The use of single photon emission computed tomography in lung imaging with aerosols.

The use of technetium-99m labelled diethylenetriaminopentaacetic acid (99Tcm-DTPA) aerosol and single photon emission computed tomography (SPECT) to obtain sectional ventilation images of the lung is demonstrated in a limited series of patients. SPECT perfusion and planar ventilation and perfusion are also obtained and the SPECT studies compared with the planar views to assess the efficacy of SPECT aerosol ventilation images when used in conjunction with SPECT perfusion studies. The problems encountered in SPECT aerosol lung imaging, particularly the image noise associated with the limited number of detected counts, are described. On the basis of the results it is concluded that the technique is worth further assessment.