Combination of Contrast-enhanced FlAIR and Contrast-enhanced T1WI Provides a Quick and Efficient Method in Detecting Cranial Metastases of Lung Cancers

Abstract

Abstract Purpose To evaluate the clinical value of contrast-enhanced fast fluid-attenuated inversion recovery (CE FLAIR) imaging in combination with contrast-enhanced T1 weighted imaging (CE T1WI) in detecting cranial metastases of lung cancers. Methods In 201 patients with known lung cancers and suspected cranial metastases, T1WI and FLAIR were performed before and after administration of gadopentetate dimeglumine. Two radiologists reviewed pre- and post-contrast images to determine the presence of abnormal contrast enhancement or signal intensity, and decided whether it was metastatic or not on CE T1WI (Group 1) or CE FLAIR (Group 2). The number, locations and features of abnormal enhancement/signal intensity in two groups were recorded. And areas under ROC were calculated in three groups: Group 1, Group 2 and Group 3(combination of CE FLAIR and CE T1WI). Results A total of 672 cranial metastases in 149 patients were revealed, and 42 abnormal findings were considered as nonmetastatic. Superficial and small metastases(≤ 10mm) in parenchyma and ependyma, leptomeningeal and non- expansive metastatic skull lesions were typically better seen on CE FLAIR. The areas under ROC in three groups were 0.720,0.887 and 0.973, respectively. Combination of CE T1WI and CE FLAIR was significantly better in diagnostic efficiency of cranial metastases than Group 1 (p＜0.0001) or Group 2 (p = 0.0006). Conclusion Combination of CE T1WI and CE FLAIR promotes diagnostic performance and results in better observation and characterization of cranial metastases in patients with lung cancers. It provides a rapid and effective way in detecting cranial metastases of lung cancers.