Influence of nodule enhanced viewing of dual-source CT on efficacy of detecting pulmonary nodule in lowdose CT

Abstract

Objective To evaluate efficacy in detecting lung nodules at low-dose CT (LDCT) by nodule enhanced viewing (NEV). Methods One hundred and twenty seven patients who were referred to undergo low-dose CT (LDCT) for the evaluation of pulmonary metastasis or screening lung cancer were selected randomly.Two radiologists with at least 10 years experience read the images with normal clinical reading speed to find actionable nodules≤2.0 cm in maximum diameter,and their consensus result was referred as“Standard”.NEV was adopted to detect the pulmonary nodules.Two residents with experience of less than three years read first detected suspicious nodules and recorded reading time,first consensus and mean time were recorded.Then,they made second decisions on the images with the help of NEV and the results and the reading time were recorded and analyzed by using wilcoxon test.The sensitivity and accuracy of NEV,residents and residents with NEV were analyzed. Results “Standard”,resident,NEV and resident with NEV detected 570,404,768 and 593 lung nodules≤2.0 cm in maximum diameter,respectively.More than 60% nodules were less than 0.5 cm in maximum diameter.The performance of NEV in detecting nodules≤2.0 cm as well as nodules <0.5 cm in maximum diameter was significantly higher than that of the resident (Z=-6.887,P<0.01 andZ=-7.235,P<0.01),and the performance of resident with NEV in detecting nodules≤2.0 cm as well as nodules<0.5 cm in maximum diameter was significantly higher than that of resident without NEV (Z=-6.606,P<0.01 andZ=-6.657,P<0.01).The resident,NEV and the resident with NEV detected nodules<20 mm in maximum diameter with sensitivities of 61.4%,86.3% and 95.3%,and with accuracy of 56.1%,58.1% and 87.6%,respectively.The resident achieved sensitivities of 51.4%,88.1% and 94.8%,and accuracy of 47.0%,56.9% and 87.5% for nodules<5mm in maximum diameter,respectively.The resident,NEV and resident with NEV spent 120-444 s,85-262 s and 131-1512 s per case to read the CT scans,respectively.The reading time of resident with NEV in was significantly higher than that of resident without NEV (Z=-9.781,P<0.01).The resident spent 23 s per NEV mark. Conclusion NEV considerable improves the resident' s performance in lung nodule detection,especially in maximum diameter<0.5 cm nodule detection. Key words: Multiple pulmonary nodules; Diagnosis techniques,respiratory system