Noninvasive ultrasonic measuring system for bone geometry examination

Bone deformities are typically identified through standard radiograms. Since X-ray examinations are easily applied and offer high quality imaging, noninvasive techniques are not commonly used in bone diagnostics. Nevertheless, nonradiological techniques are considered necessary because of the harmful effects of X-ray radiation.

The paper presents a new noninvasive system for bone imaging. The system allows the physician to create self-defined templates of the measured geometrical parameters and to measure the bone geometry according to the planned procedures.

The proposed system was verified by determining the fiducial location error, the fiducial registration error and the target registration error. The tests were performed on sawbones and a measuring plate. In order to verify the accuracy of reconstruction, tests on the three-dimensional phantoms were carried out. The system has been tested in clinical conditions: results of limb geometrical parameters measured on five probands were compared with MRI-based evaluation.

The system supplies critical data supporting the standard radiological examination. In the future, after further improvements it may replace invasive X-ray imaging. The main advantage of ultrasonography is noninvasive imaging (using mechanical waves), however, it demands considerable experience.