Imaging of the pulmonary system

Lung scans are predominantly used to localize pulmonary embolism. The problems in the diagnosis relate to the non-specificity of clinical signs and symptoms and relatively invasive technique and high cost associated with other diagnostic procedures like pulmonary angiography. The radionuclide lung scan is widely used as it is safe, easily performed and highly sensitive. In spite of spiral CT, radionuclide ventilation/ perfusion scan (often known as V/Q scan) is still considered as a first line diagnostic test. The utility of V/Q scan (V/P scan) has been documented in large number of studies in 35-40 years. There is almost no morbidity and relatively low cost has made V/Q scan a routine procedure in almost all nuclear medicine departments. (author)