Model-based segmentation of the facial nerve and chorda tympani in pediatric CT scans

2011 ◽  
Author(s):  
Fitsum A. Reda ◽  
Jack H. Noble ◽  
Alejandro Rivas ◽  
Robert F. Labadie ◽  
Benoit M. Dawant
Keyword(s):  
Facial Nerve ◽  
Ct Scans ◽  
Chorda Tympani ◽  
Pediatric Ct ◽  
Model Based

scholarly journals Automatic segmentation of the facial nerve and chorda tympani in pediatric CT scans

2011 ◽  
Vol 38 (10) ◽  
pp. 5590-5600 ◽  
Author(s):  
Fitsum A. Reda ◽  
Jack H. Noble ◽  
Alejandro Rivas ◽  
Theodore R. McRackan ◽  
Robert F. Labadie ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Automatic Segmentation ◽  
Ct Scans ◽  
Chorda Tympani ◽  
Pediatric Ct

scholarly journals Fully automated preoperative segmentation of temporal bone structures from clinical CT scans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. A. Neves ◽  
E. D. Tran ◽  
I. M. Kessler ◽  
N. H. Blevins
Keyword(s):  
Facial Nerve ◽  
Inner Ear ◽  
Temporal Bone ◽  
Hausdorff Distance ◽  
Sigmoid Sinus ◽  
Ct Scans ◽  
Automated Segmentation ◽  
Dice Coefficient ◽  
Lateral Skull Base ◽  
End To End

AbstractMiddle- and inner-ear surgery is a vital treatment option in hearing loss, infections, and tumors of the lateral skull base. Segmentation of otologic structures from computed tomography (CT) has many potential applications for improving surgical planning but can be an arduous and time-consuming task. We propose an end-to-end solution for the automated segmentation of temporal bone CT using convolutional neural networks (CNN). Using 150 manually segmented CT scans, a comparison of 3 CNN models (AH-Net, U-Net, ResNet) was conducted to compare Dice coefficient, Hausdorff distance, and speed of segmentation of the inner ear, ossicles, facial nerve and sigmoid sinus. Using AH-Net, the Dice coefficient was 0.91 for the inner ear; 0.85 for the ossicles; 0.75 for the facial nerve; and 0.86 for the sigmoid sinus. The average Hausdorff distance was 0.25, 0.21, 0.24 and 0.45 mm, respectively. Blinded experts assessed the accuracy of both techniques, and there was no statistical difference between the ratings for the two methods (p = 0.93). Objective and subjective assessment confirm good correlation between automated segmentation of otologic structures and manual segmentation performed by a specialist. This end-to-end automated segmentation pipeline can help to advance the systematic application of augmented reality, simulation, and automation in otologic procedures.

scholarly journals Postoperative radiological assessment of the mastoid facial canal in cochlear implant patients in correlation with facial nerve stimulation

2021 ◽  
Author(s):  
Iris Burck ◽  
Rania A. Helal ◽  
Nagy N. N. Naguib ◽  
Nour-Eldin A. Nour-Eldin ◽  
Jan-Erik Scholtz ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Cochlear Implant ◽  
Nerve Stimulation ◽  
Lateral Wall ◽  
Facial Canal ◽  
Chorda Tympani ◽  
Radiological Assessment ◽  
Canal Diameter ◽  
History Of ◽  
Facial Nerve Stimulation

Abstract Objectives To correlate the radiological assessment of the mastoid facial canal in postoperative cochlear implant (CI) cone-beam CT (CBCT) and other possible contributing clinical or implant-related factors with postoperative facial nerve stimulation (FNS) occurrence. Methods Two experienced radiologists evaluated retrospectively 215 postoperative post-CI CBCT examinations. The mastoid facial canal diameter, wall thickness, distance between the electrode cable and mastoid facial canal, and facial-chorda tympani angle were assessed. Additionally, the intracochlear position and the insertion angle and depth of electrodes were evaluated. Clinical data were analyzed for postoperative FNS within 1.5-year follow-up, CI type, onset, and causes for hearing loss such as otosclerosis, meningitis, and history of previous ear surgeries. Postoperative FNS was correlated with the measurements and clinical data using logistic regression. Results Within the study population (mean age: 56 ± 18 years), ten patients presented with FNS. The correlations between FNS and facial canal diameter (p = 0.09), wall thickness (p = 0.27), distance to CI cable (p = 0.44), and angle with chorda tympani (p = 0.75) were statistically non-significant. There were statistical significances for previous history of meningitis/encephalitis (p = 0.001), extracochlear-electrode-contacts (p = 0.002), scala-vestibuli position (p = 0.02), younger patients’ age (p = 0.03), lateral-wall-electrode type (p = 0.04), and early/childhood onset hearing loss (p = 0.04). Histories of meningitis/encephalitis and extracochlear-electrode-contacts were included in the first two steps of the multivariate logistic regression. Conclusion The mastoid-facial canal radiological assessment and the positional relationship with the CI electrode provide no predictor of postoperative FNS. Histories of meningitis/encephalitis and extracochlear-electrode-contacts are important risk factors. Key Points • Post-operative radiological assessment of the mastoid facial canal and the positional relationship with the CI electrode provide no predictor of post-cochlear implant facial nerve stimulation. • Radiological detection of extracochlear electrode contacts and the previous clinical history of meningitis/encephalitis are two important risk factors for postoperative facial nerve stimulation in cochlear implant patients. • The presence of scala vestibuli electrode insertion as well as the lateral wall electrode type, the younger patient’s age, and early onset of SNHL can play important role in the prediction of post-cochlear implant facial nerve stimulation.

Hybrid and Model-Based Iterative Reconstruction Techniques for Pediatric CT

2015 ◽  
Vol 204 (3) ◽  
pp. 645-653 ◽  
Author(s):  
Annemarie M. den Harder ◽  
Martin J. Willemink ◽  
Ricardo P. J. Budde ◽  
Arnold M. R. Schilham ◽  
Tim Leiner ◽  
...  
Keyword(s):  
Iterative Reconstruction ◽  
Pediatric Ct ◽  
Model Based

Chorda tympani neuroma masquerading as cholesteatoma

2003 ◽  
Vol 117 (12) ◽  
pp. 987-988 ◽  
Author(s):  
C. Hopkins ◽  
H. Chau ◽  
J. A. McGilligan
Keyword(s):  
Facial Nerve ◽  
Ct Scanning ◽  
Ossicular Chain ◽  
Chorda Tympani ◽  
Compensatory Mechanisms ◽  
High Resolution Computed Tomography ◽  
Total Resection ◽  
Complete Excision ◽  
High Index Of Suspicion ◽  
Slow Growing

Facial nerve neuromas occur throughout the course of the facial nerve and its branches, however lesions occurring on the chorda tympani branch are exceptionally rare.We present a case where the diagnosis was made intra-operatively; the patient was pre-operatively thought to have had a cholesteatoma.Total resection is the treatment of choice for these cases. Early diagnosis, aided by high resolution computed tomography (CT) scanning, will facilitate complete excision without damage to the facial nerve itself or the ossicular chain. The slow growing nature of the neuroma is likely to allow compensatory mechanisms to occur without the patient experiencing dysgeusia. As with any rarity the diagnosis can only be made with a high index of suspicion.

Pathogenesis of Bell's Palsy

1977 ◽  
Vol 86 (4) ◽  
pp. 549-558 ◽  
Author(s):  
Ruth Gussen
Keyword(s):  
Facial Nerve ◽  
Complete Recovery ◽  
Bell’S Palsy ◽  
Facial Canal ◽  
Chorda Tympani ◽  
Bell's Palsy ◽  
Nerve Branch ◽  
Collagen Formation ◽  
Myelin Sheaths ◽  
Metabolic Exchange

The pathogenesis of Bell's palsy is presented as retrograde epineurial compression edema with ischemia of the facial nerve. Although the etiology is unknown, an attractive theory is vasospasm, from any cause, along any facial nerve branch, with the chorda tympani, perhaps, the usual primary involvement. Retrograde vascular distension and edema, within the epineurium of the bony facial canal, compresses the nerve from outside its perineurial sheath. The compression force may be mild or severe, resulting in varying degrees of reversible or irreversible ischemic degeneration of myelin sheaths and axons, with varying degrees of cellular reaction to myelin breakdown. The edema may be resorbed, leaving reversible or irreversible nerve damage, or may stimulate collagen formation within the epineurium, with persisting fibrous compression (entrapment) neuropathy of the facial nerve. This concept is consistent with the varying results of Bell's palsy, and depends on the severity and duration of edema, and whether fibrosis occurs within the epineurium of the facial canal. Epineurial fibrosis also results in disturbance of metabolic exchange through the epineurial-permeurial-endoneurial tissues, and may ultimately result in obliteration of vascular drainage. Two temporal bone cases of Bell's palsy, one occurring ten years before death, with residual paralysis. and one two years before death, with clinical recovery, are added to the previously described four cases in the literature, three of early Bell's palsy, and one of remote palsy with almost complete recovery.

Facial nerve preservation during surgery for removal of acoustic nerve tumors

1982 ◽  
Vol 57 (6) ◽  
pp. 739-746 ◽  
Author(s):  
Richard H. Lye ◽  
John Dutton ◽  
Richard T. Ramsden ◽  
Joseph V. Occleshaw ◽  
Iain T. Ferguson ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Petrous Bone ◽  
Ct Scans ◽  
Facial Weakness ◽  
Content Type ◽  
Nerve Preservation ◽  
Increased Risk ◽  
Acoustic Nerve ◽  
Facial Function ◽  
Fine Print

✓ A series of 33 patients with 35 acoustic nerve tumors is reviewed. Tumor size was estimated from computerized tomography (CT) scans, and its influence on anatomical and functional preservation of the facial nerve was assessed. Six tumors (one invading the petrous bone, three medium and two large tumors) were not detected on CT scans. The translabyrinthine approach was used in seven instances (one small and six medium tumors) and the suboccipital transmeatal approach for 28 tumors (seven medium and 21 large tumors). Anatomical preservation of the facial nerve was achieved in 83% of operations for tumor removal, two of which were subtotal. A further two patients underwent subtotal removal, but the facial nerve was destroyed. Large tumors carried an increased risk of damage to the facial nerve, but even in this group the nerve was preserved anatomically intact in 70% of cases. Damage to the facial nerve occurred more frequently in patients with preoperative evidence of facial weakness; however, this factor did not appear to influence functional recovery of the facial nerve, provided that the nerve was intact at the end of the operation. A simple grading system for facial nerve function is described. Only 76% of anatomically intact facial nerves showed any evidence of function 1 month after surgery. Postoperatively, facial function improved with time. At the latest review, 45% of these patients had normal facial function or mild facial weakness (Grades I and II).

Early development of the facial nerve in the chick embryo with special reference to the development of the chorda tympani

1988 ◽  
Vol 182 (2) ◽  
pp. 169-182 ◽  
Author(s):  
Shigeru Kuratani ◽  
Shigenori Tanaka ◽  
Yuji Ishikawa ◽  
Chosei Zukeran
Keyword(s):  
Chick Embryo ◽  
Facial Nerve ◽  
Special Reference ◽  
Early Development ◽  
Chorda Tympani
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