The Diagnostic Value Of CT And MRI Of Retroperitoneal Tumor

PURPOSE:To evaluate the diagnostic value of Computed tomography and Magnetic resonance imaging in retroperitoneal tumor retrospectively.MATERIALS AND METHODS:Retrospectively collected the clinical data of233patients of retroperitoneal tumor proved pathology from2005to2012in our hospital. We evaluated the diagnostic value of CT and MR and assessed their sensitivity and specificity.RESULTS:Benign lesions were found in89patients (38.2%), malignant ones in144patients (61.8%). Among the233cases, mesenchymal tissue tumors were127cases (54.5%), neurogenic tumor were79cases (33.9%), embryonic urogenital tumors were8cases (3.5%) and lymphohematopoietic system tumors were13cases (5.6%). The diagnostic features of CT and MR including border, shape, and long diameter, short diameter, solid and cystic. The sensitivity and specificity of more than four indicators above of CT and MR were77.2%,81.1%(χ2=63.574, P=0.000), and72%,83.9%(χ2=24.585, P=0.000), respectively. In the special indicator part, fat-containing ingredients were mostly fatty tumors (P=0.001), and paraspinal lesions were usually neurogenic lesions (P=0.000).CONCLUSION:More accurate diagnosis of retroperitoneal tumor can be made using comprehensive analysis of combined diagnostic indicators and signs. At the same time, to observe the lesion location, as well as some special characteristic performance can make a preliminary assessment. PURPOSE:To evaluate the diagnostic value of diffusion weighted MR imaging in retroperitoneal tumor using high field strength MR.MATERIALS AND METHODS:Eighty-one patients with suspected retroperitoneal tumor underwent DWI (b=0,600) or (b=0,800) using1.5or3.0T high strength MR. The apparent diffusion coefficient (ADC) values of all patients were measured by a radiologist unaware of the pathological results. The values of the low-value region in ADC map in retroperitoneal tumor were measured and recorded as the ADC values. The retroperitoneal tumors were divided into benign and malignant group according to the pathological results of surgery or biopsy. The ADCs were compared between the benign group and the malignant group using t test (SPSS13.0). A P value of less than0.05was considered to indicate a statistically significant difference.RESULTS:In the pathologically examined81patients,31were classified into benign group, and50were classified into malignant group.46cases (56.8%) were from mesenchymal tissue,32cases (39.5%) were from neurogenic,2(2.5%) were from embryo, reproductive, urinary residual tissue,1(1.2%) was from lymphoid sources. The ADC value was1.705×10-3mm2/s for the benign group and1.185×10-3mm2/s for the malignant group, significant difference was noted between the two groups (t=3.657, P=0.000). The area under the ROC curve was0.724(P=0.001); the best threshold of ADC for the diagnosis of malignant tumor was1.2×10-3mm2/s, the diagnostic sensitivity and specificity were of64%and74.2%, respectively.CONCLUSION:The values of ADC are useful in diagnosing retroperitoneal tumor. The ADC less than1.2×10-3mm2/s is a preferable threshold to differentiate malignant tumor from benign lesion in our study.