Dynamic MR imaging of soft tissue tumors with assessment of the rate and character of lesion enhancement.
BACKGROUND
The aim of this study was to analyze the diagnostic usefulness of dynamic MRI with determination of the coefficient of enhancement rate and the character of tumor enhancement, and to assess both parameters in the differentiation of malignant lesions.


METHODS
The material consisted of 45 patients (30 sarcomas, 15 non-malignant lesions), age 16-64 years. MRI was done using an Elscint 2T unit, gradient echo techniques, apex angle 80 degrees. The repetition time (TR) was 80-200 ms, the echo time (TE) was 2-6 ms, 1 excitation; the acquisition time (TA) was 70-80 ms. The coefficient of tissue enhancement rate was calculated in the region of interest, and expressed as percent per second (erc%/s). The limit value of erc%/s was determined. The sensitivity and specificity of MRI were calculated in the differentiation of malignant tumors. The method of contrast filling of the tumors was assessed in successive phases after administration of gadolinium Gd-DTPA.


RESULTS
Dynamic MRI with determination of the index of tumor enhancement rate is highly sensitive (93%) and specific (73%) in the differentiation of malignant and benign lesions. The usefulness of the assessment of tumor enhancement character was not confirmed, since the sensitivity and specificity were 73% and 33%. Dynamic MRI with determination of erc%/s and tumor enhancement character is highly sensitive (93%) and specific (87%).


CONCLUSIONS
Dynamic MRI with determination of erc%/s and tumor enhancement character is the best method for differential diagnosis.
Tacikowska
Małgorzata
M
Department of Radiology, Institute of Oncology, ul. Zabińskiego 10/61, 02-793 Warsaw, Poland. tacikowska@2com.pl
D000293:Adolescent; D000328:Adult; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D012983:Soft Tissue Neoplasms / Q000145:classification / Q000175:diagnosis* / Q000473:pathology