Introduction - clinical aspects

Clinical needs for noninvasive radionuclide methods have often been an important stimulus to further progress in techniques. In disorders such as pulmonary thromboembolism, however, the correct interpretation can only be made with the help of a broad synoptic basis, formed by the treating physician, the X-ray, and the nuclear medicine specialist. This trivial statement has been of topical interest over the past 20 years in the history of ventilation-perfusion (V-P) scanning. Considerable achievements and promising results have undoubtedly been obtained in the examination of aerosol clearance (alveolar permeability and mucociliary transport), regional ventilation, workup for malignancy, identification of inflammation of the parenchyma in the absence of radiological signs, and in noninvasive diagnosis of pulmonary blood flow and volume. Future developments may be very expensive and require highly specialized equipment (PET, cyclotron, etc.), with no assurance that routine clinical application will be available in the near future. (orig.)