Carestream Health Research Articles

Characterization of Rigid and Flexible Digital Detector Arrays Using ASTM E2597/E2597M-22

ASTM E2597/E2597M-22 is a standard that summarizes a standard practice for characterization of digital detector arrays (DDAs) by manufacturers. The standard consists of a series of tests intended to deliver quantitative results for a given model of detector’s characteristics as they should perform upon sale. It was written for use in characterizing rigid detectors, but the tests are applicable to bendable DDAs, utilized for single viewing. Bendable DDAs, unlike their rigid counterparts, are made to conform around parts being inspected, such as pipes, in a similar application to film and computed radiography for imaging curved objects. As bendable DDAs are made using the same scintillators as flat panel DDAs and have similar pixel pitch and resolution capabilities, it is expected that the results from most characterization tests should be similar. Conformable DDAs produce similar imaging results as rigid DDAs but have the flexibility of use for curved surfaces. They offer a valuable tool for customers currently using film and CR who are looking to expedite their inspections or move away from use of consumable products. We performed these characterization procedures on conformable DDA models and rigid DDA models utilizing proprietary INDUSTREX software developed by Carestream Health, Inc. The experimental results are presented as part of this paper.

Assessment of Mesiobuccal Canals in Endodontically Treated Teeth in Indore Population by Cone Beam Computed Tomography: A Cross-Sectional Study.

Owing to the complicated anatomical nature of maxillary molars, untreated root canals may directly affect the outcome of root canal therapy. Therefore, cone beam computed tomography (CBCT) scanis an important tool in the evaluation of root canal systems, particularly for the detection of the second mesiobuccal(MB2) canalin maxillary molars. The current study was undertaken to detect and evaluate filled/unfilled MB2 canals in endodontically treated, asymptomatic maxillary molars, and its correlation with periapical pathology by utilizing cone beam computed tomography (CBCT). A retrospective study of 80 CBCTs of patients underwent scanning for various treatment modalities, with asymptomatic endodontically treated permanent maxillary first molars selected. Data collection occurred between January and June 2023. CBCT machine used was KODAK 9000 (Rochester, NY: Carestream Health) (Complementary Metal Oxide Semiconductor {CMOS} sensor, continuous mode and 12-28 sec scan time, 90-500 μm voxel size, and 5x3.5 cm field of view {FOV}). The axial images at mid-root level were used to assess the presence of the MB2 canal. The study included 39 (48.8%) right maxillary first molars and 41 (51.3%) left maxillary first molars. Overall, in 62 (77.5%) maxillary first molars, MB2 was missed by the practicing dentist, and in 13 (16.3%) maxillary first molars MB2 canal was not present. Of all the maxillary first molars with MB2 canal (n=67), 53 (79.1%) canals had a periapical infection, five (7.5%) showed widening of periodontal ligament space whereas nine (13.4%) had no abnormality. MB2 canals were present in the majority of cases and most of the unfilled MB2 canals showed evidence of periapical radiolucencies and showed a direct impact on the prognosis.

Association Between Gender, Age, and Skeletal Class With Mandibular Condyle Morphology: A Retrospective Study.

This study aimed to examine the impact of demographic variables on mandibular condyle morphology, a critical factor in orthodontic treatment and maxillofacial surgery. The investigation focuses on the relationship between gender, age, and skeletal class with the morphological dimensions of the condyle, utilizing panoramic radiography as a diagnostic tool. A retrospective analysis was conducted on 150 panoramic radiographs from individuals stratified into six groups according to gender and skeletal class. Skeletal classes were determined using Steiner and McNamara cephalometry. The Kodak Carestream software (Rochester, NY: Carestream Health) was employed to measure condylar height, width, and morphology. Statistical evaluations included ANOVA, correlation assessments, and multivariate binary logistic regression to discern the differences and associations among the variables studied. The findings revealed notable differences in condylar dimensions between genders across different skeletal classes, with males typically presenting larger condylar dimensions than females. The data also showed a moderate positive correlation between condyle height and width. Round-shaped condyles were the most common form found, with significant gender differences observed in certain skeletal classes. Additionally, logistic regression analysis identified significant associations between gender, age, and condylar width and shape. The study concludes that demographic factors, such as gender and age, significantly affect mandibular condyle morphology. These factors should be carefully considered in clinical evaluations using panoramic radiography to enhance the precision of diagnoses and the effectiveness of subsequent orthodontic and maxillofacial treatments. The results provide valuable insights for healthcare professionals in regions where more advanced imaging techniques may not be readily available.

Cone-beam CT sampling incompleteness: analytical and empirical studies of emerging systems and source-detector orbits.

Motivated by emerging cone-beam computed tomography (CBCT) systems and scan orbits, we aim to quantitatively assess the completeness of data for 3D image reconstruction-in turn, related to "cone-beam artifacts." Fundamental principles of cone-beam sampling incompleteness are considered with respect to an analytical figure-of-merit [FOM, denoted ] and related to an empirical FOM (denoted ) for measurement of cone-beam artifact magnitude in a test phantom. A previously proposed analytical FOM [, defined as the minimum angle between a point in the 3D image reconstruction and the x-ray source over the scan orbit] was analyzed for a variety of CBCT geometries. A physical test phantom was configured with parallel disk pairs (perpendicular to the -axis) at various locations throughout the field of view, quantifying cone-beam artifact magnitude in terms of (the relative signal modulation between the disks). Two CBCT systems were considered: an interventional C-arm (Cios Spin 3D; Siemens Healthineers, Forcheim Germany) and a musculoskeletal extremity scanner; Onsight3D, Carestream Health, Rochester, United States)]. Simulations and physical experiments were conducted for various source-detector orbits: (a)a conventional 360deg circular orbit, (b)tilted and untilted semi-circular (196deg) orbits, (c)multi-source (three x-ray sources distributed along the axis) semi-circular orbits, and (d)a non-circular (sine-on-sphere, SoS) orbit. The incompleteness of sampling [] and magnitude of cone-beam artifacts () were evaluated for each system and orbit. The results show visually and quantitatively the effect of system geometry and scan orbit on cone-beam sampling effects, demonstrating the relationship between analytical and empirical . Advanced source-detector orbits (e.g., three-source and SoS orbits) exhibited superior sampling completeness as quantified by both the analytical and the empirical FOMs. The test phantom and metric were sensitive to variations in CBCT system geometry and scan orbit and provided a surrogate measure of underlying sampling completeness. For a given system geometry and source-detector orbit, cone-beam sampling completeness can be quantified analytically (in terms arising from Tuy's condition) and/or empirically (using a test phantom for quantification of cone-beam artifacts). Such analysis provides theoretical and practical insight on sampling effects and the completeness of data for emerging CBCT systems and scan trajectories.

A Meta-Analysis on the Neurovascular Complications Of Extracorporeal Membrane Oxygenation In Critically Ill COVID-19 Patients (S4.004)

<h3>Objective:</h3> To determine the incidence and type of neurovascular complications in adult COVID-19 patients requiring veno-venous extracorporeal membrane oxygenation (VV-ECMO). <h3>Background:</h3> ECMO is a high-stakes intervention for patients with acute respiratory failure from severe COVID-19 infections. Introduction of extracorporeal circuit, COVID-19 associated endothelial injury and anticoagulation can predispose these patients to neurovascular complications, but the incidence of these adverse events in COVID-19 patients remains unknown. <h3>Design/Methods:</h3> We performed a systematic review and meta-analysis using MEDLINE, Embase, PsycINFO, and Cochrane databases to identify studies that reported neurological complications in adult COVID-19 patients receiving ECMO for respiratory failure. Among 840 identified studies, 28 studies (n = 3147) were included in the systematic review. Studies that had ≥95% of patients on VV-ECMO were pooled for meta-analyses. <h3>Results:</h3> The incidence of intracranial hemorrhages was 11% [95% CI, 8–15%], and the incidence of ischemic strokes was 2% [9%% CI, 1–3%] in patients with COVID-19 requiring VV-ECMO. Intraparenchymal and subarachnoid hemorrhages accounted for 73% and 8% of all intracranial hemorrhages, respectively. Higher anticoagulation targets did not influence the incidence of intracranial hemorrhages (p = 0.22). One study reported the occurrence of cerebral venous sinus thrombosis. <h3>Conclusions:</h3> Patients with COVID-19 requiring ECMO have a higher incidence of intracranial hemorrhage compared to historical data in non-COVID-19 patients (11% vs. 8%), while the incidence of ischemic stroke is similar (2%) in both cohorts. Intraparenchymal hemorrhage occurred most frequently. Despite earlier observations of higher thrombotic rates in COVID-19 patients, cerebral venous sinus thrombosis was rarely reported in COVID-19 patients requiring ECMO. Healthcare providers should be aware of these increased risks and maintain a high index of suspicion for intracranial hemorrhage in this patient population. <b>Disclosure:</b> Dr. Li has nothing to disclose. Miss Deng has nothing to disclose. Ms. Ma has nothing to disclose. Ms. Li has nothing to disclose. Ms. Dawson has nothing to disclose. Ms. Huong has nothing to disclose. Dr. Wang has nothing to disclose. The institution of Dr. Gofton has received research support from Government of Canada. The institution of Dr. Gofton has received research support from Canadian Institutes of Health Research. The institution of Dr. Gofton has received research support from Academic Medical Organisation of Southwestern Ontario. Dr. Gofton has a non-compensated relationship as a Medical Advisory Board Member with NORSE Institute that is relevant to AAN interests or activities. Dr. Nagpal has nothing to disclose. The institution of Dr. Slessarev has received research support from Carestream health . Dr. Slessarev has received intellectual property interests from a discovery or technology relating to health care.

In Vitro Trueness and Precision of Intraoral Scanners in a Four-Implant Complete-Arch Model

(1) Background: New intraoral (IOS) and laboratory scanners appear in the market and their trueness and precision have not been compared. (2) Methods: Seven IOS and two laboratory scanners were used to scan a mandibular edentulous model with four parallel internal hexagon implant analogues and PEEK scan bodies. Digital models in Standard Tessellation Language (STL) were created. The master model with the scan bodies was scanned (×10) with a computerized numerical control 3D Coordinate Measuring Machine (CMM). The short (distances of adjacent scan posts) and long distances (distances of the scan posts with non-adjacent sites in the arch) among the centroids of the four analogues were calculated using CMM special software. Trueness (comparisons with the master model) and precision (intragroup comparisons) were statistically compared with ANOVA, chi-square and Tukey tests. (3) Results: Laboratory scanners had the best trueness and precision compared to all IOSs for long distances. Only iTero (Align Technologies Inc., Milpitas, CA, USA) had comparable trueness with one laboratory scanner in short and long distances. For short distances, CS3600 (Carestream Health, Inc., Rochester, NY, USA), Omnicam, Primescan (Sirona Dental Sys-tems GmbH, Bens-heim, Germany) and TRIOS 4 (3Shape A/S, Copen-hagen, Denmark) had similar trueness to one laboratory scanner. From those, only Omnicam and Primescan had similar precision as the same laboratory scanner. Most IOSs seem to work better for smaller distances and are less precise in cross-arch distances. (4) Conclusions: The laboratory scanners showed significantly higher trueness and precision than all IOSs tested for the long-distance group; for the short distance, some IOSs were not different in trueness and precision than the laboratory scanners.

3D-printed large-area focused grid for scatter reduction in cone-beam CT.

Cone-beam computed tomography (CBCT) systems acquire volumetric data more efficiently than fan-beam or multislice CT, particularly when the anatomy of interest resides within the axial field-of-view of the detector and data can be acquired in one rotation. For such systems, scattered radiation remains a source of image quality degradation leading to increased noise, image artifacts, and CT number inaccuracies. Recent advances in metal additive manufacturing allow the production of highly focused antiscatter grids (2D-ASGs) that can be used to reduce scatter intensity, while preserving primary radiation transmission. We present the first implementation of a large-area, 2D-ASG for flat-panel CBCT, including grid-line artifact removal and related improvements in image quality. A 245 × 194 × 10 mm 2D-ASG was manufactured from chrome-cobalt alloy using laser powder-bed fusion (LPBF) (AM-400; Renishaw plc, New Mills Wotton-under-Edge, UK). The 2D-ASG had a square profile with a pitch of 9.09 lines/cm and 10:1 grid-ratio. The nominal 0.1mm grid septa were focused to a 732 mm x-ray source to optimize primary x-ray transmission and reduce grid-line shadowing at the detector. Powder-bed fusion ensured the structural stability of the ASG with no need for additional interseptal support. The 2D-ASG was coupled to a 0.139-mm element pitch flat-panel detector (DRX 3543, Carestream Health) and proper alignment was confirmed by consistent grid-line shadow thickness across the whole detector array. A 154-mm diameter CBCT image-quality-assurance phantom was imaged using a rotary stage and a ceiling-mounted, x-ray unit (Proteus XR/a, GE Medical Systems, 80kVp, 0.5mAs). Grid-line artifacts were removed using a combination of exposure-dependent gain correction and spatial-frequency, Fourier filtering. Projections were reconstructed using a Parker-weighted, FDK algorithm and voxels were spatially averaged to 357 × 357 × 595 µm to improve the signal-to-noise characteristics of the CBCT reconstruction. Finally, in order to compare image quality with and without scatter, the phantom was scanned again under the same CBCT conditions but with no 2D-ASG. No additional antiscatter (i.e., air-gap, bowtie filtration) strategies were used to evaluate the effects in image quality caused by the 2D-ASG alone. The large-area, 2D-ASG prototype was successfully designed and manufactured using LPBF. CBCT image-quality improvements using the 2D-ASG included: an overall 14.5% CNR increase across the volume; up to 48.8% CNR increase for low-contrast inserts inside the contrast plate of the QA phantom; and a 65% reduction of cupping artifact in axial profiles of water-filled cross sections of the phantom. Advanced image processing strategies to remove grid line artifacts did not affect the spatial resolution or geometric accuracy of the system. LPBF can be used to manufacture highly efficient, 2D-focused ASGs that can be easily coupled to clinical, flat-panel detectors. The implementation of ASGs in CBCT leads to reduced scatter-related artifacts, improved CT number accuracy, and enhanced CNR with no increased equivalent dose to the patient. Further improvements to image quality might be achieved with a combination of scatter-correction algorithms and iterative-reconstruction strategies. Finally, clinical applications where other scatter removal strategies are unfeasible might now achieve superior soft-tissue visualization and quantitative capabilities.

Evaluation of angulation between labial &amp; lingual surfaces of crown of anterior teeth &amp; 3D mapping lingual surface for development of concept of new preadjusted lingual bracket

Introduction: Lingual orthodontics grew slowly in North America in the 1980s as orthodontists grappled with the lingual technique, which needed distinct treatment planning and a different approach to biomechanics, as well as ergonomics and treatment efficacy difficulties. The early excitement of lingual orthodontic treatment faded with the discovery of "tooth-colored" labial brackets manufactured from single-crystal sapphire and later from ceramics, and much of the improvement of lingual orthodontics occurred outside the United States. Removable orthodontic aligners, rather than lingual braces, have become the treatment option for patients seeking invisible orthodontics with the introduction. The present work focuses of digital analysis and evaluation of angulation between labial &amp; lingual surface of crown of each anterior tooth and lingual curvature for the development of pre adjusted lingual bracket system. Material &amp; Methods: Sample consists of 100 dental cast (maxillary &amp; mandible) and 100 CBCT scans made at Santosh Dental College, Ghaziabad which were selected on the basis of Angle’s Class I molar relationship without any crowding, rotation, attrition, abrasion, erosion, abfraction &amp; anomaly on any tooth with the patient age group between 16 years to 20 years. CBCT scans were taken by KODAK 9500 Cone Beam 3D System (Carestream Health, Inc. &#x0D;

Artificial intelligence-based cephalometric landmark annotation and measurements according to Arnett's analysis: can we trust a bot to do that?

To assess the reliability of CEFBOT, an artificial intelligence (AI)-based cephalometry software, for cephalometric landmark annotation and linear and angular measurements according to Arnett's analysis. Thirty lateral cephalometric radiographs acquired with a Carestream CS 9000 3D unit (Carestream Health Inc., Rochester/NY) were used in this study. The 66 landmarks and the 10 selected linear and angular measurements of Arnett's analysis were identified on each radiograph by a trained human examiner (control) and by CEFBOT (RadioMemory Ltd., Belo Horizonte, Brazil). For both methods, landmark annotations and measurements were duplicated with an interval of 15 days between measurements and the intraclass correlation coefficient (ICC) was calculated to determine reliability. The numerical values obtained with the two methods were compared by a t-test for independent variables. CEFBOT was able to perform all but one of the 10 measurements. ICC values > 0.94 were found for the remaining eight measurements, while the Frankfurt horizontal plane - true horizontal line (THL) angular measurement showed the lowest reproducibility (human, ICC = 0.876; CEFBOT, ICC = 0.768). Measurements performed by the human examiner and by CEFBOT were not statistically different. Within the limitations of our methodology, we concluded that the AI contained in the CEFBOT software can be considered a promising tool for enhancing the capacities of human radiologists.

Assessment of the position and level of mental nerve for placement of implants using cone-beam computed tomography & panoramic radiograph in the Saudi population

Background and objectiveIn surgical dentistry, shape, location, position, and extent of the anterior loop of mental foramen plays a deliberately imperative landmark during an osteotomy procedure. To evade any neurological disturbance during implant surgery radiological assessment is compulsory. Therefore, the aim of the study was to assess the position and level of mental nerve for placement of implants using Cone-beam computed tomography & Panoramic radiography in the Saudi population. Materials and methodsA total of 150 CBCT and Panoramic radiographs were taken from the patients who visited the Department of Oral Medicine and Radiology. The data collection was done by using the same radiographic pieces of equipment for both CBCT and Panoramic radiographs. CBCT images taken from Kodak 9000 3D, Carestream Health, Inc., New York, USA, and Panoramic Radiographs taken from Panoramic Planmeca ProMax, Helsinki, Finland (Vujanovic-Eskenazi et al., 2015). The Chi-square test student test was used for statistical analysis. ResultsThe most frequent shape and location of mental foramen in both CBCT and Panoramic radiographs were oval and in between the first and second premolar, both in CBCT & PR views. The visibility of mental loop on CBCT & PR view showed that; visibility of mental loop in CBCT was higher with 42(56%) as compared with PR view 26(34.66%) with statistically significant p-value 0.014. The mean length of the mental loop on CBCT was statistically significant (p = 0.001). But the mean distance from the lower point of the mental foramen to the lower border of the mandible was not statistically significant. ConclusionBased on the results of the present study; the visibility of the mental loop and its extension is more in CBCT as compared with PR views. Therefore, we recommended CBCT, during of implant surgery.

Cone beam evaluation of pharyngeal airway space in adult skeletal class II div I and class II div II patients with different growth patterns

Objective: To determine and compare the relationship between pharyngeal volume in subjects with class II div I and div II malocclusions. And To determine the relationship between different growth patterns and pharyngeal volume. Materials and Method: This study was conducted among 60 patients in the age group of 18 to 45 years of North Indian origin with class II malocclusions requiring CBCT, reporting to the department of Orthodontics and Dentofacial Orthopaedics at RUHS College of Dental Sciences, Jaipur out of which 30 were class II div I (15 vertical and 15 horizontal growth pattern) and 30 were class II div II (15 vertical and 15 horizontal growth pattern Cone beam computed tomography scans were taken using Carestream CS9300 imaging system (CS 3D Imaging v3.5.7; Carestream Health Inc New York, USA) using FOV of 17x11 cm. Two characteristics in each cbct were measured using the dr Able ( 3d doctor) software : pharyngeal volume in (cm) cube in relation to type of class II malocclusion and pharyngeal volume in (cm) cube in relation to type of growth pattern in class II malocclusion. Results: No significant difference in pharyngeal volume found between skeletal class II div I and div II group Significantly Reduced pharyngeal volume found in vertical growth pattern group. Conclusion: Pharyngeal volume in class II div II group was less as compared to class II div I group but difference was statistically insignificant Vertical growth pattern patients have lower pharyngeal volume as compared to horizontal growth pattern in both sub divisions of class II malocclusion confirming an association between pharyngeal airway space and a vertical skeletal pattern.

THE EFFECTS OF 3D MODELING ON PLANNING OF MAXILLOFACIAL SURGERY: A Preliminary CBCT STUDY

Abstract: Objectives: The aim is to evaluate the contribution of 3D modeling data to the planning of the maxillofacial surgery and to determine the indications of 3D modeling. Materials and Methods: In this preliminary study, CBCT images of 2 patients with the Kodak 9000 3D (Kodak Carestream Health, Trophy, France) system were used. The segmentation procedures of the pathologies were performed manually, and was followed by the construction of the 3D models. A questionnaire was prepared by consensus of the research team, including the parameters which are critical in preoperative maxillofacial surgery planning. Five oral and maxillofacial surgeons independently evaluated both the traditional CBCT data and 3D model assisted data under the same viewing conditions. The extent of their decision change was scored using a 2 point Likert scale. Conventional (pre 3D model) versus 3D model assisted data (post 3D model) scores were analyzed. Pair-wise comparisons were completed using Fisher’s exact test (P &amp;lt; 0.05). Kappa was used to measure inter-observer agreement. Results: In both of the evaluation sessions (pre and post 3D model), operation time, defect size and complication risk factors showed the highest variation for both patients. The difference between the decision change proportions for the variables of pre and post 3D model sessions were not statistically significant (p&amp;gt;0.05). Except 2 observers with excellent agreement for both evaluations (p=0.036), the agreement rates were fair without statistical significance. Conclusions: The results confirmed that personalized 3D modeling constructed by CBCT data may lead to changes in surgical treatment planning protocol of complex cases.

Smartphone Use for Tomographic Evaluation: Application in Endodontic Diagnosis

IntroductionPortable equipment that allows quick exchanges of information, such as smartphones, is increasingly important in dentistry. Thus, they have become frequently used, with the potential to contribute to the tomographic evaluation. This study aimed to evaluate the accuracy of smartphone applications for diagnosing the root canal system (RCS) and measuring the root canal length. MethodsDigital Imaging and Communications in Medicine files of 92 lower incisor teeth were evaluated by 2 trained and calibrated examiners using CS 3D Imaging software (Carestream Health, Rochester, NY) and 2 smartphone applications (DroidRender; Startm, Zhubei, Taiwan and Horos Mobile; iCat Solutions Ltd, Norwich, United Kingdom). The RCS was assessed according to Vertucci’s classification, and the tooth length was measured using linear cusp-apex measurements. The diagnostic reference standard was obtained by the mode and the mean of the evaluations made by 3 experienced examiners using the CS 3D Imaging software. The diagnostic performance of RCS was evaluated using sensitivity (Se), specificity (Sp), and overall accuracy (Ac). Bland-Altman analysis was used to assess the agreement of linear measurements. ResultsThe diagnostic tests showed similar performance between the smartphone applications (DroidRender: Se = 1.00, Sp = .95, and Ac = 0.97; Horos: Se = 0.95, Sp = .94, and Ac = 0.95) and the computer software (Se = 0.97–0.95, Sp = .93–0.96, and Ac = 0.95–0.96). The smartphone applications showed discrepancies greater than 1.0 mm for the dental lengths, which may signal relevant differences in some clinical situations. ConclusionsSmartphone applications offered similar diagnostic performance in comparison with the computer software for the RCS evaluation.

STATIN USE IS ASSOCIATED WITH SUBTLE CHANGES IN MUSCLE COMPOSITION AND QUALITY: A QUANTITATIVE IMAGING ANALYSIS USING OAI DATA

Subjective statin-associated musculoskeletal symptoms such as myalgia are commonly reported and contribute to statins' non-adherence. Several trials have recently suggested that in the absence of rare myositis, such symptoms are probably a placebo effect. However, no longitudinal study has been conducted to investigate whether statin use can be associated with deterioration in muscle quality. Such an association can be of particular clinical concern in older patients with or at-risk of knee OA, in whom muscle changes can affect the knee OA clinical outcomes. To assess longitudinal changes of validated thigh muscle quality biomarkers associated with statin use in people with or at-risk of knee OA. OAI Statin users at baseline or any of the four annual follow-up visits and non-users were matched for confounding by indication using 1:1 propensity-score (PS) matching. Potential confounders as covariates of the PS-matching included a wide range of demographic variables, comorbid diseases, risk factors, and medications. After PS-matching, 3,772 thighs of 1,910 participants were included (1,886 thighs of statin-users: 1,886 of non-users; age: 62±9 years (average ± SD), range: 45-79; female/male ratio: 1). Participants were further stratified according to baseline radiographic knee OA status (with versus at-risk of knee OA). We trained, tested, and used an automated deep learning model with a 2D U-Net structure to segment thigh muscle MRIs, with similar results to manual segmentation and quantification. Longitudinal muscle quality biomarkers included cross-sectional area (CSA), intramuscular adipose tissue (intra-MAT), contractile percent, and knee extensors and flexors maximum contractile force and specific contractile force (contractile force/CSAs) at baseline, 2nd, and 4th-year follow up. Linear mixed-effects models were used. At baseline, there was no statistically significant imbalance in PS-matching variables or muscle quality biomarkers between PS-matched statin-users and non-users. During four years, statin use was associated with a slight decrease in muscle quality, indicated by decreased knee extensor (quadriceps) maximum and specific contractile forces (mean difference (% of baseline value), 95%CI: -1.85 Newton/year (0.5% of 355.15N at baseline), -3.23 – -0.47, and -0.04 N/cm2/year (0.6% of 6.96N/cm2 at baseline), -0.07 – -0.01), contractile percent of the thigh muscles (-0.03%/year (0.03% of 95.32% at baseline), -0.06 – -0.01), and increased thigh intra-MAT (3.06 mm2/year (0.7% of 461.45mm2 at baseline), 0.53–5.59). However, stratification analysis showed that these results were only present in participants at-risk of knee OA but not those with the existing radiographic knee OA at baseline. Statin use is associated with decreased muscle quality, indicated by reduced contractility of the extensor (quadriceps) muscle and increased intra-muscular fat deposition. However, considering the small size of changes in muscle quality compared to substantial favorable cardiovascular effects of statins in clinical practice, these muscle changes might be considered clinically negligible. NIH NIAMS, under Award Number R01AR079620-01. AG reported receiving funding from Merck Serono, AstraZeneca, Galapagos, Pfizer, Roche, TissueGene (for consultation), and Boston Imaging Core Lab (as the president and stockholder). SD reported that he received funding from Toshiba Medical Systems (for consultation) and grants from GERRAF and Carestream Health (for a clinical trial study). CORRESPONDENCE ADDRESS: sdemehri1@jhmi.edu

THIGH MUSCLE CHANGES CAN WORSEN SUBSEQUENT KNEE OA CLINICAL OUTCOMES: USE OF DEEP LEARNING AND PROPENSITY-SCORE MATCHING ON OAI DATA

Thigh muscles play an important role in knee joint biomechanical stability, and changes in their size and quality are associated with knee OA incidence. There are currently no known disease-modifying medications for mitigating knee OA-related symptom worsening and delaying TKA. Therefore, non-surgical, non-pharmacological approaches targeting thigh muscle strengthening and composition have important clinical implications. The structural therapeutic effects of such interventions can be quantified using muscle MRI. However, no conclusive longitudinal data is available on the association of quantitative thigh muscle MRI markers with knee OA-related clinical outcomes. We aimed to investigate the longitudinal changes in quantitative muscle cross-sectional area (CSA) and adipose tissue in knee OA and their association with downstream symptom worsening and TKA. We trained, tested, and implemented a fully automated supervised deep learning model to segment longitudinal thigh MRIs of a large sample of the OAI participants. In an analysis of OAI data, knees of participants with available quality thigh MRIs at baseline and at least one follow-up visit were included and classified as with and without knee OA according to baseline radiographic KLG ≥2 and matched for confounders using propensity score matching. An automated deep learning model for thigh MRI 2D-segmentation was developed and tested. Markers of muscle CSA and intramuscular adipose tissue (intra-MAT) were measured at baseline, 2nd and 4th-years follow-up (period-1) and compared between knees with and without knee OA using linear mixed-effect regression models. Furthermore, in knees with knee OA, the association of period-1 changes in muscle markers with risk of TKA (Cox proportional-hazards) and symptom worsening (mixed-effect models) during the 4th- to 9th-year (period-2) was evaluated. This study included 4,634 matched-thighs (2,317:2,317 with:without knee OA) of 2,344 participants (mean age±SD:62±9, 1,292 females). Compared with those without, knees with knee OA had a decrease in quadriceps CSA (mean difference: -8.21mm2/year, p:.004) and an increase in quadriceps intra-MAT (1.98mm2/year, p:.007). Decreased CSA and increased intra-MAT of quadriceps during period-1 predicted downstream (period-2) knee OA symptom worsening (WOMAC total score, odds ratios:0.24 (negative association), p<.001, and 1.38, p:.019, respectively). Quadriceps CSA changes, negatively associated with higher future TKA risk (hazard ratio:0.70, p<.001). Knee osteoarthritis was associated with longitudinal MRI-derived decreased quadriceps cross-sectional area and increased intramuscular adipose tissue. These potentially modifiable risk factors predicted downstream symptom worsening and knee replacement. NIH NIA, Award Number P01AG066603 NIH NIAMS, Award Number R01AR079620-01 AG reported receiving funding from Merck Serono, AstraZeneca, Galapagos, Pfizer, Roche, TissueGene (for consultation), and Boston Imaging Core Lab (as the president and stockholder). SD reported that he received funding from Toshiba Medical Systems (for consultation) and grants from GERRAF and Carestream Health (for a clinical trial study). Authors acknowledge OAI staff and team. CORRESPONDENCE ADDRESS: Mohajer.bahram@gmail.com .

DEEP‐LEARNING ASSESSED BONE MARROW LESIONS CAN PREDICT FUTURE RADIOGRAPHIC OSTEOARTHRITIS INCIDENCE AND SYMPTOM WORSENING: OAI DATA

Bone marrow lesions (BMLs) are the MRI hallmark of bone involvement in knee OA and correlate with knee pain. While they may have great prognostic values, their assessment in large-scale datasets can be time-consuming and subject to inter-reader variability. we aimed to develop a validated deep-learning (DL) method for accurate classification of knee BMLs and to investigate their predictive role in the radiographic incidence and symptom worsening in patients with baseline pre-radiographic knee OA (i.e., KLG <2). We used coronal MPR and sagittal intermediate-weighted MRIs from 2488 knees with available semi-quantitative MRI Osteoarthritis Knee Scores (MOAKS) reading of the Osteoarthritis Initiative (OAI) cohort to train and 5-fold cross-validation of convolutional neural networks. Using the developed DL algorithm, participants were dichotomized according to baseline BML status as “no/minimal” (≤2 knee subregions affected and maximum BML grade ≤1) or “moderate/severe.” The model was then used to predict BML status at the baseline visit of the remaining knees without available MOAKS readings. Knees with moderate/severe and with no/minimal BMLs were selected using 1:1/2 propensity score (PS) matching for potential confounders. Survival and mixed models were used to assess the association between baseline BML and risk and odds of radiographic incidence and symptom worsening over 9 years, respectively. The DL model had an AUC of 0.84±0.01, sensitivity of 0.85±0.02, and specificity of 0.63±0.03. The PS matched cohorts with moderate/severe and no/minimal BML consisted of 2065 and 1236 knees. Having moderate/severe BMLs at baseline was associated with almost twice the risk of knee OA radiographic incidence (hazard ratio, 95%CI: 1.92, 1.56–2.36) and odds of symptom worsening (WOMAC total score OR:1.76, 1.07–2.88) in 9 years of follow-up in knees with pre-radiographic knee OA. DL models can classify knee MRIs according to BML status with combined MOAKS measures of the number of affected subregions and maximum BML grade. Using these predictions, we could show that baseline BMLs can predict downstream knee OA incidence and symptom worsening in patients with pre-radiographic knee OA. NIH National Institute of Aging (NIA) under Award Number P01AG066603 and NIH National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) under Award Number R01AR079620-01. AG reported receiving funding from Merck Serono, AstraZeneca, Galapagos, Pfizer, Roche, TissueGene (for consultation), and Boston Imaging Core Lab (as the president and stockholder). SD reported that he received funding from Toshiba Medical Systems (for consultation) and grants from GERRAF and Carestream Health (for a clinical trial study). Authors acknowledge OAI staff and team. CORRESPONDENCE ADDRESS: sdemehri1@jhmi.edu .

LEVOTHYROXINE USE MAY BE ASSOCIATED WITH LONGITUDINAL QUADRICEPS ATROPHY AND SUBSEQUENT KNEE OA RISK: PRELIMINARY ANALYSIS FROM OAI COHORT

Levothyroxine, the primary treatment for hypothyroidism, is prescribed for more than 7% of Americans. Levothyroxine use, or the underlying hypothyroidism can be associated with musculoskeletal symptoms; however, no prior work has investigated this association using sensitive biomarkers. We examined the association between levothyroxine use and longitudinal MRI biomarkers for thigh muscle mass and composition in participants at-risk of knee OA and their mediatory role in subsequent knee OA radiographic and symptomatic incidence. Thighs and knees of OAI participants without established radiographic knee OA were included. Levothyroxine users were defined as self-reported use at all annual follow-up visits until the 4th-year and were matched with nonusers for potential confounders using 1:2/3 propensity-score (PS) matching. We developed and validated a deep learning method for automated thigh segmentation and assessed the association between levothyroxine use and 4-year longitudinal changes in muscle mass, including cross-sectional area (CSA) and muscle composition biomarkers including intramuscular adipose tissue (intra-MAT), contractile percentage, and specific force (force per CSA). We further assessed whether levothyroxine use is associated with an 8-year risk of standard knee OA radiographic and symptomatic incidence. Finally, we assessed whether the association between levothyroxine use and knee OA incidence is mediated via muscle changes. We included 1485 matched thighs/knees (387:1098 users:non-users; age: 62±9 years, female/male:3.1). Levothyroxine use was associated with decreased quadriceps CSAs (mean difference, 95%CI:-15.46mm2/year, -25.11– -5.82) but not thigh muscles’ composition biomarkers. Levothyroxine use was also associated with an increased 8-year risk of radiographic (hazard ratio (HR):1.59, 1.15–2.20) and symptomatic knee OA incidence (HR:1.60, 1.12–2.29). A decrease in quadriceps CSA partially mediated the increased risk of knee OA incidence associated with levothyroxine use. Our exploratory analyses suggest that levothyroxine users might have increased risk of thigh muscle atrophy and subsequent knee OA. Study interpretation should consider underlying thyroid function as a potential confounder or effect modifier and therefore, future studies are warranted to investigate the underlying thyroid function biomarkers for longitudinal thigh muscles atrophy and associated knee OA incidence risk. NIH National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) under Award Number R01AR079620-01. AG reported receiving funding from Merck Serono, AstraZeneca, Galapagos, Pfizer, Roche, TissueGene (for consultation), and Boston Imaging Core Lab (as the president and stockholder). SD reported that he received funding from Toshiba Medical Systems (for consultation) and grants from GERRAF and Carestream Health (for a clinical trial study). Authors acknowledge OAI staff and team. CORRESPONDENCE ADDRESS: sdemehri1@jhmi.edu .

How has the COVID-19 pandemic affect the rejection rates and repeat reasoning of digital radiography?

Objectives:To compare the digital radiology rejection rates and reasoning pre-COVID-19 (PC) and during COVID-19 (DC) from September 2019 to August 2020.Methods:This record-base retrospective study where data were extracted from the radiography equipment (Carestream Health, Rochester, New York, USA) at the Department of Radiology, King Abdulaziz University Hospital, Jeddah, Saudi Arabia over 12 months. The data were equally divided into PC and DC.Results:The DC rejection rate decreased from PC by 2.6% with a significant p=0.00001. During COVID-19 there were 15,376 images of different body parts, versus 23,861 images during PC. Position errors were the main reasons for rejection for both PC (39.8%) and DC (42.7%), followed by technique errors (PC: 19.2%) (DC: 17.2%).Conclusion:Different sectors in hospitals were affected by COVID-19, including diagnostic radiology, in the positive direction. Thus, the DC rejection rate was markedly reduced compared with PC. This may be due to radiology technicians becoming more cautious in dealing with patients.

Ethnic variation in medial orbital wall anatomy and its implications for decompression surgery

BackgroundTo describe the inter-ethnic variation in medial orbital wall anatomy between Chinese, Malay, Indian and Caucasian subjects.MethodsSingle-centre, retrospective, Computed Tomography (CT)-based observational study. 20 subjects of each ethnicity, were matched for gender and laterality. We excluded subjects younger than 16 years and those with orbital pathology. OsiriX version 8.5.1 (Pixmeo., Switzerland) and DICOM image viewing software CARESTREAM Vue PACS (Carestream Health Inc., USA) were used to measure the ethmoidal sinus length, width and volume, medial orbital wall and floor angle and the relative position of the posterior ethmoid sinus to the posterior maxillary wall. Statistical analyses were performed using Statistical Package for Social Sciences version 25.0 (IBM, USA).ResultsThere were 12 males (60 %) in each group, with no significant difference in age (p = 0.334–0.994). The mean ethmoid sinus length in Chinese, Malay, Indian and Caucasian subjects, using the Chinese as reference, were 37.2, 36.9, 38.0 and 37.4mm, the mean width was 11.6, 10.5, 11.4 and 10.0mm (p = 0.020) and the mean ethmoid sinus volume were 3362, 3652, 3349 and 3898mm3 respectively. The mean medial orbital wall and floor angle was 135.0, 131.4, 131.0 and 136.8 degrees and the mean relative position of posterior ethmoid sinus to posterior maxillary wall were − 2.0, -0.2, -1.5 and 1.6mm (p = 0.003) respectively.ConclusionsNo inter-ethnic variation was found in decompressible ethmoid sinus volume. Caucasians had their posterior maxillary sinus wall anterior to their posterior ethmoidal walls unlike the Chinese, Malay and Indians. Awareness of ethnic variation is essential for safe orbital decompression.

The dental pulp chamber evaluation by using cone-beam computed tomography

Background: Cone-beam computed tomographic (CBCT) imaging is a valuable tool in dental practice. It is widely used in endodontic treatment for the root canal morphology examination. Therefore, the purpose of this study was to use CBCT to calculate the volume of the pulp chamber at different tooth groups. Material and methods: This study conforms to protocols approved and in accordance with the ethics committee’s requirements, informed consent was obtained from each patient. Morphologic measurements of 120 maxillary and 120 mandibular molars (from 40 patients, aged 18–45 years) were included in this study. CBCT images were taken using a Kodak 9500 (Dental Systems, Carestream Health) operated at 90 kVp with a voxel size of 300 mm and a field of view of 90-50 mm. All scans were taken following the manufacturer’s recommendation protocol. According to the examination requirements, C-shaped roots, single-rooted molars, crowned teeth, and teeth with caries and/or restorations violating the pulp chamber were excluded. All measurements were taken on the coronal plane view. Results: In the present study, we used CBCT imaging to gather information regarding pulp chamber volume. With the scanned 3-dimensional images, we were able to clinically determine the pulp chamber parameters using a standardized and defined spatial approach. Conclusions: The data we collected here serve as a proof of principle for the analysis of dental landmarks before collecting stem cells. In this particular study, existing CBCT scans were used to provide useful information that can be used as a guide to determine the volume of the pulp chamber