RATIONALE AND OBJECTIVES: The authors have been developing a dual-energy quantitative computed tomography (DE-QCT) technique that requires calibration standards that mimic the x-ray attenuation properties of bone, red marrow, and yellow marrow. To resolve questions regarding the compositions of red and yellow marrow that appear in the literature, the authors performed chemical analyses of bone marrow samples. The newly derived compositions were used in a simulation study to test the accuracy of the DEQCT technique. METHODS: Red marrow samples were extruded from the vertebrae of cadavers of young boys. Yellow marrow samples were removed directly from the femurs of cadavers of elderly women. The fat, protein, water, and mineral contents of these samples were determined. The compositions of 12 mixed marrow samples extruded from cadaver vertebrae also were measured. A computer simulation study was performed in which calibration standards with the new compositions were employed to estimate the fat and bone contents of spongiosas containing the 12 mixed marrows. RESULTS AND CONCLUSIONS: The red marrow samples contained 3% to 6% fat, 6% to 8% protein, 82% to 86% water, and 0.5% to 1% mineral. The yellow marrow samples contained 71% to 92% fat, 1% to 2% protein, 7% to 26% water, and 0.2% to 0.4% mineral. The simulation study yielded good results in three cases and mediocre to poor results in nine cases. An alternative approach was tried in which an average fat-free marrow was derived from the compositions of the 12 mixed marrows, and this substance, fat, and bone were used as the calibration standards. The DEQCT technique with these standards was applied to simulated spongiosas containing the 12 original mixed marrows plus nine additional mixed marrows. All of the estimates were in good agreement with the true compositions. The rms error of the mass fractions of fat was 0.03, and the rms error of the bone concentrations was 3.7 mg/mL.
RATIONALE AND OBJECTIVES: The authors have been developing a dual-energy quantitative computed tomography (DE-QCT) technique that requires calibration standards that mimic the x-ray attenuation properties of bone, red marrow, and yellow marrow. To resolve questions regarding the compositions of red and yellow marrow that appear in the literature, the authors performed chemical analyses of bone marrow samples. The newly derived compositions were used in a simulation study to test the accuracy of the DEQCT technique. METHODS: Red marrow samples were extruded from the vertebrae of cadavers of young boys. Yellow marrow samples were removed directly from the femurs of cadavers of elderly women. The fat, protein, water, and mineral contents of these samples were determined. The compositions of 12 mixed marrow samples extruded from cadaver vertebrae also were measured. A computer simulation study was performed in which calibration standards with the new compositions were employed to estimate the fat and bone contents of spongiosas containing the 12 mixed marrows. RESULTS AND CONCLUSIONS: The red marrow samples contained 3% to 6% fat, 6% to 8% protein, 82% to 86% water, and 0.5% to 1% mineral. The yellow marrow samples contained 71% to 92% fat, 1% to 2% protein, 7% to 26% water, and 0.2% to 0.4% mineral. The simulation study yielded good results in three cases and mediocre to poor results in nine cases. An alternative approach was tried in which an average fat-free marrow was derived from the compositions of the 12 mixed marrows, and this substance, fat, and bone were used as the calibration standards. The DEQCT technique with these standards was applied to simulated spongiosas containing the 12 original mixed marrows plus nine additional mixed marrows. All of the estimates were in good agreement with the true compositions. The rms error of the mass fractions of fat was 0.03, and the rms error of the bone concentrations was 3.7 mg/mL.
Authors: Mitchell M Goodsitt; Apeksha Shenoy; Jincheng Shen; David Howard; Matthew J Schipper; Scott Wilderman; Emmanuel Christodoulou; Se Young Chun; Yuni K Dewaraja Journal: Med Phys Date: 2014-05 Impact factor: 4.071
Authors: Susanta K Hui; Luke Arentsen; Thanasak Sueblinvong; Keenan Brown; Pat Bolan; Rahel G Ghebre; Levi Downs; Ryan Shanley; Karen E Hansen; Anne G Minenko; Yutaka Takhashi; Masashi Yagi; Yan Zhang; Melissa Geller; Margaret Reynolds; Chung K Lee; Anne H Blaes; Sharon Allen; Bruno Beomonte Zobel; Chap Le; Jerry Froelich; Clifford Rosen; Douglas Yee Journal: Bone Date: 2014-12-20 Impact factor: 4.398
Authors: Luke Arentsen; Karen E Hansen; Masashi Yagi; Yutaka Takahashi; Ryan Shanley; Angela McArthur; Patrick Bolan; Taiki Magome; Douglas Yee; Jerry Froelich; Susanta K Hui Journal: J Bone Miner Metab Date: 2016-12-09 Impact factor: 2.626