The comparative study of MR perfusion-weighted imaging and 1 H-MR spectroscopy in diagnosing soft tissue tumors

Objective To evaluate multiple magnetic resonance (MR) imaging techniques in the differentiation of benign and malignant soft tissue tumors by comparing different information from MR perfusion-weighted Imaging (MR-PWI) and 1 HMR spectroscopy (1 H-MRS).Methods Forty patients with soft tissue tumors underwent conventional MR imaging,dynamic contrast-enhanced T2*-weighted MR-PWI and 1 H proton MR spectroscopy.The differences of perfusion and 1 H-MRS parameters of benign and malignant tumors were analyzed with t test.Results There was significant difference between benign and malignant tumoral tissues of BF value and Cho/Cr ratio(t=2.531,2.927,P < 0.05),while BV,MTT,Cho,Cr or Lip peak value were not.TIC was different between benign group (Ib) and malignant group (Ia).When the threshold value of BF was 4.35 ml ·100 mg-1·min-1,sensitivity and specificity for determining malignant tumors were 81.8%(18/22),72.2%(13/18),respectively.When the threshold value of Cho/Cr ratio was 3.22,Sensitivity and specificity for determining malignant tumors were 86.4% (19/22),88.9% (16/18),respectively.The abnormal wave crest is detected at 2.0-2.1ppm in 5 malignant tumors (2 malignant schwannoma and 3 malignant fibrous histiocytoma),while the other 35 cases were not.Conclusion The BF value and Cho/Cr ratio were both valuable diagnostic parameters in differentiating benign and malignant soft tissue tumors.TIC was helpful to distinguish malignant tumors from benign tumors,while the sensitivity and specificity of 1 H-MRS in diagnosing malignant soft tissue tumors were both higher. Key words: Soft tissue neoplasms;  Magnetic resonance imaging;  Magnetic resonance spectroscopy;  Comparative study