RESUMEN
Objective To evaluate the diagnostic value of contrast-enhanced digital subtraction MRI in vertebra]metastatic tumors.Methods Forty-four vertebral metastatic tumors in thirty patients were scanned by routine MRI including SE T_1WI,SE T_2WI,STIR and enhanced T_1WI with an injection of Gd-DTPA(0.1 mmol/kg).Digital subtraction was performed between pre-contrast and enhanced T_1 weighted images.All the images of vertebral malignant tumors were evaluated by means of signal intensity ratio(SIR) and nose ratio(NR).The quality of images was also evaluated by comparing subtraction MRI with routine MRI.Results SIR and NR of subtraction MRI was 2.93,0.98 respectively.SIR of routine MRI (enhanced T_1WI,SE T_1 WI,SE T_2WI,STIR)was as follows:1.15,1.16,1.26,1.69.While NR of those was 5.25,3.44,4.56,23.32 respectively.SIR and NR of subtraction MRI images had significant statistical differences from those of routine MRI images(P