Perirenal lymphatic systems: Evaluation using spectral presaturation with inversion recovery T2-weighted MR images with 3D volume isotropic turbo spin-echo acquisition at 3.0T

Purpose To evaluate the normal anatomy of the perirenal lymphatics using spectral presaturation with inversion recovery (SPIR) T2‐weighted magnetic resonance imaging (MRI) with 3D volume isotropic turbo spin‐echo acquisition (VISTA) at 3.0T. Materials and Methods This retrospective study was approved by the two Institutional Review Boards and informed consent was waived. Thin‐collimated axial images obtained using SPIR T2‐weighted MR imaging sequences with 3D VISTA at 3.0T from 50 patients (100 kidneys) with normal renal function were retrospectively reviewed. The perirenal lymphatic vessels were defined as fluid signal intensity structures on this MRI sequence. Two readers independently assessed the degree of visualization of the perirenal lymphatics using a 4‐point scale in four anatomical regions, including the renal hilar, capsular, communicating pericapsular, and subfascial lymphatics, and interobserver agreement was evaluated with weighted kappa statics. The detectability of each lymphatic system was calculated for each reader using confidence level ratings of grades 1 and 2 as positive and grades 3 and 4 as negative. Results Interobserver agreement for the visualization grades was almost perfect (kappa value = 0.9). The renal hilar lymphatics along the renal vein were clearly identified in all patients. The detectability of other perirenal lymphatics was 44% for the capsular lymphatics, 39% for communicating pericapsular lymphatics, and 22% for the subfascial lymphatics. There was no laterality regarding the detectability of the perirenal lymphatics. Conclusion The findings of this study support the feasibility of SPIR T2‐weighted MR images with 3D‐VISTA at 3.0T for evaluating the perirenal lymphatic systems. J. MAGN. RESON. IMAGING 2016;44:897–905.