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Machine Learning in Radio Imaging
Published in Punit Gupta, Dinesh Kumar Saini, Rohit Verma, Healthcare Solutions Using Machine Learning and Informatics, 2023
Nitesh Pradhan, Punit Gupta, Anita Shrotriya
Tristan Whitmarsh et al. [17] proposed a reconstruction model for the 3-D shape of the proximal femur from a single DXA. This technique uses a statistical model applied to a large data set of quantitative computerized tomography (QCT) scans (Table 2.2).
Diagnosis
Published in Peter V. Giannoudis, Thomas A. Einhorn, Surgical and Medical Treatment of Osteoporosis, 2020
Radiological methods that can aid in the diagnosis and management of osteoporosis include conventional radiography, dual-energy x-ray absorptiometry (DEXA), quantitative computed tomography (QCT), and high-resolution imaging techniques. Of these, DEXA is currently the most widely used technique for the clinical diagnosis of osteoporosis. Central and peripheral QCT have advantages over DEXA but at present are predominantly used as research tools.
X-ray Vision: Diagnostic X-rays and CT Scans
Published in Suzanne Amador Kane, Boris A. Gelman, Introduction to Physics in Modern Medicine, 2020
Suzanne Amador Kane, Boris A. Gelman
Quantitative computed tomography (QCT) takes advantage of the ability of standard CT scanners to actually measure the average attenuation coefficient in each tiny voxel of tissue. Since x-ray absorption is related to density, and the mass attenuation coefficient is known in advance (Figure 5.14), CT also yields the bone mineral density at each voxel, as well as anatomical information. Thus, it can reveal any changes in the shape of the spine or the hip, as well as the distribution of bone loss in different types of bone tissue. Since bones can “remodel” – change their shape in response to bone density loss – to recover some strength, this is important information lost in DEXA. QCT presently is used less frequently than DEXA, primarily for measurements on the vertebra.
Progress in understanding and management of premature ovarian insufficiency
Published in Climacteric, 2021
The assessment of bone health in young women with POI has been problematic due to the fact that maximal bone density is not achieved until their mid to late twenties. Prediction of a young woman’s peak bone strength according to her individual genetic potential is difficult. Bone mineral density (BMD) measured by dual-energy X-ray absorptiometry has limitations. As stated by the author of the bone health paper, it does not distinguish cortical from trabecular bone, or provide information on bone quality, and the relationship between BMD and fracture risk is not well established in young cohorts. It is therefore important that new techniques such as high-resolution quantitative computed tomography are developed for the POI population. Review of the bone data in POI shows that most are from short-term trials and observational analyses; better quality data are required for both bone and muscle health. In the meantime, clinical management of women with POI should focus on maximizing bone health through dietary, lifestyle and hormonal interventions. The use of non-hormonal bone-sparing preparations such as bisphosphonates, denosumab and selective estrogen receptor modulators remains problematic due to the lack of data for efficacy and long-term safety in young women.
Nutritional Intake and Bone Health Among Adults With Probable Undiagnosed, Untreated Celiac Disease: What We Eat in America and NHANES 2009–2014
Published in Journal of the American College of Nutrition, 2020
Lara H. Sattgast, Sina Gallo, Cara L. Frankenfeld, Alanna J. Moshfegh, Margaret Slavin
Probable CD status was associated with lower BMD of the femur and femoral neck. Similar results have been documented by other studies that have found lower BMD of the femur and femoral neck in individuals with untreated CD than those without CD (2,9). No differences were found in BMD of the total spine from this study. Other studies have found lower BMD of the lumbar spine in individuals with untreated CD than those without CD (11,47,48), but less information exists on BMD of the total spine for this group. The spine has different proportions of trabecular and cortical bone than the femur and femoral neck, which have been found to be lost at different rates initially among osteoporotic patients (49), and this may explain this difference. A more sensitive technique such as peripheral quantitative computed tomography may be helpful for explaining these findings.
Bone health in women with breast cancer
Published in Climacteric, 2019
S. K. Ramchand, Y. M. Cheung, M. Grossmann
As is evident from the preceding discussion of the limited evidence, many important questions remain, such as which antiresorptive to use and how long for, especially in young premenopausal women. While RCTs assessing zoledronic acid in women with early breast cancer have used 4 mg every 6 months, whether alternative dosing schedules such as using 5 mg every 12 months, a schedule with proven antifracture efficacy in postmenopausal osteoporosis59, is similarly effective in women with early breast cancer is not known. Moreover, the clinical utility of bone remodeling markers and alternative bone imaging to DXA, such as high-resolution peripheral quantitative computed tomography, in fracture risk assessment and in monitoring treatment response requires further study. The optimal choice of antiresorptive therapy in postmenopausal women is also not settled. For example, while bisphosphonates have proven oncologic benefits56, but currently no proven antifracture efficacy, denosumab has proven antifracture efficacy but no proven oncologic benefits23. While in postmenopausal women tamoxifen treatment may have modest benefits on skeletal health21, when to add antiresorptive treatment is not clear, but may need to be considered in women at high fracture risk.