Allizad, Azra

Thyroid imaging with conventional ultrasound scanners does not always lead to conclusive results. Furthermore, current ultrasound imaging technology has difficulty in detecting important microcalcifications. Ambiguities in ultrasound and other thyroid imaging methods lead to a large number of unnecessary biopsies. For these reasons, alternative imaging methods capable of detecting both microcalcifications and lesions in thyroid are of great interest. This paper describes recent results on imaging human thyroids with vibro-acoustography. Experiments were conducted on eight excised human thyroids from autopsy. The specimens were each imbedded in a block of gel to simulate the surrounding tissue and to facilitate scanning. Three types of images were acquired from each specimen: X-ray, B-mode ultrasound, and vibro-acoustography. Anatomical details seen in the images were correlated and image quality was compared. X-ray images displayed calcifications with high contrast, but did not show anatomical details of soft tissue. B-mode displayed some soft tissue structures; however, the speckle masked the details and reduced the contrast. Vibro-acoustography displayed calcifications, anatomical details, and some nodules where they existed. Furthermore, vibro-acoustography images displayed tissue structures with high contrast and free from speckle. It is concluded that vibro-acoustography may be a suitable technique for thyroid imaging.