Computed Tomography Measurements Research Articles

Multimodal imaging assessment of mitral valve area after transcatheter mitral valve implantation: A three-dimensional echocardiographic and CT scan study

The assessment of mitral bioprosthetic area remains a technical challenge, and its calculation by the continuity equation using transthoracic echocardiography (TTE) may be invalidated in several situations, especially after transcatheter mitral valve implantation (TMVI). This study aims to develop a new technique to measure the mitral valve area after a TMVI using a multimodal three-dimensional echocardiographic and computed tomography (CT) approach. Among the patients hospitalized for TMVI at Bichat Hospital between June 2017 and February 2021, we selected 24 who had both a transesophageal echocardiography (TEE) and a cardiac CT after TMVI and before discharge. We performed two area measurements by planimetry: the geometric orifice area (GOA) corresponding to the area delimited by the edges of the open valve leaflets after alignment in the plane of the proximal coaptation point of the bioprosthesis leaflets; and the smallest valve area (SVA) defined by the smallest measurable area of the open prosthesis, at the free edges of the leaflets. In our cohort, the GOA was 1.73 ± 0.41 cm2 on 3D TEE and 1.75 ± 0.42 cm2 on CT. The SVA was 1.40 ± 0.31 cm2 on 3D TEE and 1.49 ± 0.37 cm2 on CT. There was a good agreement between the two techniques for GOA and SVA (ICC > 0.6, P < 0.01) and a good correlation between the two measurements on 3D TEE as well as on CT (Pearson 0.88 and 0.91 respectively, P < 0.001). Our work suggests a new approach to multimodal assessment of prosthetic mitral valve area after TMVI, using 3D TEE and CT scan. Further studies are needed to complete our results, especially to confirm the feasibility and reproducibility of the measurements. It would also be interesting to correlate these area measurements with the clinical prognosis of patients after TMVI. Agreement between 3D TEE and CT measurements (Fig. 1).

A Multimodality Imaging Approach to Defining Risk in Patients With Acute Pulmonary Embolism

Morbidity and mortality for acute pulmonary embolism (PE) remain high. Therapies such as catheter-directed thrombolysis may improve outcomes, but these are generally reserved for higher-risk patients. Imaging may help guide the use of the newer therapies, but current guidelines focus more on clinical factors. Our goal was to create a risk model that incorporated quantitative echocardiographic and computed tomography (CT) measures of right ventricular (RV) size and function, thrombus burden, and serum biomarkers of cardiac overload or injury. This was a retrospective study of 150 patients evaluated by a PE response team. Echocardiography was performed within 48hours of diagnosis. Computed tomography measures included RV/left ventricular (LV) ratio and thrombus load (Qanadli score). Echocardiography was used to obtain various quantitative measures of RV function. We compared characteristics of those who met the primary endpoint (7-day mortality and clinical deterioration) to those who did not. Receiver operating curve analysis was used to assess the performance of different combinations of clinically relevant features and the association with adverse outcomes. Fifty-two percent of patients were female, with age 62±17 years, systolic blood pressure 123±25mm Hg, heart rate 98±19, troponin 3.2±35ng/dL, and b-type natriuretic peptide (BNP) 467±653. Fourteen (9.3%) were treated with systemic thrombolytics, 27 (18%) underwent catheter-directed thrombolytics, 23 (15%) were intubated or required vasopressors, and 14 (9.3%) died. Patients who met the primary endpoint (44%) versus those who did not (56%) had lower RV S' (6.6 vs 11.9cm/sec; P<.001) and RV free wall strain (-10.9% vs -13.6%; P=.005), higher RV/LV ratio on CT, and higher serum BNP and troponin levels. Receiver operating curve analysis demonstrated an area under the curve of 0.89 for a model that included RV S', RV free wall strain and tricuspid annular plane systolic excursion/RV systolic pressure ratio from echo, thrombus load and RV/LV ratio from CT, and troponin and BNP levels. A combination of clinical, echo, and CT findings that reflect the hemodynamic effects of the embolism identified patients with adverse events related to acute PE. Optimized scoring systems that focus on reversible abnormalities attributable to PE may allow more appropriate triaging of intermediate- to high-risk patients with PE for early interventional strategy.

Transcranial sonographic measurement of the third ventricle to detect hydrocephalus in children population: Correlation to computed tomography.

In neuro-intensive care, transcranial temporal ultrasound is used in adults and children to monitor brain-injured patients. It is accepted as a valuable tool for exploring brain structures. Our study aims to establish a correlation between the measurement of the third ventricle (V3) by transcranial ultrasound via temporal window and a reference method, computed tomography (CT), which could validate the method for hydrocephalus detection in the children population. This is a prospective double-blind study of 34 children under 15 years. Two consultants in intensive care performed the ultrasound while a radiologist performed the CT measurements. Of the 34 patients included, the V3 could be measured in 88% of cases. Among these 30 patients, there is a good correlation between CT and ultrasound measurements with a Spearman correlation coefficient of 0.773. This correlation is more important as the diameter of the V3 increases. We could determine a threshold of 3.65 mm in diameter to identify hydrocephalus on ultrasound with a detection sensitivity of 100%, and a specificity of 94.1%. Measuring the diameter of the V3 by trans-cranial sonography remains a simple, reproducible, non-invasive tool and has a good correlation with reference examinations such as CT.

Resonant ultrasound spectroscopy measurement and modeling of additively manufactured octet truss lattice cubes

In this work, the elastic characteristics of additively manufactured Ti-5553 octet truss lattice cubes were examined using resonant ultrasound spectroscopy (RUS) techniques and correlated to X-ray computed tomography measurements of strut continuity. RUS models and measurements identified an outlier lattice possessing lower effective modulus despite larger effective density. Experimental measurements of density and effective Young's modulus were treated as input parameters in a homogenous anisotropic continuum model. The continuum model exhibited good agreement with experimental RUS measurements, thus confirming the potential for a simplified approximation of the octet truss lattice.

Method to visualize the effect of violin string pressure on the body structure by computed tomography measurements

Method to visualize the effect of violin string pressure on the body structure by computed tomography measurements

Geometrical Influence on Material Properties for Ti6Al4V Parts in Powder Bed Fusion

One major advantage of additive manufacturing is the high freedom of design, which supports the fabrication of complex structures. However, geometrical features such as combined massive volumes and cellular structures in such parts can lead to an uneven heat distribution during processing, resulting in different material properties throughout the part. In this study, we demonstrate these effects, using a complex structure consisting of three conic shapes with narrow cylinders in between hindering heat flux. We manufacture the parts via powder bed fusion of Ti6Al4V by applying a laser beam (PBF-LB/M) as well as an electron beam (PBF-EB). We investigate the impact of the different thermal regimes on the part density, microstructure and mechanical properties aided by finite element simulations as well as by thermography and X-ray computed tomography measurements. Both simulations and thermography show an increase in inter-layer temperature with increasing part radius, subsequently leading to heat accumulation along the build direction. While the geometry and thermal history have a minor influence on the relative density of the parts, the microstructure is greatly affected by the thermal history in PBF-LB/M. The acicular martensitic structure in the narrow parts is decomposed into a mix of tempered lath-like martensite and an ultrafine α + β microstructure with increasing part radius. The EBM part exhibits a lamellar α + β microstructure for both the cylindric and conic structures. The different microstructures directly influence the hardness of the parts. For the PBF-LB part, the hardness ranges between 400 HV0.5 in the narrow sections and a maximum hardness of 450 HV0.5 in the broader sections, while the PBF-EB part exhibits hardness values between 280 and 380 HV0.5.

Computed tomography measure of lung injury and future interstitial features: the CARDIA Lung Study.

Visually normal areas of the lung with high attenuation on computed tomography (CT) imaging, termed CT lung injury, may represent injured but not yet remodelled lung parenchyma. This prospective cohort study examined if CT lung injury is associated with future interstitial features on CT and restrictive spirometry abnormality among participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study. CARDIA is a population-based cohort study. CT scans obtained at two time points were assessed objectively for amount of lung tissue characterised as CT lung injury and interstitial features. Restrictive spirometry was defined as having a forced vital capacity (FVC) <80% predicted with forced expiratory volume in 1 s/FVC ratio >70%. Among 2213 participants, the median percentage of lung tissue characterised as CT lung injury at a mean age of 40 years was 3.4% (interquartile range 0.8-18.0%). After adjustment for covariates, a 10% higher amount of CT lung injury at mean age 40 years was associated with a 4.37% (95% CI 3.99-4.74%) higher amount of lung tissue characterised as interstitial features at mean age 50 years. Compared to those with the lowest quartile of CT lung injury at mean age 40 years, there were higher odds of incident restrictive spirometry at mean age 55 years in quartile 2 (OR 2.05, 95% CI 1.20-3.48), quartile 3 (OR 2.80, 95% CI 1.66-4.72) and quartile 4 (OR 3.77, 95% CI 2.24-6.33). CT lung injury is an early objective measure that indicates risk of future lung impairment.

Validation of a Novel Method of Measuring Cup Orientation Using BiPlanar Simultaneous Radiographic Images

BackgroundAccurate acetabular component positioning is paramount to the success of total hip arthroplasty (THA). Two-dimensional imaging alone remains a popular tool for implant position assessment despite known limitations. We investigated the accuracy of a novel method for assessing acetabular component position based upon orthogonal simultaneous biplanar X-ray images. MethodsThere were forty consecutive patients who had a preexisting THA on the contralateral side who underwent both computed tomography (CT) and simultaneous orthogonal biplanar radiographic scans for preoperative planning of THA. The operative inclination (OI) and operative anteversion (OA) of the acetabular cup were calculated by a new measurement method using the biplanar simultaneous scans. Those measurements were compared to measurement of the cup orientation on CT. The measurements were made by 2 independent observers. Interobserver correlation coefficients were calculated between the 2 observers to measure reliability. ResultsThe mean error in OA measurement of the acetabular cup between simultaneous orthogonal biplanar radiographic and CT imaging was 0.5° (SD: 1.9°, minimum −4.0°, maximum 5.0°), the mean error in OI was 0.0° (SD: 1.7°, minimum −5.0°, maximum 4.0°). The average absolute error was 1.5° for OA and 1.2° for OI. Interobserver correlation coefficient was 0.83 for OA and 0.93 for OI. ConclusionThe novel method of measuring cup orientation using simultaneous biplanar radiographic scans utilized in this study was accurate and reproducible between observers compared to CT measurements.

Long-Term Outcomes after Pediatric Mandibular Reconstruction Using Vascularized Free Fibula Flap.

The purpose of this study was to evaluate the long-term outcomes of mandibular reconstruction with vascularized free fibula flap in pediatric patients. Consecutive cases of mandibular reconstruction with vascularized free fibula flaps in pediatric patients at Peking University School and Hospital of Stomatology between 1999 and 2019 were reviewed. Postoperative computed tomography (CT) data of all patients were collected at each postoperative follow-up point, and after the age of 18 years. The length and height of the grafted fibula and the length of the remaining mandible were evaluated by measuring the three-dimensional CT data using ProPlan CMF 3.0 software. Lower limb function was evaluated using the Enneking evaluation scale. Facial symmetry was self-evaluated and scored. Statistical analysis was performed on the data obtained. Fourteen patients were included in this study. All flaps were successful. The CT measurement results showed growth in the length of the grafted fibula that reconstructed the mandibular ramus and the residual mandible ( P < 0.05). The height of the grafted fibula remained stable ( P > 0.05). Eight patients were followed up until they were older than 18 years, and the CT measurement results after 18 years showed an essentially symmetric mandible profile ( P > 0.05). All patients were satisfied with their postoperative facial symmetry. Enneking evaluation scores showed good recovery of lower limb functions. The vascularized free fibula flap for mandibular reconstruction in pediatric patients is safe and reliable. It also provides good cosmetic and functional outcomes, as it demonstrated positive growth. Therapeutic, IV.

Validation of direct CT measurement of malrotation in femoral neck fractures: A bone model study.

While postoperative malrotation in the subtrochanteric region is a well-known problem, malrotation after osteosynthesis in proximal femoral fractures has not been extensively studied. In this context, many methods for perioperatively assessment of femoral torsion have been described, but none of them is applicable in the basicervical region of the proximal femur. As an important difference in femoral neck fractures, the discontinuous neck fails to serve as a significant "pointer" for measurements and malfunctions to be placed in relation to the condylar plane. Considering postoperative maltorsion at any location as a substantial negative effect on patients' outcome and functional expectations, precise and patient-friendly rotation measurement standards in femoral neck fractures are desired in clinical practice. Recently, a novel computed tomography (CT) based geometric technique was described named "direct measurement" with promising results covering this diagnostic disparity, but still requires validation. Thus, we aimed to validate the previously described technique using a controlled range of displacement in a femoral neck fracture Sawbone® model. A goniometer was designed to set retro- and anteversion of the proximal femur in a reproducible manner. Prospectively, all femurs underwent a CT scan and were measured 3D for displacement. The interclass correlation between the CT measurements and the goniometer measurements was calculated and was found to be very high (1.00, 95% confidence interval: 0.99-1.00; p < 0.001). For the mean of all measurements, the Pearson's correlation was 1.00 (p < 0.001). No significant differences in the measurements of both investigators were observed, with 20° of retroversion not significant (-1.20 ± 1.71; 95% confidence interval: -2.43-0.03; p = 0.054). This CT-based 3D measurement technique may allow for perioperative malrotation assessment in basicervical femoral neck fractures and appears to be feasible in femoral neck fractures when it comes to rare cases of osteosynthesis. Further investigations are still needed to define the thresholds of malrotation provoking functional impairment after osteosynthesis in basicervical femoral neck fractures.

Quantitative CT Lung Imaging and Machine Learning Improves Prediction of Emergency Room Visits and Hospitalizations in COPD.

Predicting increased risk of future healthcare utilization in chronic obstructive pulmonary disease (COPD) patients is an important goal for improving patient management. Our objective was to determine the importance of computed tomography (CT) lung imaging measurements relative to other demographic and clinical measurements for predicting future health services use with machine learning in COPD. In this retrospective study, lung function measurements and chest CT images were acquired from Canadian Cohort of Obstructive Lung Disease study participants from 2010 to 2017 (https://clinicaltrials.gov, NCT00920348). Up to two follow-up visits (1.5- and 3-year follow-up) were performed and participants were asked for details related to healthcare utilization. Healthcare utilization was defined as any COPD hospitalization or emergency room visit due to respiratory problems in the 12 months prior to the follow-up visits. CT analysis was performed (VIDA Diagnostics Inc.); a total of 108 CT quantitative emphysema, airway and vascular measurements were investigated. A hybrid feature selection method with support vector machine classifier was used to predict healthcare utilization. Performance was determined using accuracy, F1-measure and area under the receiver operating characteristic curve (AUC) and Matthews's correlation coefficient (MC). Of the 527 COPD participants evaluated, 179 (35%) used healthcare services at follow-up. There were no significant differences between the participants with or without healthcare utilization at follow-up for age (p=0.50), sex (p=0.44), BMI (p=0.05) or pack-years (p=0.76). The accuracy for predicting subsequent healthcare utilization was 80% ± 3% (F1-measure=74%, AUC=0.80, MC=0.6) when all measurements were considered, 76% ± 6% (F1-measure=72%, AUC=0.77, MC=0.55) for CT measurements alone and 65% ± 5% (F1-measure=60%, AUC=0.67, MC=0.34) for demographic and lung function measurements alone. The combination of CT lung imaging and conventional measurements leads to greater prediction accuracy of subsequent health services use than conventional measurements alone, and may provide needed prognostic information for patients suffering from COPD.

PD26-07 TESTOSTERONE IS ASSOCIATED WITH ABDOMINAL BODY COMPOSITION DERIVED FROM COMPUTED TOMOGRAPHY: A LARGE CROSS SECTIONAL STUDY

You have accessJournal of UrologyCME1 Apr 2023PD26-07 TESTOSTERONE IS ASSOCIATED WITH ABDOMINAL BODY COMPOSITION DERIVED FROM COMPUTED TOMOGRAPHY: A LARGE CROSS SECTIONAL STUDY Ji Hyung Yoon, Chongsuk Chae, Taekmin Kwon, Sungchan Park, Kyung Hyun Moon, Sang Hyeon Cheon, and Seong Cheol Kim Ji Hyung YoonJi Hyung Yoon More articles by this author , Chongsuk ChaeChongsuk Chae More articles by this author , Taekmin KwonTaekmin Kwon More articles by this author , Sungchan ParkSungchan Park More articles by this author , Kyung Hyun MoonKyung Hyun Moon More articles by this author , Sang Hyeon CheonSang Hyeon Cheon More articles by this author , and Seong Cheol KimSeong Cheol Kim More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003304.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: A close relationship exists among testosterone, metabolic syndrome, and abdominal body composition. However, few studies have evaluated the relationship between testosterone and abdominal body composition after adjusting for metabolic syndrome. We evaluated the association between serum testosterone and abdominal body composition based on abdominopelvic computed tomography measurements after adjusting for individual metabolic syndrome components in a large cohort who voluntarily underwent health examinations. METHODS: We performed a cross-sectional study using subjects who underwent a general health examination with abdominopelvic computed tomography and testosterone measurements at our hospital between March 2014 and June 2019. Body composition was evaluated with abdominopelvic computed tomography. To confirm an association between testosterone and abdominal body composition, we conducted linear regression analysis. The effect of abdominal body composition was adjusted for important clinical factors such as age, albumin, and metabolic components in the multivariable regression analysis. RESULTS: Overall, 1,453 subjects were included in the primary analysis. The mean age of the study participants was 55.2±8.4 years, and the mean serum testosterone level was 4.36±1.73 ng/ml. In the univariable linear regression analyses, the loge-transformed testosterone had a negative correlation with hemoglobin A1c (unstandardized β=-0.060, p<0.001) and C-reactive protein ≥2.0 mg/dL (unstandardized β=-0.381, p<0.001). All metabolic syndrome components had a negative correlation with the loge-transformed testosterone. Regarding abdominal body composition, subcutaneous fat area index (unstandardized β=-0.048, p<0.001), visceral fat area index (unstandardized β=-0.026, p<0.001), total abdominal muscle area index (unstandardized β=0.110, p<0.001), and normal attenuation muscle area index (unstandardized β=0.076, p<0.001) had an association with the loge-transformed testosterone. After adjustment for age, individual metabolic syndrome components, albumin, hemoglobin A1c, and C-reactive protein ≥2 mg/dL, we found that subcutaneous fat area index (unstandardized β=-0.042, p<0.001), total abdominal muscle area index (unstandardized β=0.115, p<0.001), normal attenuation muscle area index (unstandardized β=0.070, p<0.001), and loge-transformed lower attenuation muscle area index (unstandardized β=0.140, p=0.002) had an association with loge-transformed testosterone level. CONCLUSIONS: After adjusting for individual metabolic syndrome components, testosterone was significantly associated with subcutaneous fat, but not visceral fat. In addition, testosterone was positively correlated with abdominal muscle regardless of qualitative features such as fat-rich and fat-free. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e737 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ji Hyung Yoon More articles by this author Chongsuk Chae More articles by this author Taekmin Kwon More articles by this author Sungchan Park More articles by this author Kyung Hyun Moon More articles by this author Sang Hyeon Cheon More articles by this author Seong Cheol Kim More articles by this author Expand All Advertisement PDF downloadLoading ...

Straight Egyptian Arabian skull morphology presents unique surgical challenges compared to the Thoroughbred: a computed tomography morphometric anatomical study

The objective of this study was to compare the skull morphology of the Straight Egyptian Arabian (SEAR) to the Thoroughbred (TB), using computed tomography (CT) in the context of surgical procedures commonly performed on the equine head. Measurements relating to surgical considerations of the equine head were taken from 29 clinically normal adult horses (15 SEAR, 14 TB). A clinical prospective study. Standing skull CTs were performed. Fourteen gross and 10 CT measurements were taken. Several variables showed a significant difference between groups, in all cases greater in TB. Head length (P < .001) and facial crest length (P < .001) were significantly shorter in SEAR than TB. The head length was shorter relative to body height in SEAR (P < .001). The lateral length of a virtual maxillary bone flap was shorter in SEAR (P < .001). SEAR had smaller craniofacial angles than TB (P = .018). SEAR skull morphology differs significantly from TB, making surgical approaches potentially more challenging. Compared with TB, the shorter facial crest in the SEAR group could contribute to poor surgical access to the maxillary sinus in SEAR due to shorter maxillary flap lengths. Significant differences in the craniofacial angles between SEAR and TB suggest similarities between SEAR and brachycephalic dog breeds, warranting further investigation.

Can sarcopenia predict complete response after total neoadjuvant therapy in advanced rectal cancer? A multicentre observational cohort study.

The association between sarcopenia and response to neoadjuvant treatment remains unclear. This study investigates sarcopenia as a predictor of overall complete response (oCR) after Total Neoadjuvant Therapy (TNT) for advanced rectal cancer. A prospective observational study was performed of patients with rectal cancer undergoing TNT at three South Australian hospitals between 2019 and 2022. Sarcopenia was diagnosed by pretreatment computed tomography measurement of psoas muscle cross-sectional area at the third lumbar vertebra level, normalised for patient height. The primary endpoint was oCR rate defined as the proportion of patients who achieved either clinical complete response (cCR) or pathological complete response. This study included 118 rectal cancer patients with an average age of 59.5 years, 83 (70.3%) of whom formed the non-sarcopenic group (NSG) and 35 (29.7%) the sarcopenic group (SG). The oCR rate was significantly higher in NSG compared with the SG (p < 0.001). cCR rate was significantly greater in NSG compared with the SG (p = 0.001). Multivariate analysis revealed sarcopenia (p = 0.029) and hypoalbuminemia (p = 0.040) were risk factors for cCR and sarcopenia was an independent risk factor for oCR (p = 0.020). Sarcopenia and hypoalbuminemia were negatively associated with tumour response following TNT in advanced rectal cancer patients.

Correlation between auditory response telemetry (ART) and computerized tomography measurements in detection of cochlear implant electrode position

Correlation between auditory response telemetry (ART) and computerized tomography measurements in detection of cochlear implant electrode position

Causes, Diagnose and Treatment of Osteoporosis

Osteoporosis is a chronic degenerative bone disease that seriously affects human health. This study analyzes the causes of osteoporosis in detail, expounds the common diagnostic methods, and proposes some corresponding treatment programs. Dual Energy X-ray Absorptiometry has high accuracy, image quality improvement, fast speed, rich clinical applications, and is suitable for scientific research. Quantitative Computed tomography measures true volumetric bone mineral density using initial CT data. This method is not affected by obesity, hyperosteoplasia, vascular calcification and vertebral size. Osteoporosis has the primary and secondary causes, primary osteoporosis covers the osteoporosis when women go through menopause (Type I), and osteoporosis of senile (Type II), and secondary osteoporosis refers to osteoporosis caused by certain medical conditions or medications. Exercise can help patients treat osteoporosis, and drugs could help prevent falls help prevent fractures. However, the treatment effect of most osteoporosis patients is not satisfactory. To treat osteoporosis, only one drug "single-handedly" has limited efficacy, and to effectively combat osteoporosis, it is necessary to emphasize "multi-service combat".

CT-measured hernia parameters can predict component separation: a cross-sectional study from China.

Currently, there are no reliable preoperative methods for predicting component separation (CS) during incisional hernia repair. By quantitatively measuring preoperative computed tomography (CT) imaging, we aimed to assess the value of hernia defect size, abdominal wall muscle quality, and hernia volume in predicting CS. The data of 102 patients who underwent open Rives-Stoppa retro-muscular mesh repair for midline incisional hernia between January 2019 and March 2022 were retrospectively analyzed. The patients were divided into two groups: ''CS group'' patients who required CS to attempt fascial closure, and ''non-CS'' group patients who required only Rives-Stoppa retro-muscular release to achieve fascial closure. Hernia defect width, hernia defect angle, rectus width, abdominal wall muscle area and CT attenuation, hernia volume (HV), and abdominal cavity volume (ACV) were measured on CT images. The rectus width to defect width ratio (RDR), HV/ACV, and HV/peritoneal volume (PV; i.e., HV + ACV) were calculated. Differences between the indices of the two groups were compared. Logistic regression models were applied to analyze the relationships between the above CT parameters and CS. Receiver operator characteristic (ROC) curves were generated to evaluate the potential utility of CT parameters in predicting CS. Of the102 patients, 69 were in the non-CS group and 33 were in the CS group. Compared with the non-CS group, hernia defect width (P < 0.001), hernia defect angle (P < 0.001), and hernia volume (P < 0.001) were larger in the CS group, while RDR (P < 0.001) was smaller. The abdominal wall muscle area in the CS group was slightly greater than that in the non-CS group (P = 0.046), and there was no significant difference in the CT attenuation of the abdominal wall muscle between the two groups (P = 0.089). Multivariate logistic regression identified hernia defect width (OR 1.815, 95% CI 1.428-2.308, P < 0.001), RDR (OR 0.018, 95% CI 0.003-0.106, P < 0.001), hernia defect angle (OR 1.077, 95% CI 1.042-1.114, P < 0.001), hernia volume (OR 1.002, 95% CI 1.001-1.003, P < 0.001), and CT attenuation of abdominal wall muscle (OR 0.962, 95% CI 0.927-0.998, P = 0.037) as independent predictors of CS. Hernia defect width was the best predictor for CS, with a cut-off point of 9.2cm and an area under the curve (AUC) of 0.890. The AUCs of RDR, hernia defect angle, hernia volume, and abdominal wall muscle CT attenuation were 0.843, 0.812, 0.747, and 0.572, respectively. Quantitative CT measurements are of great value for preoperative prediction of CS. Hernia defect size, hernia volume, and the CT attenuation of abdominal wall muscle are all preoperative predictive indicators of CS.

Distal Clavicle Autograft Versus Traditional and Congruent Arc Latarjet Procedures: A Comparison of Surface Area and Glenoid Apposition With 3-Dimensional Computed Tomography and 3-Dimensional Magnetic Resonance Imaging

Background: Limited studies have compared graft-glenoid apposition and glenoid augmentation area between the Latarjet procedure and distal clavicle graft in glenohumeral stabilization. Additionally, preoperative planning is typically performed using computed tomography (CT), and few studies have used 3-dimensional (3D) magnetic resonance imaging (MRI) reformations to assess graft dimensions. Purpose: The purpose of this study was 2-fold: (1) to compare bony apposition, glenoid augmentation, and graft width among coracoid and distal clavicle bony augmentation techniques and (2) to determine the viability of 3D MRI to assess bone graft dimensions. Study Design: Controlled laboratory study. Methods: A total of 24 patients with recurrent glenohumeral instability and bone loss were included in this study. 3D CT and 3D MRI reformations were utilized to measure pertinent dimensions for 5 orientations of coracoid and distal clavicle autografts: (1) standard Latarjet procedure (SLJ), (2) congruent arc Latarjet procedure (CLJ), (3) distal clavicle attached by its posterior surface (DCP), (4) distal clavicle attached by its inferior surface (DCI), and (5) distal clavicle attached by its resected end (DCR). Glenoid augmentation was defined as the graft surface area contributing to the glenoid. Bone-on-bone apposition was defined as the graft-glenoid contact area for bone healing potential, and graft width was pertinent for fixation technique. Glenoid bone loss ranged from 0% to 34%. Paired t tests were used to compare graft sizes between patients and compare 3D CT versus 3D MRI measurements. Results: The CLJ had the largest graft surface area (mean, 318.41 ± 74.44 mm2), while the SLJ displayed the most bone-on-bone apposition (mean, 318.41 ± 74.44 mm2). The DCI had the largest graft width (mean, 20.62 ± 3.93 mm). Paired t tests revealed no significant differences between the Latarjet techniques, whereas distal clavicle grafts varied significantly with orientation. All 3D CT and 3D MRI measurements were within 1 mm of each other, and only 2 demonstrated a statistically significant difference (coracoid width: 13.03 vs 13.98 mm, respectively [P = .010]; distal clavicle thickness: 9.69 vs 10.77 mm, respectively [P = .002]). 3D CT and 3D MRI measurements demonstrated a strong positive correlation (r > 0.6 and P < .001 for all dimensions). Conclusion: Glenoid augmentation, bony apposition, and graft width varied with coracoid or distal clavicle graft type and orientation. Differences between 3D CT and 3D MRI were small and likely not clinically significant. Clinical Relevance: 3D MRI is a viable method for preoperative planning and graft selection in glenoid bone loss.

Quantitative analysis of calcium oxalate monohydrate and dihydrate for elucidating the formation mechanism of calcium oxalate kidney stones.

We sought to identify and quantitatively analyze calcium oxalate (CaOx) kidney stones on the order of micrometers, with a focus on the quantitative identification of calcium oxalate monohydrate (COM) and dihydrate (COD). We performed Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD), and microfocus X-ray computed tomography measurements (microfocus X-ray CT) and compared their results. An extended analysis of the FTIR spectrum focusing on the 780 cm-1 peak made it possible to achieve a reliable analysis of the COM/COD ratio. We succeeded in the quantitative analysis of COM/COD in 50-μm2 areas by applying microscopic FTIR for thin sections of kidney stones, and by applying microfocus X-ray CT system for bulk samples. The analysis results based on the PXRD measurements with micro-sampling, the microscopic FTIR analysis of thin sections, and the microfocus X-ray CT system observation of a bulk kidney stone sample showed roughly consistent results, indicating that all three methods can be used complementarily. This quantitative analysis method evaluates the detailed CaOx composition on the preserved stone surface and provides information on the stone formation processes. This information clarifies where and which crystal phase nucleates, how the crystals grow, and how the transition from the metastable phase to the stable phase proceeds. The phase transition affects the growth rate and hardness of kidney stones and thus provides crucial clues to the kidney stone formation process.

Artificial Intelligence Autonomously Measures Cup Orientation, Corrects for Pelvis Orientation, and Identifies Retroversion From Antero-Posterior Pelvis Radiographs

BackgroundMeasuring cup orientation is time consuming and inaccurate, but orientation influences the risk of impingement and dislocation following total hip arthroplasty (THA). This study designed an artificial intelligence (AI) program to autonomously determine cup orientation, correct for pelvis orientation, and identify cup retroversion from an antero-posterior pelvic radiographs. MethodsThere were 2,945 patients between 2012 and 2019 identified to have 504 computed tomographic (CT) scans of their THA. A 3-dimensional (3D) reconstruction was performed on all CTs, where cup orientation was measured relative to the anterior pelvic plane. Patients were randomly allocated to training (4,000 x-rays), validation (511 x-rays), and testing (690 x-rays) groups. Data augmentation was applied to the training set (n = 4,000,000) to increase model robustness. Statistical analyses were performed only on the test group in their accuracy with CT measurements. ResultsAI predictions averaged 0.22 ± 0.03 seconds to run on a given radiograph. Pearson correlation coefficient was 0.976 and 0.984 for AI measurements with CT, while hand measurements were 0.650 and 0.687 for anteversion and inclination, respectively. The AI measurements more closely represented CT scans when compared to hand measurements (P < .001). Measurements averaged 0.04 ± 2.21°, 0.14 ± 1.66°, −0.31 ± 8.35°, and 6.48° ± 7.43° from CT measurements for AI anteversion, AI inclination, hand anteversion, and hand inclination, respectively. AI predictions identified 17 radiographs as retroverted with 100.0% accuracy (total retroverted, n = 45). ConclusionThe AI algorithms may correct for pelvis orientation when measuring cup orientation on radiographs, outperform hand measurements, and may be implemented in a timely fashion. This is the first method to identify a retroverted cup from a single AP radiograph.