ULTRASOUND PROPAGATION SPEED IN ARTHRITIC SYNOVIAL TISSUE

Ultrasonic properties of knee synovial tissues destroyed by arthritis were studied by analysing 40 tissue specimens from 21 patients using a n ultrasound echo meter and an optical microscope. The idea was to com pare pathological findings to ultrasound propagation speeds, and to tr y to find any relation between them. The fresh specimens was first mea sured by the echo meter to collect data for statistical calculations o f the propagation speed vs. different pathological properties. Before pathological studies, the specimens were fixed in formalin solution. T he connective and fat tissues were evaluated within a resolution of 5% and expressed in percentages (0-100%). Inflammatory cells, edema and villus formation were also evaluated. As results, we obtained several charts of ultrasound propagation speed and their trends in the functio n of different properties. It could be seen that the trend of the prop agation speed increased from 1515 m/s to 1565 m/s when the percentage amount of connective tissue increased from 30% to 90%. The trend of th e speed decreased from 1560 m/s to 1480 m/s when the share of fat tiss ue increased from 0 to 60%. The same phenomenon is already well known from some other tissues. A special new result was that the speed varie d in a remarkable range of 1490-1660 m/s in samples of 0% fat and high connective tissue content. The overall average of the ultrasound prop agation speed in the specimens was 1548 m/s, and the average of the st andard deviations of measurements (each specimen was measured at least twice) of each tissue specimen was 8.3 m/s.