A primary analysis on measuring repeatability of the maximum diameter between CT and MR imaging for lung cancers

To investigate the measurement reproducibility of the maximum diameter on MRI routine sequence (T1WI, T2WI, DWI) and CT in peripheral and central lung cancer, and to provide reference standard for evaluating treatment responses for lung cancer.

53 patients with lung cancer underwent CT and 3.0T MR scanning. The maximum diameter was measured according to the RECIST1.1 standard on images of CT (lung and enhanced mediastinal window), MRI T2-BLADE, axial T1-VIBE and DWIb0, DWIb300, DWIb800, respectively. The reproducibility of the diameters was analyzed with intraclass correlation coefficient (ICC), and the distribution of measurement points with the Bland-Altman method. The difference analysis was assessed by paired samples t-test and nonparametric rank sum test, P < 0.05 is considered statistically significant.

Reproducibility of diameters derived from routine MRI and CT was good (ICC > 0.75). For peripheral lung cancer, there was no significant difference in diameters between CT and MRI. While for central lung cancer, there was significant difference in diameters measured between using CT and each MRI sequence. However, the diameters derived from T1-VIBE and T2-BLADE were not significantly different from all DWI sequences.

For peripheral lung cancer, the measurement on CT and routine MRI sequences can potentially replace each other after comprehensive consideration of examination purposes, but for central lung cancer, alternative use of CT and MRI in evaluating treatment responses for lung cancer should needs extra attention. The diameter measurement of lung cancer on DWI is consistent with that on T1WI and T2WI, suggesting that DWI can provide functional and morphological information.