Enhancement pattern of the normal facial nerve at 3.0 T temporal MRI

Potential Association Between COVID-19 Vaccination and Facial Palsy: Three Cases With Neuroimaging Findings

Acute onset Facial palsy was reported in four vaccinated participants in the BNT162b2 (Pfizer-BioNTech) vaccine clinical trials published on December 10, 2020. So far, few cases of Facial palsy among the mRNA vaccine groups have been previously documented in the literature. Facial palsy is cited as medically attended adverse event following immunization on April 12, 2021, after the first dose of the approved Pfizer-BioNTech COVID-19 vaccines for preventive immunization for SARS-CoV-2 is administrated to the population in Turkey. This study is aimed to describe clinical and magnetic resonance imaging features of three patients, who developed acute onset peripheral facial paralysis after administration of the BNT162b2 vaccine, without any previous medical condition. The first patient presented with right sided facial palsy within the same day following the vaccine was administrated, while the second patient presented with left sided facial palsy 2 months after vaccination. The third patient, on the other hand, presented with right sided facial palsy and abducens nerve (CN VI) paralysis two days after vaccine was administrated.

Microanatomical findings with relevance to trigeminal ganglion enhancement on post-contrast T1-weighted magnetic resonance images in dogs

Introduction

Trigeminal ganglion contrast enhancement (TGCE) is reported to be a normal and a common finding on magnetic resonance imaging studies of dogs, cats and humans. The intent of the present study was to describe the anatomical characteristics of the trigeminal ganglion, its surrounding structures, and histological features that are relevant to explain or hypothesize on the reason for TGCE on T1-weighted post-contrast MRI studies of the brain in dogs.

Methods

Eight dog cadavers were dissected to study the anatomy of the trigeminal ganglion. The presence and anatomy of vessels was studied by dissection and by histological techniques. Two trigeminal ganglia were isolated and stained with hematoxylin-eosin (HE). Two other trigeminal ganglia included in the trigeminal canal and trigeminal cavity were decalcified with formic acid/formalin for 12 weeks and stained with HE to study the related vessels. Additionally, a corrosion cast was obtained from a separate canine specimen.

Results

Leptomeninges and a subarachnoid space were identified at the level of the trigeminal nerve roots and the trigeminal ganglion. No subarachnoid space was identified and leptomeninges were no longer present at the level of the three trigeminal nerve branches. Small arterial vessels ran to and supplied the trigeminal ganglion, passing through the dura mater. No venous plexus was visualized at the level of the trigeminal ganglion in the dissections. A complex arterial vascular network was identified within the leptomeningeal covering of the trigeminal ganglion and was best appreciated in the corrosion cast. Histological examination revealed small-to moderate-sized blood vessels located in the epineurium around the ganglion; from there a multitude of arterioles penetrated into the perineurium. Small endoneurial branches and capillaries penetrated the ganglion and the trigeminal nerve branches.

Discussion

Limitations to this study include the limited number of canine specimens included and the lack of electron microscopy to further support current hypotheses included in our discussion. In conclusion, this study provides further support to the theory that TGCE in dogs may be due an incomplete blood-nerve barrier or blood-ganglion barrier at the interface between the central nervous system and the peripheral nervous system.

Incidence of Underlying Abnormal Findings on Routine Magnetic Resonance Imaging for Bell Palsy

Importance

There is no consensus on the benefits of routine magnetic resonance imaging (MRI) of the facial nerve in patients with suspected idiopathic peripheral facial palsy (PFP) (ie, Bell palsy [BP]).

Objectives

To estimate the proportion of adult patients in whom MRI led to correction of an initial clinical diagnosis of BP; to determine the proportion of patients with confirmed BP who had MRI evidence of facial nerve neuritis without secondary lesions; and to identify factors associated with secondary (nonidiopathic) PFP at initial presentation and 1 month later.

Design, Setting, and Participants

This retrospective multicenter cohort study analyzed the clinical and radiological data of 120 patients initially diagnosed with suspected BP from January 1, 2018, to April 30, 2022, at the emergency department of 3 tertiary referral centers in France.

Interventions

All patients screened for clinically suspected BP underwent an MRI of the entire facial nerve with a double-blind reading of all images.

Main Outcomes and Measures

The proportion of patients in whom MRI led to a correction of the initial diagnosis of BP (any condition other than BP, including potentially life-threating conditions) and results of contrast enhancement of the facial nerve were described.

Results

Among the 120 patients initially diagnosed with suspected BP, 64 (53.3%) were men, and the mean (SD) age was 51 (18) years. Magnetic resonance imaging of the facial nerve led to a correction of the diagnosis in 8 patients (6.7%); among them, potentially life-threatening conditions that required changes in treatment were identified in 3 (37.5%). The MRI confirmed the diagnosis of BP in 112 patients (93.3%), among whom 106 (94.6%) showed evidence of facial nerve neuritis on the affected side (hypersignal on gadolinium-enhanced T1-weighted images). This was the only objective sign confirming the idiopathic nature of PFP.

Conclusions and Relevance

These preliminary results suggest the added value of the routine use of facial nerve MRI in suspected cases of BP. Multicentered international prospective studies should be organized to confirm these results.

ACR Appropriateness Criteria® Cranial Neuropathy: 2022 Update

Cranial neuropathy can result from pathology affecting the nerve fibers at any point and requires imaging of the entire course of the nerve from its nucleus to the end organ in order to identify a cause. MRI with and without intravenous contrast is often the modality of choice with CT playing a complementary role. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Case Report: Para-infectious cranial nerve palsy after bacterial meningitis

A 27-year-old woman was admitted to our hospital for fever, associated with headache, nausea, and vomiting, and she rapidly developed mild left facial nerve palsy and diplopia. Neurological examination revealed mild meningitis associated with bilateral VI cranial nerve palsy and mild left facial palsy. As central nervous system (CNS) infection was suspected, a diagnostic lumbar puncture was performed, which revealed 1,677 cells/μl, 70% of which were polymorphonuclear leukocytes. Moreover, multiplex PCR immunoassay was positive for Neisseria meningitidis, supporting the diagnosis of bacterial meningitis. Finally, IgG oligoclonal bands (IgGOB) were absent in serum and cerebrospinal fluid (CSF). Therefore, ceftriaxone antibiotic therapy was started, and in the following days, the patient’s signs and symptoms improved, with complete remission of diplopia and meningeal signs within a week. On the contrary, left facial nerve palsy progressively worsened into a severe bilateral deficit. A second lumbar puncture was therefore performed: the CSF analysis revealed a remarkable decrease of pleocytosis with a qualitative modification (only lymphocytes), and oligoclonal IgG bands were present. A new brain MRI was performed, showing a bilateral gadolinium enhancement of the intrameatal VII and VIII cranial nerves bilaterally. Due to suspicion of para-infectious etiology, the patient was treated with oral steroid (prednisolone 1 mg/kg/day), with a progressive and complete regression of the symptoms. We suggest that in this case, after a pathogen-driven immunological response (characterized by relevant CSF mixed pleocytosis and no evidence of IgGOB), a para-infectious adaptive immunity-driven reaction (with mild lymphocyte pleocytosis and pattern III IgGOB) against VII and VIII cranial nerves started. Indeed, steroid administration caused a rapid and complete restoration of cranial nerve function.

Radial spoiled gradient T1 weighted imaging of the internal auditory canal: Is Scarpa's ganglion now an expected finding and source of fundal enhancement?

StarVIBE is a 3D gradient-echo sequence with a radial, stack-of-stars acquisition having spatial resolution and tissue contrast. With newer sequences, it is important to be familiar with sequence tissue contrasts and appearance of anatomical variants. We evaluated 450 patients utilizing this sequence; 35 patients demonstrated fluffy "cotton wool" enhancement at the internal auditory canal fundus without clear pathology. We favor this represents anatomic neurovascular enhancement that StarVIBE is sensitive to and is a touch-me-not finding.

Enhancement of cranial nerves in Lyme neuroborreliosis: incidence and correlation with clinical symptoms and prognosis

PURPOSE

Symptoms of cranial neuritis are a common presentation of Lyme neuroborreliosis (LNB). Imaging studies are scarce and report contradictory low prevalence of enhancement compared to clinical studies of cranial neuropathy. We hypothesized that MRI enhancement of cranial nerves in LNB is underreported, and aimed to assess the prevalence and clinical impact of cranial nerve enhancement in early LNB.

METHODS

In this prospective, longitudinal cohort study, 69 patients with acute LNB were examined with MRI of the brain. Enhancement of cranial nerves III-XII was rated. MRI enhancement was correlated to clinical findings of neuropathy in the acute phase and after 6 months.

RESULTS

Thirty-nine of 69 patients (57%) had pathological cranial nerve enhancement. Facial and oculomotor nerves were most frequently affected. There was a strong correlation between enhancement in the distal internal auditory canal and parotid segments of the facial nerve and degree of facial palsy (gamma = 0.95, p < .01, and gamma = 0.93, p < .01), despite that 19/37 nerves with mild-moderate enhancement in the distal internal auditory canal segment showed no clinically evident palsy. Oculomotor and abducens nerve enhancement did not correlate with eye movement palsy (gamma = 1.00 and 0.97, p = .31 for both). Sixteen of 17 patients with oculomotor and/or abducens nerve enhancement had no evident eye movement palsy.

CONCLUSIONS

MRI cranial nerve enhancement is common in LNB patients, but it can be clinically occult. Facial and oculomotor nerves are most often affected. Enhancement of the facial nerve distal internal auditory canal and parotid segments correlate with degree of facial palsy.

Approach to Facial Weakness

Facial palsy is a common neurologic concern and is the most common cranial neuropathy. The facial nerve contains motor, parasympathetic, and special sensory functions. The most common form of facial palsy is idiopathic (Bell's palsy). A classic presentation requires no further diagnostic measures, and generally improves with a course of corticosteroid and antiviral therapy. If the presentation is atypical, or concerning features are present, additional studies such as brain imaging and cerebrospinal fluid analysis may be indicated. Many conditions may present with facial weakness, either in isolation or with other neurologic signs (e.g., multiple cranial neuropathies). The most important ones to recognize include infections (Ramsay-Hunt syndrome associated with herpes zoster oticus, Lyme neuroborreliosis, and complications of otitis media and mastoiditis), inflammatory (demyelination, sarcoidosis, Miller-Fisher variant of Guillain-Barré syndrome), and neoplastic. No matter the cause, individuals may be at risk for corneal injury, and, if so, should have appropriate eye protection. Synkinesis may be a bothersome residual phenomenon in some individuals, but it has a variety of treatment options including neuromuscular re-education and rehabilitation, botulinum toxin chemodenervation, and surgical intervention.

Magnetic Resonance Imaging of Perineural Spread of Head and Neck Cancer

Perineural tumor spread (PNTS) is one of the important methods of tumoral spread in head and neck cancers. It consists of a complex process that entails the production of certain chemicals or the production of certain cell receptors. Histologic type and primary tumor site play an important role in PNTS. Any nerve could be affected; however, the trigeminal and facial nerves are the most involved nerves. Magnetic resonance imaging and computed tomography detect the primary and secondary signs of PNTS. Functional imaging such as diffusion-weighted imaging and hybrid imaging act as problem-solving techniques.

CS-VIBE accelerates cranial nerve MR imaging for the diagnosis of facial neuritis: comparison of the diagnostic performance of post-contrast MPRAGE and CS-VIBE

OBJECTIVE

We aimed to compare the diagnostic performance of post-contrast 3D compressed sensing volume-interpolated breath-hold examination (CS-VIBE) and 3D T1 magnetization-prepared rapid-acquisition gradient-echo (MPRAGE) in detecting facial neuritis.

MATERIALS AND METHODS

Between February 2019 and September 2019, 60 patients (30 facial palsy patients and 30 controls) who underwent contrast-enhanced cranial nerve MRI with both conventional MPRAGE and CS-VIBE (scan time: 6 min 8 s vs. 2 min 48 s) were included in this retrospective study. All images were independently reviewed by three radiologists for the presence of facial neuritis. In patients with facial palsy, signal-to-noise ratio (SNR) of the pons, enhancement degree and contrast-to-noise ratio (CNR_nerve-CSF) of the facial nerve were measured. The overall image quality, artifacts, and facial nerve discrimination were analyzed. The sensitivity and specificity of both sequences were calculated with the clinical diagnosis as a reference.

RESULTS

CS-VIBE had comparable performance in the detection of facial neuritis to that of MPRAGE (sensitivity and specificity, 97.8% and 99.4% vs. 100.0% and 99.4% in pooled analysis; 97.8% and 98.9% vs. 100.0% and 98.9% in patents with facial palsy, p value > 0.05 for all). CS-VIBE showed significantly lower SNR (p value < 0.001 for all), but significantly higher CNR_nerve-CSF (p value < 0.05 for all) than MPRAGE. CS-VIBE also performed better in the overall image quality, artifacts, and facial nerve discrimination than MPRAGE (p value < 0.001 for all).

CONCLUSION

CS-VIBE achieved comparable diagnostic performance for facial neuritis compared to the conventional MPRAGE, with the scan time being half of that of MPRAGE.

KEY POINTS

• Post-contrast 3D CS-VIBE MRI is a reliable method for the diagnosis of facial neuritis. • CS-VIBE reduces the scan time of cranial nerve MRI by more than half compared to conventional T1-weighted image. • CS-VIBE had better performance in contrast-to-noise ratio and favorable image quality compared with conventional T1-weighted image.

Improvement of the Diagnostic Performance of Facial Neuritis Using Contrast-Enhanced 3D T1 Black-Blood Imaging: Comparison with Contrast-Enhanced 3D T1-Spoiled Gradient-Echo Imaging

This study aims to investigate the diagnostic ability of the contrast-enhanced 3D T1 black-blood fast spin-echo (T1 BB-FSE) sequence compared with the contrast-enhanced 3D T1-spoiled gradient-echo (CE-GRE) sequence in patients with facial neuritis. Forty-five patients with facial neuritis who underwent temporal bone MR imaging, including T1 BB-FSE and CE-GRE imaging, were examined. Two reviewers independently assessed the T1 BB-FSE and CE-GRE images in terms of diagnostic performance, and qualitative (diagnostic confidence and visual asymmetric enhancement) and quantitative analysis (contrast-enhancing lesion extent of the canalicular segment of the affected facial nerve (LEC) and the affected side-to-normal signal intensity ratio (rSI)). The AUCs of each reviewer, and the sensitivity and accuracy of T1 BB-FSE were significantly superior to those of CE-GRE (p < 0.05). Regarding diagnostic confidence and visual asymmetric enhancement, T1 BB-FSE tended to be rated greater than CE-GRE (p < 0.05). Additionally, in quantitative analysis, LEC and rSI of the canalicular segment on T1 BB-FSE were larger than those on CE-GRE (p < 0.05). The T1 BB-FSE sequence was significantly superior to the CE-GRE sequence, with more conspicuous lesion visualization in terms of both qualitative and quantitative aspects in patients with facial neuritis.

Mastoid effusion on temporal bone MRI in patients with Bell's palsy and Ramsay Hunt syndrome

This study aimed to investigate the incidence of mastoid effusion on temporal bone magnetic resonance imaging (MRI) in patients with Bell’s palsy (BP) and Ramsay Hunt syndrome (RHS), and evaluate the usefulness of mastoid effusion in early differential diagnosis between BP and RHS. The incidence of mastoid effusion on 3.0 T—temporal bone MRI, which was conducted within 10 days after the onset of acute facial nerve palsy, was compared between 131 patients with BP and 33 patients with RHS. Findings of mastoid cavity on temporal bone MRI were classified into three groups as normal mastoid, mastoid effusion, and sclerotic change, and the incidence of ipsilesional mastoid effusion was significantly higher in RHS than BP (P < 0.001). Tympanic membrane was normal in 7 of 14 RHS patients with mastoid effusion, and injected without middle ear effusion in 7 patients. This study highlights significantly higher incidence of ipsilesional mastoid effusion in RHS than BP, and suggests that the presence of mastoid effusion may provide additional information for differential diagnosis between RHS and BP.

Enhancement patterns of the normal facial nerve on three-dimensional T1W fast spin echo MRI

Objectives:

With increasing neuroimaging applications of contemporary three-dimensional T₁W fast spin echo (3D T1W FSE) sequences, it was aimed to reappraise the normal patterns of skull base facial nerve gadolinium enhancement.

Methods:

Pre- and post-gadolinium 3D T1W fast spin echo imaging studies (n = 64) were retrospectively analysed in patients without suspected facial nerve pathology. Two independent observers scored the signal at each of six skull base facial nerve segments. Wilcoxon signed-rank test was used to compare changes in signal between pre- and post-gadolinium sequences at each location, and how this differed between proprietary sequences or between the pairs of facial nerves.

Results:

There was significant enhancement at the fundal canalicular (16%), geniculate ganglion (96%), tympanic (45%) and mastoid (38%) facial nerve segments (p < 0.05). Two different proprietary sequences demonstrated similar patterns of enhancement and there was symmetry between the two sides.

Conclusions:

There is a differing pattern of normal facial nerve enhancement on contemporary 3D T1W FSE sequences compared to previous studies of 2D T1W SE imaging and fundal canalicular enhancement may be physiological.

Advances in knowledge:

This is the first study to evaluate patterns of normal facial nerve enhancement using contemporary 3D T1W FSE MRI sequences.

Enhanced fallopian canal as a potential marker for temporal bone vasculitis

OBJECTIVES

This study aimed to test the hypothesis that contrast-enhanced 3D MRI with gradient-echo sequences (CE-3D-GRE) can detect signs of vasculitis in the fallopian canal, which may cause otologic involvement, in four patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV).

METHODS

CE-3D-GRE acquired at 3.0 Tesla was performed on four patients diagnosed with granulomatosis with polyangiitis or eosinophilic granulomatosis with polyangiitis, at onset or relapse of the disease, and in remission. Clinical correlations between otologic symptoms and radiological findings were examined for each patient. Furthermore, signal intensity of the mastoid segment of the fallopian canal was compared between the ears with active disease (n = 3) and those in remission or without vasculitis (n = 3).

RESULTS

Intense enhancement in the tympanic and mastoid segments of the fallopian canal was associated with development of external otitis, otitis media, and sensorineural hearing loss, and was unrelated to the presence of facial paresis. Maximal intensity projection images visualized the close relationship between the enhanced fallopian canal and middle ear inflammation. The findings were absent in remission. Signal intensity of the mastoid segment of the fallopian canal was higher in ears with active disease than in normal ears (P < .001) and decreased to normal levels during remission (P = .597).

CONCLUSION

CE-3D-GRE can demonstrate vasculitis in the temporal bone, reflecting disease activity and the severity of otologic manifestations, including cochlear involvement, in AAV patients. Intense enhancement of the fallopian canal on CE-3D-GRE can be a potential marker for vasculitis of the temporal bone.

LEVEL OF EVIDENCE

5.

Signal intensity pattern of the normal oculomotor nerve on contrast-enhanced 3D FLAIR at 3.0 T MRI

PURPOSE

The aim of this study was to depict the signal intensity pattern of the normal oculomotor nerve demonstrated on contrast-enhanced three-dimensional fluid-attenuated inversion recovery images.

MATERIALS AND METHODS

Eighty-one patients were included in the study. Contrast-enhanced three-dimensional fluid-attenuated inversion recovery images with magnetisation-prepared rapid acquisition were reconstructed and evaluated in the coronal plane. The signal intensity of the cisternal segment of the oculomotor nerve was graded into a visual scale of 1 to 5 as compared to the white matter, grey matter and the pituitary stalk. The signal intensity ratio of the oculomotor nerve was consequently measured.

RESULTS

By using the visual scale, more than half of the oculomotor nerves showed higher signal intensity than the grey matter signal on contrast-enhanced three-dimensional fluid-attenuated inversion recovery images (59.3-80.2%). It can demonstrate a signal intensity similar to the pituitary stalk (14.8%) by visualisation. None of them showed signal intensity equal to the normal white matter signal. By signal intensity measurement, the mean signal intensity ratio of oculomotor nerves to white matter equals 1.54±0.20 (95% confidence interval (CI) 1.51-1.57); mean signal intensity ratio to grey matter equals 1.16±0.15 (95% CI 1.14-1.18); mean signal intensity ratio to the pituitary stalk equals 0.68±0.10 (95% CI 0.64-0.70).

CONCLUSIONS

The normal oculomotor nerve visualised on contrast-enhanced three-dimensional fluid-attenuated inversion recovery images has a higher signal intensity than the white matter and may have a signal intensity similar to the grey matter or the pituitary stalk. The high signal intensity of the oculomotor nerve in contrast-enhanced three-dimensional fluid-attenuated inversion recovery should not be misinterpreted as a pathology.

Imaging of facial neuritis using T2-weighted gradient-echo fast imaging employing steady-state acquisition after gadolinium injection

BACKGROUND

MRI is the modality of choice for the imaging of facial neuritis. Previously, gadolinium-enhanced T1-weighted imaging of the petrous bone, then FLAIR sequences were thought to be most informative for acute facial neuritis imaging. The aim of this study is to evaluate the value of contrast-enhanced T2-weighted sequence for the diagnosis of acute facial neuritis and compare it to contrast-enhanced T1-weighted and FLAIR sequences.

METHODS

We included 50 patients with an acute unilateral idiopathic peripheral facial neuritis. An MRI (3 T) with three sequences was performed (T1-weighted, T2-weighted and FLAIR), all acquired after intravenous contrast-media injection.

RESULTS

The contrast-enhanced T2-weighted sequence appeared to be the most accurate one for the diagnosis of acute facial neuritis (Se 94%, Sp 100%, accuracy 98.2%, p < 0.001), with a pathological facial nerve strongly (grade 2-3) enhancing and a homogenous enhancement along the course of the entire facial nerve. Contrast-enhanced T1-weighted (Se 80%, Sp 100%, accuracy 94.1%) and FLAIR sequences (92%, Sp 88%, accuracy 90%, p < 0.001) showed lower accuracy. On T1-weighted sequence, a strong enhancement (blurred margins) of the canalicular segment was observed in 80% of the cases when it was never observed in normal nerves.

CONCLUSION

A strong (= iso to hyperintense to the petrous fat signal) and diffuse (all segments) enhancement of the facial nerve on T2-weighted steady-state free precession sequence is a sensitive and specific sign for the diagnosis of acute idiopathic facial neuritis, and appears superior to T1WI and FLAIR sequences.

MRI-based texture analysis to differentiate the most common parotid tumours

AIM

To evaluate magnetic resonance imaging (MRI) features and signal characteristics of parotid masses and investigate the added role of texture analysis (TA) in the differentiation of parotid tumours.

MATERIALS AND METHODS

Ninety-five patients (42 women, 53 men; mean age 51.67±14.15) were included in this study. The study group consisted of 40 pleomorphic adenoma, 45 Warthin's tumour, and 10 mucoepidermoid carcinomas. Two reviewers assessed the MRI sequences retrospectively. Fat-suppressed T2-weighted and contrast-enhanced T1-weighted axial images were used for TA. Receiver operating characteristic curve analyses were performed to evaluate the ability to make a diagnosis. Logistic regression analyses were conducted to explore the independent risk factors among the MRI features and to analyse the added value of TA to the qualitative analysis.

RESULTS

Significant differences were found in the tumour border (p<0.001), infiltration of the surrounding tissue (p=0.003), contrast-enhancement grading (p<0.001), perineural spread (p=0.013), and pathological lymph nodes (p<0.001) between the malignant and benign tumours. Kurtosis on contrast-enhanced T1-weighted images, and skewness and kurtosis on T2-weighted images were significantly different between the three groups (p=0.020, <0.001, 0.003; respectively). A kurtosis value on T2-weighted images <2.815 along with an ill-defined border had the highest specificity (98.8%) and positive predictive value (83.3%) in the differentiation of malignant tumours.

CONCLUSION

The addition of TA parameters to the MRI findings may contribute to distinguish benign from malignant parotid tumours.

Predictive Value of VIBE using Subtraction to Evaluate Idiopathic Facial Palsy after Starting Therapy

Purpose To determine the predictive value of 3-dimensional spoiled gradient-echo volumetric interpolated breath-hold examination (VIBE) using subtraction to evaluate the short-term effect of therapy for facial palsy.

Materials and Methods We included 97 patients with idiopathic facial palsy (52 male, 45 female; aged 50.7 ± 19.4 years) who underwent MR imaging with a contrast agent after starting therapy. The mean interval between onset and therapy was 1.55 ± 1.69 days, between therapy and MR imaging was 3.19 ± 2.78 days, and between MR imaging and assessment of the therapeutic effect was 3.50 ± 0.71 days. The degree of therapeutic effect was determined using a 4-grade scale based on the House–Brackmann scale for grading facial nerve function. Two radiologists reviewed VIBE with pre- and postcontrast subtraction using the 4-point scale. We evaluated the diagnostic performance and compared the degree of therapeutic effect and enhancement of facial nerves that were divided into 5 segments bilaterally.

Results We identified 98 facial palsy initially and significant enhancement in 55 facial nerves after the start of therapy and residual palsy in 87. Sensitivity for all facial palsy was 62.0 %, specificity was 90.9 %, positive predictive value was 98.2 %, negative predictive value was 23.3 %, and accuracy was 65.3 %. Eleven patients recovered completely, 1 showed significant enhancement, and the remaining 10 did not show significant enhancement of the facial nerve.

Conclusion VIBE has a potential to predict the prognostic outcome and assess facial palsy after the start of therapy.

Key points: 

Citation Format

Contrast leakage distant from the hematoma in patients with spontaneous ICH: A 7 T MRI study

Disruption of the blood-brain barrier (BBB) might play a role in the pathophysiology of cerebral small vessel disease-related ICH. The aim of this study was to assess presence and extent of contrast agent leakage distant from the hematoma as a marker of BBB disruption in patients with spontaneous ICH. We prospectively performed 7 tesla MRI in adult patients with spontaneous ICH and assessed contrast leakage distant from the hematoma on 3D FLAIR images. Thirty-one patients were included (mean age 60 years, 29% women). Median time between ICH and MRI was 20 days (IQR 9-67 days). Seventeen patients (54%; seven lobar, nine deep, one infratentorial ICH) had contrast leakage, located cortical in 16 and cortical and deep in one patient. Patients with contrast leakage more often had lobar cerebral microbleeds (CMBs; 77%) than those without (36%; RR 2.5, 95% CI 1.1-5.7) and a higher number of lobar CMBs (patients with contrast leakage: median 2, IQR 1-8 versus those without: median 0, IQR 0-2; p = 0.02). This study shows that contrast leakage distant from the hematoma is common in days to weeks after spontaneous ICH. It is located predominantly cortical and related to lobar CMBs and therefore possibly to cerebral amyloid angiopathy.

Peculiar Unpleasant Dysgeusia as the Sole Initial Symptom of Guillain-Barré Syndrome

Dysgeusia is rare in Guillain-Barré syndrome, particularly as the initial symptom. We herein report the case of a 59-year-old woman who presented with only dysgeusia as the initial symptom of Guillain-Barré syndrome, followed by gradually worsening muscle weakness and bilateral sensory disturbances in the extremities. Her dysgeusia was so unpleasant that she could not eat anything, so she received nasogastric tube feeding without dysphasia. We speculate that the dysgeusia in our patient was mainly caused by inflammation of the chorda tympani nerves. Guillain-Barré syndrome should be considered a possible cause of acute dysgeusia.

Imaging the facial nerve: A contemporary review of anatomy and pathology

PURPOSE

The facial nerve is the seventh paired cranial nerve which anatomically can be divided into six distinct segments. There are a wide range of pathologies that may occur along each segment of the nerve. The aim of this pictorial review is to untangle the complex appearances of the facial nerve, both in its normal anatomical course and when affected by pathology.

METHOD

This review takes an evidence-based segmental approach to the evaluation of the facial nerve in terms of its anatomy and clinical features of common pathologies affecting specific segments of the nerve. The typical multimodal radiological findings of common facial nerve pathologies are included in the review using imaging from select pathologically confirmed cases.

RESULTS

A wide range of pathologies ranging from congenital abnormalities to inflammatory, infective and neoplastic processes can affect the facial nerve. As select segments of the nerve are better evaluated on certain imaging modalities a clear understanding of the anatomy and clinical features associated with specific facial nerve pathologies enables the radiologist to tailor the imaging test to best answer the clinical question.

CONCLUSIONS

This review provides a segmental clinical-radiological approach to imaging the facial nerve. In addition, recent developments in facial nerve imaging that may come into mainstream use in the near future are touched upon.

Better continuity of the facial nerve demonstrated in the temporal bone on three-dimensional T1-weighted imaging with volume isotropic turbo spin echo acquisition than that with fast field echo at 3.0 tesla MRI

INTRODUCTION

Three-dimensional (3D) T1-weighted imaging (T1WI) is used for evaluation of the facial nerve. The signal intensity of normal and pathological facial nerves has been well evaluated at both 1.5T and 3.0T MRI after gadolinium (Gd)-enhancement with various pulse sequences. However, the continuity of the facial nerve has not been evaluated on 3D-T1WI. This study aims to compare the continuity of the normal facial nerve in the temporal bone demonstrated on T1-weighted volume isotropic turbo spin echo acquisition (T1-VISTA), which is a spin-echo sequence, to that on T1-weighted fast field echo (T1-FFE), which is a gradient-echo sequence, at 3.0T MRI.

METHODS

Forty-four normal facial nerves in 22 healthy volunteers were imaged with both sequences using 3.0T MRI without Gd-enhancement. The facial nerves were evaluated visually by two neuroradiologists in four anatomical segments with a 3-point grading system of continuity. The continuity was assessed by summing the grades of the four segments as a total score. The grades at each segment and the total scores were compared statistically between the T1-VISTA and T1-FFE.

RESULTS

The grades in all segments and the total score were significantly higher with T1-VISTA than those with T1-FFE.

CONCLUSIONS

T1-VISTA was superior to demonstrate the facial nerve as a continuous anatomical structure in the temporal bone at 3.0T MRI.

Is there a relationship between mastoid pneumatisation and facial canal dimensions?

OBJECTIVE

To evaluate mastoid pneumatisation and facial canal dimensions.

METHOD

In this retrospective study, 169 multidetector computed tomography scans of temporal bone were reviewed. Facial canal dimensions were evaluated at the labyrinthine, tympanic and mastoid segments using axial and coronal multidetector computed tomography scans of temporal bone. Mastoid pneumatisation and facial canal dehiscence were evaluated. Facial canal dehiscence was measured if it was found to be present.

RESULTS

This study showed that facial canal dimensions decreased in pneumatised mastoids. Facial canal dimensions in females were smaller than in males. Facial canal dehiscence was detected in 5.9 per cent and 6.5 per cent of the patients on the right and left sides, respectively. No correlations were found between facial canal dehiscence and mastoid pneumatisation. The length of dehiscence was 1.92 ± 0.44 mm (range, 0.86-2.51 mm) on the left side. In older subjects, left facial canal dehiscence was detected more, and the length of the dehiscence increased.

CONCLUSION

This study concluded that during surgery, facial canal dehiscence should be kept in mind in order to avoid complications.

MR Imaging of the Facial Nerve through the Temporal Bone at 3T with a Noncontrast Ultrashort Echo Time Sequence

The pointwise encoding time reduction with radial acquisition (PETRA) ultrashort echo time MR imaging sequence at 3T enables visualization of the facial nerve from the brain stem, through the temporal bone, to the stylomastoid foramen without intravenous contrast. Use of the PETRA sequence, or other ultrashort echo time sequences, should be considered in the MR imaging evaluation of certain skull base tumors and perhaps other facial nerve and temporal bone pathologies.

Visualization of Cranial Nerves Using High-Definition Fiber Tractography

BACKGROUND

Recent studies have demonstrated diffusion tensor imaging tractography of cranial nerves (CNs). Spatial and angular resolution, however, is limited with this modality. A substantial improvement in image resolution can be achieved with high-angle diffusion magnetic resonance imaging and atlas-based fiber tracking to provide detailed trajectories of CNs.

OBJECTIVE

To use high-definition fiber tractography to identify CNs in healthy subjects and patients with brain tumors.

METHODS

Five neurologically healthy adults and 3 patients with brain tumors were scanned with diffusion spectrum imaging that allowed high-angular-resolution fiber tracking. In addition, a 488-subject diffusion magnetic resonance imaging template constructed from the Human Connectome Project data was used to conduct atlas space fiber tracking of CNs.

RESULTS

The cisternal portions of most CNs were tracked and visualized in each healthy subject and in atlas fiber tracking. The entire optic radiation, medial longitudinal fasciculus, spinal trigeminal nucleus/tract, petroclival portion of the abducens nerve, and intrabrainstem portion of the facial nerve from the root exit zone to the adjacent abducens nucleus were identified. This suggested that the high-angular-resolution fiber tracking was able to distinguish the facial nerve from the vestibulocochlear nerve complex. The tractography clearly visualized CNs displaced by brain tumors. These tractography findings were confirmed intraoperatively.

CONCLUSION

Using high-angular-resolution fiber tracking and atlas-based fiber tracking, we were able to identify all CNs in unprecedented detail. This implies its potential in localization of CNs during surgical planning.

ABBREVIATIONS

CN, cranial nerveDSI, diffusion spectrum imagingDTI, diffusion tensor imagingHCP, Human Connectome ProjectHDFT, high-definition fiber tractographyMLF, medial longitudinal fasciculusODF, orientation distribution functionROI, region of interest.

Comparison of normal facial nerve enhancement at 3T MRI using gadobutrol and gadopentetate dimeglumine

Background and purpose The facial nerve is unique among cranial nerves in demonstrating normal enhancement of particular segments. The effect of varying T1 relaxivities of gadolinium-based contrast agents on facial nerve enhancement is unclear. In this study, we assess differences in normal facial nerve enhancement with two different gadolinium-based contrast agents, gadobutrol and gadopentetate dimeglumine. In addition, we evaluate differences in facial nerve enhancement with spin-echo (SE) T1 versus 3D inversion recovery prepared fast spoiled gradient-echo (FSPGR) post-contrast sequences. Methods A total of 140 facial nerves in 70 individuals were evaluated (70 with gadobutrol and 70 with gadopentetate dimeglumine) by two blinded reviewers. Differences in enhancement of facial nerve segments between the two agents were analyzed. Differences in enhancement between SE T1 and FSPGR imaging were also evaluated. Results There was no significant difference in facial nerve enhancement between gadobutrol and gadopentetate dimeglumine. Enhancement was commonly observed in the geniculate, tympanic and mastoid segments (98%-100%) with either contrast agent; enhancement was less common in the labyrinthine segments (9%-14%) and lateral canalicular segment (2%-5%). There was a smaller enhancing proportion of labyrinthine and tympanic segments with FSPGR as compared to SE T1 images with gadobutrol. Conclusion There is no significant difference in overall enhancement of the facial nerve between gadobutrol and gadopentetate dimeglumine. Mild enhancement of the lateral canalicular portion of the facial nerve may be a normal finding. With FSPGR sequence, there is lesser perceived enhancement of the labyrinthine and tympanic segments of the facial nerve with gadobutrol.

Cranial Nerve Disorders in Children: MR Imaging Findings

Cranial nerve disorders are uncommon disease conditions encountered in pediatric patients, and can be categorized as congenital, inflammatory, traumatic, or tumorous conditions that involve the cranial nerve itself or propagation of the disorder from adjacent organs. However, determination of the normal course, as well as abnormalities, of cranial nerves in pediatric patients is challenging because of the small caliber of the cranial nerve, as well as the small intracranial and skull base structures. With the help of recently developed magnetic resonance (MR) imaging techniques that provide higher spatial resolution and fast imaging techniques including three-dimensional MR images with or without the use of gadolinium contrast agent, radiologists can more easily diagnose disease conditions that involve the small cranial nerves, such as the oculomotor, abducens, facial, and hypoglossal nerves, as well as normal radiologic anatomy, even in very young children. If cranial nerve involvement is suspected, careful evaluation of the cranial nerves should include specific MR imaging protocols. Localization is an important consideration in cranial nerve imaging, and should cover entire pathways and target organs as much as possible. Therefore, radiologists should be familiar not only with the various diseases that cause cranial nerve dysfunction, and the entire course of each cranial nerve including the intra-axial nuclei and fibers, but also the technical considerations for optimal imaging of pediatric cranial nerves. In this article, we briefly review normal cranial nerve anatomy and imaging findings of various pediatric cranial nerve dysfunctions, as well as the technical considerations of pediatric cranial nerve imaging. Online supplemental material is available for this article. (©)RSNA, 2016.

Thiol/disulphide homeostasis in Bell's palsy as a novel pathogenetic marker

OBJECTIVES

The aim of this study was to investigate the relationship between Bell's palsy and a novel oxidative stress parameter, thiol/disulphide homeostasis.

DESIGN

A prospective study evaluating oxidative stress in Bell's palsy.

SETTING

This research took place in the department of Otorhinolaryngology, Ataturk Training and Research Hospital.

PARTICIPANTS

Totally, 77 patients with Bell's palsy and 38 healthy controls were included in this study.

MAIN OUTCOME MEASURES

The blood levels of total and native thiol and disulphide activity were assessed, and their levels were compared in the patients and controls.

RESULTS

There were statistically significant differences between the patients and controls regarding thiol/disulphide parameters. The mean native thiol and total thiol were significantly lower and disulphide levels were higher in the Bell's palsy than controls. On binary logistic regression analysis, the created model showed 45.3% variation. The cut-off value was 18.95 for disulphides.

CONCLUSION

Native and total thiol levels were low in the Bell's palsy. This metabolic disturbance may have a role in the pathogenesis of Bell's palsy.

Importance of Contrast-Enhanced Fluid-Attenuated Inversion Recovery Magnetic Resonance Imaging in Various Intracranial Pathologic Conditions

Intracranial lesions may show contrast enhancement through various mechanisms that are closely associated with the disease process. The preferred magnetic resonance sequence in contrast imaging is T1-weighted imaging (T1WI) at most institutions. However, lesion enhancement is occasionally inconspicuous on T1WI. Although fluid-attenuated inversion recovery (FLAIR) sequences are commonly considered as T2-weighted imaging with dark cerebrospinal fluid, they also show mild T1-weighted contrast, which is responsible for the contrast enhancement. For several years, FLAIR imaging has been successfully incorporated as a routine sequence at our institution for contrast-enhanced (CE) brain imaging in detecting various intracranial diseases. In this pictorial essay, we describe and illustrate the diagnostic importance of CE-FLAIR imaging in various intracranial pathologic conditions.

Cranial base manifestations of neurosarcoidosis: a review of 305 patients

OBJECTIVE

Neurosarcoidosis is a rare granulomatous disease that can result in cranial neuropathy, chronic meningitis, and intracranial granuloma formation. Meningeal involvement may cause focal nodular enhancement that can simulate common cranial base tumors. The objective of the current study is to further define the clinical features of neurosarcoidosis in a large cohort of patients, focusing on characteristics relevant to the skull base surgeon.

STUDY DESIGN

Retrospective series.

SETTING

Two tertiary academic referral centers.

PATIENTS

Consecutive patients diagnosed with neurosarcoidosis.

INTERVENTION(S)

Review of clinical presentation, physical examination, radiologic findings, biopsy results, and laboratory testing.

MAIN OUTCOME MEASURES

Prevalence and distribution of cranial neuropathy, radiologic features of meningeal enhancement, and patterns of simulated tumors.

RESULTS

A total of 305 patients met study criteria. The mean age at diagnosis was 47 years and 53% were female. The optic nerve was the most commonly involved cranial nerve, followed by the trigeminal and the facial nerve. Meningeal enhancement was present in 67% of cases with 17% demonstrating focal or multicentric nodular enhancement simulating tumor. The most common locations of inflammatory tumor development included the cavernous sinus, petrous temporal bone, and sphenoid wing; six patients had bilateral internal auditory canal lesions, several mimicking neurofibromatosis type II.

CONCLUSION

Establishing the diagnosis of neurosarcoidosis remains challenging. Meningeal involvement and cranial neuropathy often mimic other more common conditions. Careful review of patient history and clinical imaging can reveal important clues toward the diagnosis of neurosarcoidosis. The clinician must maintain a high index of suspicion in patients with atypical presentation to avoid misdiagnosis and facilitate early medical treatment.

Facial neuropathy with imaging enhancement of the facial nerve: a case report

A young women developed unilateral facial neuropathy 2 weeks after a motor vehicle collision involving fractures of the skull and mandible. MRI showed contrast enhancement of the facial nerve. We review the literature describing facial neuropathy after trauma and facial nerve enhancement patterns with different causes of facial neuropathy.

Elevated neutrophil-to-lymphocyte ratio in Bell's palsy and its correlation with facial nerve enhancement on MRI

OBJECTIVE

The aim of this study was to investigate the role of inflammation and atherothrombosis in Bell's palsy (BP) by using neutrophil-to-lymphocyte ratio (NLR) and mean platelet volume (MPV), respectively, and to study their relations with the facial nerve enhancement on temporal gadolinium-enhanced magnetic resonance imaging (TGd-MRI).

STUDY DESIGN

Case control study.

SETTING

Tertiary health institution.

SUBJECTS AND METHODS

This study was performed on 65 patients who were diagnosed with BP and a control group of 35 healthy individuals. The BP patients were also divided into 2 groups, those with facial nerve enhancement on TGd-MRI and those without enhancement. The NLR and MPV of each group were compared.

RESULTS

The NLRs of the BP patients were significantly higher than control group (P = .001). The NLRs of patients with facial nerve enhancement on TGd-MRI were significantly higher than patients without enhancement (P = .001). There was a positive and significant correlation between NLR and House-Brackmann (HB) grade of the patients (r = 0.641; P < .05). MPV did not show any significant correlation with any of the parameters studied (P > .05).

CONCLUSION

NLR can be used as a new and important marker in BP since it is high in BP patients and significantly correlated with HB grade and facial nerve enhancement on TGd-MR. On the other hand, MPV does not have such correlations. These results offer evidence to support an inflammatory theory rather than microvascular response theory in the etiopatogenesis of BP.

Redefining normal facial nerve enhancement: healthy subject comparison of typical enhancement patterns--unenhanced and contrast-enhanced spin-echo versus 3D inversion recovery-prepared fast spoiled gradient-echo imaging

OBJECTIVE

Normal facial nerve enhancement patterns derived from spin-echo (SE) sequences have not been systematically compared on contrast-enhanced 3D inversion recovery-prepared fast spoiled gradient-echo (IR-FSPGR) sequences, now in widespread use. We hypothesize that features unique to IR-FSPGR may engender differences in the appearance of the normal facial nerve, which may confound analysis of pathologic enhancement. We compared unenhanced and contrast-enhanced SE and IR-FSPGR sequences in a cohort of patients without facial nerve pathology.

MATERIALS AND METHODS

Twenty-three patients without facial nerve pathology were examined. Unenhanced and contrast-enhanced signal intensity (SI) of seven facial nerve segments was assessed on SE and IR-FSPGR by two neuroradiologists. SI was assigned a value of 0-3 (0, absent; 1, faint; 2, equivalent to brain; 3, equivalent to enhancing dural sinus). Statistically significant differences were assessed for each segment.

RESULTS

Significantly higher unenhanced and contrast-enhanced SI was present in most facial nerve segments on IR-FSPGR compared with SE, including cisternal, canalicular, labyrinthine, and geniculate segments (p ≤ 0.01). Enhancement patterns were generally similar; however, significant enhancement of the labyrinthine segment was detected only on SE (p = 0.011). For unenhanced images, mean kappa statistic was 0.32, and for the contrast-enhanced images, mean kappa statistic was 0.04, implying fair and slight agreement between readers, respectively.

CONCLUSION

Significantly greater SI is observed in most facial nerve segments on both unenhanced and contrast-enhanced IR-FSPGR among healthy subjects and may be misinterpreted as pathologic when evaluated in the context of existing enhancement paradigms. Examiners should remain cognizant of normal deviations from expected enhancement patterns in IR-FSPGR imaging to avoid misdiagnosis and other interpretive pitfalls.

Usefulness of contrast-enhanced 3-dimensional T1-VISTA in the diagnosis of facial neuritis: comparison with contrast-enhanced T1-TSE

BACKGROUND AND PURPOSE

Compared with 2-dimensional imaging, 3D-reformatted imaging is a valuable technique that offers improved anatomic accuracy with minimal flow artifact and thinner sections without gaps between slices. Our aim was to evaluate the usefulness of CE 3D T1-VISTA with fat suppression sequences compared with CE T1-TSE with fat suppression sequences in patients with facial neuritis.

MATERIAL AND METHODS

The study enrolled 32 consecutive patients who underwent IAC MR imaging for Bell's palsy. IAC MR scanning, including CE T1-VISTA and CE T1-TSE, was performed in all patients using a 3T scanner. The order of the scans was random. Signal intensity was measured at three segments (canalicular, labyrinthine, and anterior genu) of the facial nerve by drawing a ROI along the affected side and the normal side in each segment. We compared the quantitative CR of the two MR sequences with paired t-tests.

RESULTS

In all three segments, the lesion-to-normal contrast ratios on CE 3D T1-VISTA (canalicular: 2.32; labyrinthine: 2.22; anterior genu: 1.97) were greater than those on CE T1-TSE (canalicular: 2.17; labyrinthine: 1.72; anterior genu: 1.68). The labyrinthine and anterior genu segments had significantly higher lesion-to-normal contrast ratios on CE 3D T1-VISTA in patients with facial neuritis (labyrinthine: P<0.001; anterior genu: P=0.002).

CONCLUSION

CE 3D T1-VISTA was superior to CE T1-TSE in terms of image contrast between lesions and the normal facial nerve.

Facial nerve: from anatomy to pathology

The facial nerve (CN VII) emerges from the facial nerve nucleus in the pons. It is accompanied by CN VIII along its cisternal pathway, as well as at the internal auditory meatus. Its petrous pathway includes a labyrinthine segment, a horizontal tympanic segment and a vertical mastoid segment until the stylomastoid foramen. It then continues to the parotid gland. Pontine impairment is usually associated with other neurological symptoms. Lesions of the cerebellopontine angle (most often meningioma and schwannoma) initially result in impairment of CN VIII. The impairment of CN VII takes second place. Peripheral impairment (outside of a traumatic context) is most often due to Bell's palsy.

Clinical feasibility of temporal bone magnetic resonance imaging as a prognostic tool in idiopathic acute facial palsy

OBJECTIVE

To assess the feasibility of temporal bone magnetic resonance imaging for evaluating the severity and prognosis of idiopathic acute facial nerve palsy.

METHODS

Forty-four patients with idiopathic acute facial nerve palsy who had undergone gadolinium-enhanced magnetic resonance imaging were selected retrospectively. The degree of radiological facial nerve enhancement was determined using quantitative analysis (with region-of-interest measurements for separate facial nerve segments) and using subjective visual analysis. The clinical severity of facial nerve palsy was then correlated with the degree of facial nerve enhancement.

RESULTS

The visually determined degree of facial nerve enhancement did not correlate significantly with the House-Brackmann grade at either the early or late stages (p > 0.05). Results using the region-of-interest system were similar (p > 0.05).

CONCLUSION

Temporal bone magnetic resonance imaging is not essential for patients with acute facial nerve palsy.

MR diagnosis of facial neuritis: diagnostic performance of contrast-enhanced 3D-FLAIR technique compared with contrast-enhanced 3D-T1-fast-field echo with fat suppression

BACKGROUND AND PURPOSE

Current MRI with the CE T1-weighted sequence plays a limited role in the evaluation of facial neuritis due to prominent normal facial nerve enhancement. Our purpose was to retrospectively investigate the usefulness of the CE 3D-FLAIR sequence compared with the CE 3D-T1-FFE sequence in facial neuritis patients.

MATERIALS AND METHODS

We assessed 36 consecutive patients who underwent temporal bone MR imaging at 3T for idiopathic facial palsy. Two readers independently reviewed CE 3D-T1-FFE and CE 3D-FLAIR images to determine the degree of enhancement in each of 5 segments of the facial nerve. We compared AUCs using the Z-test, compared diagnostic performance of 2 MR techniques with the McNemar test, and evaluated interobserver agreement. The Pearson χ(2) test was used for each segment of the facial nerve.

RESULTS

The AUC of CE 3D-FLAIR (reader 1, 0.754; reader 2, 0.746) was greater than that of CE 3D-T1-FFE (reader 1, 0.624; reader 2, 0.640; P < .001). The diagnostic sensitivities, specificities, and accuracies were 97.2%, 86.1%, and 91.7%, respectively, for CE 3D-FLAIR, and 100%, 56.9%, and 78.5%, respectively, for CE 3D-T1-FFE. The specificity and accuracy of CE 3D-FLAIR were greater than those of CE 3D-T1-FFE (specificity, P = .029; accuracy, P = .008). The interobserver agreements for CE 3D-FLAIR (κ-value, 0.831) and CE 3D-T1-FFE (κ-value, 0.694) were excellent. Enhancement of the canalicular and anterior genu segments on CE 3D-FLAIR were significantly correlated with the occurrence of facial neuritis (P < .001 for canalicular; P = .032 and 0.020 for anterior genu by reader 1 and reader 2, respectively).

CONCLUSIONS

CE 3D-FLAIR can improve the specificity and overall accuracy of MR imaging in patients with idiopathic facial palsy.