Ear CT Research Articles

CT features of abnormally whole-course wide eustachian tubes with microtia and atresia

Objective: To study the clinical and CT features of the abnormal whole-course wide of eustachian tube (AWWET) with microtia and atresia(MA). Methods: The clinical and CT data of 19 patients (20 ears) from January 2017 to December 2021 with AWWET with MA were retrospectively analyzed, including 15 males and 4 females. The age ranged from 5 to 16 years, with an average of 9.5 years. 50 patients with common MA without wide eustachian tube(ET) as a case control group, including 32 males and 18 females.The age ranged from 5 to 16 years, with an average of 9.2 years. 20 patients (40 ears) who had normal ear CT for tinnitus, otalgia as a normal control group, including 12 males and 8 females. The age ranged from 5 to 16 years, with an average of 12.5 years. We measured the dimension and length of the bony portion of the ET, the total length, the angle between the bony portion and the cartilage portion, and the horizontal angle of ET on CT imagings, and compared with 40 normal ears by SPSS 27.0 software. Results: According to the relationship between AWWET and tympanum, patients were divided into the communicated group and the blocked group. A male predominance, left ear predominance, with high incidence of hemifacial microsomia exhibited in both groups. AWWET was presented as a widened lumen on CT. In 11 ears (4 ears in the communicated group, 7 ears in the blocked group), ETs bifurcated, the upper bony tube extended to the sphenoid body, the lower part continued down to cartilaginous ET and opened onto the nasopharynx, with"mastoid-like"pneumatization of the sphenoid body in 6 ears. The middle ear deformity in case group was more serious than MA control group, especially the blocked group. The incidence of otitis media in the communicated group was lower than that in the MA control group, and 4 cases in the blocked group had effusion in the ET. Compaired with normal ear, the bony ET elongated significantly in the AWWET groups, and the whole course of ET was significantly shortened, specially in the blocked group. The angle between the bony ET and the cartilaginous ET was decreased and the horizontal angle of the ET increased in the AWWET groups, the difference was considered to indicate statistical significance(P<0.05). Conclusions: AWWET with MA is rare, a male predominance, left ear predominance, and with high incidence of hemifacial microsomia. The middle ear deformity is more serious than common MA, especially in the blocked group. The incidence of otitis media in the communicated group is significantly lower than that in the common MA, and the blocked group may be accompanied by ET inflammation.

Analysis of 59 cases of large vestibular aqueduct syndrome SLC26A4gene mutation frequency and new mutation sites

Objective:To study the frequency of SLC26A4 gene mutation sites in children with enlarged vestibular aqueduct deafness in Yunnan, report the new mutation sites of SLC26A4 gene, further clarify the mutation spectrum of SLC26A4gene, and explore the association between biallelic and monoallelic mutations of SLC26A4 gene and CT phenotype of inner ear, so as to provide basis for clinical and genetic diagnosis of deafness. Methods:Review the results of temporal bone CT examination of 390 children after cochlear implantation in the Department of Otolaryngology, Kunming Children's Hospital from August 2016 to September 2021. Sanger sequencing of SLC26A4 gene was performed in 59 children with enlarged vestibular aqueduct. According to the genetic test results, the children who underwent temporal bone CT examination were divided into two groups: SLC26A4 biallelic mutation group（homozygous mutation and compound heterozygous mutation）, monoallelic mutation group, and the association with inner ear CT phenotype was analyzed, and the new sites were summarized and analyzed. Results:The c.919-2a>g mutation was the most common mutation in children with enlarged vestibular aqueduct with SLC26A4 gene mutation. Three new variants of SLC26A4 gene were found; CT examination combined with genetic testing found that a part of children with enlarged vestibular aqueduct was associated with SLC26A4 monoallelic mutation or no SLC26A4 gene mutation was detected. Further research is needed to investigate the involvement of other pathogenic factors in the pathogenesis of EVA.

Effects of basilar-membrane lesions on dynamic responses of the middle ear

Background Numerical simulations can reflect the changes in physiological properties caused by various factors in the cochlea. Aims/Objective To analyze the influence of lesions of the basilar membrane (BM) on the dynamic response of the middle ear. Method Based on healthy human ear CT scan images, use PATRAN software to build a three-dimensional finite element model of the human ear, then apply NASTRAN software to conduct analysis of solid-fluid coupled frequency response. The influence of lesions in the BM on the dynamic response of the middle ear is simulated through the method of numerical simulation. Result Through comparing experimental data and the frequency-response curve of displacement of BM and stapes, the validity of the model in this paper was verified. Conclusion Regarding sclerosis in BM, the most obvious decline of displacement and velocity exists in the range of 800–10,000Hz and 800–2000Hz frequency, respectively. The higher degree of sclerosis, the more obvious decline becomes. The maximal decline of hearing can reach from 6.2 dB to 9.1 dB. Regarding added mass in BM, the most obvious decline of displacement exists in the range of 600–1000Hz frequency, and the maximal decline of hearing can reach 4.0 dB. There is no obvious decline in velocity.

Identification of a novel mutation of NOG in family with proximal symphalangism and early genetic counseling

BackgroundProximal symphalangism is a rare disease with multiple phenotypes including reduced proximal interphalangeal joint space, symphalangism of the 4th and/or 5th finger, as well as hearing loss. At present, at least two types of proximal symphalangism have been identified in the clinic. One is proximal symphalangism-1A (SYM1A), which is caused by genetic variants in Noggin (NOG), another is proximal symphalangism-1B (SYM1B), which is resulted from Growth Differentiation Factor 5 (GDF5) mutations.Case presentationHere, we reported a Chinese family with symphalangism of the 4th and/or 5th finger and moderate deafness. The proband was a 13-year-old girl with normal intelligence but symphalangism of the 4th finger in the left hand and moderate deafness. Hearing testing and inner ear CT scan suggested that the proband suffered from structural deafness. Family history investigation found that her father (II-3) and grandmother (I-2) also suffered from hearing loss and symphalangism. Target sequencing identified a novel heterozygous NOG mutation, c.690C > G/p.C230W, which was the genetic lesion of the affected family. Bioinformatics analysis and public databases filtering further confirmed the pathogenicity of the novel mutation. Furthermore, we assisted the family to deliver a baby girl who did not carry the mutation by genetic counseling and prenatal diagnosis using amniotic fluid DNA sequencing.ConclusionIn this study, we identified a novel NOG mutation (c.690C > G/p.C230W) by target sequencing and helped the family to deliver a baby who did not carry the mutation. Our study expanded the spectrum of NOG mutations and contributed to genetic diagnosis and counseling of families with SYM1A.

Canine and feline vestibular syndrome

Signs of vestibular dysfunction (head tilt, asymmetric ataxia, spontaneous nystagmus, unilateral falling and rolling) are characteristic enough to be easily recognized without difficulty, even by inexperienced clinicians. Further differentiation between the peripheral (inner ear, vestibular nerve) and the central (vestibular nuclei, cerebellar peduncles, fastigial nucleus and flocculonodular lobe of the cerebellum) vestibular system should be based on a thorough history and an astute neurological examination. Affected animals should be reevaluated by serial neurological reexaminations to improve the accuracy of the initial assessment. Concomitant neurological signs, such as spastic hemiparesis or tetraparesis, proprioceptive déficits, other cranial nerve dysfunction and/or behavioral changes are indicative of central than peripheral vestibular syndrome. Apart from the minimum data base (complete blood count, serum biochemistry, urinalysis), the diagnostic evaluation should also include otoscopy, plain radiography of tympanic bullae (peripheral vestibular lesions), ear CT, brain MRI and cererebrospinal fluid analysis (central vestibular lesions). The present review first describes the clinical features of the vestibular syndrome from a differential point of view, regarding its neuroanatomical origin and secondly the most common conditions primarily characterized by vestibular dysfunction in the dog and cat.

Analysis of the SLC26A4 mutation from 230 deafness patients in Guangxi region

Objective:To investigate the mutation characteristics of SLC26A4 gene from 230 hearing loss patients in Guangxi region.Method:Two hundred thirty patients with hearing loss were enrolled in the study. Eight mutation sites in SLC26A4 gene were tested; the types of gene mutation and the inner ear CT features of the mutationpositive patients were analyzed.Result:Among 230 deafness patients,the total mutation rate of SLC26A4 gene is 2.61%(6/230). The types of gene mutation include SLC26A4 IVS7-2A> G heterozygous in 2 case(0.87%).1226G> A homozygous in 1 cases(0.43%),IVS7-2A>G，IVS11+47T>C and 1548insC mutations in 2 cases(0.87%).Conclusion:The mutation rate of SLC26A4 gene in Guangxi region is lower than the national average level. The main mutation type in Guangxi region is SLC26A4 IVS7 2A>G. In this study, two gene mutations (SLC26A4 IVS11+47T> C and 1548insC) are firstly found, suggesting that some rare mutation types of SLC26A4 may exist in patients living in Guangxi region.

Determining compliance of ear CT scan with interaoperative findings in deaf children with cochlear implantation

IntroductionDefecated or impaired hair cell function of the cochlea causes deafness. Cochlear implantation allows transmission of sound information through central auditory pathways using direct electric stimulation of auditory nerve dendrites. Using radiologic imaging, including CT scan is very helpful in selection of candidates and evaluation after implantation. The purpose of this study is to determine compliance of CT findings in deaf children undergoing cochlear implantation compared with the intra-operative findings. MethodIn a periodical-descriptive study, 100 patients (56 male and 44 female), 6 months to 6 years of age, who were candidates for cochlear implantation at Baqiyatallah Hospital in Tehran between January 2010 and October 2011, were studied. After getting informed consent form the parents of patients, demographic data was recorded. CT scan and surgical data were double blindly collected in the designed questionnaire which was approved by three radiologists and three ENT specialists. Finally, surgical and radiological data were compared and t-test and chi-square test was used. ResultsAtic status in 89 patients (89%) was statistically significant between radiology and surgery (P=0.06). Positive Predictive Value and Negative Predictive Value were respectively 100 and 92.8. Middle ear space was same in 85 patients (85%) in the two methods (P=0.01) (NVP=63.4). Pyramid status was similar in radiology and surgery results in 67 patients (67%) (P=0.000) and PPV and NPV were 100 and 63.4 respectively. Jugular bulb was similar in 73 patients (73%) (P=0.00). There was no significant difference between other modalities. ConclusionIn most cases examined in this study, compliance between the surgical and radiological findings was above 80%. In some cases, CT scan could give confidence to the surgeon, but in atic, middle ear space, pyramid and jugular bulb there might be insufficient reliance to CT findings and there would be need to more accurate observation during surgery.

Spatial resolution improvement and dose reduction potential for inner ear CT imaging using a z‐axis deconvolution technique

To assess the z-axis resolution improvement and dose reduction potential achieved using a z-axis deconvolution technique with iterative reconstruction (IR) relative to filtered backprojection (FBP) images created with the use of a z-axis comb filter. Each of three phantoms were scanned with two different acquisition modes: (1) an ultrahigh resolution (UHR) scan mode that uses a comb filter in the fan angle direction to increase in-plane spatial resolution and (2) a z-axis ultrahigh spatial resolution (zUHR) scan mode that uses comb filters in both the fan and cone angle directions to improve both in-plane and z-axis spatial resolution. All other scanning parameters were identical. First, the ACR CT Accreditation phantom, rotated by 90° so that the high-contrast spatial resolution targets were parallel to the coronal plane, was scanned to assess limiting spatial resolution and image noise. Second, section sensitivity profiles (SSPs) were measured using a copper foil embedded in an acrylic cylinder and the full-width-at-half-maximum (FWHM) and full-width-at-tenth-maximum (FWTM) of the SSPs were calculated. Third, an anthropomorphic head phantom containing a human skull was scanned to assess clinical acceptability for imaging of the temporal bone. For each scan, FBP images were reconstructed for the zUHR scan using the narrowest image thickness available. For the CT accreditation phantom, zUHR images were also reconstructed using an IR algorithm (SAFIRE, Siemens Healthcare, Forchheim, Germany) to assess the influence of the IR algorithm on image noise. A z-axis deconvolution technique combined with the IR algorithm was used to reconstruct images at the narrowest image thickness possible from the UHR scan data. Images of the ACR and head phantoms were reformatted into the coronal plane. The head phantom images were evaluated by a neuroradiologist to assess acceptability for use in patients undergoing clinically indicated CT imaging of the temporal bone. The limiting spatial resolution was 12 lp/cm for the FBP-zUHR images and the IR-UHR images, although visual assessment indicated a slight improvement for the IR-UHR images. Image noise was 213.0, 181.8, and 153.5 for the FBP-zUHR, IR-zUHR, and IR-UHR images, respectively. While the FWHM was essentially the same for the FBP-zUHR and IR-UHR images, the FWTM of the IR-UHR images was almost 50% smaller compared to the FBP-zUHR images (0.83 vs 1.25 mm, respectively). Images of the anthropomorphic head phantom were judged to be of higher quality for the IR-UHR images compared to the FBP-zUHR images. With use of a z-axis deconvolution technique, z-axis spatial resolution was improved for scans acquired using a comb filter only in the fan angle direction relative to FBP images acquired with a comb filter in both the fan and cone angle directions. By avoiding use of the comb filter in the cone angle direction and use of an IR algorithm, image noise was substantially reduced for the same scanner output (CTDIvol). Thus, overall image quality (spatial resolution and image noise) can be maintained relative to the FBP-zUHR technique at a lower radiation dose.

Characteristics and application of inner ear CT in 20 cases of sensorineural hearing loss in children

Conclusion: This study shows that a number of children with sensorineural hearing loss (SNHL) have inner ear malformations demonstrated by multi-slice spiral computed tomography (MSCT). MSCT allows a comprehensive assessment of various congenital inner ear malformations through high quality multiplanar reformation (MPR) and can display the site and degree of the malformation three-dimensionally and intuitively. This is very useful for cochlear implantation. Objective: To evaluate the feasibility and usability of MSCT in pediatric SNHL with inner ear malformations. Methods: Sixty-five patients were diagnosed with SNHL by brainstem auditory evoked response (BAER). Inner ear MSCT scan and coronal MPR reconstruction were performed in all cases. Results: This study demonstrated 20 cases (33 ears) with inner ear malformations, which included 10 ears with cochlear malformations, 7 with vestibular malformations, 5 with semicircular canal malformations, 8 with internal auditory canal (IAC) malformations, and 15 with vestibular malformations. Cochlear malformations included one ear with Michel deformity, two ears with common cavity deformity, one with cochlear aplasia, one with hypoplastic cochlea, two with incomplete partition type I, and three with incomplete partition type II (Mondini deformity).

Pendred syndrome in Tunisia

We report a clinical and genetic study of three consanguineous Tunisian families affected by Pendred syndrome. Three families from the south of Tunisia were identified as affected by Pendred syndrome. The patients and their families underwent ENT and general examination and audiovestibular and radiological tests. Molecular DNA analysis was performed by the Sfax Human Molecular Genetics Department. Forty-three patients (mean age: 21 years [2-60 years]) were affected. Tonal audiometry showed bilateral sensorineural hearing loss in 87.5% of cases, and mixed hearing loss in 12.5% with bilateral high frequency sensorineural hearing loss and conductive hearing loss at lower frequencies. Deafness was severe in 21% and profound in 79% of cases. Thyroid goiter was found in 46.5% of cases. Inner ear CT scan found enlarged bilateral vestibular aqueducts in all cases. Hormone analysis was normal and perchlorate test negative in all cases. A single Pendred syndrome (PDS) gene mutation, L445W, was found. Pendred syndrome is the most frequent congenital deafness syndrome. It is characterized by great intrafamilial phenotype variability.

Evaluation of radiation doses from MDCT-imaging in otolaryngology

The purpose of this study was to clarify patient doses in the current otolaryngological multi-detector row computed tomography (MDCT) examinations. Patient doses were measured with an in-phantom dosimetry system which was composed of 48 photodiode dosimeters embedded within an anthropomorphic phantom. Organ and effective doses were evaluated according to the International Commission on Radiological Protection Publication 103. In neck CT, doses for salivary glands and for thyroid were high, 7.6-29.9 and 13.4-60.3 mGy, respectively. In sinus CT, brain and lens doses were high, 7.6-24.6 and 10.6-32.0 mGy, respectively, and in inner ear CT, lens dose was 8.0-35.3 mGy. Effective doses were 1.8-6.6 mSv in neck CT, 0.5-0.9 mSv in sinus CT and 0.3-0.6 mSv in inner ear CT. The present dose data would be used to estimate radiation risks for patients undergoing otolaryngological MDCT examinations.

Individually Fitted Hearing Aid Device Manufactured Using Rapid Prototyping Based on Ear CT

Rapid prototyping is the technology of automatic freeform fabrication of physical objects from virtual CAD (computer aided design) models. For medical objects the models may be created using data from CT, MR or rotational angiography. We descriobe the case of a 83-year-old woman with essential bilateral hearing impairment as the effect of chronic otitis media. An individually fitted hearing aid was produced for the patient using stereolithography technology and vacuum casting based on data obtained during ear CT. Rapid prototyping may help in manufacturing individually adjusted biomedical prostheses, reducing the time of device production and improving its fitting.

耳小骨連鎖離断のない外傷性アブミ骨底板陥入例

A 46-year-old male with an earpick-induced trauma in his left ear was referred to our hospital due to profound mixed hearing loss persisting after myringoplasty at another hospital. The preoperative middle ear CT did not demonstrate any ossicular chain dislocation signs. Preoperative tympanometry did not show a clear Ad type, but stapedial reflex was eliminated on the left side. During middle ear surgery, we found the stapedial footplate had subsided and fixed into the oval window, although the ossicular chain seemed to remain intact. After stapedectomy with ossicular reconstruction using Y-shaped cartilage was performed the air-bone gap definitely improved. There have been many reports about ossicular chain dislocation due to earpick-induced trauma, however there have been few reports describing stapedial footplate subsidence into the oval window without ossicular chain dislocation. In the literature, 10-25% of trauma-induced ossicular chain dislocation may just be stapedial subsidence into the oval window. We conclude as that it is necessary to consider stapedial subsidence when treating middle ear trauma, and that stapedial subsidence on its own should be classified as a pattern of ossicular chain disruption.

Vestibular anomalies in CHARGE syndrome: investigations on and consequences for postural development.

Recently, vestibular anomalies have been described as a frequent feature in children with coloboma-heart-atresia-retarded-genital-ear (CHARGE) syndrome. They are likely to play an important role in the psychomotor retardation affecting these children. In order to test this hypothesis, we prospectively performed complete vestibular investigations in a series of 17 CHARGE syndrome patients including inner ear CT scan and functional vestibular evaluation of both canal and otolith functions. These results were correlated with the postural anomalies observed during the children's development and showed that vestibular dysfunction is a constant feature in CHARGE syndrome and has very good sensitivity for confirming the diagnosis. Anomalies of semicircular canals were frequently found (94%), easily detectable on CT scan and associated with no response on canal function evaluation. They were considered as partly responsible for the retardation of postural stages. Vestibular functional tests were consistently abnormal but allowed detection of residual otolith function in most patients (94%). All children of this series had an atypical pattern of postural behaviour that we consider to be related to their vestibular anomalies. Residual otolith function seems to have a positive influence for postural development. Vestibular investigations are valuable for diagnosis, developmental assessment, and adaptation of specific rehabilitation programmes in CHARGE syndrome patients.

一側メニエール病の患側判定における内耳ＣＴ画像所見の役割

一側メニエール病の患側判定における内耳ＣＴ画像所見の役割