Premium
An In Vitro Study of the Ultrasonic Axial Transmission Technique at the Radius: 1‐MHz Velocity Measurements Are Sensitive to Both Mineralization and Intracortical Porosity
Author(s) -
Bossy Emmanuel,
Talmant Maryline,
Peyrin Françoise,
Akrout Leïla,
Cloetens Peter,
Laugier Pascal
Publication year - 2004
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1359/jbmr.040513
Subject(s) - mineralization (soil science) , porosity , ultrasonic sensor , radius , materials science , biomedical engineering , acoustics , composite material , physics , geology , medicine , soil science , computer science , computer security , soil water
The ultrasonic axial transmission technique allows for investigating skeletal sites such as the cortical layer of long bones (radius, tibia, phalanges). Using synchrotron radiation μCT, we investigated, in vitro, the relationships between 1‐MHz axial transmission SOS measurements at the radius and site‐matched measurements of C.Th, POR, MIN, and vBMD. Introduction: The ultrasonic axial transmission technique allows for investigating skeletal sites such as the cortical layer of long bones (radius, tibia, phalanges). Materials and Methods: Using synchrotron radiation μCT, we investigated, in vitro, the relationships between 1‐MHz axial transmission speed of sound (SOS) measurements at the radius and site‐matched measurements of cortical thickness (C.Th), intracortical porosity (POR), tissue mineralization (MIN), and volumetric BMD (vBMD). SOS measurements were based on bidirectional axial transmission and were performed with a 1‐MHz proprietary probe on 39 excised human radii. Results: The highest correlations between SOS values and bone parameters ( R 2 SOS/POR = 0.28, p < 10 −3 ; R 2 SOS/MIN = 0.38, p < 10 −4 ; R 2 SOS/vBMD = 0.57, p < 10 −3 ) were found for bone parameters assessed in a 1‐mm‐thick periosteal region of the cortex rather than throughout the whole cortex. The observed moderate correlation between SOS and C.Th values ( R 2 SOS/C.Th = 0.20, p < 10 −2 ) disappeared when controlled for other variables. The two best multilinear predictive models, including either BMD alone or the pair of dependent variables MIN and POR (all assessed in the periosteal cortex), were equally accurate in predicting SOS values ( R 2 SOS/(POR,MIN) = 0.59, p < 10 −5 ; R 2 SOS/vBMD = 0.57, p < 10 −5 ). Conclusion: For the first time, the respective adjusted contributions of POR (−24 m/s% −1 ) and tissue mineralization (+3.5 m/s/mg/cm −3 ) to SOS values were assessed. These results suggest potential sensitivity of axial transmission SOS values to changes in cortical bone status under different pathological conditions or treatments affecting POR and/or tissue mineralization.