Diagnostic Accuracy of Dual-Energy CT Material Decomposition Technique for Assessing Bone Status Compared with Quantitative Computed Tomography

PURPOSE

The purpose of this study was to evaluate the diagnostic accuracy when using various base material pairs (BMPs) in dual-energy computed tomography (DECT), and to establish corresponding diagnostic standards for assessing bone status through comparison with quantitative computed tomography (QCT).

METHODS

This prospective study enrolled a total of 469 patients who underwent both non-enhanced chest CT scans under conventional kVp and abdominal DECT. The bone densities of hydroxyapatite (water), hydroxyapatite (fat), hydroxyapatite (blood), calcium (water), and calcium (fat) (D_{HAP (water)}, D_{HAP (fat)}, D_{HAP (blood)}, D_{Ca (water)}, and D_{Ca (fat)}) in the trabecular bone of vertebral bodies (T11-L1) were measured, along with bone mineral density (BMD) via QCT. Intraclass correlation coefficient (ICC) analysis was used to assess the agreement of the measurements. Spearman's correlation test was performed to analyze the relationship between the DECT- and QCT-derived BMD. Receiver operator characteristic (ROC) curves were generated to determine the optimal diagnostic thresholds of various BMPs for diagnosing osteopenia and osteoporosis.

RESULTS

A total of 1371 vertebral bodies were measured, and QCT identified 393 with osteoporosis and 442 with osteopenia. Strong correlations were observed between D_{HAP (water)}, D_{HAP (fat)}, D_{HAP (blood)}, D_{Ca (water)}, and D_{Ca (fat)} and the QCT-derived BMD. D_{HAP (water)} showed the best predictive capability for osteopenia and osteoporosis. The area under the ROC curve, sensitivity, and specificity for identifying osteopenia were 0.956, 86.88%, and 88.91% with D_{HAP (water)} ≤ 107.4 mg/cm³, respectively. The corresponding values for identifying osteoporosis were 0.999, 99.24%, and 99.53% with D_{HAP (water)} ≤ 89.62 mg/cm³, respectively.

CONCLUSIONS

Bone density measurement using various BMPs in DECT enables the quantification of vertebral BMD and the diagnosis of osteoporosis, with D_{HAP (water)} having the highest diagnostic accuracy.

The new fast kilovoltage-switching dual-energy computed tomography for measuring bone mineral density

Background

The update in technology may impact the accuracy in measuring bone mineral density (BMD). However, the application of the new fast kilovoltage (kV)-switching dual-energy computed tomography (DECT) for BMD measurement has not yet been reported. This study aimed to examine the accuracy and precision of the new fast kV-switching DECT in measuring BMD and to evaluate its applicability in clinical BMD measurement.

Methods

Forty sets of the new fast kV-switching DECT scans and one quantitative computed tomography (QCT) scan were performed on the European Spine Phantom. Their relative errors and relative standard deviations were compared. A retrospective analysis was performed on patients who underwent chest plain DECT and abdominal monoenergetic plain CT at the same time. The relationship between hydroxyapatite-water and hydroxyapatite-fat measured using DECT and BMD measured using QCT was analyzed by multivariate regression analysis.

Results

The relative errors of the new fast kV-switching DECT with low tube speeds (0.8 and 1.0 s/r) were all less than 6% and were less than those of QCT, except for those at 515 mA. The relative standard deviation values with high tube rotation speeds (0.5 and 0.6 s/r) were higher than those with low tube speeds (0.8 and 1.0 s/r) under most tube current conditions. The new fast kV-switching DECT-derived BMD values corrected by multiple linear regression (predicted hydroxyapatite) were significantly positively correlated with the QCT-based BMD values (R²=0.912; P<0.001). The results of the Bland-Altman analysis demonstrated high consistency between the 2 measurement methods.

Conclusions

Results of the phantom measurements indicated that the new fast kV-switching DECT could measure BMD with relatively high accuracy and precision. The results of a subsequent clinical in vivo experiment demonstrated that vertebral BMD measurements derived from DECT and QCT were mostly consistent and highly accurate. Therefore, patients who undergo DECT for other clinical indications can simultaneously have their BMD determined.

Using QCT to evaluate bone mineral and abdominal adipose changes in patients with primary hyperparathyroidism and comparing it to DXA for bone status assessment: a retrospective case-control study

Background

Patients with primary hyperparathyroidism (PHPT) show changes in bone metabolism and adipose tissue, but the results are inconsistent. Quantitative computed tomography (QCT) was reported useful for detecting bone mineral and adipose tissue change, but information on the role of QCT in PHPT is limited. We aimed to explore the changes of lumbar bone mineral density (BMD) and abdominal adipose tissue in patients with PHPT using QCT based on existed CT images, and to assess the consistency between QCT and dual-energy X-ray absorptiometry (DXA) in assessing bone status.

Methods

This retrospective case-control study was conducted on 48 PHPT patients, with healthy controls (HCs) matched by their age (±3 years) and gender, and the case-to-control ratio was approximately 1:3. Volumetric bone mineral density (vBMD), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and total adipose tissue (TAT) were measured by QCT in both PHPT and control groups and compared with the independent samples T-test. In the PHPT group, areal bone mineral density (aBMD) was measured by DXA. Pearson correlation analysis was used to investigate the association between QCT-derived vBMD and DXA-derived aBMD. Weighted kappa consistency analysis was used to clarify the agreement between QCT and DXA.

Results

Compared with HCs, the PHPT group had significantly lower vBMD (114.30±41.71 vs. 136.92±42.23 mg/cm³; P=0.002) and higher TAT (261.98±74.65 vs. 236.69±69.00 cm²; P=0.033); however, differences in SAT (120.81±40.19 vs. 109.94±36.83 cm²; P=0.085) and VAT (141.17±48.11 vs. 126.75±50.50 cm²; P=0.085) were not statistically significant. There was a strong correlation between QCT-derived vBMD and DXA-derived aBMD (all r>0.68; P<0.001), and a moderate consistency [kappa(w) =0.48; 95% CI: 0.29 to 0.68; P<0.001] was presented when defining bone status according to the respective diagnostic criteria.

Conclusions

Our study may provide useful information regarding bone status and abdominal adipose tissue change in patients with PHPT without requiring additional scan and may further extend the clinical application value of QCT.

Associations of muscle size and fatty infiltration with bone mineral density of the proximal femur bone

PURPOSE

To investigate the relationship of muscle atrophy and fat infiltration around the hip joint with areal bone mineral density (aBMD) in each subregion of the proximal femur.

MATERIALS AND METHODS

In total, 144 participants (66 women and 78 men) were examined by quantitative computed tomography (QCT), and areal bone mineral density (aBMD) of the femoral neck (FN), trochanter (TR), and intertrochanter (IT) of the proximal femur were obtained. The cross-sectional area (CSA) and proton density fat fraction (PDFF) of the gluteus maximus (G.MaxM), gluteus medius (G.MedM), gluteus minimus (G.MinM), and iliopsoas (IliopM) were obtained via magnetic resonance imaging (MRI) using the mDIXON-Quant sequence. A multivariate generalized linear model was used to evaluate the correlation of the CSA and PDFF of muscles with aBMD in all subregions of the proximal femur.

RESULTS

The FN integral (Int) aBMD was significantly associated with the G.MaxM CSA (men: P = 0.002; women: P = 0.008) and PDFF (men: P < 0.001; women: P = 0.047). Some muscle indexes were related to the FN aBMD in males or females, including the CSA of G.MedM, G.MinM, and IliopM as well as the PDFF of IliopM and G.MinM. Associations of hip muscle parameters with the TR Int aBMD in both males and females were observed, including G.MaxM CSA (men: P < 0.001; women: P = 0.028) and G.MaxM PDFF (men: P = 0.031; women: P = 0.038). Other muscle indexes, including G.MedM and IliopM, were related to the TR aBMD, mainly affecting the aBMD of TR cortical (Cort) and TR Int. The IT Int aBMD and IT Cort aBMD showed significant correlation with the muscle indexes of G. MaxM, IliopM, and G.MedM, including the PDFF and CSA in males and females. Further, more indicators of the G.MedM and IliopM correlated with the TR and IT aBMD compared to the FN aBMD.

CONCLUSIONS

The CSA of gluteus muscles and iliopsoas had a positive association with the aBMD in the proximal femur, and the PDFF of gluteus muscles and iliopsoas had a negative correlation with the aBMD in the proximal femur. In addition, there was an interaction of the proximal femur aBMD with the muscle size and fatty infiltration of hip muscles.

A phantom study comparing low-dose CT physical image quality from five different CT scanners

BACKGROUND

To systematically evaluate the physical image quality of low-dose computed tomography (LDCT) on CT scanners from 5 different manufacturers using a phantom model.

METHODS

CT images derived from a Catphan 500 phantom were acquired using manufacturer-specific iterative reconstruction (IR) algorithms and deep learning image reconstruction (DLIR) on CT scanners from 5 different manufacturers and compared using filtered back projection with 2 radiation doses of 0.25 and 0.75 mGy. Image high-contrast spatial resolution and image noise were objectively characterized by modulation transfer function (MTF) and noise power spectrum (NPS). Image high-contrast spatial resolution and image low-contrast detectability were compared directly by visual evaluation. CT number linearity and image uniformity were compared with intergroup differences using one-way analysis of variance (ANOVA).

RESULTS

The CT number linearity of 4 insert materials were as follows: acrylic (95% CI: 120.35 to 121.27; P=0.134), low-density polyethylene (95% CI: -98.43 to -97.43; P=0.070), air (95% CI: -996.16 to -994.51; P=0.018), and Teflon (95% CI: 984.40 to 986.87; P=0.883). The image uniformity values of GE Healthcare (95% CI: 3.24 to 3.83; P=0.138), Philips (95% CI: 2.62 to 3.70; P=0.299), Siemens (95% CI: 2.10 to 3.59; P=0.054), Minfound (95% CI: 2.35 to 3.65; P=0.589), and Neusoft (95% CI: 2.63 to 3.37; P=0.900) were evaluated and found to be within ±4 Hounsfield units (HU), with a range of 0.99-2.76 HU for standard deviations. There was no statistically significant difference in CT number linearity and image uniformity across the 5 CT scanners under different radiation doses with IR and DLIR algorithms (P>0.05). The resolution level at 10% MTF was 6.98 line-pairs-per-centimeter (lp/cm) on average, which was similar to the subjective evaluation results (mostly up to 7 lp/cm). DLIR at all 3 levels had the highest 50% MTF values among all reconstruction algorithms. For image low-contrast detectability, the minimum diameter of distinguishable contrast holes reached 4 mm at a 0.5% resolution. Increasing the radiation dose and IR strength reduced the image noise and NPS curve peak frequency while improving image low-contrast detectability.

CONCLUSIONS

This study demonstrated that the image quality of CT scanners from 5 different manufacturers in LDCT is comparable and that the CT number linearity is unbiased and can contribute to accurate bone mineral density quantification.

A Contemporary View of the Diagnosis of Osteoporosis in Patients With Axial Spondyloarthritis

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that primarily affects the axial joints. Altered bone metabolism associated with chronic inflammation leads to both new bone formation in the spine and increased bone loss. It is known that patients with axSpA have a high prevalence of osteoporosis and fractures. However, there is no consensus on which imaging modality is the most appropriate for diagnosing osteoporosis in axSpA. Bone mineral density measurement using dual-energy X-ray absorptiometry is the primary diagnostic method for osteoporosis, but it has notable limitations in patients with axSpA. This method may lead to the overestimation of bone density in patients with axSpA because they often exhibit abnormal calcification of spinal ligaments or syndesmophytes. Therefore, the method may not provide adequate information about bone microarchitecture. These limitations result in the underdiagnosis of osteoporosis. Recently, new imaging techniques, such as high-resolution peripheral quantitative computed tomography, and trabecular bone score have been introduced for the evaluation of osteoporosis risk in patients with axSpA. In this review, we summarize the current knowledge regarding imaging techniques for diagnosing osteoporosis in patients with axSpA.

Computed Tomography Diagnostic of Uncommon Case of Osteopetrosis in 80-Year-Old Man-Case Report

Background and Objectives: During osteopetrosis course, impaired bone remodeling induces skeletal osteosclerosis and abnormally dense bones, which, however, are brittle and susceptible to low-energy fractures. In this study, radiological evaluation and densitometric measurements of several bones of the skeleton in one of the oldest patients in the world suffering from osteopetrosis was presented. Materials and Methods: Volumetric bone mineral density measurements of the examined bones in an 80-year-old man were performed using two different quantitative computed tomography techniques. Results: The obtained results show higher values of the volumetric bone mineral density of the trabecular bone in lumbar spine than in the cortical bone compartment. T-score and Z-score in this patient reached values of 27–28 and 31–32, respectively. Conclusions: The obtained densitometric data may serve for further diagnostic purposes of osteopetrosis. As documented, the severity of the osteosclerotic changes of bones were higher in this patient than in most other described cases. Moreover, radiological signs diagnosed in this patient were characteristic for all types of osteopetrosis making this case very uncommon.

Age-related fatty infiltration of lumbar paraspinal muscles: a normative reference database study in 516 Chinese females

Background

Fatty infiltration, as a result of aging, is an essential biomarker of muscle degeneration. This research aimed to investigate the age-dependent change of fatty degeneration in the paraspinal muscles of healthy Chinese women. This study also explores the effect of body size on fatty infiltration of paraspinal muscles.

Methods

Cross-sectional area of paraspinal muscles (CSA_muscle) and intermuscular adipose tissue (CSA_IMAT) were measured at the L3 mid-vertebral level of 516 healthy females, who underwent abdomen quantitative computed tomography (QCT) scans. Subsequently, IMAT% [CSA_IMAT / (CSA_IMAT + CSA_muscle)] were calculated. The relationship between basic information and measurements was evaluated using Spearman correlations. Comparisons of QCT results among different BMI subgroups in different age groups were analyzed with the Kruskal-Wallis H test and LSD, post-hoc correction. Age-related changes were calculated after the adjustment of height and weight.

Results

The mean CSA_IMAT of 20-29 years group (n=69) and 70-79 years group (n=25) were 3.00 cm² and 11.06 cm², respectively. While the mean CSA_muscle of 20-29 years group was 38.46 cm² and 70-79 years group was 30.86 cm². The mean IMAT% difference between 20-29 years group and 70-79 years group was -18.55%. Strong, positive non-linear associations were observed between ageing and CSA_IMAT, along with IMAT% (r=0.656, P<0.01; r=0.714, P<0.01). However, CSA_muscle was shown to decrease with age in a weak, negative linear fashion (r=-0.265, P<0.01). Positive relationships between BMI and CSA_IMAT, CSA_muscle, along with IMAT%, were found. Significant differences were observed between obesity and normal BMI subgroup for all variables in three age groups. CSA_IMAT showed a larger age-related difference compared to CSA_muscle.

Conclusions

Fatty infiltration in paraspinal muscles increased with age and BMI, while muscle loss may be associated with aging. The present study provided standardized reference data for the fatty degeneration of paraspinal muscles across the adult lifespan of Chinese females, which will play a critical role in future studies.

Associations of Muscle Size and Density With Proximal Femur Bone in a Community Dwelling Older Population

Background and Purpose: Muscle weakness and bone fragility are both associated with hip fracture. In general, muscle contractions create forces to the bone, and bone strength adapts to mechanical loading through changes in bone architecture and mass. However, the relationship between impairment of muscle and bone function remain unclear. In particular, the associations of muscle with properties of proximal femur cortical and trabecular bone are still not well understood. The aim of this study was to explore the associations of hip/thigh muscle density (CT attenuation value in Hounsfield units) and size with cortical and trabecular bone mineral density (BMD) of the proximal femur. Materials and Methods: Three-dimensional quantitative computed tomography (QCT) imaging of the lumber, hip and mid-thigh was performed in a total of 301 participants (mean age 68.4 ± 6.1 years, 194 women and 107 men) to derive areal BMD (aBMD) and volumetric BMD (vBMD). Handgrip strength (HGS) and the Timed Up and Go (TUG) test were also performed. From the CT images, cross-sectional area (CSA), and density were determined for the gluteus maximus muscle (G.MaxM), trunk muscle at the vertebrae L2 level, and mid-thigh muscle. Multivariate generalized linear models were applied to assess associations. Results: Total hip (TH) aBMD was associated significantly with G.MaxM CSA (men: P = 0.042; women: P < 0.001) and density (men: P = 0.012; women: P = 0.043). In women, 0.035 cm² of mid-thigh CSA (95% CI, 0.014-0.057; P = 0.002) increased per SD increase in TH aBMD, but this significance was not observed in men (P = 0.095). Trunk muscle density and CSA were not associated with proximal femur BMD. The associations of hip/thigh muscle parameters with femoral neck BMD were weaker than those with trochanter and intertrochanter BMD. Furthermore, compared to muscle density, muscle CSA showed better associations with vBMD. G.MaxM CSA was associated with trochanter (TR) Cort. vBMD in men (β, 19.898; 95% CI, 0.924-38.871; P = 0.040) and in women (β, 15.426; 95% CI, 0.893-29.958; P = 0.038). Handgrip strength was only associated with TR aBMD (β, 0.038; 95% CI, 0.006-0.070; P = 0.019) and intertrochanter aBMD (β, 0.049; 95% CI, 0.009-0.090; P = 0.016) in men. Conclusions: We observed positive associations of the gluteus and thigh muscle size with proximal femur volumetric BMD. Specifically, the gluteus maximus muscle CSA was associated with trochanter cortical vBMD in both men and women.

The study protocol for the China Health Big Data (China Biobank) project

Background

Osteoporosis, obesity, and fatty liver are increasingly common chronic diseases that seriously threaten people's health. Low-dose chest computed tomography (LDCT) scan is frequently used for lung cancer screening in health screenings and checkups. Quantitative computed tomography (QCT) enables the accurate measurement of volumetric bone mineral density (vBMD), liver fat content, and abdominal fat area using the existing LDCT data without extra radiation. We initiated a new project, the China Health Big Data (China Biobank), which combines the LDCT scan images from lung cancer screening of participants in health checkup with QCT to investigate the added value of QCT to LDCT, in order to establish the normative reference database and diagnosis criteria for the three aforementioned conditions.

Methods

The China Biobank project is a prospective nationwide multicenter cohort study that will combine QCT technology with LDCT scans to measure bone mineral density (BMD), intra-abdominal fat distribution, and liver fat content of the generally healthy checkup participants. Mindways QCT calibration phantom (Mindways Software Inc., Austin, TX, USA) and analysis software QCT PRO v6.0 will be used for all centers. Before data collection begins, the European Spine Phantom (ESP) will be used for quality control analysis at each collaborating center. The inclusion criteria are a healthy checkup participant aged 30-90 years, with LDCT as a part of his/her health checkup protocol. Exclusion criteria are pregnant women or participants with a metal implant in the CT scan area. The LDCT images will be transferred to the Mindways workstation for analysis, and vBMD in the L1 and L2 vertebrae, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and liver fat content will be measured. As part of the health checkup, the demographic, anthropometric parameters, blood pressure, and a routine blood laboratory test will be collected. The estimated sample size will be about 30,000.

Results

The combination of QCT with LDCT of the chest was validated in this project. The vBMD of spine, visceral fat and liver fat can be measured with a LDCT chest scan.

Conclusions

The China Biobank project will assess the added value of QCT to LDCT, and enable accurate evaluation of the prevalence of osteoporosis, obesity, and fatty liver disease in a very large Chinese cohort.

Update on bone density measurements and their interpretation in children and adolescents

Following the increased awareness about the central role of the pediatric age in building bone for life, clinicians face more than ever the necessity of assessing bone health in pediatric subjects at risk for early bone mass derangements or in healthy children, in order to optimize their bone mass accrual and prevent osteoporosis. Although the diagnosis of osteoporosis is not made solely upon bone mineral density measurements during growth, such determination can be very useful in the follow-up of pediatric patients with primary and secondary osteoporosis. The ideal instrument would give information on the mineral content and density of the bone, and on its architecture. It should be able to perform the measurements on the skeletal sites where fractures are more frequent, and it should be minimally invasive, accurate, precise and rapid. Unfortunately, none of the techniques currently utilized fulfills all requirements. In the present review, we focus on the pediatric use of dual-energy X-ray absorptiometry (DXA), quantitative computed tomography (QCT), peripheral QCT (pQCT), and magnetic resonance imaging (MRI), highlighting advantages and limits for their use and providing indications for bone densitometry interpretation and of vertebral fractures diagnosis in pediatric subjects.

Quantitative computed tomographic evaluation of bone mineral density in beagle dogs: comparison with dual-energy x-ray absorptiometry as a gold standard

This study aimed to demonstrate the higher accuracy and reproducibility of quantitative computed tomography (QCT) compared with dual-energy X-ray absorptiometry (DXA) as a gold standard for measuring canine bone mineral density (BMD). Seven middle-aged beagle dogs underwent lumbar vertebral and bilateral femoral DXA and QCT scans. BMD (mg/cm²) was measured at the vertebral body from L2 to L6, femoral neck, and proximal and distal femoral diaphyses. The BMD values were measured 3 times and compared. The BMD value on QCT was higher than that on DXA for femoral BMD but not for vertebral BMD. The correlation was strong for the lumbar vertebrae (r=0.66) and was strongest for L3 (r=0.85). No correlation was found for the femoral neck (P=0.35), and only moderate correlations were found for the proximal and distal femoral diaphyses (r=0.43 and r=0.40, respectively). The limits of agreement were narrower for vertebral BMD than for femoral BMD, and L3 had the narrowest limits of agreement. The intraclass correlation (ICC) was higher for DXA than for QCT at all lumbar and femoral sites measured, but the ICC of QCT was higher than 0.7. In conclusion, L3 can be used to monitor changes in BMD, and relative values and sequential monitoring of femoral BMD can also be useful because of the high reproducibility of QCT measurements. QCT would be a useful technique for evaluation of BMD in veterinary practice.

Quantitative Computed Tomography-Current Status and New Developments

This review focuses on new developments and current controversies in the field of quantitative computed tomography. Recent positions of the International Society for Clinical Densitometry acknowledged the clinical value of quantitative computed tomography of the spine and the hip using clinical whole-body computed tomography (CT) scanners. Opportunistic screening summarizes a number of new approaches describing the dual use of clinical CT scans. For example, CT scans may have been taken for tumor diagnosis but may also be used for the prediction of high or low fracture risks as an additional benefit for the patient. The assessment of the cortical parameters is another topic of current research. In CT images of the spine and the hip, a number of techniques have been developed to determine the thickness, mass, and bone density of the cortex. In higher-spatial resolution peripheral CT images of the radius and tibia obtained from special purpose scanners, 1 focus is the measurement of cortical porosity. Two different approaches, one based on the direct segmentation of the pores and one based on cortical density, will be reviewed.

Interrelationships between Morphological, Densitometric and Mechanical Properties of Eggs in Japanese Quails (Coturnix Japonica)

Eggshell quality in birds results from mineral density and composition determining its mechanical endurance. The aim of the study was to determine interrelationships between morphological, densitometric and mechanical properties of eggs in Japanese quails. Twenty four eggs randomly collected from 17-week-old quails were subjected to morphological, denstiometric and mechanical evaluation using dual-energy X-ray absorptiometry (DEXA), quantitative computed tomography (QCT) and three-point bending test. Weight, height and width of eggs were positively correlated with the densitometric parameters obtained using DEXA (egg mineral density (EMD) and egg mineral content (EMC)) and QCT (total egg volume (TEvol) and total eggshell volume (TESvol)). Positive correlations were stated between TEvol and TESvol (r=0.52; P<0.05) and EMD and EMC r=0.83; P<0.05). Egg mineral density revealed positive correlations with TEvol and mean volumetric eggshell mineral density (MvESMD), while EMC was positively correlated with TEvol, TESvol and MvESMD (all P<0.05). Eggshell breaking strength was positively correlated with MvESMD (r=0.53; P<0.05) and negatively correlated with eggshell thickness (r=−0.50; P<0.05). In conclusion, the results obtained in this study showed numerous interrelationships between morphological, densitometric and mechanical properties of eggs in Japanese quails. Both DEXA and QCT were shown to be valuable tools for evaluation of whole egg and eggshell quality with superior prognostic value of QCT for eggshell mechanical endurance prediction. The elaborated experimental model may serve for further investigations on physiological, pharmacological, environmental, nutritional and toxicological factors influencing egg quality.

Clinical Use of Quantitative Computed Tomography-Based Advanced Techniques in the Management of Osteoporosis in Adults: the 2015 ISCD Official Positions-Part III

The International Society for Clinical Densitometry (ISCD) has developed new official positions for the clinical use of computed tomography (CT) scans acquired without a calibration phantom, for example, CT scans obtained for other diagnosis such as colonography. This also addresses techniques suggested for opportunistic screening of osteoporosis. The ISCD task force for quantitative CT reviewed the evidence for clinical applications of these new techniques and presented a report with recommendations at the 2015 ISCD Position Development Conference. Here we discuss the agreed upon ISCD official positions with supporting medical evidence, rationale, controversy, and suggestions for further study. Advanced techniques summarized as statistical parameter mapping methods were also reviewed. Their future use is promising but the clinical application is premature. The clinical use of QCT of the hip is addressed in part I and of finite element analysis of the hip and spine in part II.

Clinical Use of Quantitative Computed Tomography-Based Finite Element Analysis of the Hip and Spine in the Management of Osteoporosis in Adults: the 2015 ISCD Official Positions-Part II

The International Society for Clinical Densitometry (ISCD) has developed new official positions for the clinical use of quantitative computed tomography (QCT)-based finite element analysis of the spine and hip. The ISCD task force for QCT reviewed the evidence for clinical applications and presented a report with recommendations at the 2015 ISCD Position Development Conference. Here we discuss the agreed upon ISCD official positions with supporting medical evidence, rationale, controversy, and suggestions for further study. Parts I and III address the clinical use of QCT of the hip, and the clinical feasibility of existing techniques for opportunistic screening of osteoporosis using CT scans obtained for other diagnosis such as colonography was addressed.

Axial QCT: clinical applications and new developments

Quantitative computed tomography (QCT) is currently undergoing a renaissance, with an increasing number of studies being published and the definition of both QCT-specific osteoporosis thresholds and treatment criteria. Compared with dual-energy X-ray absorptiometry, the current standard bone mineral density technique, QCT has a number of pertinent advantages, including volumetric measurements, less susceptibility to degenerative spine changes, and higher sensitivity to changes in bone mass. Disadvantages include the higher radiation doses and less experience with fracture prediction and therapy monitoring. Over the last 10 yr, a number of novel applications have been described allowing assessment of bone mineral density and bone quality in larger patient populations, developments that may substantially improve patient care.