Figure 1
From: MR imaging features of benign retroperitoneal extra-adrenal paragangliomas
A 49-year-old asymptomatic man with incidentaloma and a histologically proven benign retroperitoneal paraganglioma at the right prevertebral region (between the inferior vena cava and aorta). The transverse and longitudinal diameters of the tumor are 2.61 cm and 3.13 cm, respectively. (A) in axial T2-weighted imaging, the tumor demonstrates high signal intensity and isointensity compared with the gluteal muscles. The intratumoral cystic areas exhibit higher signal intensity. (B) In axial DWI, the tumor exhibits ring-shaped high signal intensity. (C–E) T1-weighted imaging (in-phase, out-phase and pre-scanned imaging, respectively); the signal of the tumor is slightly lower than that of the gluteal muscle. (F) In contrast T1-weighted imaging during the arterial phase, the tumor is clearly enhanced and non-homogeneous. (G) In coronal T1-weighted imaging during the delay phase, the tumor is clearly enhanced and non-homogeneous. (H) ADC imaging; the mean ADC value of the ROI of the tumor is 0.00147 mm2/s.
