Computed Tomography Bone Research Articles

Utilizing deep learning for automatic segmentation of the cochleae in temporal bone computed tomography.

Segmentation of the cochlea in temporal bone computed tomography (CT) is the basis for image-guided otologic surgery. Manual segmentation is time-consuming and laborious. To assess the utility of deep learning analysis in automatic segmentation of the cochleae in temporal bone CT to differentiate abnormal images from normal images. Three models (3D U-Net, UNETR, and SegResNet) were trained to segment the cochlea on two CT datasets (two CT types: GE 64 and GE 256). One dataset included 77 normal samples, and the other included 154 samples (77 normal and 77 abnormal). A total of 20 samples that contained normal and abnormal cochleae in three CT types (GE 64, GE 256, and SE-DS) were tested on the three models. The Dice similarity coefficient (DSC) and Hausdorff distance (HD) were used to assess the models. The segmentation performances of the three models improved after adding abnormal cochlear images for training. SegResNet achieved the best performance. The average DSC on the test set was 0.94, and the HD was 0.16 mm; the performance was higher than those obtained by the 3D U-Net and UNETR models. The DSCs obtained using the GE 256 CT, SE-DS CT, and GE 64 CT models were 0.95, 0.94, and 0.93, respectively, and the HDs were 0.15, 0.18, and 0.12 mm, respectively. The SegResNet model is feasible and accurate for automated cochlear segmentation of temporal bone CT images.

Characterization of jugular bulb position on computed tomography (CT) with implications for excision of vestibular schwannomas.

To describe the distribution of jugular bulb position and pneumatization of posterior lip of internal auditory meatus (IAM) in patients with vestibular schwannoma (VS). This retrospective study included 43 patients who had a thin slice (< 2mm) CT temporal bone for preoperative planning of retrosigmoid approach for excision of VS between March 2011 and March 2021. On computed tomography (CT), high riding jugular bulb was defined by its relationship to IAM and correlated with type of jugular bulb according to Manjila et al. classification. The most common position of the jugular bulb was type 2a on the side of the tumor (26/43, 60.5%) and contralateral to the side of the tumor (28/43, 65.1%). High riding jugular bulb was noted in 9 (20.9%) patients. Seven among the 9 (77.9%) patients with high riding jugular bulb had Manjila et al. type 4 jugular bulb. Pneumatization of posterior lip of IAM was noted in 8 (18.6%) patients. Avoidance of drilling of the IAM in the subgroup of 23 patients who underwent total excision of the tumor was significantly associated with Manjila et al. type 4 jugular bulb (3/4, 75%, p = 0.04) and pneumatization of posterior lip (3/4, 75%, p = 0.04). Ideally all patients with VS should undergo petrous bone CT of < 2mm slice thickness as it can help in qualifying the jugular bulb position and recognizing pneumatization of the IAM. The presence of Manjila et al. type 4 jugular bulb or pneumatization of the posterior lip in patients with VS should alert the surgeon to anticipate and prevent complications related to drilling the posterior lip of the IAM.

Evaluation of Pedicle Screw Position on Computerized Tomography Using Three-Dimensional Reconstruction Software.

Background and Objectives: Recent advances in intraoperative navigation systems have improved the accuracy of pedicle screw placement in spine surgery. However, many hospitals have limited access to these advanced technologies due to resource constraints. In such settings, postoperative computed tomography (CT) evaluation remains crucial for assessing screw placement and related potential complications. Metal artifacts in CT scans often compromise the diagnostic accuracy. This study aimed to develop and validate three-dimensional (3-D) reconstruction software to enhance screw localization accuracy and facilitate its practical clinical application. Materials and Methods: This study included two phases: 3-D software development utilizing specific threshold values of Hounsfield units for titanium screws followed by internal validation. For validation, fifty pedicle screws were inserted into porcine lumbar vertebrae with random violation (superior, inferior, medial, or lateral). Three fellowship-trained surgeons evaluated screw positions using both conventional CT bone window settings and the developed software. Additional clinical validation involving 386 pedicle screws from cervical to lumbar spine was performed by two surgeons. Results: The software demonstrated significantly higher specificity (83% vs. 63%) and positive predictive value (96% vs. 91%) compared to conventional CT bone window settings, while maintaining 100% sensitivity and negative predictive value. Interobserver reliability was excellent for both methods (0.961 for bone window vs. 0.990 for software). In clinical validation, the software showed superior intraobserver (0.83 vs. 0.74) and interobserver reliability (0.855 vs. 0.513) compared to picture archiving and communication system (PACS) workstation evaluation. Conclusions: The developed software provides improved accuracy and reliability in pedicle screw position evaluation through distinct screw outline visualization and metal artifact reduction. Its equipment-independent nature and cost-effectiveness make it particularly valuable for clinical implementation.

Assessing bone quality in hounsfield units using computed tomography: what value should be used to classify bone as normal or osteoporotic?

The purpose of this study was to investigate threshold values for classifying bone as normal or osteoporotic based on Computed Tomography (CT) Hounsfield Units (HU) and to determine if clinically applicable values could be derived to aid spine surgeons evaluating bone quality using CT. This literature review was completed using PubMed and Ovid (MedLine), using syntax specific to bone quality and CT. The included articles were original clinical studies assessing bone quality and utilized composite L1-L4 HU values compared against dual-energy X-ray absorptiometry (DEXA) values. Extracted data study descriptors, CT measurement technique, and CT threshold values. CTs were measured from L1-L4 using either axial or sagittal images, and must classify their bone quality findings for any of the following 3 categories: normal, osteopenia, or osteoporosis. This review located 34 studies measuring bone density using CT with threshold values, of which, 10 were included in the final review. Number of patients ranged from 74 to 283 and cohort ages from 20s to 70.6 years. CT threshold values for assessing normal and osteoporotic bone quality ranged from 150 to 179 and 87 to 155, respectively. From combining values across studies, a HU value of ≥ 170 HU was associated with normal bone and ≤ 115 HU with osteoporosis. There is variation in HU values used to differentiate normal from compromised bone quality, even after limiting studies. For patients with HU values between or near 170 or 115 HU, a DEXA scan may be warranted for further evaluation. With ongoing investigation in this area, threshold values for classifying bone quality using CT will be continually refined.

Inter-observer and intra-observer agreement of bone reporting and data system (Bone-RADS) in the interpretation of bone tumors on computed tomography

ObjectiveTo assess inter-observer & intra-observer agreement of the American College of Radiology (ACR) bone reporting and data system (Bone-RADS) in the interpretation of bone tumors on computed tomography (CT). MethodsThis retrospective study included 273 bone tumors 184 (67.4 %) benign and 89 (32.6 %) malignant. Two blinded radiologists independently reviewed the CT images to assess the defined CT features of bone lesions and assign a bone-RADS category. A third observer reviewed the CT images twice with one month interval and reported the specified CT features and final bone-RADS category for bone lesions. Inter-observer and intra-observer agreement of bone-RADS were analyzed. ResultsThere was almost perfect inter-observer agreement between the two reviewers for all defined variables as well as bone-RADS categories (Kappa = 92.2 %). Overall intra-observer agreement was also perfect for all defined CT features and bone RADS categories with higher percentage than inter-observer one (κ = 98.3 %). ConclusionBone-RADS is an effective clinical tool for practicing radiologists in the risk assessment and management of bone tumors with perfect agreement among observers. To our knowledge, no studies have been conducted for assessing reliability or validity of the recent ACR Bone-RADS using CT. Hence, this study could serve as a cornerstone for further upcoming studies to assess the reproducibility and validity of the ACR Bone-RADS.

Effect of contrast media on CT bone density assessment: comparative analysis of low-dose chest CT and abdominopelvic CT

Detecting individuals with low bone mineral density (BMD) before clinical fractures occur may help improve the outcomes of osteoporosis and osteopenia. Although computed tomography (CT) is useful for opportunistic BMD measurement, the modality most suitable for opportunistic screening remains unclear. In this retrospective study, we compared the diagnostic performance of low-dose chest CT (LDCT) and contrast-enhanced abdominopelvic CT (APCT) for measuring BMD at L1 level using dual-energy X-ray absorptiometry (DEXA) as a reference in individuals who underwent LDCT, APCT, and DEXA assessments on the same day. We included 512 individuals (median age: 60 years; interquartile range, 55−65 years; 307 men). Both LDCT (r = 0.706; P < 0.001) and APCT (r = 0.643; P < 0.001) exhibited strong correlation with DEXA T-scores. As T-scores decreased, the relative difference between LDCT and APCT Hounsfield unit values increased (b = − 6.456; P < 0.001). LDCT outperformed APCT in diagnosing both osteoporosis (AUC, 0.865 vs. 0.833; P = 0.035) and low BMD (AUC, 0.844 vs. 0.815; P = 0.006), which may be attributable to the greater effect of intravenous contrast media on CT scan characteristics in individuals with lower T-scores. These results may help inform the selection of imaging methods suitable for screening.

Management of Massive Iatrogenic Temporal Lobe Meningoencephalocele and Bacterial Meningitis Following Pediatric Cochlear Implant Surgery.

To review the management of meningitis, large lateral skull base defect, and meningoencephalocele following pediatric cochlear implant (CI) surgery. Case report. Patient demographics, medical and surgical history, computed tomography (CT). An 8-year-old male with congenital severe to profound sensorineural hearing loss underwent uncomplicated right CI surgery at 18 months of age. He returned to his home country and received a bilateral sequential left ear CI at age 2. Five years following his second CI surgery, he presented to his local emergency room with worsening fever, headache, back pain, and vomiting. Lumbar puncture confirmed bacterial meningitis, and he was managed with intravenous antibiotics. The hospital course was complicated by a right-sided facial nerve paresis, prompting a temporal bone CT. Imaging demonstrated a tegmen defect measuring 15 mm × 10 mm with soft tissue opacification involving the entire mastoid and CI harness. He was then referred by family back to our institution. Intraoperatively, we identified a massive temporal lobe meningoencephalocele involving the entire mastoid cavity and engulfing the entire proximal electrode harness. Following middle cranial fossa craniotomy and revision mastoidectomy, proximal and distal array were separated, encephalocele transected, and remaining temporal lobe reduced. The lateral skull base was reconstructed with calvarial bone, temporalis fascia, and bovine collagen graft. The remnant electrode array was removed, a new CI receiver stimulator was fixed postero-superiorly to the cranial defect, and a new multichannel array inserted. A titanium cranioplasty completed the repair. A lumbar drain was placed for 3 days. Recovery and CI activation occurred uneventfully. Risk of encephalocele and meningitis underscores the importance of early identification, adequate repair, and long-term radiologic follow-up of iatrogenic tegmen defects during pediatric CI surgery.

Estimating elbow loading conditions through the motion behaviors of subchondral bone density during joint movements

Evaluating complicated stress across the elbow under joint motion remains difficult. Here, we aimed to evaluate the distribution of the subchondral bone density in the normal elbow bones and further characterize their spatial relationships during elbow motion to estimate the loading stress across the articular surface using three-dimensional computed tomography bone models. The normal elbow joint exhibited a consistent distribution pattern of subchondral bone density. High-density regions were distributed in the capitellum and posterior humeral trochlea, sagittal ridge of the ulnar trochlear notch and ulnar-volar side of the radial head. Motion analyses revealed that the high-density regions proximate with elbow flexion with forearm pronation in the radiocapitellar joint and in the fully extended position in the ulnohumeral joint. This reasonably reflects the stress acting on the joint surface under actual loading conditions. These findings suggest that daily activities involving lifting or carrying objects in these positions are stress-prone activities.

Feasibility of thin-slice, low noise images created using multi-kernel synthesis to replace multiple image series in head CT.

SynthesiZed Improved Resolution and Concurrent nOise reductioN (ZIRCON) is a multi-kernel synthesis method that creates a single series of thin-slice computed tomography (CT) images displaying low noise and high spatial resolution, increasing reader efficiency and minimizing partial volume averaging. To compare the diagnostic performance of a single set of ZIRCON images to two routine clinical image series using conventional CT head and bone reconstruction kernels for diagnosing intracranial findings and fractures in patients with trauma or suspected acute neurologic deficit. In total, 50 patients underwent clinically indicated head CT in the ER (15 normal, 35 abnormal cases). A non-reader neuroradiologist established the reference standard. Three neuroradiologists reviewed two routine clinical series (head and bone kernels) and a single ZIRCON series, detecting intracranial findings or fractures and rating confidence (0-100). Sensitivity, specificity, and jackknife free-response receiver operating characteristic (JAFROC) figure of merit (FOM) were compared (limit of non-inferiority: -0.10). ZIRCON and conventional images demonstrated comparable performance for fractures (sensitivity: 51.5% vs. 54.5%; specificity: 40.2% vs. 34.2%) and intracranial findings (sensitivity: 88.2% vs. 91.4%; specificity: 77.2% vs. 73.7%).The estimated difference of JAFROC FOM demonstrated ZIRCON non-inferiority for acute pathologies overall (0.003 [95% CI=-0.051-0.057]) and fractures (0.048 [95% CI=-0.050-0.145]) but not for intracranial findings alone (-0.024 [95% CI=-0.100-0.052]). Thin-slice, low noise, and high spatial resolution images can be created to display intracranial findings and fractures replacing multiple images series in head CT with similar performance. Future studies in more patients and further algorithmic development are warranted.

Radiographic Estimation of Superior Canal Dehiscence Area in a Prediction Model of Surgical Outcome.

Computed tomography (CT) imaging of the temporal bone constitutes an integral element in the diagnostic workup of superior canal dehiscence (SCD). This study explores the utility of a clinically efficient method of manually estimating SCD size on CT imaging in predicting surgical outcomes. Cohort study. Tertiary center. Consecutive middle fossa repairs of SCD between 2011 and 2022 were included. Measurements of approximate dehiscence area (ADA), a previously established estimation method, on temporal bone CT imaging were performed by trained raters blind to clinical information. Surgical outcomes, evaluated with symptom resolution and audiometric improvement following repair, were assessed in multivariable regression models with ADA as the primary predictor and patient demographics and other history factors as covariates. Among 311 cases included, mean ADA was 2.68 mm2, and 71% of cases achieved overall symptom improvement (OSI). Every 1 mm2 rise in ADA predicted on average 3 dB greater narrowing of low-frequency air-bone gap (β 95% confidence interval, CI [-5.4, -0.7]) but 50% lower odds of OSI (adjusted odds ratio: 95% CI [0.32, 0.78]) among unilateral SCD cases. A model incorporating ADA, patient demographics, and history factors predicted OSI with a sensitivity, specificity combination as high as 85%, 73% and a positive predictive value, negative predictive value combination as high as 85%, 82% (area under the curve: 95% CI: 0.76-0.93). Increased ADA predicts more pronounced audiometric improvement but poorer symptomatic response among unilateral SCD cases. ADA is an efficient and practical method of estimating SCD size and demonstrated clinical utility in accurately predicting surgical outcomes.

Using Dynamic Stereo X-ray Imaging for In Vivo Acromioclavicular Joint Kinematics Assessment: A Preliminary Investigation.

Acromioclavicular joint (ACJ) disruption occurs frequently in athletes engaged in contact sports. However, the current understanding of ACJ biomechanics during muscle-driven functional activities and the influence of different treatment approaches (eg, reconstruction surgery vs nonoperative methods) on ACJ kinematics and stability remains limited. The absence of precise in vivo biomechanical measurement modalities for scapular and clavicular kinematics contributes significantly to this lack of understanding. The purposes of this study were to determine whether dynamic stereo x-ray (DSX) imaging can be used to evaluate the in vivo kinematics of the ACJ and to provide preliminary comparative data on ACJ kinematics, range of motion, and isometric strength of surgically reconstructed or nonoperatively treated ACJ shoulders and their uninjured contralateral shoulders. It was hypothesized that ACJ kinematics could be measured successfully using DSX and that surgically and nonoperatively treated shoulders would show abnormal 3-dimensional (3-D) ACJ kinematics compared with the uninjured contralateral. Controlled laboratory study. In this cross-sectional study, 11 participants who had undergone unilateral ACJ reconstruction surgery and 3 patients who received nonoperative treatment were enrolled. ACJ kinematics were assessed during active forward flexion, scaption, and abduction through high-speed DSX imaging, complemented by 3-D bone models obtained via computed tomography (CT) scans. To gauge kinematic differences, a 1-dimensional statistical parametric mapping method was employed, which compared outcomes in the index limb to those in the uninjured counterpart. In addition, the range of motion and isometric strength at various abduction angles were analyzed, employing a repeated-measures analysis of variance to compare the affected and uninjured sides. Leveraging a combination of DSX imaging and patient-specific CT bone models, ACJ kinematics was measured successfully during movements along anatomic planes. Preliminary findings from this investigation revealed no detectable differences between the surgically reconstructed and uninjured sides in ACJ biomechanics, shoulder range of motion, and isometric strength outcomes. However, on average, the nonoperatively treated shoulders demonstrated increased internal rotation, upward rotation, and posterior tilting of the scapula relative to the clavicle (no statistical analyses were performed due to the small sample size). DSX imaging is a promising tool for evaluating potential in vivo kinematic abnormalities in the ACJ during muscle-driven activities, laying the groundwork for further investigations in both ACJ-reconstructed and nonreconstructed patients. This study furnished essential data for conducting power analyses and designing future studies with an adequate sample size to investigate the impact of different treatment approaches on shoulder girdle mechanics. With its potential for accurately characterizing shoulder girdle kinematics post-ACJ injury, DSX imaging can offer valuable insights for future clinical studies, facilitating informed decisions regarding the short- and long-term impacts of treatment choices on shoulder health and function.

Selection of the Preferred Puncture Site on Manual Intraosseous Infusion: Proximal Humerus or Proximal Tibia?

Aims/Background Establishing an intraosseous infusion (IO) pathway can rapidly open an urgent route of drug administration for critically ill patients. This study aims to assess different puncture sites on the efficacy of manual intraosseous infusion. Methods Upon applying computed tomography (CT), we compared compact bone thickness and CT values at the same individual's proximal humerus and proximal tibia puncture sites (n = 40). Additionally, cadaveric experiments were used to compare the efficiency of manual puncture at two different insertion sites of the proximal humerus and proximal tibia in the same individual (n = 5). Results The compact bone thickness and CT values at the proximal humerus were significantly lower than those at the proximal tibia. The cadaveric experiments further confirmed that the proximal humerus was superior to the proximal tibia as an insertion site, indicating the proximal humerus is a more suitable insertion site for manual bone marrow puncture needles. Conclusion Selection of the puncture site markedly influences the effectiveness of manual intraosseous infusion, with the proximal humerus potentially offering better puncture efficacy than the proximal tibia.

Cochlear Apex Triangulation Utilizing Ct Measures And Middle Ear Landmarks.

To better characterize the cochlear apex in relation to surgically relevant landmarks to guide surgeons and improve procedural success of apical electrode placement. Retrospective image analysis. Tertiary referral center. Cochlear implant recipients with available preoperative computed tomography (CT) imaging. None. Cochlear dimensions and cochlear apex distance measures to surgically relevant middle ear landmarks and critical structures. Eighty-two temporal bone CT scans were analyzed utilizing multiplanar reformats. The average lateral width of promontory bone over the cochlear apex was 1.2 mm (standard deviation [SD], 0.3). The anteroposterior distance from the round window (avg, 4.2 mm; SD, 0.5), oval window (avg, 3.3 mm; SD, 0.3), cochleariform process (avg, 2.3; SD, 0.5), and superior-inferior distance from the cochleariform process (avg, -0.9; SD, 0.8) to the cochlear apex were measured. The relationship of the cochlear apex to critical structures was highly variable.A newly developed stapes vector was created and found to mark the posterior/superior boundary of the apex in 94% of patients. When a vector parallel to the stapes vector was drawn through the round window, it marked the anterior/inferior boundary of the cochlear apex in 89% of patients. This study assists in characterizing cochlear apex anatomy and its relation to surrounding structures as a means of improving procedural accuracy and reducing trauma during apical cochleostomy. Understanding both distance relationships and expected boundaries of the apex could help to inform future surgical approaches.

Radiologic evaluation of the internal carotid artery and jugular bulb in lateral temporal bone resection using 3D computed tomography.

This study investigated the internal carotid artery (ICA) and jugular bulb (JB) structures in terms of lateral temporal bone resection using 3D computed tomography (CT). We retrospectively investigated 80 ears of 40 patients using 3D reconstruction data from normal temporal bone CT. Ten critical points (P) in the temporal bone were marked in the 3D object with reference to the axial, coronal, and sagittal images of the CT scans. An imaginary plane of the facial nerve (PLf) course was also reconstructed in relation to the three points of the chorda-facial junction, P5 (second genu), and P3 (cochleariform) process. The distances (mean ± SD; mm) from points P3 to P1 (the highest level of the JB) and P2 (the posterior wall of the ascending petrous IAC at the level of the Eustachian tube) were 12.03 ± 2.56 and 9.79 ± 1.78, respectively. The distances from point P4 (chorda-facial junction) to P1 and P2 were 10.98 ± 2.70 and 17.66 ± 2.26, respectively. The angles (mean ± SD; degree) between the PLf to the line from Pa (point of the anterior bony canal) to P3 and P4 were 17.80 ± 10.05º and 8.93 ± 5.37º, respectively. The angles between the PLf to the line from P3 to P1 and P2 were - 36.35 ± 13.28º and - 24.78 ± 13.91º, respectively. The angles between the PLf to the line from P4 to P1 and P2 respectively were - 40.35 ± 15.37º and - 13.34 ± 7.63º. Understanding the anatomical relationships of P1 and P2 at P3 and P4 can be helpful in preventing iatrogenic trauma of the ICA and JB.

Middle ear-acquired cholesteatoma diagnosis based on CT scan image mining using supervised machine learning models

BackgroundDistinguishing between middle ear cholesteatoma and chronic suppurative otitis media (CSOM) is an ongoing challenge. While temporal bone computed tomography (CT) scan is highly accurate for diagnosing middle ear conditions, its specificity in discerning between cholesteatoma and CSOM is only moderate. To address this issue, we utilized trained machine learning models to enhance the specificity of temporal bone CT scan in diagnosing middle ear cholesteatoma. Our database consisted of temporal bone CT scan native images from 122 patients diagnosed with middle ear cholesteatoma and a control group of 115 patients diagnosed with CSOM, with both groups labeled based on surgical findings. We preprocessed the native images to isolate the region of interest and then utilized the Inception V3 convolutional neural network for image embedding into data vectors. Classification was performed using machine learning models including support vector machine (SVM), k-nearest neighbors (k-NN), random forest, and neural network. Statistical metrics employed to interpret the results included classification accuracy, precision, recall, F1 score, confusion matrix, area under the receiver operating characteristic curve (AUC), and FreeViz diagram.ResultsOur training dataset comprised 5390 images, and the testing dataset included 125 different images. The neural network, k-NN, and SVM models demonstrated significantly higher relevance in terms of classification accuracy, precision, and recall compared to the random forest model. For instance, the F1 scores were 0.974, 0.987, and 0.897, respectively, for the former three models, in contrast to 0.661 for the random forest model.ConclusionThe performance metrics of the presented trained machine learning models hold promising prospects as potentially clinically useful aids.

External auditory canal cholesteatoma in children: clinical manifestations

PurposeThe purpose of this study was to explore the characteristics of external auditory canal cholesteatoma (EACC) among children and to describe its radiological findings on high-resolution computed tomography (CT) of the temporal bone in order to improve the diagnostic accuracy of primary EACC.MethodsThe clinical records and CT imaging features of 44 patients who were diagnosed with EACC between January 2017 and May 2022 at Shenzhen Children’s Hospital were retrospectively reviewed. Clinical features, including external auditory canal wall findings, hearing damage, symptoms and physical examination findings, were analysed against the level of lesion involvement. The correlation between different types of EACC and the incidence of different clinical symptoms was analysed, and the degree of hearing impairment and the rate of bone wall destruction were examined using CT.ResultsThe mean age at EACC onset was 9.02 ± 3.15 years, and the mean age at onset for EACC involving the right ear was older than that of EACC involving the left ear (P < 0.05). There were 44 patients (46 ears), including 10 ears with type I EACC, 23 ears with type II EACC, and 13 ears with type III EACC. Conductive hearing loss was the main type of hearing impairment observed among EACC patients. There were differences in types I, II and III EACC in terms of hearing impairment; specifically, there was a significant difference in moderate hearing impairment between type II and type III EACC patients (P < 0.05). The four most common symptoms were otorrhea, otalgia, itching and bleeding. The incidence of itching symptoms was greater in type I EACC than the incidence of otorrhea, and the incidence of otorrhea symptoms in type II and type III EACC was significantly greater than that in type I EACC(P < 0.05). There were no significant differences in the fracture rates of the anterior, posterior, superior or inferior walls of the external auditory canal within or between type II and type III EACC patients (P > 0.05). The failure rate of scute damage was significantly higher in type III EACC patients than in type II EACC patients (P < 0.05).ConclusionThe presence of otorrhea and hearing loss as well as the identification of granulation tissue during otoscopy suggest the need for a temporal bone CT scan. This imaging modality can aid in the early detection and accurate classification of EACC, thereby guiding the selection of appropriate surgical interventions and greatly assisting in preventing further progression of hearing impairment.

Elevated modiolus density on high-resolution computed tomography as an indicator of cochlear neurodysplasia: a retrospective case-control study.

Cochlear neurodysplasia (CND) is recognized as a contributing factor to sensorineural hearing loss in children. This study aimed to investigate the relationship between modiolus density on high-resolution computed tomography (HRCT) and CND, and to evaluate its performance in diagnosing CND. This retrospective study collected HRCT images of 34 patients diagnosed with unilateral neurological hearing loss in the Children's Hospital of Chongqing Medical University from March 2018 to December 2023, who were also diagnosed with unilateral CND by computed tomography (CT) and magnetic resonance imaging (MRI) hydroimaging. CT values of the modiolus and petrous bone were measured on the affected and healthy sides, in addition to determining the width of cochlear nerve foramina and the width of internal auditory tract. The receiver operator characteristic (ROC) curve was used to evaluate the diagnostic performance of these features. Simultaneously, comparisons were conducted with parameters obtained from normal children. A total of 29 patients without CND were randomly selected as a control group. The unilateral sensorineural hearing loss group had 34 patients, comprising 18 males and 16 females, with a median age of 4.5 years, ranging from 0.7 to 11 years. The normal children group consisted of 20 males and 9 females, with a median age of 5.9 years, ranging from 0.5 to 12.0 years. Statistically significant differences were observed in the CT values of the modiolus, modiolus/petrous bone CT value ratio, width of cochlear nerve foramina, and width of internal auditory tract between the affected and healthy sides in patients with unilateral sensorineural hearing loss (P<0.05). The area under the ROC curve (AUC) of the modiolus CT value and the width of cochlear nerve foramina for the diagnosis of unilateral sensorineural hearing loss was 0.98 [95% confidence interval (CI): 0.95-1.00] and 0.99 (95% CI: 0.98-1.00), respectively. the modiolus density was significantly elevated in the affected sides in patients with unilateral CND. The optimal cut-off value of modiolus CT values was 983 Hounsfield unit (HU). The elevated density of the modiolus on HRCT holds significant value in diagnosing CND.

Machine learning models can define clinically relevant bone density subgroups based on patient-specific calibrated computed tomography scans in patients undergoing reverse shoulder arthroplasty

Reduced bone density is recognized as a predictor for potential complications in reverse shoulder arthroplasty (RSA). While humeral and glenoid planning based on preoperative computed tomography (CT) scans assist in implant selection and position, reproducible methods for quantifying the patients' bone density are currently not available. The purpose of this study was to perform bone density analyses including patient specific calibration in an RSA cohort based on preoperative CT imaging. It was hypothesized that preoperative CT bone density measures would provide objective quantification of the patients' humeral bone quality. This study consisted of three parts, (1) analysis of a patient-specific calibration method in cadaveric CT scans, (2) retrospective application in a clinical RSA cohort, and (3) clustering and classification with machine learning models. Forty cadaveric shoulders were scanned in a clinical CT and compared regarding calibration with density phantoms, air muscle, and fat (patient-specific) or standard Hounsfield unit. Post-scan patient-specific calibration was used to improve the extraction of three-dimensional regions of interest for retrospective bone density analysis in a clinical RSA cohort (n=345). Machine learning models were used to improve the clustering (Hierarchical Ward) and classification (Support Vector Machine (SVM)) of low bone densities in the respective patients. The patient-specific calibration method demonstrated improved accuracy with excellent intraclass correlation coefficients (ICC) for cylindrical cancellous bone densities (ICC>0.75). Clustering partitioned the training data set into a high-density subgroup consisting of 96 patients and a low-density subgroup consisting of 146 patients, showing significant differences between these groups. The SVM showed optimized prediction accuracy of low and high bone densities compared to conventional statistics in the training (accuracy=91.2%; AUC=0.967) and testing (accuracy=90.5 %; AUC=0.958) data set. Preoperative CT scans can be used to quantify the proximal humeral bone quality in patients undergoing RSA. The use of machine learning models and patient-specific calibration on bone mineral density demonstrated that multiple 3D bone density scores improved the accuracy of objective preoperative bone quality assessment. The trained model could provide preoperative information to surgeons treating patients with potentially poor bone quality.

Computer-Assisted Hip Arthroscopic Surgery for Secondary Femoroacetabular Impingement After Rotational Acetabular Osteotomy Using Capsular Takedown Techniques

Secondary femoroacetabular impingement (FAI) is a severe complication observed after acetabular osteotomy; however, the diagnostic and treatment strategies of FAI have not been well established, especially with respect to arthroscopic techniques. We here describe hip arthroscopic osteochondroplasty for secondary FAI using computer-assisted techniques. The main features and tips of our technique are preoperative computed tomography (CT)-based surgical planning and the intraoperative capsule takedown method. Computer modeling produces a patient-specific 3-dimensional CT bone model. Subsequently, we identify the impingement point between the acetabulum and the femoral neck using dynamic simulation. The excess bony bumps are resected through computer surgical simulation, and pre- and postoperative 3-dimensional CT bone models are combined to identify the appropriate resection area. For the surgical technique, it is important to detach the capsule to visualize the acetabulum bony excess. Once the resection area has been sufficiently visualized, the bone resection is performed. Finally, the capsule is reattached to the excavated acetabulum, and the delaminated labrum is sewn up with the capsule in a round bale shape.

Synthetic temporal bone CT generation from UTE-MRI using a cycleGAN-based deep learning model: advancing beyond CT-MR imaging fusion.

The aim of this study is to develop a deep-learning model to create synthetic temporal bone computed tomography (CT) images from ultrashort echo-time magnetic resonance imaging (MRI) scans, thereby addressing the intrinsic limitations of MRI in localizing anatomic landmarks in temporal bone CT. This retrospective study included patients who underwent temporal MRI and temporal bone CT within one month between April 2020 and March 2023. These patients were randomly divided into training and validation datasets. A CycleGAN model for generating synthetic temporal bone CT images was developed using temporal bone CT and pointwise encoding-time reduction with radial acquisition (PETRA). To assess the model's performance, the pixel count in mastoid air cells was measured. Two neuroradiologists evaluated the successful generation rates of 11 anatomical landmarks. A total of 102 patients were included in this study (training dataset, n = 54, mean age 58 ± 14, 34 females (63%); validation dataset, n = 48, mean age 61 ± 13, 29 females (60%)). In the pixel count of mastoid air cells, no difference was observed between synthetic and real images (679 ± 342 vs 738 ± 342, p = 0.13). For the six major anatomical sites, the positive generation rates were 97-100%, whereas those of the five major anatomical structures ranged from 24% to 83%. We developed a model to generate synthetic temporal bone CT images using PETRA MRI. This model can provide information regarding the major anatomic sites of the temporal bone using MRI. The proposed algorithm addresses the primary limitations of MRI in localizing anatomic sites within the temporal bone. CT is preferred for imaging the temporal bone, but has limitations in differentiating pathology there. The model achieved a high success rate in generating synthetic images of six anatomic sites. This can overcome the limitations of MRI in visualizing key anatomic sites in the temporal skull.