Quantitative Computed Tomography Research Articles

Decreased attenuation difference between non-contrast and portal-venous phases of CT predicts the ultrasonography-unspecified adnexal torsion

ObjectivesTo evaluate the value of contrast-enhanced CT in diagnosing ultrasonography-unspecified adnexal torsion (AT).MethodsSurgically confirmed patients with painful pelvic masses (n = 165) were retrospectively collected from two institutes. Two senior radiologists independently reviewed the CT images and determined the Hounsfield unit difference between non-contrast vs portal venous phases (ΔHUPV-NC) in both derivation and validation samples. The cutoff value, sensitivity, specificity, predictivity, and reproducibility of the ΔHUPV-NC and other visually assessed CT signs were analyzed and compared using the receiver-operating characteristic curve, multivariable regression, and inter-rater agreement assays, respectively.ResultsWomen with twisted (n = 73 [47 ± 19 years]) or untwisted (n = 92 [40 ± 15 years]) adnexal lesions were reviewed. The ΔHUPV-NC ≤ 17.5 HU (AUC: 0.91 [95% CI: 0.86, 0.96]; sensitivity: 95% [95% CI: 87, 98]; and specificity: 88% [95% CI: 80, 94]) was the independent predictor of AT (OR: 137 [95% CI: 39, 481], p < 0.001). After training in ΔHUPV-NC measurement, the agreement between two junior residents and the consensus increased from fair (resident-1: 0.29 [95% CI: 0.17, 0.41]; resident-2: 0.24 [95% CI: 0.1, 0.39]) to substantial (resident-1: 0.75 [95% CI: 0.65, 0.85]; resident-2: 0.72 [95% CI: 0.62, 0.83]). The post-training diagnostic accuracy (both residents: 81% [95% CI: 74, 87]) was higher than the pre-training accuracy (resident-1: 67% [95% CI: 59, 74], p = 0.007; resident-2: 66% [95% CI: 58, 73], p = 0.002).ConclusionThe sign of ΔHUPV-NC ≤ 17.5 HU in contrast-enhanced CT can be used to predict the ultrasonography-unspecified AT.Critical relevance statementThe decreased attenuation difference between non-contrast vs portal venous phases, a quantitative measurement-based CT sign, highlights the value of using contrast-enhanced CT as a second-line imaging approach after an equivocal ultrasonographic examination to diagnose AT in emergency settings.Key PointsThe value of contrast-enhanced CT in diagnosing ultrasonography-unspecified AT is underestimated.The ΔHUPV-NC ≤ 17.5 HU is the only predictor to diagnose the ultrasonography-unspecified AT.Contrast-enhanced CT can be used as a second-line imaging approach after an equivocal ultrasonographic examination.Graphical

GOLD grade-specific characterization of COPD in the COSYCONET multi-center trial: comparison of semiquantitative MRI and quantitative CT.

We hypothesized that semiquantitative visual scoring of lung MRI is suitable for GOLD-grade specific characterization of parenchymal and airway disease in COPD and that MRI scores correlate with quantitative CT (QCT) and pulmonary function test (PFT) parameters. Five hundred ninety-eight subjects from the COSYCONET study (median age = 67 (60-72)) at risk for COPD or with GOLD1-4 underwent PFT, same-day paired inspiratory/expiratory CT, and structural and contrast-enhanced MRI. QCT assessed total lung volume (TLV), emphysema, and air trapping by parametric response mapping (PRMEmph, PRMfSAD) and airway disease by wall percentage (WP). MRI was analyzed using a semiquantitative visual scoring system for parenchymal defects, perfusion defects, and airway abnormalities. Descriptive statistics, Spearman correlations, and ANOVA analyses were performed. TLV, PRMEmph, and MRI scores for parenchymal and perfusion defects were all higher with each GOLD grade, reflecting the extension of emphysema (all p < 0.001). Airway analysis showed the same trends with higher WP and higher MRI large airway disease scores in GOLD3 and lower WP and MRI scores in GOLD4 (p = 0.236 and p < 0.001). Regional heterogeneity was less evident on MRI, while PRMEmph and MRI perfusion defect scores were higher in the upper lobes, and WP and MRI large airway disease scores were higher in the lower lobes. MRI parenchymal and perfusion scores correlated moderately with PRMEmph (r = 0.61 and r = 0.60) and moderately with FEV1/FVC (r = -0.56). Multi-center semiquantitative MRI assessments of parenchymal and airway disease in COPD matched GOLD grade-specific imaging features on QCT and detected regional disease heterogeneity. MRI parenchymal disease scores were correlated with QCT and lung function parameters. Question Do MRI-based scores correlate with QCT and PFT parameters for GOLD-grade specific disease characterization of COPD? Findings MRI can visualize the parenchymal and airway disease features of COPD. Clinical relevance Lung MRI is suitable for GOLD-grade specific disease characterization of COPD and may serve as a radiation-free imaging modality in scientific and clinical settings, given careful consideration of its potential and limitations.

Noninvasive Quantitative CT for Diffuse Liver Diseases: Steatosis, Iron Overload, and Fibrosis.

Chronic diffuse liver disease continues to increase in prevalence and represents a global health concern. Noninvasive detection and quantification of hepatic steatosis, iron overload, and fibrosis are critical, especially given the many relative disadvantages and potential risks of invasive liver biopsy. Although MRI techniques have emerged as the preferred reference standard for quantification of liver fat, iron, and fibrosis, CT can play an important role in opportunistic detection of unsuspected disease and is performed at much higher volumes. For hepatic steatosis, noncontrast CT provides a close approximation to MRI-based proton-density fat fraction (PDFF) quantification, with liver attenuation values less than or equal to 40 HU signifying at least moderate steatosis. Liver fat quantification with postcontrast CT is less precise but can generally provide categorical assessment (eg, mild vs moderate steatosis). Noncontrast CT can also trigger appropriate assessment for iron overload when increased parenchymal attenuation values are observed (eg, >75 HU). A variety of morphologic and functional CT features indicate the presence of underlying hepatic fibrosis and cirrhosis. Beyond subjective assessment, quantitative CT methods for staging fibrosis can provide comparable performance to that of elastography. Furthermore, quantitative CT assessment can be performed retrospectively, since prospective techniques are not required. Many of these CT quantitative measures are now fully automated via artificial intelligence (AI) deep learning algorithms. These retrospective and automated advantages have important implications for longitudinal clinical care and research. Ultimately, regardless of the indication for CT, opportunistic detection of steatosis, iron overload, and fibrosis can result in appropriate clinical awareness and management. ©RSNA, 2024 See the invited commentary by Yeh in this issue.

Diagnostic accuracy in coronary CT angiography analysis: artificial intelligence versus human assessment

BackgroundVisual assessment of coronary CT angiography (CCTA) is time-consuming, influenced by reader experience and prone to interobserver variability. This study evaluated a novel algorithm for coronary stenosis quantification (atherosclerosis imaging...

Radiomics models based on thoracic and upper lumbar spine in chest LDCT to predict low bone mineral density

This study aims to develop and validate different radiomics models based on thoracic and upper lumbar spine in chest low-dose computed tomography (LDCT) to predict low bone mineral density (BMD) using quantitative computed tomography (QCT) as standard of reference. A total of 905 participants underwent chest LDCT and paired QCT BMD examination were retrospectively included from August 2018 and June 2019. The patients with low BMD (n = 388) and the normal (n = 517) were randomly divided into a training set (n = 622) and a validation set (n = 283). Radiomics features (RFs) were extracted from the single and consecutive vertebrae in chest LDCT images to construct the single vertebra RFs models, mixed RFs models and Radscore models, respectively. The performance of these models was evaluated by the area under the curve (AUC) of receiver operator characteristic curve, using QCT as standard of reference. The Radscore models, mixed RFs models, and single vertebra RFs models yielded the AUC values ranging from 0.809 to 0.906, 0.792 to 0.883, and 0.731 to 0.884 for predicting low BMD in the validation set, respectively. For predicting low BMD, the Radscore model of L1-L2 vertebrae yielded the highest AUC of 0.906, and of T1-T3 yielded the lowest AUC of 0.809 (P < 0.05), respectively. However, there was no significant difference among the AUC values of three Radscore models constructed on the vertebrae of T4-T6 (AUC = 0.855), T7-T9 (AUC = 0.845), and T10-T12 (AUC = 0.871) for predicting low BMD in the validation set (P > 0.1). The Radscore model of L1-L2 have potential to serve as an important tool for predicting and screening low BMD from normal in chest LDCT images.

Individuals with Heterogenous Trabecular Bone Texture by Clinical MRI have Lower Bone Strength and Stiffness by QCT Based Finite Element Analysis.

Opportunistic screening is essential to improve the identification of individuals with osteoporosis. Our group has utilized image texture features to assess bone quality using clinical MRIs. We have previously demonstrated that greater heterogeneity of MRI texture related to history of fragility fractures, lower bone density, and worse microarchitecture. The present study investigated relationships between MRI-based texture features and biomechanical properties of bone using CT-based finite element analyses (FEA). We hypothesized that individuals with greater texture heterogeneity would have lower stiffness and failure load. Thirty individuals included in this prospective study had CT and MRI of L1 and L2 vertebrae. Using T1-weighted MR images, a gray-level co-occurrence matrix was generated to characterize the distribution and spatial organization of voxelar signal intensities to derive the following texture features: contrast (variability), entropy (disorder), angular second moment (ASM; uniformity), and inverse difference moment (IDM; homogeneity). Features were calculated in five directions relative to the image plane. Whole-bone stiffness and failure load were calculated from phantom-calibrated lumbar QCT. Mean age of subjects was 59 ± 11years (57% female). Individuals with lower vertebral stiffness had greater texture heterogeneity; specifically, higher contrast (r = -0.54, P<.01), higher entropy (r = -0.52, P<.01), lower IDM (r = 0.54, P<.01) and lower ASM (r = 0.51, P<.01). Lower vertebral failure load and lower vBMD were similarly associated with greater texture heterogeneity. Relationships were unchanged when using the average of texture in all directions or the vertical direction in isolation. In summary, individuals with more heterogeneous MRI-based trabecular texture had lower stiffness and failure load by FEA, and lower vBMD by central quantitative CT. These results-the first relating MRI-based texture features and biomechanical properties of bone-provide further support that MRI-based texture measurements can be used to opportunistically detect skeletal fragility.

Association between quantitative CT body composition analysis and prognosis in cetuximab-based first-line treatment for advanced colorectal cancer patients

BackgroundThe objective of this study is to investigate the potential association between change in body composition before and after cetuximab-based therapy and the prognostic outcomes among individuals diagnosed with advanced colorectal cancer.MethodsA retrospective analysis was undertaken on a cohort of 81 patients diagnosed with RAS wild-type (WT) metastatic colorectal cancer (mCRC) who were treated with cetuximab-based first-line therapy. To assess relevant body composition parameters, quantitative computed tomography (QCT) scans were conducted both before and after cetuximab treatment. These parameters encompassed measurements of visceral fat area (VFA), subcutaneous fat area (SFA), total muscle area (TMA) at the third lumbar vertebra level (L3), and bone mineral density (BMD) at the first and second vertebrae levels (L1/2). The skeletal muscle index (SMI) was subsequently calculated, and changes in parameters (∆VFA, ∆SFA, ∆SMI, ∆BMD) were standardized.ResultsThe cut-off values for ∆VFA, ∆SFA, ∆SMI, and ∆BMD were 0.28%, -2.76%, -2.97%, and -7.98%, respectively. CEA, ∆VFA, ∆SMI, and ∆BMD were associated with poor outcomes of cetuximab-based first-line chemotherapy (P < 0.05). The risk of disease progression was higher when ∆VFA < 0.28%, ∆SFA < -2.76%, ∆SMI < -2.97%, and ∆BMD < -7.98%. Multivariate analysis indicated that CEA (HR: 0.396, 95% CI: 0.160–0.980, P = 0.045), ∆VFA (HR: 0.307, 95% CI: 0.145–0.651, P = 0.002), and∆SMI (HR: 0.725, 95% CI: 0.322–1.630, P = 0.001) have significant prognostic value for progression-free survival (PFS) in RAS WT mCRC patients treated with cetuximab-based first-line chemotherapy.ConclusionsCEA, ∆VFA, and ∆SMI are independent predictors for PFS in patients with advanced colorectal cancer. High levels of CEA, ∆VFA, and low levels of ∆SMI may indicate poorer outcomes. CEA, ∆VFA, and ∆SMI can be used to predict PFS in mCRC patients receiving cetuximab-based first-line chemotherapy.Trial registrationThis study was approved by the Ethics Committee of Anhui Provincial Cancer Hospital of Anhui Medical University (Batch No:2024-ZNY-02). All subjects signed an informed consent form.

Comparative effectiveness of four techniques for identifying vertebral fragility fractures among elderly patients.

The incidence of vertebral fragile fractures peaked among the elderly population, and identifying individuals at high risk of vertebral fractures and promptly instituting preventions are of critical importance. This study aims to determine the efficacy and values of Hounsfield unit (HU) values, vertebral bone quality (VBQ) scores, bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA), and quantitative computed tomography (QCT) to discriminate between patients with and without vertebral fractures. A thorough search was conducted across PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, and Wan Fang Database to identify potential studies that met the eligibility criteria. Studies that evaluated the utility of HU values, VBQ scores, QCT-measured BMD, and DXA-measured BMD in discriminating vertebral fractures were qualified. The combined results showed that there were significant differences in HU values, VBQ scores, QCT-measured BMD, and DXA-measured BMD between the fracture and non-fracture groups. Moreover, the pooled sensitivity, specificity, and AUC of HU values were 0.82, 0.67, and 0.76, respectively; the pooled sensitivity, specificity, and AUC of VBQ scores were 0.70, 0.75, and 0.78; the pooled sensitivity, specificity, and AUC of QCT-measured BMD were 0.85, 0.76 and 0.88. All four methods, namely HU values, VBQ scores, QCT-measured BMD, and DXA-measured BMD can effectively distinguish between patients with and without vertebral fragile fractures. Among these, QCT-measured BMD exhibited a relatively high efficacy in discriminating vertebral fractures. VBQ scores and HU values demonstrated comparable efficacy for discriminating vertebral fractures among elderly patients. Question Can four different imaging modalities effectively discriminate vertebral fragility fracture status among elderly patients? Findings These methods can effectively distinguish vertebral fractures status among elderly patients, and quantitative computed tomography (QCT)-measured bone mineral density (BMD) exhibited a relatively high efficacy. Clinical relevance The clinical applications of Hounsfield unit values, vertebral bone quality scores, and BMD measured by dual-energy X-ray absorptiometry and QCT show promising outcomes in identifying individuals at high risk of vertebral fractures.

Characteristics of lipid metabolism and fat distribution in patients with primary hyperparathyroidism and their Mendelian randomization study.

Primary hyperparathyroidism (PHPT) is characterized by elevated parathyroid hormone (PTH) levels and hypercalcemia. Although research suggests a potential link between PTH and lipid metabolism, the evidence remains inconclusive. This study investigated lipid metabolism and fat distribution in PHPT patients. We studied 157 PHPT patients and strictly matched 1:1 controls based on sex, age, and BMI from our hospital (2020-2023). We recorded clinical data and used quantitative computed tomography (QCT) to measure lumbar spine bone mineral density and assess visceral and subcutaneous fat areas. Mendelian randomization analysis, utilizing genome-wide association study (GWAS) data, investigated the causal relationships between PHPT and various anthropometric measures, including body mass index (BMI), waist-to-hip ratio (WHR), and waist circumference (WC). Additionally, the analysis examined the associations between PTH levels and these same anthropometric traits: BMI, WHR, and WC. The study included 47 males and 110 females in each group. There were no statistically significant differences between the two groups regarding BMI, triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total fat area (TFA), abdominal visceral fat area (VFA), subcutaneous fat area (SFA), or the VFA/SFA ratio (P > 0.05). After adjusting for albumin-corrected calcium, estimated glomerular filtration rate (eGFR), and 25-hydroxyvitamin D (25OHD), correlations between PTH and BMI, TG, TC, HDL-C, LDL-C, and the VFA/SFA ratio were not significant in either group (P > 0.05). Furthermore, when all the study subjects were divided into three groups based on PTH tertiles, correlations between PTH and the aforementioned indices remained nonsignificant after adjusting for albumin-corrected calcium, eGFR, and 25OHD (P > 0.05). In a two-sample Mendelian randomization study, no significant associations were observed between PHPT and BMI, WHR, or WC. Similarly, no significant associations were identified between PTH levels and BMI, WHR, or WC. No statistically significant disparities were discerned in lipid metabolism markers or fat distribution between PHPT patients and controls. No significant correlation exists between PTH levels and lipid metabolism or fat distribution. Furthermore, no causal relationship was established between PHPT and BMI, WHR, or WC, nor between PTH levels and these anthropometric measures.

Associations of Habitual Skeletal Loading with Bone Changes During the Menopausal Transition: A Follow-up Study.

While weight-bearing physical activity (PA) benefits bone health, it remains unclear whether PA can counteract hormone-driven menopausal bone deterioration. This secondary analysis of a population-based prospective follow-up study examined changes in bone health indicators around menopause and evaluated whether accelerometer-measured habitual skeletal loading is associated with these changes. A total of 189 initially perimenopausal women without estrogen therapy (mean age 52 [SD 2] years) were followed until they became postmenopausal (mean follow-up time 15 [9] months). Femoral neck bone mineral density (FN BMD) and bone mineral content (BMC) were measured with dual x-ray absorptiometry (DXA). Femoral and tibial shaft volumetric BMD (vBMD), cross-sectional geometry, and stress-strain index (SSI) were assessed using quantitative computed tomography (QCT) in a subset of 61 women. Habitual skeletal loads (mean daily osteogenic index [OI] and low, medium, and high-intensity impact counts) were evaluated with multiple-day free-living accelerometry records. Longitudinal associations of habitual skeletal loads and bone outcomes were analyzed with GEE models. Consistent decreases were observed in FN BMD and BMC, and femoral and tibial shaft vBMD and SSI (p < 0.001) over the follow-up. Slight decreases over the follow-up were also observed in OI and medium impacts in the full sample, and medium and high impact counts in the subsample (p < 0.05). Medium impacts were associated with tibial shaft vBMD and SSI (β = 0.204, 95% CI [0.018, 0.391] and β = 0.077 95% CI [0.000, 0.154], respectively). High impacts were associated with femoral shaft vBMD (β = 0.186 95% CI [0.006, 0.366]. However, no association was observed between habitual skeletal loads and changes in bone characteristics over the follow-up. We observed a rather uniform skeletal response to the menopausal transition at all measured bone sites. Positive associations were found between medium and high-intensity impacts and bone characteristics at the femoral and tibial shafts. However, habitual skeletal loading did not seem to counteract bone deterioration during the menopausal transition.

Effects of acute-phase COVID-19-related indicators on pulmonary fibrosis and follow-up evaluation

BackgroundPost-COVID-19 pulmonary fibrosis is a significant long-term respiratory morbidity affecting patients’ respiratory health. This exploratory study aims to investigate the incidence, clinical characteristics, and acute-phase risk factors for pulmonary fibrosis in COVID-19 patients. Additionally, it evaluates pulmonary function and chest CT outcomes to provide clinical evidence for the early identification of high-risk patients and the prevention of post-COVID-19 pulmonary fibrosis.MethodsWe retrospectively analyzed 595 patients hospitalized for COVID-19 from January 2022 to July 2023. Patients were divided into fibrosis and nonfibrosis groups on the basis of imaging changes. Baseline data, including demographics, disease severity, laboratory indicators, and chest imaging characteristics, were collected. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors for pulmonary fibrosis. Pulmonary function and chest CT follow-ups were conducted for the fibrosis group. The data were processed via SPSS 26.0, with P < 0.05 considered statistically significant.ResultsThe incidence of pulmonary fibrosis was 4.37%, with 2.08% in moderate cases and 8.22% in severe cases. Significant differences were found between the fibrosis and nonfibrosis groups in sex; disease severity; NLR; ALB and LDH levels; and percentages of lung reticular lesions, consolidations, and GGOs (P < 0.05). Multivariate analysis revealed LDH (OR = 1.004, 95% CI 1.000–1.007, P = 0.035), ALB (OR = 0.871, 95% CI 0.778–0.974, P = 0.015), lung reticular lesion volume (OR = 1.116, 95% CI 1.040–1.199, P = 0.002), and lung consolidation volume (OR = 1.131, 95% CI 1.012–1.264, P = 0.030) as independent risk factors. The follow-up results revealed significant improvements in pulmonary function, specifically in the FVC%, FEV1%, and DLCO%, but not in the FEV1/FVC. Quantitative chest CT analysis revealed significant differences in lung reticular lesions, consolidation, and GGO volumes but no significant difference in honeycomb volume.ConclusionsThe incidence of pulmonary fibrosis post-COVID-19 increases with disease severity. LDH, ALB, lung reticular lesions, and consolidation volume are independent risk factors for patients with fibrosis.

Automated bone property analysis using corrected in vivo dental cone-beam CT data of human wrists

Fracture liaison services are essential to mitigate underdiagnosis and undertreatment of osteoporosis-related fractures. However, it often suffers from limited access to dual-energy X-ray absorptiometry (DXA) or high-resolution peripheral quantitative CT equipment. This in vivo study of 21 patients aims to evaluate the feasibility of dental cone beam CT (dCBCT) to analyse bone properties of human wrists, comparing with DXA and finite element (FE) analysis. dCBCT grey-scale values were transformed to HU using a phantom containing materials with known HU values. Strong correlations were found between bone mineral content (BMC) from dCBCT and DXA (r = 0.78 to 0.84, p < 0.001), as well as between BMC from dCBCT FE-predicted stiffness (r = 0.91) and maximum force (r = 0.93), p < 0.001. BMC values from dCBCT were higher than DXA measurements (2.34 g vs. 1.5 g, p < 0.001). Cortical thickness strongly correlated to bone mineral density (BMD) from dCBCT (r = 0.83, p < 0.001). No statistically significant correlations were found between trabecular bone microstructure and FE predictions. The results indicate the feasibility to analyse osteoporosis related bone properties of human wrists from corrected dCBCT data. The dCBCT values of BMD and BMC were strongly correlated with DXA.

Enhancing the Opportunistic Bone Status Assessment Using Radiomics Based on Dual-Energy Spectral CT Material Decomposition Images.

Retrospective data were collected from 307 patients who underwent both quantitative computed tomography (QCT) and full-abdomen DEsCT scans at our institution. Based on QCT measurements, patients were divided into three categories: normal bone mineral density (BMD), osteopenia, and osteoporosis. Using the abdominal DEsCT data, six types of MD images were reconstructed, including HAP (Water), HAP (Fat), Ca (Water), Ca (Fat), Fat (Ca), and Fat (HAP). Patients were randomly divided into a training cohort (n = 214) and a validation cohort (n = 93) at a ratio of 7:3. Focusing on the L1 to L3 vertebrae, density values from the six MD images were measured. Six density value models and six radiomics models were constructed using a random forest (RF) classifier. The performance of these models in assessing bone status was evaluated using the receiver operating characteristic (ROC) curves, and the DeLong test was employed to compare performance differences between the models. The macro-area under the curve (AUC) values for the density value models based on HAP (Water), HAP (Fat), Ca (Water), and Ca (Fat) MD images were 0.870, 0.870, 0.847, and 0.765, respectively, which outperformed those of Fat (Ca) (AUC = 0.623) and Fat (HAP) (AUC = 0.618) density value models. In the comparison of radiomics models, the trends of model performance were consistent with the density value models across the six MD images. However, the models based on HAP (Water), Ca (Water), HAP (Fat), Ca (Fat), Fat (Ca), and Fat (HAP) images exhibited superior performance than those of the density value models with the corresponding MD images, with values of 0.946, 0.941, 0.934, 0.926, 0.831, and 0.824, respectively. Bone status assessment can be accurately conducted using density values from HAP (Water), HAP (Fat), Ca (Water), and Ca (Fat) MD images. However, radiomics models derived from MD images surpass traditional density measurement methods in evaluating bone status, highlighting their superior diagnostic potential.

Editorial Comment: Quantitative CT Offers Promising Advances for Image Interpretation in Interstitial Lung Disease.

Editorial Comment: Quantitative CT Offers Promising Advances for Image Interpretation in Interstitial Lung Disease.

Comparative evaluation of trabecular bone density in Hounsfield units in the lumbar native CT cross-section for osteoporosis diagnosis and fracture risk determination by different examiners

An increasing loss of bone mineral density (BMD) in the axial skeleton leads to osteoporosis and fractures, with an increase found in the thoracic and thoracolumbar regions. The extent to which an examiner-independent assessment of the extent of osteoporosis and fracture risk determination is possible by determining the trabecular density in Hounsfield units (HU) in the spine should be examined. The next question was whether quantitative BMD values can be calculated from the HU values. 225 patients (pt.) with an average age of 64.9 ± 13.1 years and abody-mass-index (BMI) of 26.8 ± 6.8 kg/m2, of which 37were men and 188 were women, were examined to determine whether they had osteoporosis. The BMD was determined in mg/cm3 using quantitative computed tomography (QCT) in the lumbar region. After anonymization by three experienced radiologists, an additional measurement of the trabecular bone density in HU, was carried out in the same vertebral bodies (atotal of 675 vertebral bodies), each using aregion of interest (ROI) positioned in the midvertebral cancellous space in the sagittal reformed CT image. In additional lateral X‑rays of the thoracic and lumbar spine, vertebral fractures were detected and graded. Sacral insufficiency fractures that occurred at the same time were also recorded. The median BMD was 73.2 (57.05-104.17) mg/cm3 and the median HU was 89.93 (67.90-126.95). With acorrelation of 0.988 (p < 0.001), quantitative values in mg/cm3 can be calculated using the following formula: Xq = 12.1 + 0.68 × HU. With HU values less than 69.84 and aBMD of the lumbar spine below 59.54 mg/cm3, there was asignificantly increased number of OVF. At least one OVF was found in 137/225 pt. In 17/137 pt., sacral fractures were also found; these patients showed the significantly lowest values with amedian BMD of 41.81 (16.2-53.7) mg/cm3. Comparable HU values were determined independently of the examiners (p > 0.05). The trabecular density measurements in HU values can be converted into quantitative BMD values in mg/cm3, which enables agood assessment of osteoporosis and fracture risk. Taking the results obtained into account, an opportunistic evaluation using HU values in native CT alone seems quite possible. Experienced examiners have arrived at comparable results.

Untreated Osteoporosis in Lumbar Fusion Surgery Patients: Prevalence, Risk-factors and Effect on Bone Metabolism.

Secondary analysis of a prospective single-center study. To analyze the prevalence and risk factors for untreated osteoporosis in patients undergoing lumbar spinal fusion surgery (LFS) and its impact on bone mineral density (BMD) and bone turnover markers. Osteoporosis is a risk factor for mechanical complications in LFS, which can be mitigated by antiosteoporotic treatment. However, there's limited research on factors leading to untreated osteoporosis before LFS and its impact on preoperative bone status. A secondary analysis of a prospective study enrolling adults undergoing LFS for degenerative conditions (2014-2024) with preoperative quantitative CT osteoporosis screening was performed. Demographic data and medical history were analyzed for prevalence and risk factors of untreated osteoporosis, while BMD, vitamin D, PTH levels, and bone turnover markers were assessed for the effects of lacking treatment. A total of 445 patients (48% female, median age 64) were included, of which 137 patients (31%) had osteoporosis. Of these, 66 (48%) were untreated and 71 (52%) were treated, with 40 (56%) receiving pharmacological and 31 (44%) non-pharmacologic treatment including vitamin D supplementation and lifestyle modifications. Of the untreated patients, 55 (80%) were identified by preoperative screening. 71% of osteoporotic men versus 35% of osteoporotic women were untreated (P<0.001). Multivariable logistic regression confirmed male sex as an significant contributing factor (OR 4.3, 95% CI 1.9-10.1, P<0.001) for untreated osteoporosis. Treated osteoporotic patients had higher BMD (P<0.001), higher VitD levels P=0.023) and lower levels of bone resorption parameters (P=0.004) than untreated patients. Untreated osteoporosis is common before LFS, especially in men, with the untreated having lower BMD and higher bone resorption marker levels than treated patients. Identification of osteoporotic cases and subsequent osteological optimization could potentially reduce the risks of adjacent fractures or screw loosening.

Development of a machine learning model in prediction of the rapid progression of interstitial lung disease in patients with idiopathic inflammatory myopathy.

Rapidly progressive interstitial lung disease (RP-ILD) significantly impacts the prognosis of patients with idiopathic inflammatory myopathies (IIM). High-resolution computed tomography (HRCT) is a crucial noninvasive technique for evaluating interstitial lung disease (ILD). Utilizing quantitative computed tomography (QCT) enables accurate quantification of disease severity and evaluation of prognosis, thereby serving as a crucial computer-aided diagnostic method. This study aimed to establish and validate a machine learning (ML) model to predict RP-ILD in patients with idiopathic inflammatory myopathy-related interstitial lung disease (IIM-ILD) based on QCT and clinical features. A total of 514 patients (367 females, median age 54 years) with IIM-ILD in the China-Japan Friendship Hospital were retrospectively included, out of which 249 cases (165 females, median age 55 years) were identified as having RP-ILD. To extract the quantitative features on HRCT, deep learning (DL) methods were employed, along with demographic factors, pulmonary function test results, and blood gas analysis results; these factors were integrated into a final prediction model. Logistic regression was chosen as the final model due to its superior area under the curve (AUC) and explainability compared to the other seven ML models. The validation dataset yielded an AUC of 0.882 [95% confidence interval (CI): 0.797-0.967], indicating that the combined QCT and clinical features model outperformed both the QCT-only model and the clinically-only model. In calibration and clinical decision curve analysis, the final model demonstrated minimal prediction bias (concordance index: 0.887, 95% CI: 0.800-0.974, P<0.001) and provided greater net benefit across most thresholds. The nomogram encompassed the incorporation of the following variables: subtype, gender, forced expiratory volume in one second (FEV1%), diffusing capacity for carbon monoxide (DLCO%), oxygenation index (OI), and quantitative ground-glass opacities (GGOs), consolidation, pulmonary vascular, and branches on HRCT. When utilizing ML techniques, the baseline QCT has the potential to predict rapid progression in patients with IIM-ILD. The prediction performance will be further improved by incorporating clinical data alongside HRCT features. Idiopathic inflammatory myopathy (IIM); rapidly progressive interstitial lung disease (RP-ILD); high-resolution computed tomography (HRCT); machine learning (ML); quantitative computed tomography (QCT).

Is Quantitative Radiographic Measurement of Acetabular Version Reliable in Anteverted and Retroverted Hips?

The acetabular version is crucial for hip function, and its accurate assessment is necessary for treating patients with hip disorders. Current studies reveal discrepancies in the precision of quantitative radiographic measurements versus CT measurements, but there is a lack of focused analysis on anteverted versus retroverted hips. This study aims to fill this gap by directly comparing the reliability of these two methods in assessing varied hip configurations. (1) How reliable are quantitative radiographic and CT methods in measuring the acetabular version angle? (2) Is there any difference in the reliability of acetabular version angle measurements using radiography compared with CT in anteverted and retroverted hips? (3) What is the extent of variation in acetabular version measurements when quantitative radiographic and CT methods are compared in anteverted and retroverted hips? We searched our image archives for patients who had received both radiographs and CT scans between January 2020 and June 2022 and found 84 patients who met the criteria. From these patients, we selected those who presented with hip pain of different causes and who had no previous elective and/or hip trauma surgery, no hip dysplasia, and results from adequate radiographic examinations. Accordingly, 73% (61 of 84) of the patients were included in this study, and angle measurements were performed on both hips of these patients (122 hips). Standardized positioning was meticulously verified for all plain radiographs and CT scans utilized in the measurement process. We measured quantitative angles and assessed qualitative signs of retroversion, including crossover, posterior wall, and ischial spine findings. We considered a hip with at least one of these findings a retroverted hip, and the hips without these findings were included in the anteverted hip group. Three clinicians took measurements independently. Measurement reliability and agreement were examined using intraobserver and interobserver intraclass correlation coefficients (ICCs), with statistical analyses including paired and independent t-tests. To investigate the reliability of quantitative radiographic and CT methods, we assessed both intraobserver and interobserver agreements. To explore the reliability disparities in measuring the acetabular version via radiography and CT in anteverted and retroverted hips, we analyzed the agreement between measurements from both modalities in the hip groups. Furthermore, to evaluate the degree of variation in acetabular version measurements when comparing quantitative radiographic and CT methods in anteverted and retroverted hips, we utilized paired and independent t-tests to examine the measurement differences within these hip categories. The difference between radiographic and CT measurements was also evaluated by Bland-Altman analysis. Quantitative radiographic measurements showed intraobserver and interobserver reliabilities with ICCs of 0.87 (95% CI 0.84 to 0.91) and 0.78 (95% CI 0.75 to 0.82), respectively, and CT measurements demonstrated higher reliabilities with ICCs of 0.92 (95% CI 0.90 to 0.93) and 0.91 (95% CI 0.89 to 0.92), respectively. The reliability of measuring the acetabular version in anteverted hips was moderate, with an ICC of 0.59 (95% CI 0.49 to 0.68). In contrast, retroverted hips showed an ICC of -0.41 (95% CI -1.17 to 0.08), indicating a lack of consistency between quantitative radiographic and CT measurements. Variation in measurement on plain radiographs in anteverted hips was less than that of retroverted hips (mean ± SD absolute difference between anteverted hips and retroverted hips 3° ± 3° versus 6° ± 4°; p = 0.0001), indicating greater variability in the radiographic measurement of retroverted hips. According to Bland-Altman analysis, we observed that the difference between radiographic and CT measurements was well outside the CI, especially in retroverted hips. Although quantitative radiographic measurement demonstrates acceptable intraobserver and interobserver reliabilities, its precision is lower than that of CT-based measurements. Specifically, quantitative radiographic methods are prone to a larger margin of error in retroverted hips. For more precise assessments of acetabular version, especially in retroverted hips, we recommend using CT measurement instead of the radiographic method. Level III, diagnostic study.

Quantitative computed tomography analysis of proximal femur bone mineral density and its relation to hip fracture risk.

Hip fractures significantly reduce the quality of life and mobility of older adults. This study aimed to analyze the correlation between volumetric bone mineral density (vBMD) in different regions of the proximal femur as measured by quantitative computed tomography (QCT) and various subtypes of hip fractures. This case-control study included patients over the age of 65 years admitted to Huadong Hospital Affiliated to Fudan University for hip fractures from November 2022 to December 2023; additionally, patients from the health examination center or outpatient center treated during the same period were included as a control group. Age and gender were matched to eliminate potential confounding factors. The vBMD at the femoral neck (FN), intertrochanteric (IT), and subtrochanteric (ST) regions in the hip fracture groups [FN fracture (FNF) and IT fracture (ITF)] and control group were measured using QCT. A total of 107 patients with FNF, 77 with ITF, and 72 controls were included. After matching for age and gender was completed, 48 individuals were included in each of the three groups. The vBMD at the IT, FN, and ST regions were significantly lower in patients with hip fractures compared to those in the control group for both genders (P<0.001). The vBMD of the FN and IT regions of females in the ITF group was lower than that of those in the FNF group (P<0.05). Additionally, the vBMD of the ST region in both genders was lower in the ITF group than in the FNF group (male: P<0.05; female: P<0.001). In all three groups, females had a significantly lower vBMD in all three regions compared to males (P<0.001). The decline in vBMD was more pronounced in the ITF group than in the FNF group for both genders, with the largest reduction compared to controls observed in the ST region of females in the ITF group. Older adult individuals with a lower hip vBMD are more susceptible to experiencing osteoporotic hip fracture than are those with a normal vBMD. Reduced ST vBMD may serve as an indicator for ITF, especially among females.

Distinct physiological, transcriptomic, and imaging characteristics of asthma-COPD overlap compared to asthma and COPD in smokers

The clinical and pathological features of asthma and chronic obstructive pulmonary disease (COPD) can converge in smokers and elderly individuals as asthma-COPD overlap (ACO). This overlap challenges the diagnosis and treatment of the distinct aetiologies underlying these conditions. We analysed 2453 smokers (≥10 pack-years), aged 45-80 years, from the Genetic Epidemiology of COPD (COPDGene) Study, stratified as Control, Asthma, COPD, and ACO based on Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. A comprehensive assessment was performed, encompassing symptomatology, pulmonary function tests (PFTs), complete blood counts (CBCs), bulk RNA sequencing (RNA-seq), and high-resolution quantitative computed tomography (QCT) imaging to evaluate clinical impact, lung function, systemic inflammation, and structural alterations contributing to disease progression across respiratory phenotypes. Differential expression (DE) analysis was performed using whole blood RNA-seq (BH-corrected FDR < 0.01), followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Group differences were assessed using the Mann-Whitney U-test (MWU) or Chi-squared test (χ2), with Bonferroni correction applied for multiple comparisons. Multivariate linear regression models were used to adjust the associations between disease status and specific clinical outcomes for confounders, with one-way ANOVA and Tukey's Honest Significant Difference (HSD) post-hoc test applied for pairwise comparisons. Our analysis aimed to delineate the extent and variability of clinical features among disease phenotypes to guide targeted therapeutic strategies. Our study highlights distinct yet overlapping profiles across ACO, asthma, and COPD. We effectively isolated disease-specific mechanisms by comparing each phenotype to smoking controls (GOLD 0) while accounting for baseline smoking-related inflammation. ACO exhibited the most severe symptom burden, with significantly higher COPD Assessment Test (CAT) score (18.32, 95% CI: [17.02, 19.63], P<0.0001) and Modified Medical Research Council (mMRC) Dyspnea score (2.14, 95% CI: [1.92, 2.35], P<0.0001) compared to COPD and asthma. ACO also displayed reduced lung capacity (forced expiratory volume in 1s [FEV1]: 52.5%, 95% CI: [50.08, 54.93], P<0.0001) and airflow limitation (FEV1/forced vital capacity [FVC]: 0.55, 95% CI: [0.5471, 0.5546], P<0.0001), closely resembling COPD but significantly worse than asthma. The inflammatory profile of ACO exhibited a mixed response, featuring elevated neutrophil counts (4.57K/μL, 95% CI: [4.28, 4.86], P<0.0001) and eosinophil levels (0.22K/μL, 95% CI: [0.20, 0.25], P<0.01), contrasting with the predominantly neutrophilic inflammation in COPD and the absence of systemic inflammation in asthma. Structurally, ACO demonstrated significant airway remodelling (Pi10: 2.87, 95% CI: [2.83, 2.91], P<0.0001), intermediate emphysema (5.66%, 95% CI: [4.72, 6.60], P<0.0001), and moderate small airway disease (parametric response mapping for functional small airway disease [PRMfSAD]: 22.94%, 95% CI: [21.53, 24.34], P<0.0001), reflecting features of both asthma and COPD. COPD was characterised by more extensive emphysema (8.9%, 95% CI: [8.34, 9.45], P<0.0001), small airway disease (PRMfSAD: 27.09%, 95% CI: [26.51, 27.66], P<0.0001), and gas trapping (37.34%, 95% CI: [36.33, 38.35], P<0.0001), alongside moderate airway remodelling. At a molecular level, DE analysis revealed enrichment of the Hypoxia-Inducible Factor 1 (HIF-1) pathway in ACO, highlighting unique hypoxia-driven metabolic adaptations, while COPD was associated with neutrophil extracellular trap (NET) formation and necroptosis. In contrast, asthma exhibited significant airway remodelling (Pi10: 2.09, 95% CI: [2.05, 2.13], P<0.0001), minimal parenchymal damage, and no systemic gene expression changes. Collectively, our findings underscore the lung function impairments, systemic inflammation, molecular mechanisms, and structural correlates distinguishing ACO from COPD and asthma, emphasising the need for precise clinical management and the potential for novel therapeutic interventions. This work was supported by National Heart, Lung, and Blood Institute (NHLBI) grants U01 HL089897 and U01 HL089856, as well as by National Institutes of Health (NIH) contract 75N92023D00011. Additional support was provided by grants R01 HL166231 (C.P.H.) and K01 HL157613 (A.S.).