MRI-confirmed cochlear artery infarct clinically diagnosed in a patient with sickle cell disease: a case report.

PURPOSE: To corroborate the vascular etiology of sudden sensorineural hearing loss (SNHL) utilizing magnetic resonance imaging (MRI). PATIENT: A 24-year-old male with a history of sickle cell disease experienced sudden SNHL and right horizontal nystagmus, without accompanying vertigo. INTERVENTION: Audiometric evaluation revealed left-sided SNHL, predominantly affecting high frequencies. Video head impulse testing demonstrated isolated dysfunction of the left posterior semicircular canal. An urgent brain MRI identified a recent punctiform ischemic stroke in the frontal region. A subsequent MRI, conducted with a 4-hour delay and post-contrast enhancement, highlighted a hyperintense signal within the left cochlear region and the left posterior semicircular canal. CONCLUSION: The investigative results substantiate an infarction in the territory of the cochlear artery, precipitated by a vaso-occlusive event, thereby reinforcing the vascular hypothesis of cochleovestibular artery syndrome. This case underscores the congruence between clinical observations and delayed post-contrast MRI findings.

Clinical Value of a Novel Magnetic Resonance Imaging Protocol and Prognostic Model Establishment for Sudden Sensorineural Hearing Loss: A Prospective Study.

INTRODUCTION: Sudden sensorineural hearing loss (SSNHL) is one of the most common acute symptoms in the otolaryngology department. Etiological diagnosis is the premise of effective treatment of SSNHL, and prognostic evaluation is the key. However, most of the patients are diagnosed as idiopathic due to a lack of overall assessment, while prognostic factors of SSNHL are numerous and controversial. Our purpose was to validate the potential value of a novel three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) MR protocol in SSNHL and to establish a clinical-image prognostic model for unilateral SSNHL. METHODS: This prospective study included consecutive patients from May 2019 to November 2021. Pathogenic diagnosis relied on expertise-based estimation and the associations of MR findings with clinical features of unilateral SSNHL were assessed. The prognostic evaluation of unilateral SSNHL was adopted for recovery and no recovery groups and complete and incomplete recovery groups. Significant clinical and MR features were compared and screened out by single-factor analyses. The primary clinical-image prognosis assessment model was built by multifactor logistic regression analyses. RESULTS: A total of 101 patients were enrolled in our study who acquired the correct etiological diagnosis based on the novel 3D-FLAIR MR combined with clinical examination. Among the 93 patients with unilateral SSNHL, 30.1% (28/93) showed labyrinthine abnormalities on 3D-FLAIR images. The severity of initial hearing loss in the MR+ group was worse than that in the MR- group (p < 0.05), and patients with positive MR findings tended to have poor recovery. An excellent prognostic model was built for hearing complete recovery and no recovery. The combination of three independent risk factors, including abnormal distortion products otoacoustic emission and transient evoked otoacoustic emission, the period from onset to treatment, and PTA at the onset, was adopted for hearing recovery/no recovery (accuracy = 90.2%, AUC = 0.820). Furthermore, adding the factor of positive MRI findings could improve the confidence for the judgment of hearing no recovery. The only independent risk factor, PTA at the onset, was adopted for complete/incomplete hearing recovery (accuracy = 86.1%, AUC = 0.874). CONCLUSION: The novel MR protocol had a good advantage in pathogenic diagnosis. Labyrinthine MR 3D-FLAIR signal abnormalities were related to the severity of an initial hearing loss and had a greater tendency to be found in patients with no recovery. A prognostic model with two main steps of unilateral SSNHL, mainly for SSNHL with no recovery and complete recovery, was built successfully and needed further verification by larger series of patients.

Cortical involvement and leptomeningeal inflammation in myelin oligodendrocyte glycoprotein antibody disease: A three-dimensional fluid-attenuated inversion recovery MRI study.

BACKGROUND: Cortical demyelination and meningeal inflammation have been detected neuropathologically in multiple sclerosis (MS) and recently in myelin oligodendrocyte glycoprotein antibody disease (MOGAD). OBJECTIVES: To assess in vivo cortical and leptomeningeal involvement in MOGAD. METHODS: We prospectively evaluated 11 MOGAD and 12 relapsing-remitting MS (RRMS) patients combining three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) and 3D-T1-weighted (3D-T1w) sequences at 3-Tesla magnetic resonance imaging (MRI). Leptomeningeal contrast enhancement (LMCE) was assessed on 3D-FLAIR post-gadolinium (3D-FLAIRGd). Cerebral cortical lesions (CCLs) were classified as either intracortical-subpial (IC-SP) or leukocortical (LC). RESULTS: CCLs were present in 8/11 MOGAD and 12/12 RRMS patients, with the number of CCLs being significantly lower in MOGAD (median (interquartile range (IQR)) 3 (0.5-4) vs 12 (4.75-19), p = 0.0032). In MOGAD, IC-SP lesions were slightly more prevalent than LC lesions (2 (0-2.5) vs 1 (0-2), p = 0.6579); whereas in RRMS, IC-SP lesions were less prevalent than LC lesions (3.5 (2.75-5.5) vs 9 (2-12.75), p = 0.27). LMCE was observed in 3/11 MOGAD and 1/12 RRMS patients; MOGAD with LMCE showed an increased median number of CCLs compared with MOGAD without LMCE (8 (4-9) vs 2.5 (0.75-3.25), p = 0.34). No correlation was observed between MOGAD MRI findings and (a) MOGAD duration, (b) serum MOG-immunoglobulin G1 titers, and (c) oligoclonal band presence. CONCLUSION: We described cortical lesion topography and detected for the first time LMCE using 3D-FLAIRGd sequences in MOGAD patients.

Diagnosis of Menière's disease on MRI: feasibility at 1.5 Tesla.

BACKGROUND: Menière's disease (MD) is clinically characterized by the triad sensorineural hearing loss, tinnitus and/or aural fullness, and vertigo. Endolymphatic hydrops (EH) is the histopathological basis associated with MD, which can be demonstrated on magnetic resonance imaging (MRI). Currently, most studies are done on a 3-T MRI scanner and to date it is believed that EH can only be demonstrated on a 3-T magnet. We report the feasibility of demonstrating EH on a 1.5-T scanner using the standard 20-channel head and neck coil and the current standard 4-h delayed intravenous gadolinium-enhanced three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequence. PURPOSE: To investigate whether current standard 4-h delayed intravenous gadolinium-enhanced 3D-FLAIR imaging can demonstrate endolymphatic hydrops on a 1.5-T MRI scanner. MATERIAL AND METHODS: The 3D-FLAIR sequence was taken from a 3-T MRI protocol and tested on a volunteer patient with clinically "definite" MD, after 4-h delayed intravenous contrast injection. Good image quality was obtained after reducing both the matrix and the bandwidth, with clear demonstration of EH. Subsequently, eight more patients with unilateral disease were imaged. Five patients had "definite" MD and four had "probable" MD. RESULTS: We imaged nine patients with unilateral disease and detected EH in eight of nine ears. One patient with "probable" MD did not show any abnormality, but the images were degraded by motion artifacts. CONCLUSION: At a cost of 2 min extra scanning time compared to a 3-T scanner, EH can be confidently demonstrated with the current standard 3D-FLAIR sequence on a 1.5-T magnet.

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

BACKGROUND: Clinically, 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. METHODS: The 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. RESULTS: The 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). CONCLUSION: The 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.

Injected 3T-3D-FLAIR-MRI labyrinthine patterns match with the severity and tonotopic alteration in sudden sensorineural hearing loss.

PURPOSE: The aim of the study was to assess a correlation between MRI labyrinthine changes detected with IV-gadolinium optimized high-resolution 3D-FLAIR sequences 4 h after injection (OPT4-3DFLAIR) and the type of SSNHL, in terms of frequency alteration and severity. METHODS: This was a prospective monocentric study achieved from July 2019 to December 2020. The inclusion criterion was acute hearing loss of at least 30 dB over three contiguous frequencies occurring within a 72-h period, documented by a pure-tone audiometry (PTA). The primary endpoint was the visual assessment of hyperintensity in labyrinthine structures on OPT4-3DFLAIR performed on 3T MRI. RESULTS: Thirty-six affected ears were included (20 men, 15 women; mean age: 54.5 ± 16.3 years) with 69.4% full-spectrum hearing loss. The median hearing loss, expressed as median and interquartile range [IQR] was 91 dB [74-120], with 47.2% of concomitant acute vestibular syndrome. Pathological signal was found in 26 out of 36 ears (72.2%). Basal turn enhancement was found in all abnormal MRIs, with 73.1% of apical turn enhancement and 50% of vestibular enhancement. Seventeen on 19 cases (89.5%) with apical involvement on MRI had low-frequency hearing loss. Vestibular involvement on MRI was significantly associated with a wider frequency range of hearing loss (p = 0.0002) and the severity of SSNHL (84.5 [71.7-92.5] dB versus 120 [85.8-120] dB, p = 0.0158). CONCLUSION: This report shows that in pathological MRI in SSNHL, a pathologic cochlear base signal is always detected, a cochlear apical turn enhancement matches with low-tone impairment, and a pathological signal within the posterior labyrinth is associated with an impairment of all frequencies and the severity of SSNHL.

Detailed insight into magnetic resonance assessment of Ménière's disease - description of methodology and imaging findings in a case series.

Purpose: The study aimed to describe the methodology and detailed interpretation of magnetic resonance imaging (MRI) in patients with Ménière's disease (MD). Material and methods: MRIs were performed on a 3T scanner. The three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequence 4 hours after a double dose of intravenous contrast was added to the standard MRI protocol in patients with clinically diagnosed MD. MRI findings of 7 patients with unilateral MD were analysed using 2 qualitative grading systems by Barath and Bernaerts. Results: In MRI, the following changes in the group of patients with MD were observed: lack of endolymphatic hydrops (cases #1 and #7), various grades of cochlear hydrops (cases #2 and #3), various grades of vestibular hydrops (cases #4, #5, and #6), endolymphatic hydrops herniation into the semi-circular canal (case #6), and more robust perilymphatic enhancement (case #7). Conclusions: In patients with MD, endolymphatic hydrops can be studied on MRI using 3D-FLAIR delayed post-contrast images. The qualitative grading system may be easily used in endolymphatic hydrops assessment. Recently described new radiological signs of MD such as increased perilymphatic enhancement of the cochlea and an extra low-grade VH may increase MD diagnosis sensitivity. MRI not only supports the clinical diagnosis of MD but also may help to understand its pathophysiology.

Signal and morphological changes in the endolymph of patients with vestibular schwannoma on non-contrast 3D FLAIR at 3 Tesla.

BACKGROUND: Non-contrast FLAIR revealed increased signal within the inner ear in patients with vestibular schwannoma, which is generally assumed to occur in the perilymph; however, the majority of previous studies did not differentiate between the endolymph and perilymph. Therefore, endolymph signal changes have not yet been investigated in detail. The purpose of the present study was three-fold: (1) to assess perilymph signal changes in patients with vestibular schwannoma on heavily T2-weighted (T2W) 3D FLAIR, also termed positive perilymphatic images (PPI), (2) to evaluate signal and morphological changes in the endolymph on PPI, and (3) to establish whether vertigo correlates with the signal intensity ratios (SIR) of the vestibular perilymph or vestibular endolymphatic hydrops. METHODS: Forty-two patients with unilateral vestibular schwannoma were retrospectively recruited. We semi-quantitatively and qualitatively evaluated the perilymph signal intensity on the affected and unaffected sides. We also quantitatively examined the signal intensity of the vestibular perilymph and assessed the relationship between vertigo and the SIR of the vestibular perilymph on the affected side. We semi-quantitatively or qualitatively evaluated the endolymph, and investigated whether vestibular hydrops correlated with vertigo. RESULTS: The perilymph on the affected side showed abnormal signal more frequently (signal intensity grade: overall mean 1.45 vs. 0.02; comparison of signal intensity: overall mean 36 vs. 0 cases) and in more parts (the entire inner ear vs. the basal turn of the cochlea and vestibule) than that on the unaffected side. No significant difference was observed in the SIR of the vestibular perilymph with and without vertigo (5.54 vs. 5.51, p = 0.18). The endolymph of the vestibule and semicircular canals showed the following characteristic features: no visualization (n = 4), signal change (n = 1), or vestibular hydrops (n = 10). A correlation was not observed between vestibular hydrops and vertigo (p = 1.000). CONCLUSIONS: PPI may provide useful information on signal and morphological changes in the endolymph of patients with vestibular schwannoma. Further research is warranted to clarify the relationship between vertigo and the MR features of the inner ear.

Isolated enhancement of the superior semi-circular canal on inner ear MRI: acute vestibular syndrome or superior semi-circular canal dehiscence?

PURPOSE: Recently, it has been reported that patients with acute vestibular syndrome (AVS) could present a marked enhancement of the semi-circular canals, involving mostly the superior semi-circular canals on delayed inner ear MRI. METHODS: We reported one patient having AVS and another one having superior semi-circular canal dehiscence syndrome (SCDS) who underwent delayed inner ear MRI performed 4 h after contrast media administration. RESULTS: On delayed inner ear MRI, a marked enhancement of the superior semi-circular canal was observed in both patients. Although the clinical presentation is clearly not the same, the co-existence between these two disorders is possible. For this reason, in patients with AVS, the presence of a marked enhancement of the superior semi-circular canal should rule out the presence of a co-existing SCDS on temporal bone CT, particularly if the patient reported cochlear symptoms such as pulsatile tinnitus and/or autophony. CONCLUSION: To our knowledge, this is the first report showing this finding on delayed inner ear MRI in a patient with SCDS. In AVS patients, this radiological anomaly could be particularly disturbing and should rule out the presence of a co-existing SCDS.

Detection of intralabyrinthine abnormalities using post-contrast delayed 3D-FLAIR MRI sequences in patients with acute vestibular syndrome.

PURPOSE: 3D-FLAIR sequences with delayed acquisition after contrast medium injection have demonstrated new insights into blood-labyrinthine barrier (BLB) abnormalities in various diseases. The aim of this study was to assess the BLB in patients referred with unilateral acute vestibular syndrome (UAVS). MATERIALS AND METHODS: In this retrospective multicenter imaging study, we performed 3D-FLAIR and steady-state free precession (SSFP) sequences 4 h after contrast medium administration in 26 healthy volunteers and in 30 patients with UAVS. Two radiologists, blinded to the clinical data, independently assessed the asymmetrical enhancement of the labyrinthine structures and the vestibular nerve on 3D-FLAIR sequences, and the signal of the labyrinthine structures on SSFP sequences. Inter-reader agreement tests were performed. RESULTS: An asymmetrical enhancement of the semicircular canals was observed in 26 out of 30 ears (86.6%, p < 0.001) and never observed in healthy subjects. An asymmetrical enhancement of the vestibular nerve was never observed in either patients or healthy subjects. An asymmetrical enhancement of the cochlea was observed on the 3D-FLAIR sequence in 6 out of 30 ears only in the patients' group (20%, p = 0.03) and always associated with an enhancement of at least one semicircular canal. A low signal on SSFP sequences was observed only in 11 out of 30 symptomatic ears (36.7%, p < 0.001), involving the utricle in 7 ears and the superior semicircular canal in 4 ears. CONCLUSION: Patients with typical UAVS presented with semicircular canal enhancement on MRI, while an asymmetrical enhancement of the vestibular nerve was not displayed. TRIAL REGISTRATION: NCT02529475 KEY POINTS: • Patients with typical vestibular neuronitis presented with semicircular canal enhancement on MRI in 87% of cases. • An enhancement of the vestibular nerve was never displayed.

Evaluation of a high-signal lesion posterior to the intracranial vertebral artery using 3D balanced fast-field echo imaging.

Previous reports have identified a small, benign, high-signal lesion (HSL) posterior to the intracranial vertebral artery and associated with the ipsilateral spinal accessory nerve (SAN) using 3D fluid-attenuated inversion recovery (3D FLAIR) imaging as an emerging new entity. To elucidate the relationship between HSLs and SAN, 76 patients with 86 HSLs were evaluated using 3D FLAIR and 3D balanced fast-field echo (3D bFFE imaging). All HSLs showed contact with ipsilateral SAN on both the sequences. 3D bFFE imaging clearly distinguished between the two structures unlike 3D FLAIR. Moreover, SAN was surrounded by HSLs on 3D bFFE images, which may be a characteristic of this entity.

Post-contrast 3D-FLAIR in idiopathic sudden sensorineural hearing loss.

PURPOSE: Our study investigated correlations between clinical characteristics, particularly hearing recovery, interval time between onset and three-dimensional fluid attenuation inversion recovery magnetic resonance imaging (3D-FLAIR MRI), and the signal intensity of post-contrast 3D-FLAIR MRI in patients with idiopathic sudden sensorineural hearing loss (SSNHL). METHODS: The study enrolled 100 SSNHL patients. The signal intensities and asymmetry ratios of the inner ear structures, including the cochleae, vestibules and vestibulocochlear nerve, were evaluated and calculated. The relationships between the clinical characteristics and MRI findings were assessed. RESULTS: After intravenous gadolinium (Gd) injection, 3D-FLAIR revealed high signal intensities in 65 patients. The corrected asymmetry ratios of cochlea correlated closely with interval time between onset and MRI. The asymmetry ratios of the inner ear structures were significantly lower in patients with final complete to partial hearing recovery. The corrected asymmetry ratios of the inner ear structures correlated with initial/final pure tone audiometry (PTA) and hearing recovery in the affected ear. Notably, it was shown that the corrected asymmetry ratios identified a poor prognosis for hearing recovery, with a sensitivity and specificity of 67.9% and 75.0% in the cochlea, 83.3% and 75.0% in the vestibule, and 52.4% and 81.2% in the vestibulocochlear nerve, respectively. CONCLUSIONS: Post-contrast 3D-FLAIR after intravenous Gd injection in SSNHL can be used to assess the permeability of the blood-labyrinth and blood-nerve barriers. The asymmetry ratios of the inner ear structures may identify patients with poor prognosis for hearing recovery. Signal characteristics are closely related to interval time between onset and MRI.

Circumventricular organs of human brain visualized on post-contrast 3D fluid-attenuated inversion recovery imaging.

PURPOSE: Although contrast-enhanced three-dimensional T2 fluid-attenuated inversion recovery (3D T2-FLAIR) images are useful for assessing various neuronal diseases, physiological enhancement of the circumventricular organs on the images have not been investigated. We aimed to assess the physiological appearance of the circumventricular organs on contrast-enhanced 3D T2-FLAIR images. METHODS: We studied 3-T MR images of the brain of 30 individuals with no apparent brain abnormalities. In ten areas of the brain, the degree of contrast enhancement on 3D T2-FLAIR and magnetization-prepared rapid gradient-echo (MPRAGE) images was evaluated using a 4-point grading system. The pre- and post-contrast mean contrast ratios (CRs) of the anterior pituitary gland, median eminence, and pineal gland were compared. RESULTS: On post-contrast 3D T2-FLAIR images, marked enhancement was most frequently scored in the median eminence, followed by the choroid plexus, posterior pituitary gland, and pineal gland. In 10 of the 30 cases, the vascular organ of the lamina terminalis and the area postrema were enhanced but the subcommissural organ was not. The difference in the mean pre- and post-contrast CRs of the median eminence and pineal gland was statistically significant, while that of the anterior pituitary gland was not. CONCLUSION: On contrast-enhanced 3D T2-FLAIR images, the circumventricular organs show variable enhancement. Our findings help to recognize physiological and abnormal enhancement of brain structures on contrast-enhanced 3D T2-FLAIR images.

Small high-signal lesions posterior to the intracranial vertebral artery incidentally identified by 3D FLAIR: retrospective study of 127 patients.

PURPOSE: A small, benign high-signal lesion (HSL) posterior to the intracranial vertebral artery (VA) at the foramen magnum is a new entity revealed by a 3D FLAIR sequence. However, this entity has not been sufficiently investigated. We aimed to investigate the MR imaging findings of HSLs posterior to the intracranial VA that were incidentally detected by 3D FLAIR. METHODS: We retrospectively evaluated 3717 patients using a 3-T MR unit. HSLs on 3D FLAIR were assessed for prevalence, size, contact with the spinal accessory nerve (SAN), and size changes on follow-up images. RESULTS: Of 3717 patients, 127 (3.4%) (58 males and 69 females; age, 60.0 ± 18.9 years) showed 142 HSLs posterior to the intracranial VA. In total, 114 patients (89.8%) had a single lesion, whereas 13 patients (10.2%) had multiple lesions. The mean lesion size was 3.8 ± 1.6 mm. All HSLs showed contact with the ipsilateral SAN. Of 69 HSLs that were imaged during follow-up, the size was stable in 91.3% and increased in 8.7%. CONCLUSION: HSLs posterior to the intracranial VA were incidentally detected in 3.4% of patients by 3D FLAIR. Our results indicated a possible association between HSLs and SAN. These lesions appear to be benign in etiology and thus would not require any surgical intervention without continuous growth in a short period or relevant signs and symptoms.

3D fluid attenuated inversion recovery (FLAIR) magnetic resonance imaging at different stages of otosclerosis.

PURPOSE: The aim of this work is to study otosclerotic patients by 3D-FLAIR (fluid attenuated inversion recovery) sequence magnetic resonance imaging (MRI) with and without Gadolinium administration (-/+ Gd), to understand whether there is a direct relationship between radiological findings at 3D FLAIR MRI sequences and some clinical features of otosclerosis, such as the presence and entity of sensorineural involvement, duration of disease, patient gender, and other factors. METHODS: 38 patients affected by different stages of unilateral or bilateral otosclerosis underwent 3D FLAIR MRI+/- Gd. 11 subjects with normal hearing, previously submitted to 3T MRI for other minor diseases, unrelated with otosclerosis, had been retrospectively enrolled as control group. RESULTS: We found significant correlations between 3D FLAIR MRI findings and some clinical features of otosclerosis, such as severity of cochlear damage (in terms of entity of sensorineural loss) and duration of disease. These findings indicate that at 3D-FLAIR MRI different patterns may depend on the level of blood labyrinth barrier damage in the cochlea, and be related to different stages of cochlear involvement in otosclerotic patients. CONCLUSIONS: We believe that our findings may contribute in understanding the pathogenesis of cochlear damage in otosclerosis and may have further prognostic value. Our results led us to consider the possible use of 3D-FLAIR sequences in monitoring the effectiveness of any medical therapy of otosclerosis and in selecting the patients eligible for treatment.

3D-Flair sequence at 3T in cochlear otosclerosis.

PURPOSE: To assess the capability of three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequences in detecting signal alterations of the endolabyrinthine fluid in patients with otosclerosis. MATERIALS AND METHODS: 3D-FLAIR before and after (-/+) gadolinium (Gd) administration was added to the standard MR protocol and acquired in 13 patients with a clinical/audiological diagnosis of severe/profound hearing loss in otosclerosis who were candidates for cochlear implantation and in 11 control subjects using 3-T magnetic resonance imaging (MRI) equipment. The MRI signal of the fluid-filled cochlea was assessed both visually and calculating the signal intensity ratio (SIR = signal intensity cochlea/brainstem). RESULTS: We revealed no endocochlear signal abnormalities on T1-weighted -/+ Gd images for either group, while on 3D-FLAIR we found bilateral hyperintensity with enhancement after Gd administration in eight patients and bilateral hyperintensity without enhancement in one patient. No endocochlear signal abnormalities were detected in other patients or the control group. CONCLUSION: Using 3-T MRI equipment, the 3D-FLAIR -/+ Gd sequence is able to detect the blood-labyrinth barrier (BLB) breakdown responsible for alterations of the endolabyrinthine fluid in patients with cochlear otosclerosis. We believe that 3D-FLAIR +/- Gd is an excellent imaging modality to assess the intra-cochlear damage in otosclerosis patients. KEY POINTS: • Gd-enhanced T1-weighted MRI has limited application to detect intra-cochlear damage. • 3D-FLAIR is less sensitive to flux artefacts and allows multiplanar reconstruction. • Post-Gd 3D-FLAIR is advantageous as it may highlight the BLB breakdown. • Using 3D-FLAIR -/+ Gd, we were able to identify intra-cochlear signal hyperintensities. • 3D-FLAIR might be applied for monitoring disease progression and treatment response.

Correlation of 3D FLAIR and Dopamine Transporter Imaging in Patients With Parkinsonism.

OBJECTIVE: The purpose of this study is to evaluate direct in vivo visualization of nigrosome-1 in substantia nigra (SN) with 3D FLAIR imaging and its diagnostic value in predicting the intactness of presynaptic dopaminergic function of the nigrostriatal pathway. MATERIALS AND METHODS: Forty-five patients showing parkinsonism who underwent both 3D FLAIR and dopamine transporter (DAT) imaging were recruited. In total, 90 SNs were reviewed on axial 3D FLAIR images. We regarded oval or linear hyperintensities on the posterolateral side of SN as intact nigrosome-1. Two neuroradiologists independently evaluated the appearance of nigrosome-1, and disagreements were settled by consensus. Kappa values for interrater agreement were calculated. Diagnostic performances of the appearance of nigrosome-1 for predicting presynaptic dopaminergic function on DAT imaging and Parkinson disease (PD) were calculated. RESULTS: The diagnostic performances of a loss of nigrosome-1 on 3D FLAIR images were sensitivity of 85.7%, specificity of 85.4%, positive predictive value (PPV) of 83.7%, and negative predictive value (NPV) of 87.2% for predicting impaired presynaptic dopaminergic function on DAT imaging, and sensitivity of 94.7%, specificity of 76.9%, PPV of 85.7%, and NPV of 90.9% for predicting PD. When only oval hyperintensity was considered as intact nigrosome-1, its sensitivity and NPV were increased up to 95.2% and 91.7%, respectively, for predicting impaired presynaptic dopaminergic function on DAT imaging, and both increased to 100% for predicting PD. Interobserver agreement for the appearance of nigrosome-1 on 3D FLAIR images was substantial (κ = 0.625). CONCLUSION: Nigrosome-1 could be visualized on 3D FLAIR images, and its loss can be used to predict presynaptic dopaminergic function and to diagnose PD with high accuracy.

Reduced scan time three-dimensional FLAIR using modulated inversion and repetition time.

BACKGROUND: The purpose of this study is to design and evaluate a new reduced scan time three-dimensional (3D) FLuid Attenuated Inversion Recovery (FLAIR) sequence. METHODS: The 3D FLAIR sequence was modified so that the repetition time was modulated in a predetermined smooth manner (3D mFLAIR). Inversion times were adjusted accordingly to maintain cerebrospinal fluid (CSF) suppression. Simulations were performed to determine SNR for gray matter (GM), white matter (WM), and CSF. Fourteen volunteers were imaged using the modified and product sequence. SNR measurements were performed in GM, WM, and CSF. Mean value and the 95% confidence interval ([CI]) were assessed. Scan time for the 3D FLAIR and 3D mFLAIR sequences was measured. RESULTS: There was no statistically significant difference in the SNR measured in GM (P value = 0.5; mean SNR = 42.8 [CI]: 38.2-45.5 versus 42.2 [CI]: 38.3-46.1 for 3D FLAIR and 3D mFLAIR, respectively) and WM (P value = 0.25; mean SNR = 32.1 [CI]: 30.3-33.8 versus 32.9 [CI]: 31.1-34.7). Scan time reduction greater than 30% was achieved for the given parameter set with the 3D mFLAIR sequence. CONCLUSION: Scan time for 3D FLAIR can be effectively reduced by modulating repetition and inversion time in a predetermined manner while maintaining the SNR and CNR of a constant TR sequence.

Diagnostic value of 3D fluid attenuated inversion recovery sequence in multiple sclerosis.

BACKGROUND: Magnetic resonance imaging (MRI) is an indispensable tool in the diagnostic work-up of multiple sclerosis (MS). To date, guidelines suggest MRI protocols containing axial dual-echo, unenhanced and post-contrast T1-weighted sequences. Especially the usage of dual-echo sequences has markedly improved the ability of MRI to detect cortical and infratentorial lesions. Newer 3D FLAIR sequences are supposed to provide even more positive imaging features such as improved detection of white matter lesions and a better resolution due to smaller slice thickness. PURPOSE: To evaluate the diagnostic impact of 3D FLAIR sequences in comparison to conventional T2 and PD sequences. MATERIAL AND METHODS: Examinations of 20 MS patients (10 women, 10 men) were reviewed retrospectively. All patients received MRI standard protocol containing PD and T2 sequences and a mid-sagittal T2 sequence. Additionally an isotropic 3D FLAIR sequence was performed. Whole-brain lesion load and number of lesions in juxtacortical, infratentorial, and midcallosal localizations were assessed by two observers independently and compared. RESULTS: Whole lesion load and the count of detectable lesions at the 3D FLAIR sequence were significantly higher in the juxtacortical and infratentorial regions compared to the PD/T2 sequence. Detection rate of midcallosal lesions did not differ significantly in sagittal T2 and 3D FLAIR sequence. CONCLUSION: 3D FLAIR sequences can improve the detection of brain lesions in patients with MS and are even more sensitive in depicting lesions in cortical and infratentorial locations than current dual-echo sequences. The sequence can replace both PD/T2 sequences and mid-sagittal T2 sequences of the corpus callosum.

Visualization of brain white matter tracts using heavily t2-weighted three-dimensional fluid-attenuated inversion-recovery magnetic resonance imaging.

The purpose of this study was to elucidate which white matter (WM)-tracts are visualized on heavily T2-weighted three-dimensional fluid-attenuated inversion-recovery (hT2w-3D-FLAIR) images. Records of seven patients who underwent hT2w-3D-FLAIR and diffusion tensor imaging (DTI) of the head at 3 Tesla were analyzed. Two neuroradiologists determined WM-tracts visualized on hT2w-3D-FLAIR and identified anatomical points through which they ran. A third neuroradiologist determined the WM-tracts running through those points on DTI. Correspondence between hT2w-3D-FLAIR and DTI WM-tracts was used to confirm technique validity. As a result, the corticospinal tract (CST), medial lemniscus (ML), and superior cerebellar peduncle (SCP) were visualized as high intensity on hT2w-3D-FLAIR and ran through the following points: CST, 20 mm lateral from the lateral margin of the third ventricle at the thalamic level; ML, 6 mm anterior to the anterior margin of the fourth ventricle at the trigeminal nerve level; and SCP, just lateral to the fourth ventricle at the trigeminal nerve level. The third neuroradiologist determined that the WM-tracts ran through those points on DTI in all patients. Consequently, WM-tracts determined on hT2w-3D-FLAIR and DTI completely corresponded. In conclusion, the CST, ML, and SCP were visualized as high intensity on hT2w-3D-FLAIR. This technique is a potentially supplemental DTI neurographic modality.