To Explore the Low-dose CT and QCT “One-stop-shop”Scan Technology for Physical Examination Crowd

Objective: To explore the application of noise index combined with automatic tube current regulation technology in the one-stop scanning of chest and lumbar QCT physical examination. Method: 100 patients who unferwent thoracic CT and lumbar QCT scan in our medical examination were prospectively collected and randomly divided into two groups( conventional dose group and ow dose group). There were 50 patients in the conventianl group (noise index set to NI=8.5) and 50 patients in the low dose group (noise index set to NI=14). Their height, weight and BMI were recorded, as well as the mean BMD of L1, L2 in both radiation and low dose groups, and L1, L2 in the conventional dose group. The differences of radiation dose and mean bone mineral density between the two groups were compared. Results: The average scanning dose was 387.65 mGy in the conventional dose group and 73.18 mGy in the low dose group. There was statistical differences in radiation dose between the two groups. The mean bone mineral density (BMD) of L1 and L2 was 119.71 in the conventional dose group, and that of L1 and L2 was 123.65 in the low dose group. There was no statistical difference between the two groups. Conclusion: Low dose CT scan of thoracic and lumbar spine can not only meet the needs of lung screening and bone mineral density assessment but also greatly reduce radiation dose. It can be widely used in physical examination.