Magnetic Resonance Cisternography Research Articles

Automated volumetric analysis of the inner ear fluid space from hydrops magnetic resonance imaging using 3D neural networks

Due to the development of magnetic resonance (MR) imaging processing technology, image-based identification of endolymphatic hydrops (EH) has played an important role in understanding inner ear illnesses, such as Meniere’s disease or fluctuating sensorineural hearing loss. We segmented the inner ear, consisting of the cochlea, vestibule, and semicircular canals, using a 3D-based deep neural network model for accurate and automated EH volume ratio calculations. We built a dataset of MR cisternography (MRC) and HYDROPS-Mi2 stacks labeled with the segmentation of the perilymph fluid space and endolymph fluid space of the inner ear to devise a 3D segmentation deep neural network model. End-to-end learning was used to segment the perilymph fluid and the endolymph fluid spaces simultaneously using aligned pair data of the MRC and HYDROPS-Mi2 stacks. Consequently, the segmentation performance of the total fluid space and endolymph fluid space had Dice similarity coefficients of 0.9574 and 0.9186, respectively. In addition, the EH volume ratio calculated by experienced otologists and the EH volume ratio value predicted by the proposed deep learning model showed high agreement according to the interclass correlation coefficient (ICC) and Bland–Altman plot analysis.

Diagnostic Accuracy of Combined High-Resolution Computed Tomography and MR Cisternography in Evaluation of CSF Rhinorrhea Patients, Taking Surgical Findings As Gold Standard

Objective: To determine the diagnostic accuracy of combined high-resolution computed tomography and MR Cisternography in evaluation of CSF rhinorrhea patients, taking surgical findings as gold standard. Methodology: The Observational Cross-sectional study was conducted at Benazir Bhutto and Holy Family Hospital, Rawalpindi for a total period of 12 months from 1 June 2022 to 1 May 2023. All patients having CSF rhinorrhea (discharge of cerebrospinal fluid (CSF) from the nose) of >1-month duration was enrolled and underwent HRCT/MR cisternography subsequently followed by surgery and results of both modalities were compared. Results: Out of a total of 156 patients enrolled, 136 (87.1%) were males and 20 (12.8%) females. The results of this study yielded a sensitivity of 93.3%, specificity of 61.9%, positive predictive value of 94% and a negative predictive value of 59%. The overall accuracy of combined HRCT/MR Cisternography for the diagnosis of CSF rhinorrhea was found to be 89.1% in comparison to surgery. Conclusion: The use of Combined HRCT/MR cisternography for the diagnosis of CSF rhinorrhea is a feasible, safer and highly accurate modality for correctly identifying such cases and circumvents the limitations imposed by the use of any single modality in these patients.

The study of management of cerebrospinal fluid rhinorrhea at tertiary care center

Background: CSF Rhinorrhea is clinically emergency condition in Otorhinolaryngology. Patients were presented with unilateral watery nasal discharge. In the evolving world, CSF leak repair done via endoscopic method. Recurrence is very less with endoscopic repair method of CSF leak. Methods: We took complete history, complete Ear, Nose, Throat and Head and Neck examination, Endoscopic examination of nasal cavity followed by Radiological test in the form of MR Cisternography. Depending upon the site of leak, CSF leak repair done via endoscopic method of overlay and underlay and with the help of fascia, fat, surgical, flap, fibrin glue and cartilage. Results: Total 30 cases analysed where 63.33% & 26.67% patients have defect at cribriform plate & fovea ethmoidal is respectively. 63.33% patients are male, almost all patients are adults. 73.33% are spontaneous & rest are traumatic, 43.33% have circular defect, 36.67% have horizontal defect, 53.33% are treated with fat, surgical, fascia, fibrin glue, 40% are treated with above-mentioned things with flap, 6.67% patients are treated with above-mentioned things with cartilage. Conclusions: Most of CSF leak are spontaneous in nature, most of patients had defect in cribriform plate that too in anterior portion of the plate, almost all patients were adults, more females had defect than males, circular defects are slightly more common than horizontal ones, and most of the patients didn’t need flap or cartilage during surgery.

Peri-Aneurysmal Contact as a Risk Factor for Aneurysmal Rupture in Unruptured Intracranial Aneurysms: An Overview

The occurrence and growth of unruptured intracranial aneurysms are believed to be influenced by intraluminal factors of blood flow dynamics and pathological factors of the aneurysm wall. In addition to these, the deformation and rupture of aneurysms require consideration of physical extra-luminal factors due to contact between the aneurysm and surrounding structures including brain parenchyma, cranial nerves, arteries, veins, cranial base bone and dura mater. The extra-luminal factors of aneurysms were evaluated based on the presence of peri-aneurysmal contact. Peri-aneurysmal contact, depending on the type, location, and size of aneurysms, influenced the growth pattern of the aneurysm. Recently, with the imaging of magnetic resonance cisternography, it had become possible to non-invasively assess the anatomical relationship between the outer wall of aneurysms and the surrounding structures. Fusion images overlaying 3D magnetic resonance cisternography with 3D computed tomography angiography or 3D magnetic resonance angiography detailed the anatomical relationship of peri-aneurysmal contact, position of contact sites, and depth. We depicted the anatomical construction of peri-aneurysmal contact and bleb in unruptured intracranial aneurysms using fusion images and studied the intraluminal blood flow dynamics using computational fluid dynamics. As a result, peri-aneurysmal contact was observed to be involved as an independent variable in the process of bleb formation. It was suggested that factors extra-luminal to the aneurysm, such as peri-aneurysmal contact, might have a greater impact on bleb formation than intraluminal factors like blood flow dynamics. Peri-aneurysmal contact emerged as a noteworthy extra-luminal factor, particularly associated with bleb formation, presenting a substantial risk of rupture in unruptured intracranial aneurysms. These findings underscore the importance of considering the presence and extent of peri-aneurysmal contact alongside intraluminal and wall-related factors in future evaluations. The implications of this overview extend to the development of risk assessment protocols, providing valuable insights for guiding early intervention strategies and ultimately contributing to improved patient outcomes.

Imaging Update of Congenital Hearing Loss: A Recent Insight Imaging Including 3D MRI Cisternography Prior to Cochlear Implant.

SNHL in children is an important issue. Cochlear implant is a highly technological device that is surgically inserted in the cochlea to solve this issue. To evaluate types of anomalies of the inner ear in children with sensorineural hearing loss in a tertiary care hospital and confirm that the routine MRI, MR cisternography and HRCT provides the surgeon with the imaging finding and criteria of patients candidates for CI. Patients and method: 600 patients with SNHL underwent HRCT and MRI. CT examinations were normal in 457 patients (76.2%) and 143 patients (23.8%) with inner ear anomalies. MRI examinations were normal in 440 patients (73.3%) and had inner ear anomalies in 160 patients (26.7%). 3D bFFE and 3D DRIVE was summarized. The 3D bFFE sequence was statistically significantly better than the 3D DRIVE for the demonstration of the cochlear vestibule. Superior, inferior vestibular nerves and facial nerves while 3D DRIVE is superior to 3D bFFE in the visualization of the semicircular canals. HRCT and MRI provide accurate anatomical delineation of complex inner ear structures and 3D improves pre-implant evaluation.

Reliability of High-resolution Gadolinium-enhanced MR Cisternography and Gasket-seal Technique for Management of Anterior Skull Base Defects

PurposePrecise preoperative localization of anterior skull base defects is important to plan surgical access, increase the success rate and reduce complications. A stable closure of the defect is vital to prevent recurrence of cerebrospinal fluid (CSF) rhinorrhea. The purpose of this retrospective case series was to evaluate the reliability of a new high-resolution gadolinium-enhanced compressed-sensing SPACE technique (CS T1 SPACE) for magnetic resonance (MR) cisternography to detect cerebrospinal fluid leaks of the anterior skull base and to assess the long-term success rate of the gasket-seal technique for closure of skull base defects.MethodAll patients with spontaneous or postoperative cerebrospinal fluid rhinorrhea and defects of the anterior skull base presenting to the Departments of Otorhinolaryngology and Neurosurgery between 2019 and 2020, receiving a computed tomography (CT) cisternography and MR cisternography (on a 3T whole-body MR scanner using a 64-channel head and neck coil) with CS T1 SPACE sequence and closure of the defect with the gasket-seal technique, were enrolled in the study. For the cisternography, iodinated contrast agent (15 ml Solutrast 250 M®), saline (4 mL) mixed with a 0.5 mL of gadoteridol was injected into the lumbar subarachnoid space.ResultsA total of four patients were included in the study and MR cisternography with CS T1 SPACE sequence was able to precisely localize CSF leaks in all patients. The imaging results correlated with intraoperative findings. All defects could be successfully closed with the gasket-seal technique. The mean follow-up was 35.25 months (range 33–37 months).ConclusionMR cisternography with CS T1 SPACE sequence could be a promising technique for precise localization of CSF leaks and the gasket-seal technique resulted in good closure of the CSF fistula in this case series.

To evaluate the role of Intrathecal Iohexol-enhanced Mr Cisternography in detecting CSF Rhinorrhea with correlation to Ct Cisternography

To evaluate the role of Intrathecal Iohexol-enhanced Mr Cisternography in detecting CSF Rhinorrhea with correlation to Ct Cisternography

Trigeminal neuralgia caused by a persistent primitive trigeminal artery: preoperative three-dimensional multifusion imaging and computational fluid dynamics analysis. Illustrative case.

Trigeminal neuralgia (TN) is caused by trigeminal nerve compression by colliding vessels. Preoperative three-dimensional (3D) multifusion images are useful for surgical simulations. Moreover, computational fluid dynamics (CFD) analysis of colliding vessels may be useful for hemodynamic evaluation at the site of neurovascular contact (NVC). A 71-year-old woman had TN due to compression of the trigeminal nerve by the superior cerebellar artery (SCA) fused with the persistent primitive trigeminal artery (PTA). Preoperative 3D multifusion simulation images of silent magnetic resonance (MR) angiography and MR cisternography depicted the NVC, including the trigeminal nerve, SCA, and PTA. CFD analysis revealed the hemodynamic condition of the NVC, including the SCA and PTA. The wall shear stress magnitude (WSSm) at the NVC showed a local elevation due to flow confluence from the SCA and PTA. High WSSm was observed in the NVC. Preoperative simulation images of MR angiography and MR cisternography may depict the NVC. CFD analysis can provide the hemodynamic condition at the NVC.

Magnetic resonance imaging of endolymphatic hydrops: a comparison of methods with and without gadolinium-based contrast agent administration.

In the evaluation of endolymphatic hydrops (EH) using magnetic resonance (MR) imaging, hybrid of reversed image of positive endolymph signal and native image of perilymph signal multiplied with heavily T2-weighted MR cisternography (HYDROPS-Mi2) imaging with the intravenous administration of a gadolinium-based contrast agent (IV-GBCA) has been utilized. Recently, MR cisternography (MRC) without GBCA has been proposed as a potential alternative method. However, the feasibility of EH evaluation by MRC without GBCA has not been established. The present study aimed to compare HYDROPS-Mi2 imaging with IV-GBCA to MRC without IV-GBCA for the evaluation of EH. In 40 ears of 20 patients with clinically suspected EH, MRC at pre-IV-GBCA and HYDROPS-Mi2 images from 4 h post-IV-GBCA were analyzed. The saccular height on the MRC (SH-MRC) was measured. The percentage of the volume of the endolymphatic space within the whole lymphatic space of the vestibule on the HYDROPS-Mi2 image (%ELvolume-HYD) was measured. The correlation between the SH-MRC and %ELvolume-HYD was calculated. The receiver operating characteristic (ROC) of the SH-MRC and %ELvolume-HYD for the clinical diagnosis of EH was evaluated. The Spearman's rank correlation coefficient between the SH-MRC and %ELvolume-HYD was 0.102. The areas under the ROC curve were 0.570 for the SH-MRC, and 0.926 for the %ELvolume-HYD. In conclusion, there was no significant correlation between the MRC without IV-GBCA and the HYDOROPS-Mi2 with IV-GBCA in the evaluation of EH.

Gadolinium-based MR cisternography with prepontine cisternal routine for evaluating distribution pattern of intrathecal targeted drug delivery in pain management

Gadolinium-based MR cisternography has been mainly applied in clinical evaluation of cerebrospinal fluid leaking, that is conducted by intrathecal administration of contrast media. Recently, we have reported one novel technique of intrathecal targeted drug delivery with prepontine cisternal routine to treat orofacial cancer pain. The aim of this study was to examine the distribution pattern of this intrathecal drug delivery strategy. Here, we introduce one case who suffered severe orofacial pain caused by sublingual gland tumor, and successfully attenuated by prepontine cisternal administration of analgesic agents. To assess the distribution of intrathecal drugs, postoperative MR images of brain, cervical, thoracic, and lumbar segments in axial, coronal, and sagittal planes were obtained after application of gadolinium. The perfusion rate of contrast medium was set at 0.01 mmol per hour for 24 hours prior to MR scanning. In the T1-weighted images, we can identify contrast spread not only locating around the site of the intrathecal catheter tip, but also concentrated to the lateral sides. None obvious side effect was found after intrathecal injection of contrast media. Thus, our finding demonstrated the local distribution phenomenon of intrathecal drugs through prepontine cisternal access, and the bilateral perfusion pattern may provide insights underlying the analgesic mechanism of trigeminal pain provided by this novel intrathecal therapy. Gadolinium-based MR cisternography may serve as a potential tool to confirm the therapeutic effect of intrathecal targeted drug delivery via prepontine cisternal routine in orofacial pain management.

Internal Auditory Canal (IAC) and Cerebellopontine Angle (CPA): Comparison between T2-weighted SPACE and 3D-CISS sequences at 1.5T

MR cisternography relies on three-dimensional (3D) heavily T2-weighted imaging techniques. It can be used to assess the internal auditory canal (IAC) and Cerebellopontine Angle (CPA) anatomy and pathology. There are two techniques usually used for this purpose; T2-weighted SPACE and Three-Dimensional Constructive Interference in Steady State (3D-CISS). The current study aims to evaluate differences in image quality between 3D-CISS and T2-weighted SPACE sequences and to compare their ability to differentiate the anatomy of the CPA and IAC structures. This study was conducted in 64 patients. Each patient was imaged with both 3D-CISS and T2-weighted SPACE sequences, then the images were also reviewed by two radiologists for anatomy evaluation. The results showed that T2-weighted SPACE outperforms 3D-CISS for the assessments of IAC, cranial nerve, cochlear anatomic structures, semicircular canals, and vestibule. The study also showed there is no statically significant difference between the two sequences according to the gender and the age of patients.

Parasagittal Cystic Lesions May Arise from the Pial Sheath around the Cortical Venous Wall.

It has been reported that perivenous cystic structures near the parasagittal dura are associated with the leakage of gadolinium-based contrast agents at 4 hours after intravenous administration. The origin of such cystic structures remains unknown. While reading many cases of MR cisternography, we noticed that some of the cystic structures appeared to connect to the perivenous subpial space. This new imaging finding might facilitate future research of the waste clearance system for the central nervous system.

A Rare Case of Tension Pneumocephalus with Spontaneous CSF Rhinorrhea Managed by Endoscopic Trans-Sphenoidal CSF Leak Repair.

Tension Pneumocephalus and spontaneous CSF rhinorrhea are very rare associations in clinical practice. We report a case of 65years old male with clear rhinorrhea, severe frontal headache, vomiting and lethargy for a week. MR Cisternography and CT Paranasal sinuses showed significant Tension Pneumocephalus with defect in the posterior wall of sphenoid sinus and CSF pooling in the sphenoid sinus. Endoscopic trans-sphenoidal CSF leak repair was done without any delay followed by complete resolution of Tension Pneumocephalus with in 4 post op days. Prompt precise diagnosis and early intervention of Tension Pneumocephalus is vital to avoid neurological complications.

Efficacy of Imaging Methods in the Detection and Diagnosis of Cerebrospinal Fluid Rhinorrhea.

To assess the diagnostic efficacy of various imaging methods in patients with suspected cerebrospinal fluid (CSF) rhinorrhea. The PubMed, EMBASE, SCOPUS, Web of Science, Cochrane Trials, and Google Scholar databases were searched up to December 2021. Diagnostic accuracy was compared among seven radiological methods: computed tomography (CT), CT cisternography (CTC), magnetic resonance imaging (MRI), magnetic resonance cisternography (MRC), CT + MRI, radionuclide cisternography, and intrathecal gadolinium (Gd)-MRC. Sensitivity, specificity, and accuracy were used as outcomes of the analysis. Both a traditional pairwise meta-analysis and a network meta-analysis were performed. Twenty-three trials were included in the analysis. The results of a network meta-analysis performed on a network consisting of seven diagnostic methods showed that all imaging modalities had greater diagnostic accuracy than CT, with the exception of CTC, which had lower sensitivity. Only intrathecal Gd-MRC was significantly superior to other imaging methods with regard to sensitivity and accuracy. Gd-MRC also showed the greatest surface under the cumulative ranking curve values for all of the outcomes (sensitivity: 0.9200; specificity: 0.8364; accuracy: 0.8920). This network meta-analysis demonstrates that intrathecal Gd-MRC is the most useful diagnostic method to detect CSF rhinorrhea. Laryngoscope, 133:1281-1287, 2023.

Magnetic Resonance Angiography and Cisternography fused images in acute ischemic stroke may save time during endovascular procedure revealing vessel anatomy

Background and purposeEndovascular treatment (EVT) is a time-dependent procedure that aims to remove the arterial blood flow obstruction in brain vessels in acute ischemic stroke. In our center, the MRI patient selection protocol in acute ischemic stroke is performed with DWI, FLAIR, MR angiography (MRA) and MR cisternography (MRC) sequences. MRA and MRC are promptly and automatically fused in order to have a clear detection of vessel anatomy, before and during EVT.Our study aim is to evaluate if the fusion process between MRA and MRC could be considered time-safe and could influence EVT duration or outcome. Materials and methods45 patients were retrospectively selected for the study and divided into 2 groups according to the presence of MRC sequence fused with MRA (Group 1) or not (Group 2 - controls). ResultsMRA and MRC fusion was able to depict vessel anatomy in all subjects of Group 1 (22 patients, 12 females; age 75.59 years ± 10.87). Group 1 presented EVT time reduction (p < 0.05;p = 0.040) (51.59 min ± 30.94) when compared to Group 2 (23 patients, 13 females; age 75.04 years ± 12.12) (71.96 min ± 34.55) of 20.37 min average. No differences between groups were detected evaluating: NIHSS at admission (p = 0.49) and discharge (p = 0.67), pre-stroke mRS (p = 0.89), mRS at 90 days (p = 0.62), ASPECT (p = 0.98) and ASPECT-DWI scores (p = 0.93), time from symptom onset to groin puncture (p = 0.80), thromboaspiration vs combined technique (p = 0.67), EVT success (p = 0.63). ConclusionFusion of MRA and MRC is a safe and promising technique in promptly revealing vascular anatomy beyond vessel obstruction, and can play a role in EVT duration reduction.

Combined HRCT and MR Cisternography in the Evaluation of CSF Rhinorrhea

Combined HRCT and MR Cisternography in the Evaluation of CSF Rhinorrhea

Usefulness of imaging studies for diagnosing and localizing cerebrospinal fluid rhinorrhea: A systematic review and meta-analysis.

Our aim in this study was to determine the usefulness of diagnosis by imaging studies for the localization of cerebrospinal fluid (CSF) rhinorrhea. PubMed, SCOPUS, Embase, Web of Science, and Cochrane Library databases were searched up to July 2021. True and false positive and negative data were collected along with the characteristics of each study. Methodologic quality was assessed using the QADAS-2 tool. Sixteen studies involving 472 patients were included. The diagnostic odds ratio (DOR) of imaging studies was 13.6195 (95% confidence interval [CI], 7.4756-24.8129; I2 =28.1%). The area under the summary receiver-operating characteristic curve was 0.712. Sensitivity, specificity, negative predictive value, and positive predictive value were 0.8507 (0.7773-0.9029), 72.1%; 0.7827 (0.6865-0.8556), 26.8%; 0.5828 (0.4398-0.7132), 67.4%; and 0.9407 (0.8935-0.9678), 59.1%, respectively. In the subgroup analysis, there were significant differences for sensitivity (computed tomography [CT], 0.7421; computed tomography cisternography [CTC], 0.8872; magnetic resonance imaging [MRI], 0.8365; magnetic resonance cisternography [MRC], 0.8565; intrathecal gadolinium magnetic resonance cisternography [GaMRC], and 0.9307; radionuclide cisteronography [RNC], 0.7097; p=0.0481) and for negative predictive value among imaging modalities (CT, 0.3028; CTC, 0.4848; MRI, 0.4658; MRC, 0.7465; GaMRC, 0.8611; and RNC, 0.5263; p=0.0046). There were no significant differences among imaging modalities for specificity, positive predictive value, or DOR (p>0.05). Imaging studies can be used in the diagnosis of CSF rhinorrhea. Gadolinium magnetic resonance cisternography showed the highest diagnostic accuracy. MRC showed fair diagnostic accuracy without intrathecal injection.

Feasibility of 3D T1W sequences in contrast-material enhanced MR cisternography at 3T.

We investigated the diagnostic values and artifact severities of 3D-T1W sequences in the diagnosis of cerebrospinal fluid (CSF) leakage. We retrospectively reviewed 3-tesla contrast-material enhanced MR cisternography exams of 22 patients with suspected CSF leakage in 4 years. The presence of the artifacts on 3D-T1W data was evaluated using a 4-point scale (0: none; 1: minimal; 2: moderate; 3: prominent). Agreements between CSF leakage results of the 3D-T1W sequences and consensus decisions were evaluated via kappa values. Artifact scores were analyzed by Fisher's exact test. The most compatible techniques with the consensus diagnoses were fat-saturated 3D-T1W-SPACE and 3D-T1W-VIBE sequences. The most artifact containing the 3D-T1W sequence was 3D-MPRAGE. 3D-SPACE and 3D-VIBE are more successful in evaluating CSF leakages compared to 3D-MPRAGE. 3D-SPACE has lower artifact scores compared to 3D-VIBE and 3D-MPRAGE sequences.

Diagnosis and Localization of Cerebrospinal Fluid Rhinorrhea: A Systematic Review.

BackgroundCerebrospinal fluid (CSF) rhinorrhea results from abnormal communications between the subarachnoid and sinonasal spaces. Accurate preoperative diagnosis and localization are vital for positive clinical outcomes. However, the diagnosis and localization of CSF rhinorrhea remain suboptimal due to a lack of accurate understanding of test characteristics.ObjectiveThis systematic review aims to assess the diagnostic accuracy of various tests and imaging modalities for diagnosing and localizing CSF rhinorrhea.MethodsA systematic review of the MEDLINE and EMBASE databases was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.ResultsOur search identified 4039 articles—53 cohort studies and 24 case series describing 1622 patients were included. The studies were heterogeneous and had a wide range of sensitivities and specificities. Many specificities were incalculable due to a lack of true negative and false positive results, thus precluding a meta-analysis. Median sensitivities and specificities were calculated for cohort studies of the following investigations: high-resolution computed tomography (HRCT) 0.93/0.50 (sensitivity/specificity), magnetic resonance cisternography (MRC) 0.94/0.77, computed tomography cisternography (CTC) 0.95/1.00, radionuclide cisternography (RNC) 0.90/0.50, and contrast-enhanced magnetic resonance cisternography (CEMRC) 0.99/1.00, endoscopy 0.58/1.00, topical intranasal fluorescein (TIF) 1.00/incalculable, intrathecal fluorescein (ITF) 0.96/1.00. Case series were reviewed separately. Etiology and site-specific data were also analyzed.ConclusionMR cisternography is more accurate than high-resolution CT at diagnosing and localizing CSF rhinorrhea. CT cisternography, contrast-enhanced MR cisternography, and radionuclide cisternography have good diagnostic characteristics but are invasive. Intrathecal fluorescein shows promising data but has not been widely adopted for purely diagnostic use. Office endoscopy has limited data but does not sufficiently diagnose CSF rhinorrhea independently. These findings confirm with current guidelines and evidence.

Four-Hour Delayed Gadolinium-Enhanced 3D-FLAIR MR Imaging Highlights Intralabyrinthine Micro-Schwannomas.

To demonstrate the clinical significance of 4-hour delayed gadolinium-enhanced three-dimensional fluid-attenuated inversion recovery (delayed 3D-FLAIR) in patients with intralabyrinthine schwannoma (ILS). Three patients who were clinically diagnosed with ILS. All patients underwent audiological examinations and magnetic resonance imaging (MRI) scans. The MR-protocol included axial MR cisternography, immediate gadolinium-enhanced T1-weighted sequence, and heavily T2-weighted 3D-FLAIR prior to and 4 hours after the intravenous administration of gadolinium contrast medium. All MR images were visually inspected. In all three patients with ILS, delayed 3D-FLAIR MRI demonstrated a strong signal of cochlear fluid surrounding the tumor, which highlighted a tumor region that lacked signals. Delayed 3D-FLAIR MRI may serve as a novel diagnostic tool for the early detection of intralabyrinthine micro-schwannoma. The findings also shed light on the pathophysiology of ILS.