The use of computerized tomography in the diagnosis of pulmonary nodules.

Pulmonary nodules, in particular the solitary pulmonary nodule or coin lesion, have presented diagnostic difficulties to the specialist in chest diseases. The controversy over managing such lesions ultimately involves the question of whether a given nodule is benign or malignant, and the reports of diagnostic experiences vary considerably. The criteria for diagnosing and managing pulmonary nodules prior to the advent of computerized tomography (CT) were based on anatomic descriptions from conventional and specialized X-ray techniques and on pathological consideration of tissues obtained by invasive techniques. The mathematical manipulation of the absorption coefficients of nodular lesions in the lungs, obtained in a non-invasive manner using CT, can provide additional criteria for diagnosing such lesions. In our study 20 nodules (6 malignant, 14 benign) were retrospectively studied with CT, and from the results it appears that there are distinctive patterns for malignant and benign lesions. We have explained our procedure in this paper and presented an illustrative case study.