WANG Guan-shun1, LIU Yun-xia2, LIAO Cheng-de1, ZHANG Da-fu1
1. The Third Affiliated Hospital of Kunming Medical University(The Tumor Hospital of Yunnan Province), Kunming 650118, China; 2. The Third People’s Hospital of Kunming City, Kunming 650041, China
Abstract:Objective: To investigate CT and MRI features of paraganglioma. Methods: Imaging features in 26 cases of paraganglioma confirmed by surgery and pathology were analyzed retrospectively. Among them, all of the 26 patients underwent CT scan, and 16 patients underwent MRI scan. Tumor location, size, shape, density, signal intensity and enhancement pattern were studied on CT and MRI. Results: Paraganglioma showed oval or round, irregular masses with ill- or well-defined margins. The tumors showed hypo- or iso-density in 23 cases and hyper-density in 3 cases on unenhanced CT images. Contrast-enhanced CT images demonstrated medium-intense enhancement in the arterial phase, marked enhancement in the parenchymal phase and mild decrease of enhancement in the delayed phase. The tumors revealed a continued heterogeneous or homogeneous enhancement mass with patchy bleeding and necrotic foci in 24 cases, calcification in 1 case, perilesional edema in 2 cases and bony destruction in 1 case. All 6 malignant cases showed a large mass and extensively spread to the adjacent tissues and liver with pulmonary or lymph nodes metastasis. Tumor size ranged from 2.5 to 13.5 cm(mean=6.38 cm). Paraganglioma manifested as a large mass of hypo- or iso-intensity on T1-weighted image and intermediate to high signal intensity or heterogeneous mixed intensity on T2-weighted images. The tumors showed higher intensity on DWI and marked enhancement of solid components on contrast-enhanced T1-weighted images. Conclusion: CT and MRI are an effective method of imaging examination for the quantitative and qualitative diagnosis of paraganglioma. CT can display features of the paraganglioma and correlation with surrounding tissues. The signal alteration of MRI can reflect different histological components of the tumors. CT and MRI are valuable in early discovery of lesions, detecting and differentiating paraganglioma, estimating the relation between lesion and adjacent tissues.