Rat lumbar vertebrae bone densitometry using multidetector CT

Abstract

Peripheral quantitative CT (pQCT) is the main method of bone mineral density (BMD) measurement in small animals. However, pQCT is usually only available in specialized centers, while clinical multidetector computed tomography (MDCT) is much more widely available. This study investigated the feasibility of using clinical 64-slice MDCT for measuring the BMD of rat lumbar vertebrae. The lumbar vertebrae of 18 7-month-old female Sprague-Dawley rats were studied. Two MDCT protocols (General Electric LightSpeed), comprising single 2.5-mm and continuous 0.625-mm acquisitions, and a single pQCT protocol (Scanco Densiscan 2000), comprising 1-mm acquisitions, were performed. The following comparisons were carried out: 2.5-mm MDCT densitometry versus 0.625-mm MDCT densitometry; 0.625-mm MDCT densitometry compared to pQCT densitometry; same day repeatability of 0.625-mm MDCT densitometry; longitudinal repeatability of 0.625-mm MDCT densitometry on day 0 and day 28 and longitudinal 0.625-mm MDCT densitometry in ovariectomized rats on day 0 and day 28. Comparisons were made using intra-class correlation coefficient (ICC). Examination time per animal was 5 min for MDCT and 30 min for pQCT. Acquisitions of 2.5-mm MDCT had a larger coefficient of variation (CoV) than 0.625-mm acquisitions. MDCT densitometry had good agreement with pQCT densitometry (ICC = 0.85). Same-day MDCT densitometry with 0.625-mm acquisitions had a small CoV (1.61%). MDCT densitometry of non-ovariectomized animals at 28 days showed no BMD change, while MDCT densitometry of ovariectomized animals showed a 13.7 +/- 6.7% BMD reduction at 28 days. Clinical MDCT can reliably and accurately measure rat lumbar vertebral BMD and is much faster than pQCT.

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“…Rat lumbar vertebral BMD was measured by using a clinical multidetector computed tomographic (CT) scanner (LightSpeed VCT 64; GE Healthcare, Milwaukee, Wis) with a continuous axial 0.625-mm section thickness. A more detailed description of the method we used to obtain small-animal BMD from a clinical CT scanner has been reported by Wang et al ( 18 ). Lumbar vertebral BMD for each rat was defi ned as the mean BMD of vertebrae L2 through L5.…”

MR spectroscopy for assessing the effects of oxytocin on marrow adipogenesis induced by glucocorticoid in rabbits

“…Clinical MDCT can reliably and accurately measure animal vertebral BMD and is much faster than peripheral QCT (11). We found that bone loss at lumbar spine was more obvious than that of proximal femur.…”

Organic Nitrate Maintains Bone Marrow Blood Perfusion in Ovariectomized Female Rats: A Dynamic, Contrast-Enhanced Magnetic Resonance Imaging (MRI) Study

“…Computed tomography (CT) assessment of rat lumbar vertebral BMD was measured by using a clinical multidetector CT scanner (LightSpeed VCT 64; GE Healthcare, Milwaukee) with a continuous axial 0.625-mm section thickness. A more detailed description of the method has been reported elsewhere [ 40 , 41 ]. Lumbar vertebral BMD for each rat was defined as the mean BMD of vertebrae L1 through L6.…”