Comparative study of bone mineral density estimated by various methods of single- and dual-energy quantitative computed tomography: The capability of the four-equation four-unknown method

Negative Spinal Bone Mineral Density Changes and Subclinical Ovulatory Disturbances—Prospective Data in Healthy Premenopausal Women With Regular Menstrual Cycles

“…Lumbar spine DXA provides a 2-dimensional areal estimate of BMD consisting of both cortical and trabecular bone; this measure is dependent on 2-dimensional bone size (57). QCT determines volumetric trabecular BMD without the inaccuracies caused by soft tissue, extraosseous calcifications, and hyperostosis that may confound DXA (57), although QCT may be altered by increased marrow adiposity (58).…”

AGE-RELATED CHANGES IN CORTICAL AND TRABECULAR BONE MINERAL STATUS. A quantitative CT study in lumbar vertebrae

“…The BMD of the cortical bone of the lumbar vertebrae (L2 and L3) was estimated using the SE‐QCT (80 kVp) method. The BMD of the trabecular compartment was estimated using the DE‐QCT 4E‐4U method (18). All measurements were performed on a Quantex RX (GE Yokogawa Medical Systems).…”

“…The subjects assumed the supine position and lay upon the calibration phantom (Image Analysis, Irvine, CA, USA) containing 0, 50, 100 and 200 mg/ml of hydroxyapatite (HA) as well as a fat equivalent standard. A calibration insert containing a soft tissue equivalent standard with the same diameter as the other standard inserts was attached to the calibration phantom (18). The CT values obtained from the soft tissue equivalent standard were used to estimate the BMD of the trabecular component.…”

“…Estimation of trabecular BMD and volume: With the DE‐QCT 4E‐4U method, the measured CT numbers obtained from the soft tissue equivalent standard, standards of known concentrations of HA and the fat equivalent standard in the calibration phantoms, were used to estimate BMD (18). The trabecular area was estimated as in Fig.…”

“…In our previous study (18), a 4‐equation 4‐unknown method of DE‐QCT (DE‐QCT 4E‐4U method) (8) was assessed and compared with SE‐QCT and the standard DE‐QCT method (2‐line method). The findings indicated that, when a large fat content was present, the estimation of the BMD of simulated vertebrae was more accurate using this method than using the SE‐QCT or standard DE‐QCT techniques, and that the use of DE‐QCT for estimating BMD could provide useful information for assessing the rate of bone loss and response to various metabolic and mechanical stimuli.…”