Tarlov cysts in back pain patients: prevalence, measurement method and reporting points

Determining the prevalence of Tarlov cysts in low back pain patients.

The picture archiving & communication system (PACS) & hospital information system (HIS) of a corporate hospital were retrospectively analyzed to determine the percentage of Tarlov cysts among patients undergoing spinal MRI for back pain over 3 years (January 2017 to December 2019).

384 patients had undergone spinal MRI for back pain over the study period, and 25 of them (6.51%) had Tarlov cysts. Vast majority (15 cases) showed cysts located at S2/S3 level, and few were found at S1/S2 and other levels. Single cysts were found in most (=18) of the cases, while 7 cases of multiple / bilateral cysts were found. Cyst dimensions were higher in craniocaudal than anteroposterior or transverse directions. In case of multiple cysts, one or two cysts were noted as dominant, having higher dimensions than the others. The study data revealed no gender or age predilection.

We conclude that including the entire sacrum with a T2 sagittal sequence in all MRI for low back pain can increase detection of Tarlov cysts, and thereby provide more data for further analysis.

We propose the concept of one "dominant" cyst when there are multiple Tarlov cysts. We recommend that diameter or size of Tarlov cysts be specified to their craniocaudal dimension. We also suggest reporting points for contextual structured reporting, viz. presence or absence of bony scalloping, neural foraminal narrowing, nerve root compression or extraforaminal extension.