Assessment of Lung Nodule Detection and Lung CT Screening Reporting and Data System Classification Using Zero Echo Time Pulmonary MRI

Abstract

BackgroundThe detection rate of lung nodules has increased considerably with CT as the primary method of examination, and the repeated CT examinations at 3 months, 6 months or annually, based on nodule characteristics, have increased the radiation exposure of patients. So, it is urgent to explore a radiation‐free MRI examination method that can effectively address the challenges posed by low proton density and magnetic field inhomogeneities.PurposeTo evaluate the potential of zero echo time (ZTE) MRI in lung nodule detection and lung CT screening reporting and data system (lung‐RADS) classification, and to explore the value of ZTE‐MRI in the assessment of lung nodules.Study TypeProspective.Population54 patients, including 21 men and 33 women.Field Strength/SequenceChest CT using a 16‐slice scanner and ZTE‐MRI at 3.0T based on fast gradient echo.AssessmentNodule type (ground‐glass nodules, part‐solid nodules, and solid nodules), lung‐RADS classification, and nodule diameter (manual measurement) on CT and ZTE‐MRI images were recorded.Statistical TestsThe percent of concordant cases, Kappa value, intraclass correlation coefficient (ICC), Wilcoxon signed‐rank test, Spearman's correlation, and Bland–Altman. The p‐value <0.05 is considered significant.ResultsA total of 54 patients (age, 54.8 ± 11.9 years; 21 men) with 63 nodules were enrolled. Compared with CT, the total nodule detection rate of ZTE‐MRI was 85.7%. The intermodality agreement of ZTE‐MRI and CT lung nodules type evaluation was substantial (Kappa = 0.761), and the intermodality agreement of ZTE‐MRI and CT lung‐RADS classification was moderate (Kappa = 0.592). The diameter measurements between ZTE‐MRI and CT showed no significant difference and demonstrated a high degree of interobserver (ICC = 0.997–0.999) and intermodality (ICC = 0.956–0.985) agreements.Data ConclusionThe measurement of nodule diameter by pulmonary ZTE‐MRI is similar to that by CT, but the ability of lung‐RADS to classify nodes from MRI images still requires further research.Level of Evidence2Technical EfficacyStage 2