Abstract: Objective:To compare the detection results of histopathology and MRI, CT of liposarcoma of extremities, and to provide guide for increasing the accuracy rate of clinical diagnosis. Methods:The data of 43 cases of liposarcoma of the extremities were collected.MRI plain scan and enhanced CT were used in 18 patients before operation. Sixteen cases were diagnosed by CT plain scan and enhanced scan before operation. Nine cases were diagnosed by MRI and CT plain scan and enhanced scan before operation. All the patients underwent the operation.The intraoperative pathological examination was performed in the lesion tissue.The diagnosed results were assessed according to the classification(high differentiated liposarcoma, mucoid liposarcoma, toliposarcoma and mixed liposarcoma). Results:In all the 43 cases,the upper limb lesion was found in 13 patients and the lower limb lesion was found in 30 patients. The average maximal diameter of the lesions was(14.6±6.1)cm. The fat cells were found in all the patients,with the pathological characteristics of adipocytes and lipopolysaccharide mixture exists,and accompanied by deep-stained pleomorphic cells;the CT examination results showed that the low density shadow with clear boundary and linear separated shadow after CT enhanced; the MRI image showed short signal intensity on T1 weighted imaging and long signal intensity on T2 long signal and short time reversal recovery sequence imaging and other signals; the mass existed the cord-like, linear shadow; the lesion surrounding nerve and blood vessels were squeezed, but the bone structure was relatively complete. The CT and MRI results of well-differentiated lipsarcome showed the fat signal, and the enhanced results showed the mild strengthening. The CT and MRI results of mucinous liposarcoma showed the cystic density and signal,and the enhanced results showed the clound-like orlatticed mild and moderate strengthening; the CT and MRI results of mixed liposarcoma showed the mixed imaging findings of above two types. Conclusion:The pathological examination can provide the exact basis for the diagnosis of type of liposarcoma; CT and MRI imagings can provide basis for judging the size of the tumor; MRI enhanced scan has an important role in judging tumor border.Combination of three kinds of detection methods can provide the basis for the diagnosis of the disease.

Key words: magnetic resonance imaging, computed tomography, liposarcoma, pathological examination