Detection and size quantification of pulmonary nodules using ultra-low-dose CT with tin filtration: a prospective...

To evaluate the diagnostic performance of tin-filtered 150 kV ultra-low-dose CT (ULDCT) for pulmonary nodule detection and size measurement, compared with standard-dose CT (SDCT).

This prospective study enrolled 261 patients who underwent both SDCT (120 kV) and ULDCT (150 kV with 0.6 mm tin filtration) during a single visit. Radiation dose parameters, subjective and objective image quality, and diagnostic performance were assessed using SDCT as the reference standard. Nodules were classified as solid, pure ground-glass nodules (pGGNs), or mixed ground-glass nodules (mGGNs), and nodule diameters were compared between the 2 protocols.

ULDCT reduced radiation dose by 83% compared to SDCT (1.10 ± 0.22 vs 6.55 ± 1.51 mSv, P < .001) while maintaining excellent image quality. SDCT detected 856 nodules, with ULDCT identifying 779 true-positive nodules. Subtype analysis revealed sensitivities of 99.65% for solid nodules, 100% for mGGNs, and 70.12% for pGGNs. No significant differences were observed in nodule diameter measurements between ULDCT and SDCT (P > .05).

Tin-filtered 150 kV ULDCT achieves high sensitivity for pulmonary nodule detection with significantly reduced radiation dose, and maintains clinically acceptable image quality.

This study provides clinical validation of tin-filtered 150 kV ULDCT in a heterogeneous outpatient population, demonstrating its feasibility for accurate pulmonary nodule detection beyond screening settings and highlighting its subtype-specific performance.