Diagnostic value of T2-FLAIR enhanced sequence in brain and leptomeningeal metastasis of lung cancer

LI Yeting; ZHANG Daoen; HE Shili; WU Rong; LIU Zaohui; ZHANG Gaofeng

doi:10.20258/j.cnki.1006-9011.2025.04.004

Abstract：Objective To investigate the diagnostic value of T2 fluid-attenuated inversion recovery(T2-FLAIR)enhanced se-quence in brain parenchymal metastasis and leptomeningeal metastasis of lung cancer.Methods The T1WI and T2-FLAIR en-hanced MRI images of 38 patients with brain metastases from lung cancer were retrospectively analyzed.The location,number,diameter,boundary,peritumoral edema and signal intensity of brain parenchymal metastases were evaluated.The detection abil-ity of leptomeningeal metastases(leptomeningeal nodules,leptomeningeal enhancement,cranial nerve enhancement)was com-pared between the two enhanced sequences.The detection results of the two enhanced sequences were statistically analyzed.Results A total of 178 brain parenchymal metastases were detected by T1WI and T2-FLAIR enhanced sequences in 38 patients,158 and 177 were detected by T1WI and T2-FLAIR enhanced sequences,respectively.There was significant difference in tumor size between the two sequences(Z=-3.299,P=0.001).The contrast rate(CR)of metastatic tumors in T2-FLAIR enhanced se-quence was higher than that in T1WI enhanced sequence(Z=-9.243,P<0.001),and the enhancement percentage(PI)of meta-static tumors in T1WI enhanced sequence was higher than that in T2-FLAIR enhanced sequence(Z=-2.950,P=0.003).There was a significant positive correlation between tumor diameter and PI on T1WI(r=0.404,P<0.001),but there was no significant correlation in T2-FLAIR enhancement sequence(P=0.538).Among the 38 patients,27 cases with leptomeningeal metastasis were detected by T1WI and T2-FLAIR enhanced sequences,24 cases and 27 cases were detected by T1WI and T2-FLAIR en-hanced sequences,respectively.Cranial nerve enhancement was mainly bilateral and auditory nerves.Three cases of cerebral sur-face small vessels were misdiagnosed as leptomeningeal enhancement by T1WI enhancement sequence.Conclusion T2-FLAIR enhanced sequence has a higher detection rate of brain and leptomeningeal metastasis of lung cancer than T1WI enhanced se-quence,and the combination of the two can reduce the missed diagnosis rate.