Short-term precision assessment of trabecular bone score and bone mineral density using dual-energy X-ray absorptiometry with different scan modes: an in vivo study.

OBJECTIVES: We estimated the in vivo reproducibility of trabecular bone score (TBS) from dual-energy X-ray absorptiometry (DXA) using different imaging modes to be compared to that of bone mineral density (BMD). METHODS: We enrolled 30 patients for each imaging mode: fast-array, array, high definition. Each patient underwent two DXA examinations with in-between repositioning. BMD and TBS were obtained according to the International Society for Clinical Densitometry guidelines. The coefficient of variation (CoV) was calculated as the ratio between root mean square standard deviation and mean, percent least significant change (LSC) as 2.77 × CoV, reproducibility as the complement to 100% LSC. RESULTS: Fast-array imaging mode resulted in 0.8% CoV and 2.1% LSC for BMD, 1.9% and 5.3% for TBS, respectively; array imaging mode resulted in 0.7% and 2.0% for BMD, 1.9% and 5.2%, for TBS; high-definition imaging mode resulted in 0.7% and 2.0%, for BMD; 2.0% and 5.4% for TBS, respectively. Reproducibility of TBS (95%) was significantly lower than that of BMD (98%) (p < 0.012). Difference in reproducibility among the imaging modes was not significant for either BMD or TBS (p = 0.942). CONCLUSION: While TBS reproducibility was significantly lower than that of BMD, differences among imaging modes were not significant for both TBS and BMD. KEY POINTS: • TBS is an emerging tool for assessing BMD. • TBS reproducibility is lower than that of BMD. • Differences between imaging modes are not significant for either TBS or BMD.

Increasing soft tissue thickness does not affect trabecular bone score reproducibility: a phantom study.

PURPOSE: Trabecular Bone Score (TBS) provides an indirect score of trabecular microarchitecture from lumbar spine (LS) dual energy X-ray absorptiometry. Increasing soft tissue thickness artifactually reduces TBS values; we evaluated the effect of a fictitious increase of soft tissue thickness on TBS and bone mineral density (BMD) reproducibility on a phantom model. METHODS: A Hologic spine phantom was scanned with a QDR-Discovery W Hologic densitometer. Fresh pork rind layers of 5 mm were used to simulate the in-vivo soft tissues. For each scan mode (fast array [FA], array, high definition [HD]), 25 scans were consecutively performed without phantom repositioning, at 0 (no layers), 1 cm, 3 cm, and 6 cm of thickness. BMD and TBS reproducibility was calculated as the complement to 100% of least significant change. RESULTS: Both BMD and TBS reproducibility slightly decreased with increasing soft tissue; this difference was statistically significant only for BMD using HD modality (reproducibility decreased from 99.4% at baseline to 98.4% at 6-cm of thickness). TBS reproducibility was slightly lower compared to that of BMD, and ranged between 98.8% (array, 0 cm) and 97.4% (FA, 6 cm). Without taking into account manufacturer BMI optimization, we found a progressive decrease of TBS mean values with increasing soft tissue thickness. The highest TBS difference between baseline scan and 6 cm was -0.179 (-14.27%) using HD. CONCLUSIONS: Despite being slightly lower than that of BMD, TBS reproducibility was not affected up to 6 cm of increasing soft tissue thickness, and was even less influenced by fat than BMD reproducibility.

Relevant incidental findings at abdominal multi-detector contrast-enhanced computed tomography: A collateral screening?

AIM: To investigate the prevalence of relevant incidental findings (RIFs) detected during routine abdominal contrast-enhanced computed tomography (CeCT). METHODS: We retrospectively evaluated the reports of a consecutive series of abdominal CeCT studies performed between January and May 2013. For each report, patients' age and sex, admission as inpatient or outpatient, clinical suspicion as indicated by the requesting physician, availability of a previous abdominal examination, and name of the reporting radiologist were recorded. Based on the clinical suspicion, the presence and features of any RIFs (if needing additional workup) was noted. RESULTS: One thousand forty abdominal CeCT were performed in 949 patients (528 males, mean age 66 ± 14 years). No significant difference was found between inpatients and outpatients age and sex distribution (P > 0.472). RIFs were found in 195/1040 (18.8%) CeCT [inpatients = 108/470 (23.0%); outpatients = 87/570 (15.2%); P = 0.002]. RIFs were found in 30/440 (6.8%) CeCT with a previous exam and in 165/600 (27.5%) without a previous exam (P < 0.001). Radiologists' distribution between inpatients or outpatients was significantly different (P < 0.001). RIFs prevalence increased with aging, except for a peak in 40-49 year group. Most involved organs were kidneys, gallbladder, and lungs. CONCLUSION: A RIF is detected in 1/5 patients undergoing abdominal CeCT. Risk of overdiagnosis should be taken into account.

Managing osteoporosis in ulcerative colitis: something new?

The authors revise the latest evidence in the literature regarding managing of osteoporosis in ulcerative colitis (UC), paying particular attention to the latest tendency of the research concerning the management of bone damage in the patient affected by UC. It is wise to assess vitamin D status in ulcerative colitis patients to recognize who is predisposed to low levels of vitamin D, whose deficiency has to be treated with oral or parenteral vitamin D supplementation. An adequate dietary calcium intake or supplementation and physical activity, if possible, should be guaranteed. Osteoporotic risk factors, such as smoking and excessive alcohol intake, must be avoided. Steroid has to be prescribed at the lowest possible dosage and for the shortest possible time. Moreover, conditions favoring falling have to been minimized, like carpets, low illumination, sedatives assumption, vitamin D deficiency. It is advisable to assess the fracture risk in all UC patient by the fracture assessment risk tool (FRAX(®) tool), that calculates the ten years risk of fracture for the population aged from 40 to 90 years in many countries of the world. A high risk value could indicate the necessity of treatment, whereas a low risk value suggests a follow-up only. An intermediate risk supports the decision to prescribe bone mineral density (BMD) assessment and a subsequent patient revaluation for treatment. Dual energy X-ray absorptiometry bone densitometry can be used not only for BMD measurement, but also to collect data about bone quality by the means of trabecular bone score and hip structural analysis assessment. These two indices could represent a method of interesting perspectives in evaluating bone status in patients affected by diseases like UC, which may present an impairment of bone quality as well as of bone quantity. In literature there is no strong evidence for instituting pharmacological therapy of bone impairment in UC patients for clinical indications other than those that are also applied to the patients with osteoporosis. Therefore, a reasonable advice is to consider pharmacological treatment for osteoporosis in those UC patients who already present fragility fractures, which bring a high risk of subsequent fractures. Therapy has also to be considered in patients with a high risk of fracture even if it did not yet happen, and particularly when they had long periods of corticosteroid therapy or cumulative high dosages. In patients without fragility fractures or steroid treatment, a medical decision about treatment could be guided by the FRAX tool to determine the intervention threshold. Among drugs for osteoporosis treatment, the bisphosphonates are the most studied ones, with the best and longest evidence of efficacy and safety. Despite this, several questions are still open, such as the duration of treatment, the necessity to discontinue it, the indication of therapy in young patients, particularly in those without previous fractures. Further, it has to be mentioned that a long-term bisphosphonates use in primary osteoporosis has been associated with an increased incidence of dramatic side-effects, even if uncommon, like osteonecrosis of the jaw and atypical sub-trochanteric and diaphyseal femoral fractures. UC is a long-lasting disease and the majority of patients is relatively young. In this scenario primary prevention of fragility fracture is the best cost-effective strategy. Vitamin D supplementation, adequate calcium intake, suitable physical activity (when possible), removing of risk factors for osteoporosis like smoking, and avoiding falling are the best medical acts.