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Objectives: Recent studies with lung MRI (MRI) have shown high sensitivity (Sn) and specificity (Sp) for lung nodule detection and characterization relative to low-dose CT (LDCT). Using this background data, we sought to compare the potential screening performance of MRI vs. LDCT using a Markov model of lung cancer screening., Methods: We created a Markov cohort model of lung cancer screening which incorporated lung cancer incidence, progression, and mortality based on gender, age, and smoking burden. Sensitivity (Sn) and Sp for LDCT were taken from the MISCAN Lung Microsimulation and Sn/Sp for MRI was estimated from a published substudy of the German Lung Cancer Screening and Intervention Trial. Screening, work-up, and treatment costs were estimated from published data. Screening with MRI and LDCT was simulated for a cohort of male and female smokers (2 packs per day; 36 pack/years of smoking history) starting at age 60. We calculated the screening performance and cost-effectiveness of MRI screening and performed a sensitivity analysis on MRI Sn/Sp and cost., Results: There was no difference in life expectancy between MRI and LDCT screening (males 13.28 vs. 13.29 life-years; females 14.22 vs. 14.22 life-years). MRI had a favorable cost-effectiveness ratio of $258,169 in men and $403,888 in women driven by fewer false-positive screens. On sensitivity analysis, MRI remained cost effective at screening costs < $396 dollars and Sp > 81%., Conclusions: In this Markov model of lung cancer screening, MRI has a near-equivalent life expectancy benefit and has superior cost-effectiveness relative to LDCT., Key Points: • In this Markov model of lung cancer screening, there is no difference in mortality between yearly screening with MRI and low-dose CT. • Compared to low-dose CT, screening with MRI led to a reduction in false-positive studies from 26 to 2.8% in men and 26 to 2.6% in women. • Due to similar life-expectancy and reduced false-positive rate, we found a favorable cost-effectiveness ratio of $258,169 in men and $403,888 in women of MRI relative to low-dose CT.

While the inauguration of national low dose computed tomographic (LDCT) lung cancer screening programs has started in the USA, other countries remain undecided, awaiting the results of ongoing trials. The continuous technical development achieved by stronger gradients, parallel imaging and shorter echo time has made lung magnetic resonance imaging (MRI) an interesting alternative to CT. For the detection of solid lesions with lung MRI, experimental and clinical studies have shown a threshold size of 3-4mm for nodules, with detection rates of 60-90% for lesions of 5-8mm and close to 100% for lesions of 8mm or larger. From experimental work, the sensitivity for infiltrative, non-solid lesions would be expected to be similarly high as that for solid lesions, but the published data for the MRI detection of lepidic growth type adenocarcinoma is sparse. Moreover, biological features such as a longer T2 time of lung cancer tissue, tissue compliance and a more rapid uptake of contrast material compared to granulomatous diseases, in principle should allow for the multi-parametric characterization of lung pathology. Experience with the clinical use of lung MRI is growing. There are now standardized protocols which are easy to implement on current scanner hardware configurations. The image quality has become more robust and currently ongoing studies will help to further contribute experience with multi-center, multi-vendor and multi-platform implementation of this technology. All of the required prerequisites have now been achieved to allow for a dedicated prospective large scale MRI based lung cancer screening trial to investigate the outcomes from using MRI rather than CT for lung cancer screening. This is driven by the hypothesis that MRI would reach a similarly high sensitivity for the detection of early lung cancer with fewer false positive exams (better specificity) than LDCT. The purpose of this review article is to discuss the potential role of lung MRI for the early detection of lung cancer from a technical point of view and to discuss a few of the possible scenarios for lung cancer screening implementation using this imaging modality. There is little doubt that MRI could play a significant role in lung cancer screening, but how and when will depend on the threshold needed for positive screens (e.g. lesion volume and required diagnostic accuracy), cost-effectiveness and improved patient outcomes from a reduction in the need to follow up benign nodules. Potential applications range from lung MRI as the first choice screening modality to the role of an ad hoc on site test for the detailed evaluation of a subgroup of positive screening results., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)