Dual-energy X-ray Absorptiometry T-scores Research Articles

MRI-based porosity index (PI) and suppression ratio (SR) in the tibial cortex show significant differences between normal, osteopenic, and osteoporotic female subjects.

Ultrashort echo time (UTE) MRI enables quantitative assessment of cortical bone. The signal ratio in dual-echo UTE imaging, known as porosity index (PI), as well as the signal ratio between UTE and inversion recovery UTE (IR-UTE) imaging, known as the suppression ratio (SR), are two rapid UTE-based bone evaluation techniques developed to reduce the time demand and cost in future clinical studies. The goal of this study was to investigate the performance of PI and SR in detecting bone quality differences between subjects with osteoporosis (OPo), osteopenia (OPe), and normal bone (Normal). Tibial midshaft of fourteen OPe (72 ± 6 years old), thirty-one OPo (72 ± 6 years old), and thirty-seven Normal (36 ± 19 years old) subjects were scanned using dual-echo UTE and IR-UTE sequences on a clinical 3T scanner. Measured PI, SR, and bone thickness were compared between OPo, OPe, and normal bone (Normal) subjects using the Kruskal-Wallis test by ranks. Spearman's rank correlation coefficients were calculated between dual-energy x-ray absorptiometry (DEXA) T-score and UTE-MRI results. PI was significantly higher in the OPo group compared with the Normal (24.1%) and OPe (16.3%) groups. SR was significantly higher in the OPo group compared with the Normal (41.5%) and OPe (21.8%) groups. SR differences between the OPe and Normal groups were also statistically significant (16.2%). Cortical bone was significantly thinner in the OPo group compared with the Normal (22.0%) and OPe (13.0%) groups. DEXA T-scores in subjects were significantly correlated with PI (R=-0.32), SR (R=-0.50), and bone thickness (R=0.51). PI and SR, as rapid UTE-MRI-based techniques, may be useful tools to detect and monitor bone quality changes, in addition to bone morphology, in individuals affected by osteoporosis.

Abstract P5-08-13: Frequency of low bone mineral density in young women with breast cancer and associated factors

Abstract Background: Young women with breast cancer (YWBC) may experience bone mineral density (BMD) loss due to the effects of cancer treatment on estrogen levels. Studies assessing BMD in breast cancer (BC) patients have had a limited representation of young women. This study aimed to analyze the frequency of low BMD and its associated factors in this specific age group. Methods: This retrospective, multicenter study included women ≤40 years diagnosed with stage 0-III BC, treated with chemotherapy (CT) and/or endocrine therapy (ET) between 2010-2020, and with no documented bone metastases during follow-up. The protocol was conducted in 5 BC referral centers in Mexico. Demographic, clinical and treatment data were collected, as well as bone dual-energy X-ray absorptiometry (DEXA) results. Low BMD was defined as T-score <-1.0 or Z-score ≤-2.0 at the lumbar spine (L1-L4) or femoral neck. The frequency of low BMD was analyzed with descriptive statistics. Binary logistic regression using complete case analysis was conducted to calculate odds ratios (OR) and 95% confidence intervals (95%CI) of experiencing low BMD according to demographic, clinical and therapeutic factors. Results: In total, 716 YWBC met inclusion criteria. Median age at BC diagnosis was 36 years (21-40); 708 (99%) women were premenopausal at diagnosis. Most were married (355; 50%), had higher education (381; 53%), were unemployed (433; 61%), and were non-smokers (552; 77%). Body mass index (BMI) was < 18.5 kg/m2 (underweight) and ≥25.0 kg/m2 (overweight/obese) in 14 (2%) and 392 (58%) cases, respectively. The most common BC subtype was hormone receptor (HR) positive/HER2 negative (371; 52%), followed by triple negative (168; 24%), HR positive/HER2 positive (122; 17%) and HR negative/HER2 positive (55; 8%). Patients were mostly diagnosed with stage II (346; 48%) or III (276; 39%) disease. As for treatment, CT in 667 (93%), ET in 468 (65%), anti-HER2 therapy in 168 (24%), and radiotherapy was administered in 562 (79%) cases. DEXA scans were documented in 213/716 (30%) patients. In total, 286 DEXA results were available. The time elapsed from the start of the first systemic treatment to the DEXA result was 0-12 months in 42 cases (15%); 13-36 months in 103 (36%); 37-60 months in 72 (25%); and >60 months in 69 (24%). Overall, 133/213 patients (62%; 95%CI 56-69%) had at least one low BMD report after the start of CT or ET. T-scores and Z-scores in each period are detailed in the Table. No fractures were recorded in any case after BC diagnosis. The only variable associated with at least one low BMD result was BMI ≥25.0 kg/m2 (OR, 1.88; 95%CI, 1.04-3.40). The described demographic, clinical and treatment factors were not significantly associated with low BMD. Conclusion: This study showed a suboptimal frequency of bone DEXA monitoring in YWBC. A considerable proportion of YWBC experienced low BMD after initiation of CT and/or ET; and a significant association was found between obesity/overweight at BC diagnosis and subsequent low BMD. These data reflect the importance of requesting DEXA scans in young patients on a regular basis and promoting the maintenance of an adequate body weight, in line with international recommendations. Further studies evaluating the degree of BMD loss and its determinants would contribute to establish the optimal periodicity to monitor BMD in relation to BC therapy, allow timely offering of interventions to reduce bone morbidity, as well as improve the quality and life and survivorship of this young group of patients. Table. DEXA T-scores and Z-scores. Citation Format: Fernanda Mesa-Chavez, Yanin Chavarri-Guerra, Sandy Ruiz-Cruz, Paula Cabrera-Galeana, Christopher Jesus del Rio-Martinez, Carmen Guadalupe Bermudez-Barrientos, Brizio Moreno-Jaime, Abigail Samayoa-Mateos, David Vega-Morales, Cynthia Villarreal-Garza. Frequency of low bone mineral density in young women with breast cancer and associated factors [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-08-13.

Correlation between bone density measurements on CT or MRI versus DEXA scan: A systematic review

BackgroundNovel methods of bone density assessment using computed tomography (CT) and magnetic resonance imaging (MRI) have been increasingly reported in the spine surgery literature. Correlations between these newer measurements and traditional Dual-Energy X-ray Absorptiometry (DEXA) is not well known. The purpose of this study is to perform an updated systematic review of correlations between bone mineral density (BMD) from CT or MRI and DEXA. MethodsArticles published between 2011 and 2021 that reported correlations between the CT-HU or MRI measurements to DEXA t-scores or BMD of lumbar spine or hip were included in this systematic review. ResultsA total of 25 studies (15 CT, 10 MRI) met the inclusion criteria with a total number of 2,745 patients. The pooled correlation coefficient of spine CT-HU versus spine DEXA, spine CT-HU versus hip DEXA and spine CT-HU versus lowest t-score were 0.60, 0.50 and 0.60 respectively. Regarding spine DEXA parameters, the pooled r2 for spine CT-HU versus spine t-score was 0.684 and spine CT-HU versus spine BMD was 0.598. Furthermore, in patients undergoing spine surgery in four studies, the pooled correlation between spine CT and spine DEXA was (r2: 0.64). In MRI studies, the pooled r2 of spine MRI versus spine DEXA and spine MRI versus hip DEXA were -0.41 and -0.44 respectively. ConclusionsCT-HU has stronger correlations with DEXA than MRI measurements. Lumbar CT-HU has the highest pooled correlation (r2 = 0.6) with both spine DEXA and lowest skeletal t-score followed by lumbar CT-HU with hip DEXA (r2 = 0.5) and lumbar MRI with hip (r2 = 0.44) and spine (r2 = 0.41) DEXA. Both imaging modalities achieved only a moderate correlation with DEXA. Few studies in both modalities have investigated the correlation in spine surgery populations and the available data shows that the correlations are worse in the degenerative spine population. A careful interruption of CT HU and MRI measurement when evaluation of BMD as they only moderately correlated with DEXA scores. At this time, it is unclear which modality is a better predictor of mechanical complications and clinical outcomes in spine surgery patients.

Vertebral bone quality score provides preoperative bone density assessment for patients undergoing lumbar spine surgery: a retrospective study.

The novel MRI-based vertebral bone quality (VBQ) score has been described as an opportunistic screening tool for osteoporosis, but the stability and practical value of this score deserve further investigation. The purpose of this study was to assess whether preoperative VBQ scores could assist in identifying reduced bone mineral density (BMD) or osteoporosis and evaluating the consistency between MRI systems with different field strengths. The VBQ scores of the patients who underwent surgery for lumbar disc herniation and the single-level VBQ scores of each L1-4 vertebral body were measured and calculated with preoperative lumbar MRI noncontrast T1-weighted phases. The VBQ scores were evaluated for correlation analysis using dual-energy x-ray absorptiometry (DEXA) T-scores. The receiver operating characteristic (ROC) curve was used to evaluate the ability of the VBQ scores to identify patients with reduced BMD and with osteoporosis. Differences in CSF measurements at different levels of L1-4 were compared. Twenty-four patients who had been examined using another MRI machine were used as controls to test the interdevice agreement of the VBQ scores. The study included 100 patients with mean VBQ scores of 2.81 ± 0.28 (normal BMD), 3.06 ± 0.36 (osteopenia), and 3.43 ± 0.37 (osteoporosis). VBQ scores differed significantly between BMD subgroups (p < 0.001). The Pearson correlation coefficient showed a moderate negative linear correlation between novel VBQ scores and the lowest DEXA T-scores (r = -0.524). ROC analysis showed good discrimination of VBQ scores in patients with reduced BMD (area under the curve [AUC] 0.793) and with osteoporosis (AUC 0.810). The diagnostic thresholds of reduced BMD and osteoporosis according to the maximum Youden index were 3.06 (sensitivity 0.636, specificity 0.870, positive predictive value [PPV] 0.942, negative predictive value [NPV] 0.417) and 3.05 (sensitivity 0.875, specificity 0.618, PPV 0.519, NPV 0.913), respectively. CSF measurements at the L2, L3, and L4 levels were essentially identical and did not significantly affect the final VBQ scores (p > 0.05), whereas CSF measurements at the L1 level were found to be heterogeneous (p < 0.001). No significant differences were found in VBQ scores between the same brand of MRI machines at different field strengths (1.5 and 3.0 T, p = 0.107). The new VBQ score provides an additional screening opportunity for preoperative BMD assessment. A VBQ score < 3.05 essentially excludes osteoporosis, whereas a VBQ score ≥ 3.05 (especially ≥ 3.06) suggests the need for further examination. The VBQ score is comparable between different MRI systems.

Correlation between Forearm Bone Mineral Density Measured by Dual Energy X-ray Absorptiometry and Hounsfield Units Value Measured by CT in Lumbar Spine.

Our aim was to determine if the dual-energy X-ray absorptiometry (DXA)-measured forearm bone mineral density (BMD) correlates with the Hounsfield unit (HU) values obtained from computed tomography (CT). A retrospective analysis of 164 patients with degenerative diseases of the lumbar spine was performed. DXA was used to measure the BMD and T-scores of each patient's forearm. Lumbar CT was used to measure the CT HU values in three axial images of the L1-L4 vertebral bodies, and the average was calculated. According to the preoperative DXA T-score, they were divided into a normal group, an osteopenia group, and an osteoporosis group. Pearson's correlation coefficient was used to analyze the correlations of CT HU values in L1-L4 with BMD and T-scores in the corresponding vertebral body. The receiver operating characteristic curve (ROC) was used to determine the CT HU thresholds between osteoporosis and non-osteoporosis groups. Forearm BMD was moderately correlated with L1-L4 CT HU values (0.4<R2<0.6), and the correlation coefficients (R2) were 0.552, 0.578, 0.582, and 0.577, respectively (all p<0.001). Forearm T-scores were moderately correlated with L1-L4 CT HU values (0.4<R2<0.6), and the correlation coefficients (R2) were 0.595, 0.609, 0.605, and 0.605, respectively (all p<0.001). The thresholds of L1-L4 between the osteoporosis group (t ≤ -2.5) and the non-osteoporosis group (t>-2.5) were 110.0HU (sensitivity 74% and specificity 76%), 112.5HU (sensitivity 67% and 83% specificity), 92.4HU (81% sensitivity and 70% specificity), and 98.7HU (74% sensitivity and 78% specificity), respectively. Based on the moderate positive correlation between forearm DXA-measured BMD and HU values, forearm DXA provides a theoretical basis for evaluating lumbar vertebral bone mass. Preoperative forearm DXA may be useful in the formulation of surgical plans and the prevention of postoperative complications in patients with lumbar degenerative diseases.

Discordance in lumbar bone mineral density measurements by quantitative computed tomography and dual-energy X-ray absorptiometry in postmenopausal women: a prospective comparative study

Background ContextLevel-specific lumbar bone mineral density (BMD) evaluation of a single vertebral body can provide useful surgical planning and osteoporosis management information. Previous comparative studies have primarily focused on detecting spinal osteoporosis but not at specific levels. PurposeTo compare the detection rate of lumbar osteoporosis between quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA); to explore and analyze the distribution models of QCT-derived BMD and DXA T-score at the specific levels; and to evaluate the diagnostic accuracy of level-specific BMD thresholds for the prediction of osteoporotic vertebral compression fracture (OVCF) in postmenopausal women. Study Design/SettingA comparative analysis of prospectively collected data comparing QCT-derived BMD with DXA T-score. Patient SampleA total of 296 postmenopausal women who were referred to the spine service of a single academic institution were enrolled. Outcome MeasuresQCT-derived BMD and DXA T-score at specific levels, with or without osteoporotic vertebral compression fracture. MethodsPostmenopausal women who underwent QCT and DXA within a week of admission from May 2019 to June 2022 were enrolled. The diagnostic criteria for osteoporosis recommended by the World Health Organization and the American College of Radiology were used for lumbar osteoporotic diagnosis. To evaluate differences in lumbar BMD measurements at specific levels, a threshold of T score=-2.5 and QCT-derived BMD = 80 mg/cm3 were used to categorize level-specific lumbar BMD into low and high BMD. Disagreements in BMD categorization between DXA and QCT were classified as a minor or major discordance based on the definition by Woodson. Data between QCT and DXA were visualized in a stacked bar plot and analyzed. Correlations between DXA and QCT at the specific levels were evaluated using Pearson's linear correlation and scatter plots. Curve fitting of BMD distribution, receiver operating characteristic (ROC) and area under the curve (AUC) for each single vertebral level was performed. ResultsOf the 296 patients, QCT diagnosed 61.1% as osteoporosis, 30.4% as osteopenia and 8.4% as normal. For those screened with DXA, 54.1% of the patients had osteoporosis, 29.4% had osteopenia and 16.6% had normal BMD. Diagnoses were concordant for 194 (65.5%) patients. Of the other 102 discordant patients, 5 (1.7%) were major and 97 (32.8%) were minor. Significant correlations in level-specific BMD between DXA and QCT were observed (p<.001), with Pearson's correlation coefficients ranging from 0.662 to 0.728. The correlation strength was in the order of L1 > L2 > L3 > L4. The low BMD detection rate for QCT was significantly higher than that for DXA at the L3 and L4 levels (65% vs. 47.9% and 68.1% vs 43.7, respectively, p<.001). Patients with OVCF showed significantly lower QCT-derived BMD (47.2 mg/cm3 vs. 83.2 mg/cm3, p<.001) and T-score (-3.39 vs. -1.98, p<.001) than those without OVCF. Among these patients, 82.8% (101/122) were diagnosed with osteoporosis by QCT measurement, while only 74.6% (91/122) were diagnosed by DXA. For discrimination between patients with and without OVCF, QCT-derived BMD showed better diagnosed performance (AUC range from 0.769 to 0.801) than DXA T-score (AUC range from 0.696 to 0.753). ConclusionQCT provided a more accurate evaluation of lumbar osteoporosis than DXA. The QCT-derived BMD measurements at a specific lumbar level have a high diagnostic performance for OVCF.

Novel MRI-based vertebral bone quality score as a predictor of cage subsidence following transforaminal lumbar interbody fusion.

Decreased bone mineral density as measured by dual-energy x-ray absorptiometry (DEXA) has been reported to be associated with cage subsidence following transforaminal lumbar interbody fusion (TLIF). However, DEXA is not often available or routinely performed before surgery. A novel MRI-based vertebral bone quality (VBQ) score has been developed and reported to be correlated with DEXA T-scores. The authors investigated the ability of the VBQ score to predict cage subsidence and other risk factors associated with this complication. In this retrospective study, the authors reviewed the records of patients who had undergone single-level TLIF from March 2014 to October 2015 and had a follow-up of more than 2 years. Cage subsidence was measured as postoperative disc height loss and was graded according to the system proposed by Marchi et al. The MRI-based VBQ score was measured on T1-weighted images. Univariable analysis and multivariable binary logistic regression analysis were performed. Ad hoc analysis with receiver operating characteristic curve analysis was performed to assess the predictive ability of the significant continuous variables. Additional analyses were used to determine the correlations between the VBQ score and T-scores and between the significant continuous variables and the amount of cage subsidence. Among 242 patients eligible for study inclusion, 111 (45.87%) had cage subsidence after the index operation. Multivariable logistic regression analyses demonstrated that an increased VBQ score (OR 14.615 ± 0.377, p < 0.001), decreased depth ratio (OR 0.011 ± 1.796, p = 0.013), and the use of kidney-shaped cages instead of bullet-shaped cages (OR 2.766 ± 0.358, p = 0.008) were associated with increased cage subsidence. The VBQ score was shown to significantly predict cage subsidence with an accuracy of 85.6%. The VBQ score was found to be moderately correlated with DEXA T-scores of the total hip (r = -0.540, p < 0.001) and the lumbar spine (r = -0.546, p < 0.001). The amount of cage subsidence was moderately correlated with the VBQ score (r = 0.512, p < 0.001). Increased VBQ scores, posteriorly placed cages, and kidney-shaped cages were risk factors for cage subsidence. The VBQ score was shown to be a good predictor of cage subsidence, was moderately correlated with DEXA T-scores for the total hip and lumbar spine, and also had a moderate correlation with the amount of cage subsidence.

Comparison of the Coincidence of Osteoporosis, Fracture, Arthritis Histories, and DEXA T-Score between Monozygotic and Dizygotic Twins: A Cross-Sectional Study Using KoGES HTS Data.

We explored the genetic and environmental inter-relationships among osteoporosis, fracture, arthritis, and bone mineral density concordance in monozygotic twins compared to those in dizygotic twins. This cross-sectional research assessed data of 1032 monozygotic and 242 dizygotic twin pairs aged >20 years included in the Healthy Twin Study data of the Korean Genome and Epidemiology Study between 2005 and 2014. Outcomes of interest included illness concordance and absolute differences in dual-energy X-ray absorptiometry (DEXA) T-scores. We found comparable concordances of osteoporosis, fractures, osteoarthritis, and rheumatoid arthritis between monozygotic and dizygotic twins. Medical histories of osteoporosis, fractures caused by accident or falling, osteoarthritis, and rheumatoid arthritis were not distinct between monozygotic and dizygotic twins. Accidental fracture occurrence in both monozygotic twins showed significantly lower odds than that in dizygotic twins. Genetic influence on liability to fracture risk might thus be maintained. DEXA T-scores for bone mineral density indicated more comparable tendencies within monozygotic twin pairs than within dizygotic ones, suggesting the relative importance of genetic contribution to bone mineral density. The relative importance of genetic factors in bone mineral density is sustained between monozygotic twins; overt disease expression of osteoporosis, fractures, or arthritis may be affected by environmental factors.

Dual-Energy CT-Based Bone Mineral Density Has Practical Value for Osteoporosis Screening around the Knee.

Introduction: Adequate bone quality is essential for long term biologic fixation of cementless total knee arthroplasty (TKA). Recently, vertebral bone quality evaluation using dual-energy computed tomography (DECT) has been introduced. However, the DECT bone mineral density (BMD) in peripheral skeleton has not been correlated with Hounsfield units (HU) or central dual-energy X-ray absorptiometry (DXA), and the accuracy remains unclear. Materials and methods: Medical records of 117 patients who underwent TKA were reviewed. DXA was completed within three months before surgery. DECT was performed with third-generation dual source CT in dual-energy mode. Correlations between DXA, DECT BMD and HU for central and periarticular regions were analyzed. Receiver operating characteristic (ROC) curves were plotted and area under the curve (AUC), optimal threshold, and sensitivity and specificity of each region of interest (ROI) were calculated. Results: Central DXA BMD was correlated with DECT BMD and HU in ROIs both centrally and around the knee (all p < 0.01). The diagnostic accuracy of DECT BMD was higher than that of DECT HU and was also higher when the T-score for second lumbar vertebra (L2), rather than for the femur neck, was used as the reference standard (all AUC values: L2 > femur neck; DECT BMD > DECT HU, respectively). Using the DXA T-score at L2 as the reference standard, the optimal DECT BMD cut-off values for osteoporosis were 89.2 mg/cm3 in the distal femur and 78.3 mg/cm3 in the proximal tibia. Conclusion: Opportunistic volumetric BMD assessment using DECT is accurate and relatively simple, and does not require extra equipment. DECT BMD and HU are useful for osteoporosis screening before cementless TKA.

Patient physiology influences the MRI-based vertebral bone quality score

BACKGROUND CONTEXTOsteoporosis is a critical issue affecting postmenopausal women and the aging population. A novel magnetic resonance imaging (MRI)-based vertebral bone quality (VBQ) score has been proposed as a method to identify poor bone quality and predict fragility fractures. The diagnostic accuracy of this tool is not well understood. PURPOSETo examine the ability of VBQ to predict osteoporosis and osteopenia, its correlation with dual-energy x-ray absorptiometry (DEXA), and the influence of patient-specific factors upon the score. STUDY DESIGNRetrospective cohort study. PATIENT SAMPLEPatients over the age of 18 with a DEXA scan and noncontrast, T1-weighted MRI of the lumbar spine completed within a 2-year period. OUTCOME MEASURESArea-under-curve (AUC) values of the VBQ score predicting osteopenia and osteoporosis when controlling for patient characteristics. METHODSPatients with noncontrast, T1-weighted MRIs of the lumbar spine and DEXA scans completed within a 2-year time frame were retrospectively reviewed. Patient demographics and medical risk factors for osteoporosis were identified and compared. VBQ scores were measured by two trained researchers and interrater reliability was calculated. Patients were separated into three groups defined by lowest DEXA T-score: Healthy Bone, Osteopenia, and Osteoporosis. analysis of variance, Kruskal-Wallis test, chi-square, t tests, Mann-Whitney U tests, and multivariate linear regression were performed to examine the relationship between patient characteristics, DEXA t-scores, and VBQ scores. Receiver operating characteristic analysis and AUC values were generated for the prediction of osteopenia and osteoporosis. RESULTSA total of 156 patients were included for analysis. Sufficient inter-rater reliability was determined for VBQ measures (intraclass correlation coefficient: 0.81). Most patients were female (83%), postmenopausal (81%), and had hyperlipidemia (64%). Patients with hyperlipidemia and healthy bone density by DEXA had elevated baseline VBQ scores (p<.001) reflective of values seen in osteopenia and osteoporosis. The AUC of the VBQ score predicting osteopenia and osteoporosis changed to be more concordant with DEXA results after controlling for hyperlipidemia (AUC=0.72, 0.70 vs. AUC=0.88, 0.89; p<.001). Sub-analysis of hyperlipidemia subtypes revealed that elevated high-density lipoprotein is associated with elevated VBQ scores. CONCLUSIONSHyperlipidemia increased the MRI-based VBQ score in our healthy bone population. The high signal intensities resembled values seen in osteopenia and osteoporosis, suggesting that physiologic variables which impact bone composition may influence the VBQ score. Specifically, elevated high-density lipoprotein may contribute to this. The microarchitectural changes and the clinical implications of these factors need further exploration.

Clinical risk factor status in patients with vertebral fracture but normal bone mineral density

BACKGROUND CONTEXTNormal bone mineral density (BMD) as measured by dual-energy x-ray absorptiometry (DXA) is present in approximately 10% of older adults with fracture. BMD alone does not evaluate bone quality or clinical risk factors, and therefore, may not adequately capture a patient's fracture risk. Thus, despite a normal DXA-measured BMD, the underlying bone may be abnormal, suggesting that further bone health evaluation, and potentially, pharmacologic treatment may be warranted. PURPOSETo determine the prevalence of normal BMD, clinical fracture risk factors, and quantitative risk of fracture using the Fracture Risk Assessment Tool (FRAX) in vertebral fracture patients with normal BMD enrolled in the Own the Bone registry, thus facilitating identification of those who meet criteria for anti-osteoporosis therapy. STUDY DESIGN/SETTINGRetrospective, national registry-based cohort. PATIENT SAMPLEFrom July 2016 to July 2021, 1,807 patients age ≥50 who sustained a vertebral fracture and had DXA data available from within 2 years prior to enrollment in the American Orthopaedic Association's Own the Bone (AOA OTB) registry were included. OUTCOME MEASURESWorld Health Organization (WHO) DXA T-score based bone classification criteria; FRAX risk scores of major osteoporotic fracture or hip fracture. METHODSDemographic data, prior fracture site, and clinical fracture risk factors were collected. BMD status was classified by the WHO T-score criteria: ≥ -1.0 normal, -1.1 to -2.4 osteopenia, and ≤ -2.5 osteoporosis, with low bone mass including either osteopenia or osteoporosis. In normal BMD patients, FRAX scores were calculated with and without BMD, with the treatment threshold defined as a major osteoporotic fracture risk ≥20% or hip fracture risk ≥3%. RESULTSMean±SD age was 72.0±9.7, 78.1% were female, and 92.4% were Caucasian. Normal BMD was present in 7.9%. Clinical fracture risk factors including alcohol use ≥3 units/day and history of ≥2 falls in the year prior to enrollment were more common in normal BMD (11.2% and 28%, respectively) compared to low bone mass patients (3.4% and 25.2%, respectively). A prior vertebral fracture had occurred in 49.5% with normal BMD compared to 45.8% with low bone mass, while a prior non-major osteoporotic fracture occurred in 28.9% and 29.3% of normal BMD and low bone mass patients, respectively. In normal BMD patients, either a prior fracture or FRAX risk with BMD meeting treatment thresholds was present in 85%. CONCLUSIONSClear indications for receipt of pharmacologic therapy, ie, prior fracture or elevated fracture risk, were present in most patients with vertebral fracture and normal BMD enrolled in the AOA OTB. Prior non-major osteoporotic fractures were common and may be useful indicators of underlying bone disease. Surgeons must recognize that other important risk factors apart from BMD may indicate poor bone health, and thus, help guide further bone health evaluation.

Screening for osteoporosis using L1 vertebral density on abdominal CT in an Australian population

To assess the utility of osteoporosis screening using abdominal computed tomography (CT) versus dual-energy X-ray absorptiometry (DXA) T-scores as the reference. Patients ≥30 years undergoing abdominal CT and DXA within 12 months were assessed retrospectively. Bone mineral density (BMD) was measured using axial CT attenuation at L1, correlating with DXA T-scores. Sensitivity, specificity, area under the curve (AUC), and odds ratio (OR) were calculated. The study cohort comprised 407 CT-DXA pairs (58.2% women). The prevalence of osteoporosis was 11.8%. L1 density and T-score were significantly correlated in both women (r=0.35, p<0.001) and men (r=0.15, p=0.04). The AUC to distinguish osteoporosis from osteopenia and normal BMD was 0.64 (95% CI: 0.56-0.71). In women, a threshold of 190 HU detected T-scores ≤ -2.5 with a negative predictive value (NPV) of 94.4% (OR=4.4, p<0.01). In the entire cohort, a threshold of 180 HU detected T-scores ≤ -2.5 with a NPV of 96.2% (OR=4.7, p<0.01). CT L1 attenuation correlates with L1 DXA T-scores. Density values<190 and 180 HU increased the probability of an osteoporosis diagnosis in Australian women and the overall cohort, respectively. Opportunistic screening for osteoporosis using abdominal CT is feasible, enabling identification of at-risk subjects for formal DXA imaging, thereby improving treatment initiation and reducing fracture risk.

Preoperative MRI-based vertebral bone quality (VBQ) score assessment in patients undergoing lumbar spinal fusion

BACKGROUND CONTEXTThe importance of bone status assessment in spine surgery is well recognized. The current gold standard for assessing bone mineral density is dual-energy X-ray absorptiometry (DEXA). However, DEXA has been shown to overestimate BMD in patients with spinal degenerative disease and obesity. Consequently, alternative radiographic measurements using data routinely gathered during preoperative evaluation have been explored for the evaluation of bone quality and fracture risk. Opportunistic quantitative computed tomography (QCT) and more recently, the MRI-based vertebral bone quality (VBQ) score, have both been shown to correlate with DEXA T-scores and predict osteoporotic fractures. However, to date the direct association between VBQ and QCT has not been studied. PURPOSEThe objective of this study was to evaluate the correlation between VBQ and spine QCT BMD measurements and assess whether the recently described novel VBQ score can predict the presence of osteopenia/osteoporosis diagnosed with QCT. STUDY DESIGN/SETTINGCross-sectional study using retrospectively collected data. PATIENT SAMPLEPatients undergoing lumbar fusion from 2014-2019 at a single, academic institution with available preoperative lumbar CT and T1-weighted MRIs were included. OUTCOME MEASURESCorrelation of the VBQ score with BMD measured by QCT, and association between VBQ score and presence of osteopenia/osteoporosis. METHODSAsynchronous QCT measurements were performed. The average L1-L2 BMD was calculated and patients were categorized as either normal BMD (>120 mg/cm3) or osteopenic/osteoporotic (≤120 mg/cm3). The VBQ score was calculated by dividing the median signal intensity of the L1-L4 vertebral bodies by the signal intensity of the cerebrospinal fluid on midsagittal T1-weighted MRI images. Inter-observer reliability testing of the VBQ measurements was performed. Demographic data and the VBQ score were compared between the normal and osteopenic/osteoporotic group. To determine the area-under-curve (AUC) of the VBQ score as a predictor of osteopenia/osteoporosis receiver operating characteristic (ROC) analysis was performed. VBQ scores were compared with QCT BMD using the Pearson's correlation. RESULTSA total of 198 patients (53% female) were included. The mean age was 62 years and the mean BMI was 28.2 kg/m2. The inter-observer reliability of the VBQ measurements was excellent (ICC of 0.90). When comparing the patients with normal QCT BMD to those with osteopenia/osteoporosis, the patients with osteopenia/osteoporosis were significantly older (64.9 vs. 56.7 years, p<.0001). The osteopenic/osteoporotic group had significantly higher VBQ scores (2.6 vs. 2.2, p<.0001). The VBQ score showed a statistically significant negative correlation with QCT BMD (correlation coefficient = -0.358, 95% CI -0.473 - -0.23, p<.001). Using a VBQ score cutoff value of 2.388, the categorical VBQ score yielded a sensitivity of 74.3% and a specificity of 57.0% with an AUC of 0.7079 to differentiate patients with osteopenia/osteoporosis and with normal BMD. CONCLUSIONSWe found that the VBQ score showed moderate diagnostic ability to differentiate patients with normal BMD versus osteopenic/osteoporotic BMD based on QCT. VBQ may be an interesting adjunct to clinically performed bone density measurements in the future.

Automatic phantom-less QCT system with high precision of BMD measurement for osteoporosis screening: Technique optimisation and clinical validation.

BackgroundCurrently dual-energy X-ray absorptiometry (DXA) and phantom-based quantitative computed tomography (PB-QCT) have been utilized to diagnose osteoporosis widely in clinical practice. While traditional phantom-less QCT (PL-QCT) is limited by the precision of manual calibration using body tissues, such as fat and muscle.ObjectiveThe aim of this study is to validate the accuracy and precision of one newly-developed automatic PL-QCT system to measure spinal bone mineral density (BMD) and diagnose osteoporosis.MethodsA total of 36 patients were enrolled for comparison of BMD measurement between DXA and QCT. CT images of 63 patients were analyzed by both PB-QCT and newly developed automatic PL-QCT system, then the BMD results generated by the automatic PL-QCT were utilized to diagnose osteoporosis. The diagnostic outcomes were compared with that of DXA and PB-QCT to assess the performance of the new system.ResultsBMD test results showed that the automatic PL-QCT system had higher precision than previous studies performed with QCT, while maintaining similar capability to diagnose osteoporosis as DXA and PB-QCT. Area under curve (AUC) result of PL-QCT was larger than 0.8 for predicting spine DXA T-score in receiver operating characteristic (ROC) analysis. Pearson correlation analysis (r ​= ​0.99) showed strong linear correlation and Bland-Altman analysis (bias ​= ​3.0mg/cc) indicated little difference between the two methods. The precision result (CV ​= ​0.89%) represented good reproducibility of the new system.ConclusionThe traditional PL-QCT system has relatively low reproducibility due to the manual selection of the region of interest (ROI) of body tissues. Automatic selection of ROI in this new system makes the BMD testing more convenient and improves precision significantly. Compared with traditional BMD measurement methods, the automatic PL-QCT system had higher precision in accurate diagnosis of osteoporosis with great potential in translational research and wide clinical application.Translational potential statementWith high accuracy and precision, the automatic PL-QCT system could serve as an opportunistic screening tool for osteoporosis patients in the future. It could also facilitate related researches by providing more reliable data collection, both retrospectively and longitudinally.

Radiomic Modeling of Bone Density and Rib Fracture Risk After Stereotactic Body Radiation Therapy for Early-Stage Non-Small Cell Lung Cancer

PurposeOur purpose was to determine whether bone density and bone-derived radiomic metrics in combination with dosimetric variables could improve risk stratification of rib fractures after stereotactic body radiation therapy (SBRT) for early-stage non-small cell lung cancer (NSCLC). Methods and MaterialsA retrospective analysis was conducted of patients with early-stage NSCLC treated with SBRT. Dosimetric data and rib radiomic data extracted using PyRadiomics were used for the analysis. A subset of patients had bone density scans that were used to create a predicted bone density score for all patients. A 10-fold cross validated approach with 10 resamples was used to find the top univariate logistic models and elastic net regression models that predicted for rib fracture. ResultsA total of 192 treatment plans were included in the study with a rib fracture rate of 16.1%. A predicted bone density score was created from a multivariate model with vertebral body Hounsfield units and patient weight, with an R-squared of 0.518 compared with patient dual-energy x-ray absorptiometry T-scores. When analyzing all patients, a low predicted bone density score approached significance for increased risk of rib fracture (P = .07). On competing risk analysis, when stratifying patients based on chest wall V30 Gy and bone density score, those with a V30 Gy ≥30 cc and a low bone density score had a significantly higher risk of rib fracture compared with all other patients (P < .001), with a predicted 2-year risk of rib fracture of 28.6% (95% confidence interval, 17.2%-41.1%) and 4.9% (95% confidence interval, 2.3%-9.0%), respectively. Dosimetric variables were the primary drivers of fracture risk. A multivariate elastic net regression model including all dosimetric variables was the best predictor of rib fracture (area under the curve [AUC], 0.864). Bone density variables (AUC, 0.618) and radiomic variables (AUC, 0.617) have better predictive power than clinical variables that exclude bone density (AUC, 0.538). ConclusionRadiomic features, including a bone density score that includes vertebral body Hounsfield units and radiomic signatures from the ribs, can be used to stratify risk of rib fracture after SBRT for NSCLC.

Accuracy of Opportunistic Bone Mineral Density Assessment on Staging Computed Tomography for Gynaecological Cancers.

Background and Objectives: Women with gynecological cancers constitute a high-risk cohort for loss of bone density. International guidance stipulates women undergoing cancer treatments associated with bone loss should have a quantitative assessment of bone density. Access to Dual-energy X-ray Absorptiometry (DXA) is limited. This study aimed to assess the accuracy of opportunistic bone density measurement on staging computed tomography (CT) scans for gynaecological malignancies, in comparison to the gold standard DXA. Materials and Methods: Women with a staging CT scan of the abdomen and pelvis for a new diagnosis of gynecological cancer were recruited. DXA was performed within 6 weeks of treatment for gynaecological cancer. Lumbar bone density was measured by CT attenuation values, in Hounsfield units (HU), of the anterior trabecular region. Correlations between CT and DXA parameters were analysed. Receiver Operating Characteristic(ROC) curves for diagnosis of low bone density and osteoporosis were analysed. Results: Final cohort included 48 of 50 women recruited. There was good diagnostic accuracy for abnormal bone density and osteoporosis, with areas under the ROC curve at L1 of 0.77 (p = 0.002) and 0.80 (p = 0.020) respectively. CT-HU of 170–190 yielded sensitivities of 87–90%, positive predictive values of 75–84% and negative predictive values of 71–75% for the diagnosis of low bone mineral density. CT-HU of 90–110 yielded specificities of 85–93% for the diagnosis of osteoporosis. Moderate correlations were found between CT-HU and both DXA T-scores and diagnostic categories. Conclusions: This is the first study to assess the opportunistic application of CT in the assessment of bone health in women with gynaecological cancer, a cohort at high-risk of osteoporosis. The correlation between bone density assessment in CT-HU and DXA, and strong AUC values for the diagnosis of low bone density (0.77) and osteoporosis (0.80) support this pragmatic solution in resolving the care-gap in cancer treatment-induced bone loss, often associated with poor access to DXA.

Bone Mineral Density Remains Stable in Pyruvate Kinase Deficiency Patients Receiving Long-Term Treatment with Mitapivat

Bone Mineral Density Remains Stable in Pyruvate Kinase Deficiency Patients Receiving Long-Term Treatment with Mitapivat

Preoperative bone assessment by bone mineral density and bone turnover in patients undergoing total knee arthroplasty

BackgroundThe preoperative overall bone quality in patients undergoing total knee arthroplasty (TKA) might influence the development of postoperative bone-derived complications. This study was performed to simultaneously evaluate the baseline bone mineral density (BMD) and bone turnover in these patients. MethodsWe prospectively measured the lumbar spine, total hip, and femoral neck BMD using dual-energy X-ray absorptiometry (DXA) in 214 patients (239 knees; women, 199 knees; men, 40 knees) 1 day preoperatively. Women were stratified into three age groups: <70 years (60s), <80 years (70s), and ≥80 years (80s). We assessed bone turnover using the urinary level of N-telopeptide (NTx) normalized to creatinine (NTx/Cre). ResultsThe prevalence of osteoporosis as assessed by DXA (T-score of ≤ −2.5) was 22% in women and 5% in men. A decline in BMD with aging was found in the hip but not in the lumbar spine with significant differences among ages. Women showed a higher NTx/Cre level than men (p = 0.033). An NTx/Cre level suggesting a high fracture risk (>56.5 mmol BCE/mmol Cre) was present in 54% of women and 35% of men (p = 0.037). No significant differences were found in this prevalence among age groups in women. Seventeen percent of women and 0% of men had both osteoporosis and a high fracture risk simultaneously (p = 0.002). The proportion of women in this category was lower in the 60s than 70s age group (p = 0.019). ConclusionsPreoperative bone health screening before TKA might be necessary for women aged ≥70 years to prevent complications caused by perioperative poor bone condition.

98. Preoperative MRI-based vertebral bone quality (VBQ) score assessment in patients undergoing lumbar spinal fusion

<h3>BACKGROUND CONTEXT</h3> The importance of bone quality assessment in spine surgery is well recognized. The current gold standard for assessing bone mineral density is dual-energy X-ray absorptiometry (DEXA), however the majority of patients undergoing spinal fusion do not have preoperatively available DEXA data. Furthermore, DEXA has been shown to overestimate BMD in patients with spinal degenerative disease and obesity. Consequently, alternative radiographic measurements using data routinely gathered during preoperative evaluation of spine patients have been explored for the evaluation of bone quality and fracture risk. Opportunistic quantitative computed tomography and more recently the MRI-based vertebral bone quality (VBQ) score both have been shown to correlate with DEXA T-scores and predict osteoporotic fractures. However, to date the correlation between those two modalities has not been studied. <h3>PURPOSE</h3> The objective of this study was to assess whether the recently described novel VBQ score can predict the prevalence of QCT based osteopenia/osteoporosis and to evaluate the correlation between VBQ and spine QCT BMD measurements. <h3>STUDY DESIGN/SETTING</h3> Retrospective study of lumbar spinal fusion patients from a single, academic institution. <h3>PATIENT SAMPLE</h3> Patients undergoing lumbar spinal fusion from 2014-2019 with available preoperative CT and T1-weighted MRIs of the lumbar spine. <h3>OUTCOME MEASURES</h3> VBQ correlation to BMD. <h3>METHODS</h3> For BMD assessment, asynchronous quantitative computed tomography (QCT) measurements of L1-L2 were performed. An elliptical region of interest was placed anteriorly in the trabecular bone at mid-vertebral height and displaced from the vertebral cortex. The average BMD of L1-L2 was calculated and patients were categorized as either normal BMD (>120 mg/cm3) or osteopenic/osteoporotic (<=120 mg/cm3) based on the definition by the American College of Radiology. As previously described, the VBQ measurements were performed by placing circular regions of interest within the medullary portions of the vertebral bodies of L1-L4 and within the cerebrospinal fluid space at the level of L3 on a midsagittal T1-weighted MRI image. The VBQ score was then calculated by dividing the median signal intensity of the L1-L4 vertebral bodies by the signal intensity of the cerebrospinal fluid at the L3 level. To assess inter-observer reliability of the VBQ measurements, a validation study was performed on 37 randomly selected patients. The interclass correlation coefficient (ICC) was calculated. Demographic data and the VBQ score were compared between the normal and osteopenic/group. To determine the area-under-curve (AUC) of the VBQ score as a predictor of osteopenia/osteoporosis receiver operating characteristic (ROC) analysis was performed. VBQ scores were compared with QCT BMD using Pearson's correlation. The statistical significance level was set at p<0.05. <h3>RESULTS</h3> A total of 198 patients (53% female) were included in the study. The mean age was 62 years and the mean BMI was 28.2 kg/m2. The inter-observer reliability of the VBQ measurements was excellent (ICC of 0.90; 95% confidence interval: 0.82, 0.95). When comparing the patients with normal QCT BMD to those with osteopenia/osteoporosis, no significant differences existed in terms of sex, race, and BMI. However, the patients with osteopenia/osteoporosis were significantly older compared to the patients with normal BMD (64.9 vs 56.7 years, p<0.0001). The osteopenic/osteoporotic group had significantly higher VBQ scores (2.6 vs 2.2, p<0.0001). ROC analysis revealed that the VBQ score predicts the presence of osteopenia/osteoporosis based on QCT with an accuracy of 71% (p<0.0001). The VBQ score showed a statistically significant moderate correlation with QCT BMD (correlation coefficient = -0.358, 95% CI -0.473 - -0.23, p<0.001). <h3>CONCLUSIONS</h3> We found that the VBQ score significantly differentiates patients with normal BMD vs osteopenic/osteoporotic BMD based on QCT. However, the correlation between both modalities was only moderate suggesting VBQ might not measure bone density only. Due to the fact that QCT and more recently VBQ scores have both been shown to predict osteoporotic fractures, the weak correlation of the two modalities suggests that VBQ might not solely be a measurement of bone density, but rather bone quality. Since the two modalities seem to reflect different properties of bone, VBQ may be an interesting adjunct to clinically performed bone density measurements, rather than a substitution. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Pre-screening for osteoporosis with calcaneus quantitative ultrasound and dual-energy X-ray absorptiometry bone density

Calcaneal quantitative ultrasonography (QUS) is a useful prescreening tool for osteoporosis, while the dual-energy X-ray absorptiometry (DXA) is the mainstream in clinical practice. We evaluated the correlation between QUS and DXA in a Taiwanese population. A total of 772 patients were enrolled and demographic data were recorded with the QUS and DXA T-score over the hip and spine. The correlation coefficient of QUS with the DXA-hip was 0.171. For DXA-spine, it was 0.135 overall, 0.237 in females, and 0.255 in males. The logistic regression model using DXA-spine as a dependent variable was established, and the classification table showed 66.2% accuracy. A receiver operating characteristic (ROC) analyses with Youden’s Index revealed the optimal cut-off point of QUS for predicting osteoporosis to be 2.72. This study showed a meaningful correlation between QUS and DXA in a Taiwanese population. Thus, it is important to pre-screen for osteoporosis with calcaneus QUS.