99Tcm-HMPAO single photon emission tomography in the diagnosis of cerebral barotrauma.

Cerebral barotrauma, or the neurological manifestation of the "bends", is a relatively common disease of divers and aviators. To date, however, no-one has succeeded in demonstrating a cerebral or spinal cord lesion in vivo following a decompression incident, despite the presence of definitive clinical signs and symptoms of central nervous system involvement. This paper describes the use of 99Tcm-labelled hexamethylpropyleneamine oxime (99Tcm-HMPAO) with single photon emission tomography in a study of three individuals involved in driving accidents. All three suffered cerebral barotrauma during decompression and all exhibited clinical signs and symptoms of dysbarism to a varying degree. Imaging was performed at time intervals ranging from 2 h to several days following the incidents. The results showed well defined cerebral ischaemic lesions in all three subjects. We conclude that 99Tcm-HMPAO imaging provides a significant advance in locating and demonstrating cerebral lesions following barotrauma and will contribute greatly to our understanding of the pathophysiological processes involved.