Interesting Images: PDF OnlyRole of Bone Scanning in Pulmonary Alveolar Microlithiasis Report of Two CasesPADHY, A K; SHARMA, S K*; VIJAYARAGHAVAN, M†; GOPINATH, P GAuthor Information *From the Department of Nuclear Medicine, Medicine, All India Institute of Medical Sciences, New Delhi, India †From the Department Pathology, All India Institute of Medical Sciences, New Delhi, India Clinical Nuclear Medicine: June 1991 - Volume 16 - Issue 6 - p 458-460 Buy Abstract Two cases of pulmonary alveolar microlithiasis showing intense pulmonary uptake of Tc-99m MDP are reported. Pulmonary alveolar microlithiasis, which is a relatively rare disorder of unknown etiology, is characterized by the presence of innumerable tiny calcispherytes within the alveoli of the lungs. A local defect of the calcium metabolism has been implicated as the possible etiologic factor of this disorder. The calcispherytes, ranging between 0.01 to 0.3 mm in diameter, are composed chiefly of calcium and phosphorus, with apatite as the major chemical state. This chemical composition of the microliths is most probably responsible for the uptake of the bone seeking radiopharmaceutical in the lungs. © Lippincott-Raven Publishers.