Diagnosis of osteoporosis using nonlinear ultrasound

Our aim is to diagnose osteoporosis by using nonlinear acoustics to detect microscopic cracks in human bone. We constructed a system to measure 2nd harmonic generation in human heel bone, where special care was taken to suppress 2nd harmonics generated in the electronics. Experiments showed that this system did detect harmonics generated bone, and amplitude independent estimates for the 2nd harmonic strength were found. The methods were tested in two small studies comparing healthy volunteers and patients with osteoporosis. These studies have not yet been able to verify a difference between normal and osteoporotic bone. The initial studies are regarded preliminary, and suffer from weaknesses in patient selection and measurement setup. Studies with improved equipment and better patient selection are planned.