of the included patients, 48.7% showed positive MRI findings (the presence of EH and PE on 1 side). The pure-tone average (PTA) was higher in patients with cochlear PE than in those with vestibular (P=0.014) and cochlear EH (P=0.02). The canal paresis (CP) value was also higher in patients with vestibular PE than in those with vestibular (P=0.002) and cochlear EH (P=0.003). Video head impulse test (vHIT) gains were lower in patients with vestibular and cochlear PE than in those with vestibular and cochlear EH (P<0.001). A positive correlation was observed between the degree of vestibular and cochlear EH and PTA (both P values <0.001). PTA and CP with a cutoff value of 32 dB and 46.5%, respectively, yielded high sensitivity and specificity in determining positive MRI findings (P<0.001 and P=0.029, respectively). The prevalence of vascular risk factors was significantly higher in patients with PE than in those with EH (P=0.033). (I) Nearly half of the patients UPVD exhibited abnormal MRI findings. Cutoff values for PTA and CP of 32 dB and 46.5%, respectively, indicated that patients were more likely to have abnormal imaging findings. (II) The severity of EH was positively correlated with hearing impairment. (III) Patients with PE showed severe hearing impairment and vestibular dysfunction, which was presumed to be associated with vascular damage.

Usefulness of a Rim-Enhancing Pattern on the Contrast-Enhanced 3D-FLAIR Sequence and MRI Characteristics for Distinguishing Meningioma and Malignant Dural-Based Tumor.

Meningiomas are the most common type of extra-axial dural-based tumors; however, malignant dural-based tumors can mimic meningiomas on imaging. The aim of this study was to determine the efficacy of differentiating meningiomas from malignant dural-based tumors by using rim-enhancement patterns on a contrast-enhanced FLAIR sequence and MR imaging characteristics. This retrospective study included 102 patients with meningiomas and 31 patients with malignant dural-based tumors who underwent pretreatment MR imaging. The rim-enhancement patterns on contrast-enhanced FLAIR and MR imaging characteristics, including the dural tail sign, hyperostosis, bony destruction, leptomeningeal enhancement, peritumoral edema, T2-weighted signal intensity, and tumor enhancement were evaluated. Complete rim enhancement of the tumor-brain interface on contrast-enhanced FLAIR (contrast-enhanced-FLAIR rim sign) was present in most meningiomas (91/102, 89.2%) and at significantly greater frequency than in malignant dural-based tumors (2/31, 6.5%) (P < .001). Complete contrast-enhanced FLAIR rim enhancement provided high sensitivity (89.2%), specificity (93.5%), and accuracy (90.2%) for diagnosing meningioma. Additionally, hyperostosis was an MR imaging characteristic that suggested a diagnosis of meningioma. In contrast, bony destruction with cortical breakthrough and leptomeningeal enhancement suggested malignant dural-based tumors. There were limitations of meningiomas of <2.0 cm or at cavernous sinus locations that did not demonstrate contrast-enhanced FLAIR rim enhancement. The rim-enhancement pattern on contrast-enhanced FLAIR could help differentiate meningiomas and malignant dural-based tumors. The presence of complete rim enhancement on contrast-enhanced FLAIR was a robust predictive sign for meningioma.

Correlation Between Quantitative Value of Endolymphatic Hydrops and Hearing Threshold Using Magnetic Resonance Imaging.

This study investigated the relationship between quantitative value of endolymphatic hydrops in the affected ear and the hearing threshold in patients with unilateral Meniere's disease. Prospective study. Forty patients with unilateral definite Meniere's disease were diagnosed in outpatient clinic. We recorded their clinical symptoms (duration of vertigo and tinnitus and duration of vertigo attacks), and obtained the hearing thresholds of high, middle, and low by pure tone audiometry. A 3D-FLAIR MRI revealed endolymphatic hydrops and assessed quantitative values of cochlear and vestibular endolymphatic hydrops. We assessed the correlation between hearing thresholds and quantitative values of endolymphatic hydrops. All patients showed varying degrees of endolymphatic hydrops in the affected ear. With the duration of vertigo, tinnitus and vertigo attacks as control variables, partial correlation analysis showed that the correlation coefficients between quantitative value of cochlear hydrops and hearing thresholds of low, middle, and high tone in the affected ear were 0.581, 0.610, and 0.125, respectively. The correlation coefficients between quantitative value of vestibular hydrops and hearing thresholds of low, middle, and high tone in the affected ear were 0.727, 0.569, and 0.201, respectively. The degree of endolymphatic hydrops in Meniere's disease can be revealed and assessed by 3D-FLAIR MRI after intravenous administration of double doses of gadoterate meglumine. Clinical evaluation of endolymphatic hydrops in Meniere's disease can be assisted by low- and middle-tone hearing thresholds, thereby providing anatomical support for the clinical symptoms of Meniere's disease.

Comparison between 3D-FLAIR and 3D-real IR MRI sequences with visual classification method in the imaging of endolymphatic hydrops in Meniere's disease

BackgroundClinically, the evidence of endolymphatic hydrops (EH) in Meniere's disease (MD) primarily relies on audiological examinations, such as glycerol tests and electrocochleography, to suggest the presence of EH indirectly. However, these techniques lack sensitivity and specificity, and they do not sufficiently assess the degree of EH. This study aims to explore the application of three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) and three-dimensional real inversion recovery (3D-real IR) sequence imaging of EH in MD and to assess the image quality and grading of EH. MethodsThe study included 50 patients with definite MD. The 3D-FLAIR and 3D-real IR sequence images were performed 24 h after bilateral intratympanic injection of gadolinium. The image quality of both sequences was reviewed by two experienced radiologists. The vestibular and cochlear EH grades of both sequences were reviewed by two experienced otologists using a visual grading method. The Cohen's kappa and Pearson tests were used to analyze the data. ResultsThe reliability of image quality between the two radiologists was excellent (0.7 < kappa < 0.9). There were significant statistical differences in the image quality between the 3D-real IR and 3D-FLAIR sequences (p = 0.023 and p = 0.035, respectively). The reliability for the grading of vestibular and cochlear EH between the two otologists was excellent (0.7 < kappa < 0.9). The 3D-real IR sequence detected more severe hydrops than did the 3D-FLAIR sequence (p < 05). ConclusionThe image quality of the 3D-real IR sequence is better than that of the 3D-FLAIR sequence, and there are differences in the vestibular and cochlear EH grades of both sequences. The sensitivity of the 3D-real IR sequence in the cochlea is higher. The method of visual grading can be applied to both technologies when combined with 3D-real IR.

The changes of blood-labyrinth barrier in idiopathic sudden sensorineural hearing loss and the relationship with clinical features and prognosis

Objective: To investigate the clinical features and prognosis in patients with idiopathic sudden sensorineural hearing loss (ISSNHL) with blood-labyrinth barrier breakdown (BLB-B). Methods: Clinical data of patients with unilateral ISSNHL hospitalized from December 2017 to December 2018 were retrospectively analyzed. According to the results of 3D-FLAIR MRI and enhanced MRI scanning, these patients were divided into two groups, i.e., normal and abnormal inner ear groups. The patients in abnormal inner ear group were further divided into two subgroups: BLB-B and BLB-B with exudation. The differences and correlations among the groups in clinical characteristics, in terms of gender, age, deafness side, basic diseases, dizziness/vertigo, vestibular function, hearing loss degree, as well as classification of hearing curve, and prognosis were analyzed by statistical software SPSS 23.0. Results: Data were collected from 150 cases, in which 68 were male and 82 were female, aged (46.2±14.6) years, including 67 cases with normal inner ears and 83 cases with abnormal inner ears (13 cases with BLB-B; 70 cases with BLB-B and exudation). The dizziness/vertigo incidence, side ratio, hearing loss degree, classification of hearing curve, vestibular dysfunction (vestibular double temperature test, HIT and VAT) and therapeutic effect were different between normal and abnormal inner ear groups (P<0.05). The dizziness/vertigo incidence, side ratio, hearing loss degree, classification of hearing curve, vestibular dysfunction (vestibular double temperature test, o/cVEMP, HIT and VAT) and therapeutic effect were different among normal inner ear, BLB-B and BLB-B with exudation groups (P<0.05). Pairwise comparison between groups revealed that vestibular dysfunction (vestibular double temperature test, o/cVEMP, HIT and VAT) and therapeutic effect were different between normal inner ear and BLB-B groups (P<0.05); The dizziness/vertigo incidence, side ratio, hearing loss degree, classification of hearing curve, vestibular dysfunction (vestibular double temperature test, o/cVEMP, HIT and VAT) and therapeutic effect were different between normal inner ear and BLB-B with exudation groups (P<0.05). There was no significant different between BLB-B and BLB-B with exudation groups. Conclusion: BLB-B displayed by 3D-FLAIR MRI manifestation in ISSNHL patients indicates more serious cochlear and vestibular dysfunction, and worse therapeutic effect.

Correlation analysis of 3D-FLAIR MRI characteristics of the inner ear and vestibular function in the patients with vestibular neuritis

Objective: The characteristics of 3D-FLAIR MRI images of the inner ear of patients with vestibular neuritis were preliminarily studied to explore the possible pathogenesis of vestibular neuritis, and the correlation analysis was conducted in combination with vestibular function to provide a basis for accurate diagnosis of vestibular neuritis. Methods: A total of 36 patients with vestibular neuritis (VN) from December 2019 to October 2020 were collected from the Vertigo Department of Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University. There were 36 cases (18 females, 18 males) with unilateral acute vestibular neuritis, 17 cases of left ear and 19 cases of right ear. According to the results of 3D-FLAIR MRI in the inner ears, the patients were divided into the enhanced group and the non-enhanced group (the health side served as the normal control group). The results of vestibular function examination in the two groups were compared. SPSS19.0 software was used for statistical processing to analyze the relationship between the vestibular function and the characteristics of 3D-FLAIR imaging in the inner ears. Results: Abnormal enhancement of 3D-FLAIR was found in 31 cases (86.1%) of the 36 cases, including 14 cases of both vestibular nerve and vestibular terminal organ enhancement, eight cases of superior vestibular nerve enhancement alone, seven cases of vestibular terminal organ enhancement alone, and two cases of cochlear enhancement alone. Observation of abnormal reinforcement of vestibular nerve showed: twenty-one cases of superior vestibular nerve reinforcement, one case of superior and inferior vestibular nerve reinforcement. No abnormalities were found in 3D-FLAIR of inner ear in 5 cases. According to the analysis of vestibular function results, there were 19 cases (52.8%) with total vestibular involvement, sixteen cases (44.4%) with superior vestibular involvement alone, and one case (2.8%) with inferior vestibular involvement alone. Comparison of vestibular function between the five cases (non-enhancement group) and the 31 cases (enhanced group) in the 3D-FLAIR group of the inner ears showed that the CP values of caloric tests in the enhanced group were higher (60.81±3.49 vs 34.12±7.37), with statistically significant difference (t=-2.898, P<0.01). Conclusion: In patients with vestibular neuritis, 3D-FLAIR MRI scan of the inner ear provides visual imaging evidence for clinical practice, considering that the lesion site of vestibular neuritis is not only in the vestibular nerve, but also in the vestibular end organ. Patients with 3D-FLAIR enhanced in the inner ear may have more significant vestibular function damage.

Correlation of semi-quantitative findings of endolymphatic hydrops in MRI with the audiometric findings in patients with Meniere's disease

Purpose: To investigate the correlation between vestibular hydrops (VH), cochlearhydrops (CH), vestibular aqueduct non-visibility (VANV), and visually increased perilymphatic enhancement (VIPE) with the findings of pure-tone audiometry (PTA) in Meniere’s disease (MD) patients.Methods: In this cross-sectional study, 53 ears belonging to 48 patients were divided into two groups and evaluated. In group “MD patients,” there were 24 ears of 19 patients diagnosed with the definite MD (14 patients with unilateral and 5 patients withbilateral involvements). The “control group” consisted of 29 non-symptomatic ears belonging to patients diagnosed with unilateral sudden sensory-neural hearing loss or unilateral schwannoma. All the patients underwent 2 sessions of temporal bone MRI using the same 3T system: an unenhanced axial T1, T2, and 3D-FLAIR MRI, an intravenous gadolinium-enhanced axial T1 fat-sat, and 4 h after the injection, an axial 3D-T2 cube and 3D-FLAIR session. VH, CH, VANV, and VIPE were assessed. Subsequently, the correlation between EH indices and PTA findings (in three frequency domains of low, middle, and high) were evaluated, and the predictive value of MRI was calculated.Results: VH was significantly correlated with the hearing threshold in the low, middle, and high-frequency domains. CH was also correlated with the hearing threshold in the low and middle domains. Contrarily, VIPE was not associated with hearing thresholds, and VANV was only correlated with the hearing threshold in low frequencies.Conclusion: The grade of VH, CH, and VANV were significantly correlated with the hearing thresholds in PTA.

Atherosclerotic risk is associated with cerebral perfusion – A cross-sectional study using arterial spin labeling MRI

BackgroundArterial spin labeling (ASL) magnetic resonance imaging (MRI) may be a promising technique to evaluate the presence of cerebral atherosclerosis. We tested whether the new and easily calculated ASL MRI parameter for vascular and tissue signal distribution - ‘spatial coefficient of variation’ (ASL-sCoV) - is a better radiological marker for atherosclerotic risk than the more conventional markers of white matter hyperintensity (WMH) volume and cerebral blood flow (ASL-CBF). MethodsParticipants of the preDIVA trial (n = 195), aged 72–80 years with systolic hypertension (>140 mmHg) underwent two MRI scans two to three years apart. WMH volume was derived from 3D FLAIR-MRI; gray matter ASL-CBF and ASL-sCoV from ASL-MRI. Atherosclerotic risk was operationalized as 10-year cardiovascular risk by the Systematic COronary Risk Evaluation Older Persons (SCORE O.P) and calculated at baseline and follow-up. Data were analyzed using linear regression. ResultsASL-CBF was associated with atherosclerotic risk scores at baseline (standardized-beta = -0.26, 95 %CI = -0.40 to −0.13, p < 0.001) but not at follow-up (standardized-beta = -0.14, 95 %CI = -0.33 to 0.04, p = 0.12). ASL-sCoV was associated with atherosclerotic risk scores at both time points (baseline standardized-beta = 0.23, 95 %CI = 0.10 to 0.36, p < 0.0001, follow-up standardized beta = 0.20, 95 %CI = 0.03 to 0.36, p = 0.02). WMH volume was not associated with atherosclerotic risk scores at either time-point. There were no longitudinal associations between changes in MRI parameters and baseline atherosclerotic risk scores. ConclusionsOur findings suggest that ASL-sCoV correlates better with atherosclerotic risk than the more conventional markers ASL-CBF and WMH volume. Our data reaffirm that non-invasive imaging with MRI is highly informative and could provide additional information about cerebrovascular damage.

Clinical Value of 3D-FLAIR MRI in Idiopathic Sudden Sensorineural Hearing Loss

Three-dimensional fluid-attenuated inversion recovery sequence magnetic resonance imaging (3D-FLAIR MRI) has been used in the diagnosis of inner ear diseases. However, the relevance of 3D-FLAIR MRI appearances with multiple features and prognosis of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) remains unclear. This study was a retrospective trial. We recruited 1300 patients with unilateral ISSNHL hospitalized from May 2017 to January 2019. They were divided into four groups according to their 3D-FLAIR MRI appearances: normal (n = 739), inner ear hemorrhage (n = 218), increased protein content (n = 288), and blood-labyrinth barrier damage (n = 55). The correlation between 3D-FLAIR MRI appearances and the degree or type of deafness of the participants was analyzed. There was a statistical difference in the deafness side (p < 0.001) and vestibular dysfunction (p < 0.001) among the four groups. There was a statistical difference in the duration of treatment (p < 0.001) and the incidence of dizziness or vertigo (p < 0.001) for patients among these groups. The degree of deafness in the patients in the inner ear hemorrhage group was significantly more severe than that of the patients in the other three groups (p < 0.001). 3D-FLAIR MRI appearances were correlated with the prognosis of patients with ISSNHL.

Utility of 4D digital subtraction angiography in operative localization of micro-arteriovenous malformations

Background: Micro-arteriovenous malformations (mAVM), defined with a nidus smaller than one centimeter, can lead to intracranial hemorrhage. Surgery can be curative, but precise intra-operative localization of the nidus is often challenging. Finding the mAVM is particularly important when in an eloquent area. Due to their small size, mAVMs that are diagnosed on high quality angiography (occult on non-invasive imaging) may not be seen with intra-operative image guidance systems. Time-resolved 3D angiography (4D DSA) fuses the 3D volumes from different angiographic acquisition phases, and may help with mAVM localization. To illustrate the utility of 4D DSA in the localization of mAVMs for pre-operative surgical planning and during intra-operative resection.Methods: We present 4 surgically managed cases of ruptured paracentral mAVM where 4D DSA proved useful. First, 3D FLAIR MRI was used for cortical surface segmentation.4D DSA was then used to select two 3D volumes; one at time of maximal shunting (to show the mAVM nidus) and one with maximal venous filling (to show normal venous anatomy). These were merged using a neuronavigation system as 3D objects, fused to the 3D FLAIR volume, and used pre- and intra-operatively to precisely locate the mAVM.Results: Intra-operatively, segmentation of sulco-gyral and normal venous anatomy were used to confirm the accuracy of surgical planning. In all cases, the mAVM at ‘maximal shunt’ time guided the dissection to precisely locate the nidus. There were no instances of neurological deterioration with surgery, and complete resection was confirmed by indocyanine green fluorescent angiography, followed by delayed (3 months) catheter angiography.Conclusions: 4D DSA may be useful for surgical planning and precise intra-operative localization of mAVMs.

Hydropic Ear Disease: Correlation Between Audiovestibular Symptoms, Endolymphatic Hydrops and Blood-Labyrinth Barrier Impairment.

Research Objective: To investigate the correlation between clinical features and MRI-confirmed endolymphatic hydrops (EH) and blood-labyrinth barrier (BLB) impairment.Study Design: Retrospective cross-sectional study.Setting: Vertigo referral center (Haga Teaching Hospital, The Hague, the Netherlands).Methods: We retrospectively analyzed all patients that underwent 4 h-delayed Gd-enhanced 3D FLAIR MRI at our institution from February 2017 to March 2019. Perilymphatic enhancement and the degree of cochlear and vestibular hydrops were assessed. The signal intensity ratio (SIR) was calculated by region of interest analysis. Correlations between MRI findings and clinical features were evaluated.Results: Two hundred and fifteen patients with MRI-proven endolymphatic hydrops (EH) were included (179 unilateral, 36 bilateral) with a mean age of 55.9 yrs and median disease duration of 4.3 yrs. Hydrops grade is significantly correlated with disease duration (P < 0.001), the severity of low- and high-frequency hearing loss (both P < 0.001), and the incidence of drop attacks (P = 0.001). Visually increased perilymphatic enhancement was present in 157 (87.7%) subjects with unilateral EH. SIR increases in correlation with hydrops grade (P < 0.001), but is not significantly correlated with the low or high Fletcher index (P = 0.344 and P = 0.178 respectively). No significant differences were found between the degree of EH or BLB impairment and vertigo, tinnitus or aural fullness.Conclusion: The degree of EH positively correlates with disease duration, hearing loss and the incidence of drop attacks. The BLB is impaired in association with EH grade, but without clear contribution to the severity of audiovestibular symptoms.

Increased signal intensity with delayed post contrast 3D-FLAIR MRI sequence using constant flip angle and long repetition time for inner ear evaluation

PurposeThe purpose of this study was to compare the degree of perilymphatic enhancement between 4 hour post-contrast constant flip angle three-dimensional fluid attenuated inversion recovery (3D-FLAIR) images obtained with short repetition time (TR) and those obtained with long TR. Materials and methodsThis single-center, prospective study included patients who underwent MRI of the inner ear with heavily T2-weighted sequence, 3D-FLAIR sequence with a “short” TR of 10,000 ms (s3D-FLAIR) and with a “long” TR of 16,000 ms (l3D-FLAIR). Signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) obtained with s3D-FLAIR and l3D-FLAIR were quantitatively assessed using region of interest (ROI) method and compared. The morphology of the endolymphatic space on both sequences was also evaluated. ResultsFrom March 2020 to July 2020, 20 consecutive patients were enrolled (9 women and 11 men; mean age, 52.1 ± 14.5 [SD] years; age range: 29–75 years). On l3D-FLAIR images, mean SIR (21.1 ± 8.8 [SD]; range: 7.6–46.1) was significantly greater than that on s3D-FLAIR images (15.7 ± 6.7 [SD]; range: 5.9–33.4) (P < 0.01). On l3D-FLAIR images, mean CNR (17 ± 8.5 [SD]; range: 2–40) was significantly greater than that on s3D-FLAIR images (12 ± 6.3 [SD]; range: 3.2–29.8) (P < 0.01). Kappa value for inter-rater agreement for endolymphatic hydrops, vestibular atelectasis and perilymphatic fistula were 0.93 (95% CI: 0.74–1), 1 (95% CI: 0.85–1) and 1 (95% CI: 0.85–1) respectively. ConclusionThis study demonstrates that the sensitivity of 3D-FLAIR sequences to low concentration gadolinium in the perilymphatic space is improved by elongation of the TR, with SIR and CNR increased by +34.4% and +41.3% respectively.

Applying Deep Learning to Accelerated Clinical Brain Magnetic Resonance Imaging for Multiple Sclerosis.

Background: Magnetic resonance (MR) scans are routine clinical procedures for monitoring people with multiple sclerosis (PwMS). Patient discomfort, timely scheduling, and financial burden motivate the need to accelerate MR scan time. We examined the clinical application of a deep learning (DL) model in restoring the image quality of accelerated routine clinical brain MR scans for PwMS.Methods: We acquired fast 3D T1w BRAVO and fast 3D T2w FLAIR MRI sequences (half the phase encodes and half the number of slices) in parallel to conventional parameters. Using a subset of the scans, we trained a DL model to generate images from fast scans with quality similar to the conventional scans and then applied the model to the remaining scans. We calculated clinically relevant T1w volumetrics (normalized whole brain, thalamic, gray matter, and white matter volume) for all scans and T2 lesion volume in a sub-analysis. We performed paired t-tests comparing conventional, fast, and fast with DL for these volumetrics, and fit repeated measures mixed-effects models to test for differences in correlations between volumetrics and clinically relevant patient-reported outcomes (PRO).Results: We found statistically significant but small differences between conventional and fast scans with DL for all T1w volumetrics. There was no difference in the extent to which the key T1w volumetrics correlated with clinically relevant PROs of MS symptom burden and neurological disability.Conclusion: A deep learning model that improves the image quality of the accelerated routine clinical brain MR scans has the potential to inform clinically relevant outcomes in MS.

Diagnostic value of 3D-FLAIR MRI in children with sudden deafness caused by inner ear hemorrhage

ObjectiveTo investigate the diagnostic value of three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) MRI in children with sudden deafness caused by inner ear hemorrhage.MethodsThe diagnostic efficacies of three different MRI sequences in...

Frequency characteristics of horizontal semicircular canals damage and the ultrastructure analysis of crista ampullaris in patients with Meniere's disease

Objective: To investigate the frequency characteristics and the pathological characteristics of the horizontal crista ampullaris in patients with Meniere's disease,and to analyse its structural basis. Methods: Between March, 2019 and November, 2019, seventy-two patients diagnosed as Meniere's disease (27 males and 45 females, aged from 13 to 74 years, with a course of disease ranging from 4 months to 32 years)in Shandong Provincial ENT Hospital were included.Caloric test, sinusoidal harmonic acceleration test (SHA), video-head impulse test (v-HIT), Gadolinium-enhanced inner-ear 3D-FLAIR MRI and pure tone audiometry were conducted in the patients. The function of the horizontal semicircular canal in these patients were analysed as well as its relationship with the degree of endolymphatic hydrops,clinical stage and duration. Light microscopy and transmission electron microscopy were used to observe the ultrastructure of horizontal semicircular canal crista ampullaris from six patients with refractory Meniere's disease who underwent labyrinthectomy. The number of type Ⅰ and type Ⅱ vestibular hair cells, the common pathophysiological changes of horizontal semicircular canal crista ampullaris were investigated in these patients. Statistical analysis was performed using SPSS 19.0. Results: With the increase of detection frequency, the abnormal rate decreased gradually. The abnormal rate of caloric test was 69.4% (50/72), SHA 51.4% (37/72), V-HIT 36.1% (26/72), comparation of the positive rate among the three tests showed statistically significant differences(P<0.05).Neither caloric test nor SHA had correlation with the degree of hydrops(P>0.05), but v-HIT(r=0.434,P<0.01).There was correlation with clinical stage to SHA and v-HIT(r=0.338,0.462,P<0.01), except caloric test(P>0.05).No significant relation was found with caloric test, SHA, v-HIT and course of disease(P>0.05).Morphological observation found abnormal monolayer epithelialization of the horizontal semicircular canal crista ampullaris significantly decreased number of type Ⅱ hair cells compared with type Ⅰhair cells. Hair cells showed perinuclear vacuolization, cytoplasmic vacuoles, mitochondrial electron density increasement and loss of stereocilia. Conclusions: The horizontal semicircular canal damage in the patients with Meniere's disease has a frequency-dependent characteristic, mainly occurres in low frequency area. With progress of the disease, the high frequency area of ampulla will be impaired gradually, and it is related to the degree of endolymphatic hydrops and hearing level. Hair cell injury would be observed,the frequency characteristics may be more associated with the disorder of type Ⅱ hair cells.