The effect of contrast media on CT measures of bone mineral density: a systematic review

Pelvic Bone Marrow Sparing Intensity Modulated Radiation Therapy Reduces the Bone Mineral Density Loss of Patients With Cervical Cancer

PURPOSE

To test the efficacy and feasibility of pelvic bone marrow sparing intensity modulated radiation therapy (PBMS-IMRT) in reducing bone density loss for patients with cervical cancer undergoing pelvic radiation therapy (RT).

METHODS AND MATERIALS

Patients with nonsurgical cervical cancer with stage Ib2-IIIc cancer were randomly allocated into the PBMS group or the control group. The PBMS group additionally received pelvic bone marrow dose constraint. Computed tomography (CT) imaging sets were acquired at baseline and at 1, 3, 6, 9, and 12 months after treatment. Radiation dose and Hounsfield unit were registered. Bone density loss rates and fracture events at different follow-up time points were recorded.

RESULTS

Data from 90 patients in the PBMS group and 86 patients in the control group were used for statistical analysis, which included 30 and 26 patients with extended-field radiation therapy (EFR), respectively. The median follow-up for all patients was 12 months. Compared with baseline, the bone density of all bones at the last follow-up decreased by 43% and 53% in the PBMS and control groups, respectively, with the most significant decline at 1 month after treatment. Although patients without EFR received minimal irradiation in the upper lumbar spine, a 22.33% decrease in bone density was detected. In the group of patients with EFR, the decrease was 51.18% (P < .01). Lumbar or pelvic fracture incidence rates of patients in the PBMS and control groups were 7.8% and 12.79%, respectively. Among the dosimetric parameters, mean dose had the strongest correlation with bone density loss.

CONCLUSIONS

In patients undergoing pelvic RT, the loss of bone density can begin to appear early after RT, and it can occur either inside or outside of the irradiation field. Results of this study showed that PBMS-IMRT reduced bone mineral density loss compared with IMRT alone.

Biomarkers of Body Composition

The importance and impact of imaging biomarkers has been increasing over the past few decades. We review the relevant clinical and imaging terminology needed to understand the clinical and research applications of body composition. Imaging biomarkers of bone, muscle, and fat tissues obtained with dual-energy X-ray absorptiometry, computed tomography, magnetic resonance imaging, and ultrasonography are described.

Correlation of body composition metrics with bone mineral density and computed tomography-based trabecular attenuation

PURPOSE

To investigate the relationship of body composition metrics with bone mineral density (BMD) and trabecular attenuation in a cohort of healthy individuals.

METHODS

We retrospectively analyzed data of consecutively evaluated individuals who underwent dual-energy X-ray absorptiometry (DXA) and abdominopelvic computed tomography (CT) on the same day during routine medical check-ups between January 2021 and December 2021. Trabecular attenuation was measured at L1 level, while body composition metrics, including skeletal muscle index (SMI), skeletal muscle attenuation (SMA), visceral fat index (VFI), and subcutaneous fat index (SFI), were measured at L3 level. The association of body composition metrics with BMD and trabecular attenuation was analyzed using partial correlation analysis.

RESULTS

A total of 634 patients (median age, 56 years; range 50-62 years; 392 men) were included. In men, the SMI and SMA were positively correlated with BMD and trabecular attenuation, both before (r, 0.157-0.344; p < 0.05) and after (r, 0.103-0.246; p < 0.05) adjusting for age and body mass index. The VFI showed negative correlations with trabecular attenuation in both men (r, -0.170; p = 0.001) and women (r, -0.394; p < 0.001), which remained significant after adjusting for age and body mass index (r, -0.181 to -0.122; p < 0.05).

CONCLUSION

Low skeletal muscle mass and attenuation were significantly correlated with low BMD and trabecular attenuation in men. Visceral adiposity was associated with reduced BMD and trabecular attenuation in both men and women, demonstrating a stronger correlation with trabecular attenuation.

Evaluation of deep learning-based quantitative computed tomography for opportunistic osteoporosis screening

To evaluate diagnostic efficacy of deep learning (DL)-based automated bone mineral density (BMD) measurement for opportunistic screening of osteoporosis with routine computed tomography (CT) scans. A DL-based automated quantitative computed tomography (DL-QCT) solution was evaluated with 112 routine clinical CT scans from 84 patients who underwent either chest (N:39), lumbar spine (N:34), or abdominal CT (N:39) scan. The automated BMD measurements (DL-BMD) on L1 and L2 vertebral bodies from DL-QCT were validated with manual BMD (m-BMD) measurement from conventional asynchronous QCT using Pearson's correlation and intraclass correlation. Receiver operating characteristic curve (ROC) analysis identified the diagnostic ability of DL-BMD for low BMD and osteoporosis, determined by dual-energy X-ray absorptiometry (DXA) and m-BMD. Excellent concordance were seen between m-BMD and DL-BMD in total CT scans (r = 0.961/0.979). The ROC-derived AUC of DL-BMD compared to that of central DXA for the low-BMD and osteoporosis patients was 0.847 and 0.770 respectively. The sensitivity, specificity, and accuracy of DL-BMD compared to central DXA for low BMD were 75.0%, 75.0%, and 75.0%, respectively, and those for osteoporosis were 68.0%, 80.5%, and 77.7%. The AUC of DL-BMD compared to the m-BMD for low BMD and osteoporosis diagnosis were 0.990 and 0.943, respectively. The sensitivity, specificity, and accuracy of DL-BMD compared to m-BMD for low BMD were 95.5%, 93.5%, and 94.6%, and those for osteoporosis were 88.2%, 94.5%, and 92.9%, respectively. DL-BMD exhibited excellent agreement with m-BMD on L1 and L2 vertebrae in the various routine clinical CT scans and had comparable diagnostic performance for detecting the low-BMD and osteoporosis on conventional QCT.

Computed tomography density changes of bone metastases after concomitant denosumab

OBJECTIVE

To evaluate bone density changes at the level of normal trabecular bone and bone metastases (BMs) after denosumab (DM) treatment in oncologic patients.

MATERIALS AND METHODS

We retrospectively evaluated 31 consecutive adult patients with histologically confirmed solid tumors with at least one newly diagnosed bone metastatic lesion detected at CT. Patients received treatment with DM, 120 mg subcutaneous every 28 days for at least 6 months. Bone density was determined at the level of BMs and at the level of normal trabecular bone of lumbar vertebrae using a region of interest (ROI)-based approach.

RESULTS

A progressive increase in CT bone density was demonstrated at the level of normal trabecular bone at 6 months (18% ± 5%) and 12 months (23% ± 7%) after the treatment begins. BMs showed a significant increase in CT bone density (p < 0.05) as compared to baseline after 6 months (57% ± 15%) and 12 months (1.06 ± 0.25 times higher) after treatment.

CONCLUSION

We have found that long-term treatment with DM increases bone density progressively in oncologic patients. This effect can be observed not only at the level of secondary lesions but also at the level of apparently normal trabecular bone and is more pronounced for osteolytic metastases.

Opportunistic measures of bone mineral density at multiple skeletal sites during whole-body CT in polytrauma patients

Whole-body CT in polytrauma patients revealed bone mineral density variations throughout the skeleton. Bone density was the highest in cranial bones and the lowest in proximal extremities and pelvis. Skeletal age-related changes were generally more pronounced than sex-related changes. Cranial bones did not follow the same aging pattern compared to other bones.

INTRODUCTION

Whole-body CT (WBCT) in polytrauma patients enables the detection of numerous incidental findings, such as estimates of bone mineral density (BMD) at multiple skeletal sites. This could help in better understanding of age- and sex-related changes in BMD through skeleton.

METHODS

Data were retrospectively retrieved from the WBCTs requested during a 2-year period. BMD, expressed in CT Hounsfield units (HU), was measured at frontal and occipital bone, four vertebrae (C4, Th7, L4, and S2), iliac bone, and proximal humerus and femur. Measurements were done on native and postcontrast scans. The population sample was age-, sex-, and visceral fat volume adjusted for analysis.

RESULTS

A total of 296 patients were included, with a median age of 51 years. BMD varied from the highest HU in cranial bones (629 HU) to the lowest HU in the pelvic bones (114 HU), P < 0.001. Sex differences were independent predictors of BMD in cranial bones and proximal humerus. The age-related decline in BMD was significant in all other bones, but the association with age differed among the measurement's sites. Visceral fat showed the strongest correlation with the lumbar spine and iliac wing, although multivariate analysis revealed it was not an independent predictor of bone density, such as age and sex.

CONCLUSIONS

BMD varies through skeleton, being the highest in the proximal axial skeleton. Age-related changes in BMD are significant and more pronounced than sex-related changes in almost all bones. Cranial bones do not follow the same pattern compared to other bones.