Standard-, reduced-, and no-dose thin-section radiologic examinations: Comparison of capability for nodule detection and nodule type assessment in patients suspected of having pulmonary nodules

Purpose: To compare the capability of pulmonary thin-section magnetic resonance (MR) imaging with ultrashort echo time (UTE) with that of standard-and reduced-dose thin-section computed tomography (CT) in nodule detection and evaluation of nodule type. Materials and Methods: The institutional review board approved this study, and written informed consent was obtained from each patient. Standardand reduced-dose chest CT (60 and 250 mA) and MR imaging with UTE were used to examine 52 patients; 29 were men (mean age, 66.4 years 6 7.3 [standard deviation]; age range, 48-79 years) and 23 were women (mean age, 64.8 years 6 10.1; age range, 42-83 years). Probability of nodule presence was assessed for all methods with a five-point visual scoring system. All nodules were then classified as missed, groundglass, part-solid, or solid nodules. To compare nodule detection capability of the three methods, consensus for performances was rated by using jackknife free-response receiver operating characteristic analysis, and k analysis was used to compare intermethod agreement for nodule type classification. Results: There was no significant difference (F = 0.70, P = .59) in figure of merit between methods (standard-dose CT, 0.86; reduced-dose CT, 0.84; MR imaging with UTE, 0.86). There was no significant difference in sensitivity between methods (standard-dose CT vs reduced-dose CT, P = .50; standard-dose CT vs MR imaging with UTE, P = .50; reduced-dose CT vs MR imaging with UTE, P ..99). Intermethod agreement was excellent (standard-dose CT vs reduced-dose CT, k = 0.98, P , .001; standard-dose CT vs MR imaging with UTE, k = 0.98, P , .001; reduced-dose CT vs MR imaging with UTE, k = 0.99, P , .001). Conclusion: Pulmonary thin-section MR imaging with UTE was useful in nodule detection and evaluation of nodule type, and it is considered at least as efficacious as standard-or reduceddose thin-section CT.