Fig. 2
From: MR imaging features of benign retroperitoneal paragangliomas and schwannomas
An asymptomaticpatient (age: 30–39) with a histologically proven benign retroperitoneal schwannoma. The transverse and longitudinal diameters of the tumour are 2.19 cm and 3.51 cm, respectively. a On axial T2-weighted imaging, the tumour presents with heterogeneous signal intensity compared with the gluteal muscles. b On axial DWI, the tumour appears circular, with high signal intensity. c, (d) On T1-weighted imaging (in-phase, out-of-phase imaging), the tumour’s signal is slightly lower and isointense compared with that of the gluteal muscle. The intratumoural microscopic fat areas are slightly lower in signal intensity on out-of-phase imaging. e On T1-weighted imaging (pre-scanned imaging), the tumour’s signal is slightly lower, with isointense and hyperintense spots compared with that of gluteal muscle. The intratumoural subacute haemorrhage areas present as hyperintense spots in signal intensity on pre-scanned imaging. f On contrast T1-weighted imaging during the aerial phase, the tumour presents as slightly enhanced and inhomogeneous. g On coronal T1-weighted imaging during the delay phase, the tumour presents as moderately enhanced and inhomogeneous. h On ADC imaging, the mean ADC value of the ROI of the tumour is 0.00171 mm2/s