Abstract
Background. “Rise-to-Peak time” has been proposed as an index of the probe angle during ultrasound measurement. The aim of this study is to quantitatively evaluate the effectiveness of this index as a guide for ultrasound evaluation of articular cartilage. Methods. “Acceptance”, defined as the normalized difference between the index value at a target position and the index value at a deviated position, was calculated using the “Rise-to-Peak time” for materials with varying surface roughness. Findings. Echoes from rough surfaces had lower amplitude values compared with those from flat surfaces. Meanwhile, “Rise-to-Peak time” was little-affected by the surface roughness of the reflection surface. Also, echo amplitude had a large negative “Acceptance” compared with Rise-to-Peak time. Interpretation. These results suggest that the “Rise-to-Peak time” index is effective in reducing measurement time and measurement error during articular-cartilage evaluation.
