Midpoint Width Research Articles

Diagnosis of Enlarged Vestibular Aqueduct Using Wideband Tympanometry.

Background: Wideband tympanometry (WBT) has the potential to distinguish various mechanical middle ear and inner ear pathologies noninvasively. This study investigated the diagnostic value of WBT in the diagnosis of enlarged vestibular aqueduct (EVA). Methods: The absorbance and resonance frequency (RF) of patients with EVA (40 ears, 25 patients) and matched population controls (39 ears, 28 subjects) were compared, alongside receiver operating characteristic (ROC) analysis. Correlations between VA width and RF were also examined. Results: Patients with EVA had higher absorbance at low frequencies (226-917 Hz) and lower absorbance at high frequencies (2520-4896 Hz) compared to controls. The RF of the EVA group was significantly lower versus controls (751 [391-1165] vs. 933 [628-1346] Hz). The ROC analysis revealed area under the curve values of 0.771 and 0.801, respectively, for absorbance and RF. RF had a sensitivity, specificity, positive predictive value, and negative predictive value of 74.4%, 82.5%, 76.7%, and 80.6%, respectively, for diagnosing EVA. In the EVA group, the VA midpoint width (r = -0.334) and VA petrous width (r = -0.402) both significantly correlated with RF. Conclusions: Our findings support the utility of WBT for diagnosing EVA, with RF as the optimal index used.

Anatomical features of the sphenoid ridge in the pediatric population.

To describe the relation of the sphenoid ridge (SR) with the surrounding anatomical structures in healthy children when approaching the anterior and middle fossae. Computed tomography of 180 pediatric patients (90 males / 90 females), aged 1-18 years were included the study. The size of the lesser wing (LW) and the distances of the LW to certain landmarks were measured. The LW length was 28.48 ± 8.15mm. The LW widths at the midline and the midpoint and lateral point of the SR were 7.78 ± 1.74mm, 2.84 ± 0.81mm, and 1.91 ± 0.64mm, respectively. The distance between the midpoint of the SR and the crista galli was 28.22 ± 5.56mm, and the distance between the crista alaris and internal auditory meatus was 51.73 ± 5.79mm. The linear function was calculated as y = 18.748 + 1.024 × age for SR length, y = 6.046 + 0.182 × age for the midline width of SR, y = 2.367 + 0.050 × age for the midpoint width of SR, y = 1.249 + 0.069 × age for the crista alaris width, y = 21.727 + 0.683 × age for the distance between the SR midpoint and the crista galli, and y = 43.614 + 0.855 × age for the distance between the crista alaris and internal auditory meatus. All measured parameters increased irregularly with advancing age. Furthermore, our regression equations representing the growth dynamics of SR may be used to estimate these parameters.

Fluid-solid coupling model and biological features of large vestibular aqueduct syndrome.

Objective: Computed tomography (CT) images of the temporal bone of large vestibular aqueduct syndrome (LVAS) patients were used to establish 3D numerical models based on the structure of the inner ear, which are, in turn, used to construct inner ear fluid-solid coupling models. The physiological features and pathophysiology of LVAS were analyzed from a biomechanical perspective using finite element analysis. Methods: CT images of the temporal bone were collected from five children attending the Second Hospital of Dalian Medical University in 2022. The CT images were used to build 3D models of the inner ear containing the vestibular aqueduct (VA) by Mimics and Geomagic software, and round window membrane models and fluid-solid coupling models were built by ANSYS software to perform fluid-solid coupling analysis. Results: By applying different pressure loads, the deformation of the round window membranes occurred, and their trend was basically the same as that of the load. The deformation and stress of the round window membranes increased with the increase in load. Under the same load, the deformation and stress of the round window membranes increased with the expansion of the midpoint width of the VA. Conclusion: CT images of the temporal bone used clinically could establish a complete 3D numerical model of the inner ear containing VA. Fluctuations in cerebrospinal fluid pressure could affect inner ear pressure, and VA had a limiting effect on the pressure from cerebrospinal fluid. The larger the VA, the smaller the limiting effect on the pressure.

Can MRI biomarkers for hearing loss in enlarged vestibular aqueduct be measured reproducibly?

Morphological features of an enlarged endolymphatic duct (ED) and sac (ES) are imaging biomarkers for genotype and hearing loss phenotype. We determine which biomarkers can be measured in a reproducible manner, facilitating further clinical prediction studies in enlarged vestibular aqueduct hearing loss. A rater reproducibility study. Three consultant radiologists independently measured previously reported MRI ED & ES biomarkers (ED midpoint width, maximal ED diameter closest to the vestibule, ES length, ES width and presence of ES signal heterogeneity) and presence of incomplete partition Type 2 from 80 ears (T2 weighted axial MRI). Interclass correlation coefficients (ICC) and Gwet's Agreement Coefficients (AC) were generated to give a measure of reproducibility for both continuous and categorical feature measures respectively. ES length, width and sac signal heterogeneity showed adequate reproducibility (ICC 95% confidence intervals 0.77-0.95, Gwet's AC for sac heterogeneity 0.64). When determining ED midpoint width, measurements from multiple raters are required for "good" reliability (ICC 95% CI 0.75-0.89). Agreement on the presence of incomplete partition Type 2 ranged from "moderate" to "substantial". Regarding MR imaging, the opinion of multiple expert raters should be sought when determining the presence of an enlarged ED defined by midpoint width. ED midpoint, ES length, width and signal heterogeneity have adequate reproducibility to be further explored as clinical predictors for audiological phenotype. We report which ED & ES biomarkers are reproducibly measured. Researchers can confidently utilise these specific biomarkers when modelling progressive hearing loss associated with enlarged vestibular aqueduct.

Analysis of the vestibular aqueduct development on the risk for suffering from idiopathic sudden sensorineural hearing loss

ObjectiveLarge vestibular aqueduct syndrome (LVAS) is one of the etiology of hearing loss. Clinically, we observed that the VA size of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) did not meet the diagnostic criteria of VA enlargement, but there were individual variations. Through this study, we want to understand the VA development and explore its risk for suffering from ISSNHL. Methods74 patients with ISSNHL were retrospectively reviewed in our department from June 2018 to September 2021. Meanwhile, 57 people with no ear diseases were randomly selected as the control group. All their clinical information were systematically collected. The axial thin-slice CT images of temporal bone were used to observe and measure the VA in ISSNHL and controls. ISSNHL were classified as different types and grades according to pure tone audiometry and the degree of hearing loss, respectively. Logistic regression analysis was adopted to evaluate the risk factors of different types and grades of ISSNHL. ResultsThe operculum morphology could be funnel-shaped, tubular and invisible, but they had no statistical difference in the morbidity of ISSNHL. The operculum width of the affected sides in the case group was significantly wider than that of the matched sides in the control group (0.84±0.35mm vs 0.68±0.34mm, p=0.009), but the midpoint width had no statistical difference (p=0.447). The operculum width was an independent risk factor for the total hearing loss type (p=0.036, OR=4.49, 95% CI=1.10-18.29), moderate (p=0.013, OR=17.62, 95% CI=1.82-170.95) and profound (p=0.031, OR=4.50, 95% CI=1.14-17.67) grade of ISSNHL. Hypertension was an independent risk factor for the severe grade (p=0.004, OR=12.44, 95% CI=2.19-70.64) of ISSNHL. Both the operculum width (p=0.048, OR=7.14, 95% CI=1.02-50.26) and hypertension (p=0.014, OR=6.73, 95% CI=1.46-30.97) were the risk factors for the flat type of ISSNHL. The midpoint width of the VA, gender, age, diabetes mellitus, hyperlipidemia, and plasma fibrinogen concentration had no significant effect on the risk for suffering from ISSNHL. ConclusionThe development of the VA operculum is a risk factor for some types and grades of ISSNHL. Hypertension remained a risk factor for ISSNHL.

Hearing loss patterns in enlarged vestibular aqueduct syndrome: Do fluctuations have clinical significance?

ObjectivesTo reveal hearing loss patterns in patients with enlarged vestibular aqueduct (EVA) syndrome according to demographic and clinical characteristics. MethodsA retrospective, longitudinal study design was utilized to identify patients with EVA. Ears of patients were categorized into one of four cohorts: progressive fluctuating, progressive non-fluctuating, stable fluctuating, and stable non-fluctuating patterns. Pairwise and group comparisons were performed with non-parametric tests to assess vestibular aqueduct (VA) morphology, clinical, and demographic variables between hearing loss pattern cohorts. Rates of hearing loss in the subgroups were determined utilizing a mixed linear effects model. Results44 patients (25 female, 19 male, median diagnosis age: 8.06 years) met inclusion criteria. 16 individuals demonstrated unilateral EVA and 29 had bilateral EVA, resulting in 74 total ears with EVA. Amongst the four cohorts, differences in operculum widths amongst groups were statistically significant (p = 0.049) while VA midpoint widths were not (p = 0.522). Progressive hearing loss ears without fluctuations demonstrated a 3.20 dB per year (p < 0.001) progression while progressive hearing loss ears with fluctuations reported a rate of 3.52 dB loss per year (p < 0.001). ConclusionHearing fluctuations occur similarly in EVA patients with stable and progressive hearing loss. With the exception of increased rates of hearing loss progression for fluctuating progressive hearing loss patients, vestibular aqueduct morphology, demographic, and clinical characteristics commonly reported are likely not strong predictors for whether patients will or will not experience fluctuating patterns of hearing loss.

A New Dromaeosaurid (Dinosauria: Coelurosauria) from Khulsan, Central Mongolia

Dromaeosaurid theropods represent a rare but important clade of nonavialan dinosaurs. Their close evolutionary relationship to modern birds has placed them at the center of paleontological research for the last several decades. Herein we describe a new species of dromaeosaurid—Kuru kulla, gen. et sp. nov.—based on a partial skeleton from the Late Cretaceous Khulsan locality (Barun Goyot Formation) of Mongolia. This species is diagnosed by several autapomorphies within Dromaeosauridae, including a sharp groove anterior and ventral to the narial fossa on the premaxilla, a posterolaterally directed hornlet on the posterodorsal process of the lacrimal, a deep surangular bearing two surangular foramina, and anteriorly displaced pleurocoels on the dorsal centra. The taxon is further characterized by a unique combination of characters, including a mediolaterally narrow metatarsal II, serrations on both carinae of the dentary teeth, hyposphenes that are widely separated but joined by a web of bone, and a lacrimal with a poorly developed boss on its lateral surface. Phylogenetic analysis finds Kuru kulla to be the sister taxon of Adasaurus mongoliensis, from the slightly later Nemegt Formation, with which it is united by three synapomorphies: a posterior surangular foramen that is ∼30% the depth of the surangular, absence of a fourth trochanter of the femur, and thoracic centra that are markedly longer than their midpoint widths. The recognition of this taxon has important implications for common assumptions of Mesozoic terrestrial ecosystem structure and adds new data to a recently recognized pattern in dromaeosaurid faunal composition among Late Cretaceous localities in Mongolia and Inner Mongolia (Nei Mongol Autonomous Region, China).

Morphometric analysis of the intercarpal ligaments of the equine proximal carpal bones during simulated flexion and extension of cadaver limbs

Despite many reported cases of carpal lameness associated with intercarpal ligament injuries in horses, the morphometry, movement pattern and general intrinsic biomechanics of the carpus are largely unknown. Using osteoligamentous preparation of the carpus prepared from 14 equine cadaver forelimbs (aged 9.62±4.25years), locomotory simulations of flexion and extension movements of the carpal joint were carried out to observed carpal biomechanics and, thereafter, the limbs were further dissected to obtain morphometric measurements of the medial and lateral collateral ligaments (MLC and LCL); medial and lateral palmar intercarpal ligaments (MPICL and LPICL); intercarpal ligaments between radial (Cr) and intermediate (Ci) carpal bones (Cr-Ci ICL); and intercarpal ligaments between Ci and ulnar (Cu) carpal bones (Ci-Cu ICL). The Cr, Ci, Cu and Ca are held together by a series of intercarpal ligaments and move in unison lateropalmarly during flexion, and mediodorsally during extension with a distinguishable proximo-distal sliding movement (gliding) of Cr and Ci against each other during movement. The mean length of MCL (108.82±9.64 mm) was significantly longer (p=0.042) than LCL (104.43±7.65 mm). The Cr-Ci ICL has a dorsopalmar depth of 37.58±4.14mm and a midpoint width of 12.05±3.09mm and its fibres ran diagonally from the medial side of the Ci in a proximo-palmar disto-dorsal direction (i.e. palmarodistally) to the lateral side of the Cr. The specialized movement of the Cr-Ci ICL, which appeared to be further facilitated by a longer MCL suggest a biomechanical function by which carpal damage may be minimized in the equine carpus.

Densitometric Profiles of Optic Disc Hemorrhages in the Ocular Hypertension Treatment Study

The origin of blood in glaucoma-related disc hemorrhages (DH) remains unknown. A prior clinic-based study of primary open-angle glaucoma (POAG)-related DH showed that they had grayscale pixel intensities more similar to blood from retinal macroaneurysms and adjacent retinal arterioles than to blood from retinal vein occlusions or adjacent retinal venules, suggesting an arterial source. Here we assessed the densitometric profile of DH from fundus photographs in the Ocular Hypertension Treatment Study (OHTS). Retrospective cross-sectional study of prospectively collected images. Stereo disc photographs of 161 DH events from 83 OHTS participants (mean age [standard deviation (SD)]: 65.6 [9.2] years; 46.6% female; 13.0% black race) were imported into ImageJ to measure densitometry differences (adjacent arterioles minus DH [ΔA] or venules minus DH [ΔV]). Their size as percentage of disc area, ratio of length to midpoint width, and location relative to the disc margin were also analyzed. We performed t tests to compare ΔA and ΔV, analysis of variance to compare ΔA and ΔV across DH recurrent events, and multivariable linear regression to identify determinants of ΔA and ΔV. Mean (SD) ΔA and ΔV were-2.2 (8.7) and-11.4 (9.7) pixel intensity units, respectively (P < .001). ΔA and ΔV each did not differ significantly across recurrence of DH (P ≥ .92) or between DH events with and without POAG (P ≥ .26). OHTS DH had densitometric measurements more similar in magnitude to adjacent arterioles than venules, supporting an arterial origin for DH. Vascular dysregulation may contribute to disc hemorrhage formation in ocular hypertension.

Morphometric analysis of the coracoid process and glenoid width: a 3D-CT study

BackgroundData regarding the parameters of the coracoid process and glenoid width are insufficient, and information on gender, age, and ethnic differences in the parameters appear lacking in the Chinese population. This study aimed to investigate the morphometric parameters in the coracoid process and glenoid width.MethodsUsing our institution’s electronic database, we selected 84 patients (55 males and 29 females) who underwent a shoulder computed tomography (CT) scan from January 2017 to May 2018 in this study. Mimics19.0 software was used for three-dimensional (3D) reconstruction of CT and to measure the morphometric parameters of the coracoid process and glenoid width. Subgroup analyses stratified by gender and age were conducted and the parameters were compared with previously published reports. All data were statistically analysed by SPSS23.0 Statistical Package.ResultsA positive and significant relationship between the coracoid process and the glenoid width (R > 0.758, P < 0.01) was found. The midpoint width represents 52% (41–62%) of the glenoid width; the midpoint height, 40% (31–53%) of the glenoid width. Significant differences in all parameters between males and females were noted (P < 0.05). No significant differences among the age groups were observed (P > 0.05), whereas significant differences in almost all parameters between the ethnic groups were observed (P < 0.05).ConclusionOur results could supplement the information in the shoulder joint database with morphometric parameters and provide a reference for theoretical research on coracoid osteotomy, which may in turn help surgeons in the evaluation of coracoid process transfer.

Sex-specific enlarged vestibular aqueduct morphology and audiometry.

Enlargement of the vestibular aqueduct (EVA) is one of the most common congenital malformations in pediatric patients presenting with sensorineural or mixed hearing loss. The relationship between vestibular aqueduct (VA) morphology and hearing loss across sex is not well characterized. This study assesses VA morphology and frequency-specific hearing thresholds with sex as the primary predictor of interest. A retrospective, longitudinal, and repeated-measures study was used. 47 patients at an academic tertiary care center with hearing loss and a record of CT scan of the internal auditory canal were candidates, and included upon meeting EVA criteria after confirmatory measurements of vestibular aqueduct midpoint and operculum widths. Audiometric measures included pure-tone average and frequency-specific thresholds. Of the 47 patients (23 female and 24 male), 79 total ears were affected by EVA; the median age at diagnosis was 6.60 years. After comparing morphological measurements between sexes, ears from female patients were observed to have a greater average operculum width (3.25 vs. 2.70 mm for males, p = 0.006) and a greater average VA midpoint width (2.80 vs. 1.90 mm for males, p = 0.004). After adjusting for morphology, male patients' ears had pure-tone average thresholds 17.6 dB greater than female patients' ears (95% CI, 3.8 to 31.3 dB). Though females seem to have greater enlargement of the vestibular aqueduct, this difference does not extend to hearing loss. Therefore, our results indicate that criteria for EVA diagnoses may benefit from re-evaluation. Further exploration into morphological and audiometric discrepancies across sex may help inform both clinician and patient expectations.

Is CT or MRI the optimal imaging investigation for the diagnosis of large vestibular aqueduct syndrome and large endolymphatic sac anomaly?

Background and purposeWe explored whether there was a difference between measurements obtained with CT and MRI for the diagnosis of large vestibular aqueduct syndrome or large endolymphatic sac anomaly, and whether this influenced diagnosis on the basis of previously published threshold values (Valvassori and Cincinnati). We also investigated whether isolated dilated extra-osseous endolymphatic sac occurred on MRI. Secondary objectives were to compare inter-observer reproducibility for the measurements, and to investigate any mismatch between the diagnoses using the different criteria.Materials/methodsSubjects diagnosed with large vestibular aqueduct syndrome or large endolymphatic sac anomalies were retrospectively analysed. For subjects with both CT and MRI available (n = 58), two independent observers measured the midpoint and operculum widths. For subjects with MRI (± CT) available (n = 84), extra-osseous sac widths were also measured.ResultsThere was no significant difference between the width measurements obtained with CT versus MRI. CT alone diagnosed large vestibular aqueduct syndrome or large endolymphatic sac anomalies in 2/58 (Valvassori) and 4/58 (Cincinnati), whilst MRI alone diagnosed them in 2/58 (Valvassori). There was 93% CT/MRI diagnostic agreement using both criteria. Only 1/84 demonstrated isolated extra-osseous endolymphatic sac dilatation. The MRI-based LVAS/LESA diagnosis was less dependent on which criteria were used. Midpoint measurements are more reproducible between observers and between CT/MR imaging modalities.ConclusionSupplementing MRI with CT results in additional diagnoses using either criterion, however, there is no net increased diagnostic sensitivity for CT versus MRI when applying the Valvassori criteria. Isolated enlargement of the extra-osseous endolymphatic sac is rare.

Hearing loss in unilateral and bilateral enlarged vestibular aqueduct syndrome

ObjectiveTo investigate any meaningful differences in hearing between patients with unilateral and bilateral enlarged vestibular aqueduct (EVA). EVA is a common radiological finding in children presenting with hearing loss. We hope to provide insight into the pathogenesis of EVA and provide further guidelines for unilateral EVA management. We hypothesized that hearing loss in unilateral EVA would be similar to that seen in bilateral EVA. MethodsA longitudinal retrospective study design was used. Three measures of hearing, pure tone average (PTA) word recognition score (WRS) and speech awareness threshold (SAT) and radiologic morphologies were tested for difference across unilateral versus bilateral ear EVA status. Linear mixed effects models were used to identify differences while accounting for time and multiple measurements per ear. ResultsUsing Cincinnati criteria, 89 ears fit inclusion criteria, 75 of which were from patients with bilateral EVA compared to 14 ears from patients with unilateral EVA. No significant differences across bilateral status were observed in audiological measurements. Models showed that speech recognition threshold (SRT) (p = 0.925), word recognition score (WRS)(p = 0.521) and pure tone average (PTA) of air and bone conduction from 250 to 4000 Hz (p = 0.281–0.933) were not statistically different with respect to bilateral status. Wilcoxon rank-sum tests showed no statistical difference in vestibular aqueduct width or operculum size (VA)(p = 0.234, p = 0.623). Each year after the first audiogram was associated with significantly greater SRT (p = 0.003) decreased WRS (0.014) and increased PTA (0.003.). Greater midpoint width was associated with significantly lower SRT (p = 0.004) WRS (<0.001) and PTA (<0.001.) ConclusionOur results indicate no statistically significant difference in hearing ability with respect to bilateral EVA status, suggesting that unilateral EVA patients require close follow-up. Our results also demonstrate the progressive nature of EVA and a relationship between VA midpoint width and hearing loss severity.

When is a Vestibular Aqueduct Enlarged?

A ten-year-old boy with bilateral moderate sensorineural hearing loss underwent computerized tomographic (CT) imaging (GE Brightspeed, Wisconsin, USA) of the temporal bone as part of the work-up to determine the etiology of his condition. The formal radiologic interpretation of the scan stated that the vestibular aqueducts were not enlarged. However, independent review of the axial CT images appeared to indicate the presence of enlarged vestibular aqueducts. (Figure 1) This can be contrasted with a scan from another patient with no evidence of sensorineural hearing loss. (Figure 2)&#x0D; What can explain the discrepancy between the two?&#x0D; &#x0D; If simple visual inspection of the vestibular aqueduct (VA) can lead to conflicting interpretations, then what radiographic parameters can be used to resolve the issue? Is there a more objective means of determining the presence of a clinically significant vestibular aqueduct enlargement?&#x0D; &#x0D; In 1978, Valvasorri and Clemis1 first described an association between congenital sensorineural hearing loss and an abnormality in vestibular aqueduct anatomy which they labelled as the “large vestibular aqueduct syndrome.” In this landmark study that utilized hypocycloidal polytomographic temporal bone studies, they proposed that a vestibular aqueduct is enlarged when its midpoint diameter is greater than 1.5 mm. Although this parameter is generally considered to be the defining characteristic of the condition, one must realize that this measurement was based on less accurate imaging technology and measurement tools. Contemporary studies utilize high-resolution CT imaging with digital workstation measurement software to evaluate vestibular aqueduct anatomy. Currently, the two most commonly used radiographic parameters are the VA midpoint (MP) width and the VA opercular (OP) width. (Figure 3)&#x0D; More recently, Boston et al.2 in 2007 published normative values for these parameters based on a study population of 73 children without known sensorineural hearing loss. They considered a vestibular aqueduct enlarged when one or both of the measured widths were above the 95th percentile of the normal study group measurements. On this basis, a VA midpoint width of &gt;0.9 mm and/or a VA opercular width of &gt;1.9 mm was the criteria established to define an enlarged vestibular aqueduct.&#x0D; &#x0D; The patient’s measured vestibular aqueduct midpoint width on the right was 2.1 mm, while the vestibular aqueduct opercular width was 2.9 mm. (Figure 4) These measurements, when evaluated against either the original Valvassori criteria or the newer criteria of Boston et al., confirm what was visually apparent– the presence of a clinically significant enlargement of the vestibular aqueduct as the etiology of the patient’s sensorineural hearing loss.&#x0D;

Drum Evaluation of Broilers Over 20 Years of Selection

ObjectivesAs a result of genetic selection pressures, economically important traits continue to make gains in fast growing boilers. To understand the impact that has taken place over time on profitable traits, such as live weight, as well as indirectly selected traits, whole leg and tibia parameters of 2 genetic broiler lines representing the 1995 and 2015 broiler maintained at the University of Arkansas were compared.Materials and MethodsOne hundred 20 broilers, evenly split between the 1995 RAN and 2015 RAN lines, were reared straight-run with ab libitum access to industry standard feed and water (IACUC Approval #15039). Fifteen birds were weighed, then euthanized at each time point from each line (d 0, d 14, d 28, and d 42). Left legs were disarticulated, weighed and cleaned of flesh and tendons. The following tibia measurements were collected; tibia weight, tibia lengths, proximal width-frontal, distal width-frontal, midpoint width, proximal width-sagittal, distal width-sagittal. Max load, load break, load extension, and compressive strain was calculated for d 14, d 28, and d 42 using an Instron Universal Testing Machine (IUTM). Spacing used for IUTM test are as follows: 2 cm for d 14, 4 cm for d 28, 5 cm for d 42. To compare means between data collected for each age of both lines, JMP Pro v. 12 was used though t tests with a significance level (p < 0.05).ResultsBody weight was significantly larger in 2015 RAN line compared to 1995 RAN at ages d 14, d 28, and d 42. Tibia weight was significantly smaller in the 2015 RAN line at d 0 (p = 0.0304), but surpassed the RAN 1995 line at d 14 of age (p = 0.0206). Mean weight was not significantly different between the 2 lines at d 28 and d 42. Mean leg weight to body weight ratio is significantly larger in the 1995 line on d 0 and d 28 (p = 0.0031 and p = 0.0290, respectively), and indicate no significant differences on d 24 or d 42. This trend is also seen in tibia weight to body weight ratio being significantly larger in the 1995 line on d 0 and d 28 (p = 0.0170 and p = 0.0070, respectively). Drum weight to body weight ratio indicate significantly larger ratios for 1995 RAN line on d 0 (p = 0.0008), but this trend does not continue in older ages. Dimensional ratios of tibia proximal width (sagittal) to tibia length (p = 0.0370), tibia distal width (sagittal) to tibial length (p = 0.0118), and tibial midpoint width to tibial length (p = 0.0161) all indicate significantly larger ratios in d 0 1995 RAN compared to d 0 2015 RAN lines, but this trend does not continue in older ages. No differences were detected in the max load, load at break, load extension, and compressive strain force measures.ConclusionInterestingly, many of the parameter reported indicated that at day of hatch, broilers of the 2015 RAN have reduced size associated with the tibia. Allocations of nutrients during embryonic development may be contributing to the discrepancy in birds between the 2 lines at d 0 and can act as a focus in future genetic selections aimed to reduce the incidence of lameness in broilers.

Hearing loss in enlarged vestibular aqueduct and incomplete partition type II

PurposeThe purpose of this work is to identify the role of incomplete partition type II on hearing loss among patients with enlarged vestibular aqueduct (EVA). BackgroundEVA is a common congenital inner ear malformation among children with hearing loss, where vestibular aqueduct morphology in this population has been shown to correlate to hearing loss. However, the impact of incomplete partition between cochlear turns on hearing loss has not been, despite meaningful implications for EVA pathophysiology. MethodsA retrospective review of radiology reports for patients who had computed tomography (CT) scans with diagnoses of hearing loss at a tertiary medical center between January 2000 and June 2016 were screened for EVA. CT scans of the internal auditory canal (IAC) for those patients with EVA were examined for evidence of incomplete partition type II (IP-II), measurements of midpoint width and operculum width a second time, and patients meeting Cincinnati criteria for EVA selected for analysis. Statistical analysis including chi-square, Wilcoxon rank-sum, and t-tests were used to identify differences in outcomes and clinical predictors, as appropriate for the distribution of the data. Linear mixed models of hearing test results for all available tests were constructed, both univariable and adjusting for vestibular aqueduct morphometric features, with ear-specific intercepts and slopes over time. ResultsThere were no statistically significant differences in any hearing test results or vestibular aqueduct midpoint and operculum widths. Linear mixed models, both univariable and those adjusting for midpoint and operculum widths, did not indicate a statistically significant effect of incomplete partition type II on hearing test results. ConclusionsHearing loss due to enlarged vestibular aqueduct does not appear to be affected by the presence of incomplete partition type II. Our results suggest that the pathophysiological processes underlying hearing loss in enlarged vestibular aqueduct may not be a result of cochlear malformation, and instead are more likely to involve vestibular aqueduct or cellular and molecular-level mechanisms of hearing loss.

Vestibular Aqueduct Midpoint Width and Hearing Loss in Patients With an Enlarged Vestibular Aqueduct

Elucidating the relationship between vestibular aqueduct size and hearing loss progression may inform the prognosis and counseling of patients who have an enlarged vestibular aqueduct (EVA). To examine the association between vestibular aqueduct size and repeated measures of hearing loss. For this retrospective medical record review, 52 patients with a diagnosis of hearing loss and radiologic diagnosis of EVA according to the Valvassori criterion were included. All available speech reception threshold and word recognition score data was retrieved; mixed-effects models were constructed where vestibular aqueduct size, age at diagnosis of hearing loss, and time since diagnosis of hearing loss were used to predict repeated measures of hearing ability. This study was performed at an academic tertiary care center. Variable vestibular aqueduct size, age at first audiogram, length of time after first audiogram. Speech reception threshold (dB) and word recognition score (%) during routine audiogram. Overall, 52 patients were identified (29 females [56%] and 23 males [44%]; median age at all recorded audiograms, 7.8 years) with a total of 74 ears affected by EVA. Median (range) vestibular aqueduct size was 2.15 (1.5-5.9) mm, and a median (range) of 5 (1-18) tests were available for each patient. Each millimeter increase in vestibular aqueduct size above 1.5 mm was associated with an increase of 17.5 dB in speech reception threshold (95% CI, 7.2 to 27.9 dB) and a decrease of 21% in word recognition score (95% CI, -33.3 to -8.0 dB). For each extra year after a patient's first audiogram, there was an increase of 1.5 dB in speech recognition threshold (95% CI, 0.22 to 3.0 dB) and a decrease of 1.7% in word recognition score (95% CI, -3.08 to -0.22 dB). Hearing loss in patients with an EVA is likely influenced by vestibular aqueduct midpoint width. When considering hearing loss prognosis, vestibular aqueduct midpoint width may be useful for the clinician who counsels patients affected by EVA.

Clinically relevant human temporal bone measurements using novel high-resolution cone-beam CT

ObjectiveTo test the feasibility of measuring fine temporal bone structures using a newly established cone-beam computed tomography (CBCT) system. Materials and methodsSix formalin-fixed human cadaver temporal bones were imaged using a high-resolution CBCT system that has 900 frames and copper + aluminum filtration. Fine temporal bone structures, including those of the facial nerve canal and vestibular structures, were identified and measured. ResultsThe fine structures of the middle ear, including the tympanic membrane, tendon of the tensor tympani, cochleariform process of the semicanal of the tensor tympani, pyramidal eminence, footplate of the stapes, full path of the facial nerve within the temporal bone, supralabyrinthine space, semicircular canals, pathway of the subarcuate canal, and full path of the vestibular aqueduct, were clearly demonstrated. The vestibular aqueduct has a midpoint width of 0.4 ± 0.0 mm and opercular width of 0.5 ± 0.1 mm (mean ± SD). The length of the internal acoustic meatus was 10.6 ± 1.2 mm (mean ± SD), and the diameter of the internal acoustic meatus was 3.7 ± 0.3 mm (mean ± SD). ConclusionThis novel high-resolution CBCT system has potentially broad applications in the diagnosis of inner ear disease and in monitoring associated pathological changes, surgical planning, navigation for the ear surgery, and temporal bone training.

Vestibular Aqueduct Measurements in the 45 Oblique (Po schl) Plane

The 45° oblique (Pöschl) plane allows reliable depiction of the vestibular aqueduct, with virtually its entire length often visible on 1 CT image. We measured its midpoint width in this plane, aiming to determine normal measurement values based on this plane. We retrospectively evaluated temporal bone CT studies of 96 pediatric patients without sensorineural hearing loss. Midvestibular aqueduct widths were measured in the 45° oblique plane by 2 independent readers by visual assessment (subjective technique). The vestibular aqueducts in 4 human cadaver specimens were also measured in this plane. In addition, there was a specimen that had undergone CT scanning before sectioning, and measurements made on that CT scan and on the histologic section were compared. Measurements from the 96 patients' CT images were then repeated by using findings derived from the radiologic-histologic comparison (objective technique). All vestibular aqueducts were clearly identifiable on 45° oblique-plane CT images. The mean for subjective measurement was 0.526 ± 0.08 mm (range, 0.337-0.947 mm). The 97.5th percentile value was 0.702 mm. The mean for objective measurement was 0.537 ± 0.077 mm (range, 0.331-0.922 mm). The 97.5th percentile value was 0.717 mm. Measurements of the vestibular aqueduct can be performed reliably and accurately in the 45° oblique plane. The mean midpoint width was 0.5 mm, with a range of 0.3-0.9 mm. These may be considered normal measurement values for the vestibular aqueduct midpoint width when measured in the 45° oblique plane.

Correlation of vestibular aqueduct size with air-bone gap in enlarged vestibular aqueduct syndrome.

Patients with enlarged vestibular aqueduct (EVA) often demonstrate an air-bone gap (ABG) at low frequencies on audiometric testing. The mechanism for this has not been well elucidated. We investigated vestibular aqueduct (VA) size and ABG in patients with EVA, and assessed the relationship between VA diameter and ABG. Retrospective review. We assessed 98 ears from 49 individuals diagnosed with Pendred syndrome. The VA diameters of ears in groups with (n = 60) and without (n = 38) ABG were measured using axial computed tomography images. Three different parameters of VA diameter (fundus, midpoint, and porous width) were correlated with the results of pure tone analysis. We found that patients with ABG have larger diameters of the VA than patients without ABG (fundus width = 1.13 vs. 0.71 mm, respectively; midpoint width = 3.23 vs. 2.77 mm, respectively; porous width = 2.73 vs. 2.29 mm, respectively; P < .001, .038, and .049, respectively). A cutoff value of VA fundus diameter was set at 0.865 mm. Although <5% of the variability in the ABG was explainable by variation in the diameter of the VA fundus at low frequencies, on average, larger gaps were observed with fundus diameters of >0.865 mm. Our findings suggest that the axial parameters of the VA yield information about ABG in patients with EVA. The data are consistent with the hypothesis that an EVA introduces a third mobile window into the inner ear, resulting in an ABG at low frequencies. 4. Laryngoscope, 126:1633-1638, 2016.