Ultrasound backscatter measurements of intact human proximal femurs--relationships of ultrasound parameters with tissue structure and mineral density.
Ultrasound reflection and backscatter parameters are related to the mechanical and structural properties of bone in vitro. However, the potential of ultrasound reflection and backscatter measurements has not been tested with intact human proximal femurs ex vivo. We hypothesize that ultrasound backscatter can be measured from intact femurs and that the measured backscattered signal is associated with cadaver age, bone mineral density (BMD) and trabecular bone microstructure. In this study, human femoral bones of 16 male cadavers (47.0±16.1 years, range: 21-77 years) were investigated using pulse-echo ultrasound measurements at the femoral neck in the antero-posterior direction and at the trochanter major in the anteroposterior and lateromedial directions. Recently introduced ultrasound backscatter parameters, independent of cortical thickness, e.g., time slope of apparent integrated backscatter (TSAB) and mean of the backscatter difference technique (MBD) were obtained and compared with the structural properties of trabecular bone samples, extracted from the locations of ultrasound measurements. Moreover, more conventional backscatter parameters, e.g., apparent integrated backscatter (AIB) and frequency slope of apparent integrated backscatter (FSAB) were analyzed. Bone mineral density of the intact femurs was evaluated using dual energy X-ray absorptiometry (DXA). AIB and MDB measured from the femoral neck correlated significantly (p<0.01) with the neck BMD (R2=0.44 and 0.45), cadaver age (R2=0.61 and 0.41) and several structural parameters, e.g., bone volume fraction (R2=0.33 and 0.39, p<0.05 and p<0.01), respectively. To conclude, ultrasound backscatter parameters, measured from intact proximal femurs, are significantly related (p<0.05) to structural properties and mineral density of trabecular bone.
Department of Applied Physics, University of Eastern Finland, POB 1627, FI-70211, Kuopio, Finland; Department of Clinical Neurophysiology, Kuopio University Hospital, POB 100, FI-70029, Kuopio, Finland. Electronic address: markus.malo@uef.fi.
M K H
MK
Malo
Department of Applied Physics, University of Eastern Finland, POB 1627, FI-70211, Kuopio, Finland; Department of Clinical Neurophysiology, Kuopio University Hospital, POB 100, FI-70029, Kuopio, Finland.
J
J
Töyräs
Department of Applied Physics, University of Eastern Finland, POB 1627, FI-70211, Kuopio, Finland.
J P
JP
Karjalainen
Department of Biomedical Engineering, Department of Orthopaedics, Lund University, POB 118, SE-22100, Lund, Sweden.
H
H
Isaksson
Department of Applied Physics, University of Eastern Finland, POB 1627, FI-70211, Kuopio, Finland.
O
O
Riekkinen
Department of Applied Physics, University of Eastern Finland, POB 1627, FI-70211, Kuopio, Finland.
J S
JS
Jurvelin
D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D015519:Bone Density; D002102:Cadaver; D005270:Femur Head / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography; D055114:X-Ray Microtomography; D055815:Young Adult
Backscatter; Ex vivo; Femur; Pulse-echo; Trabecular bone