|
FIG 1. 71-year-old woman with brain metastasis from ovarian cancer.
A, FLAIR image shows a high-signal-intensity necrotic tumor with prominent peritumoral edema. Irregular ringlike enhancement was seen on the T1-weighted image (not shown).
B, ADC map shows the tumor (1) and adjacent edema (2) have higher signal intensity than does the cerebellar parenchyma. Calculated ADC value (83 x 10-3 mm2/s), which is significantly lower than that of low-grade astrocytomas and nonastrocytic gliomas, helps to differentiate metastasis from low-grade malignant tumors, but not from high-grade ones.
C, MR spectrum shows low NAA level (NAA/Cho = 0.92) with prominent lactate and lipid peaks (lipid/Cr = 0.58). High lipid/Cr ratio helps to differentiate metastasis from other primary malignant tumors.
|