[Utility of helical CT for the secondary mass screening of lung cancer]

From December 1991 to 1992, helical CT scan was performed in 55 patients with having abnormal shadow in the chest X-ray on the secondary screening for lung cancer. In all patients with suspected pulmonary lesions at first screening, helical CT scan was performed with 10 mm slice thickness for 300 mm. The moving speed of the patients table is 20 mm/l rot./1.5 sec for 300 mm in a single breath-hold. Helical CT allowed shortening of examination time and providing both better data continuity and resolution than conventional CT. In conclusion, helical CT can be useful for secondary screening of lung cancer but it was considered that there are some problems such as method of final pathological diagnosis and treatment for small nodular lesion.