Boundary sign and cortex sign on MR in differentiation between solitary brain metastasis and astrocytoma / 中国医学影像技术

ABSTRACT

Objective To investigate the value of the boundary sign and cortex sign in differential diagnosis of solitary brain metastasis and astrocytoma. Methods Thirty-one patients with high grade astrocytoma and 42 patients with solitary brain metastasis diagnosed either pathologically or clinically were included in this study. The differential diagnostic value of the boundary and the cortex sign were analyzed retrospectively. Results The boundary sigh was found in 39 of 73 patients, which included 32 patients with solitary metastasis and 7 patients with astrocytoma. The sensitivity and specificity of the boundary sign was 76.20% and 77.42%, respectively, and the positive predictive value for solitary metastasis was 82.05%. The cortex sign was found in 34 of 70 patients, including 25 with astrocytoma and 9 with solitary metastasis. The sensitivity and specificity of the cortex sign was 80.65% and 78.57%, respectively, and the positive predictive value for astrocytoma was 73.53%. The boundary sigh was singlely foundin 24 patients, including 21 with astrocytoma and 3 with solitary metastasis. The area under the curve for both two signs was 0.85. Conclusion The boundary sign and the cortex sign are specific signs in differentiation between solitary brain metastasis and astrocytoma on routine MR series. Combination of this two signs is very useful in distinguishing solitary brain metastasis from astrocytoma.