Ultrasound attenuation of cortical bone correlates with biomechanical, microstructural, and compositional properties

European Radiology Experimental

Table 3 Spearman correlation coefficients of UTE-MRI-based properties with mechanical and microstructural measures of the cortical bone strips

	E	BMD	Porosity	Pore size
T1	-0.41 (p = 0.014)	0.46 (p = 0.006)	0.63 (p < 0.001)	-0.06 (p = 0.774)
MMF	0.31 (p = 0.070)	-0.37 (p = 0.026)	-0.50 (p = 0.002)	0.31 (p = 0.150)
T2-MM	-0.39 (p = 0.022)	0.32 (p = 0.065)	0.18 (p = 0.287)	-0.17 (p = 0.435)
TWPD	-0.62 (p < 0.001)	0.59 (p < 0.001)	0.42 (p = 0.013)	-0.57 (p = 0.004)
BWPD	-0.46 (p = 0.005)	0.39 (p = 0.021)	-0.01 (p = 0.962)	-0.47 (p = 0.023)
PWPD	-0.59 (p < 0.001)	0.61 (p < 0.001)	0.75 (p < 0.001)	-0.47 (p = 0.023)
MTR-800	0.42 (p = 0.013)	-0.43 (p = 0.010)	-0.56 (p = 0.001)	0.41 (p = 0.054)
MTR-600	0.40 (p = 0.019)	-0.41 (p = 0.013)	-0.50 (p = 0.002)	0.42 (p = 0.048)
MTR-400	0.29 (p = 0.094)	-0.30 (p = 0.082)	-0.41 (p = 0.015)	0.57 (p = 0.005)

BMD Bone mineral density, BWPD Bound water proton density, E Elastic modulus, μCT Microcomputed tomography, MMF Macromolecular fraction, MRI Magnetic resonance imaging, MTR Magnetization transfer ratio (MTR-800, MTR-600, and MTR-400 refer to MTR at 2KHz for 800°, 600°, and 400° pulse power level), PWPD Pore water proton density, T2-MM Macromolecular T2, TWPD Total water proton density, UTE Ultrashort echo time