CT Study Of Pulmonary Nodule

Purpose: To evaluate the value of targeted spiral CT(TCT) scan on small pulmonary nodules(SPN). Materials and methods: 70 documented SPN cases were selected, which both undergone conventional CT(CCT) and TCT scan, and which verified by surgery, puncture, sputum, anti-inflammatory therapy or 2 years of follow-up. The diameters of nodules were 0.5-3cm(mean 2.2cm). CCT took 10mm slice thickness. TCT took small FOV(14cm-20cm,including one lung and mediastinum), 2-5mm slice thickness, 1-2 pitch and 40%-67% overlapping. Surface shaded display was applied in 36 of them. Diagnoses on confidence were divided by four grades: definite, probable, possible and indefinite. Retrospective evaluation was taken on conventional CT and TCT. Results: With TCT scan, definite diagnosis were made in 36 cases(51.4 %), probable were in 27(38.6%), and possible in 4(5.7%). The accuracy of first diagnosis and overall diagnosis with TCT(51.4%, 95.7%) were superior to that with CCT(8.6%, 68.6%, p<0.01) respectively. Confidence of diagnosis with TCT was superior to that with CCT (R values of 95% confidence interval were 0.279 - 0.417, 0.108 - 0.246, respectively, p<0.05 ). Conclusion: TCT was an effective approach helpful in differentiating pulmonary nodule.