Type:
Educational Exhibit
Keywords:
Mediastinum, MR, Imaging sequences, Hyperplasia / Hypertrophy
Authors:
F. Conway, S. Datta, H. Boylan, A. Kirk
DOI:
10.26044/ecr2023/C-12461
Findings and procedure details
FINDINGS AND PROCEDURAL DETAILS:
Patients discussed at the regional multidisciplinary meeting (MDT) within the West of Scotland between June 2018 and August 2022 and identified as probably having a benign thymic mass went on to have chemical shift and contrast-enhanced MRI of the chest on a 1.5-Tesla Siemens Aera at the Royal Alexandra Hospital in Paisley. Imaging time of approximately 45 minutes.
Patients with a confident diagnosis of benign thymic hyperplasia were recommended to have a 6-month follow-up using chemical shift MRI sequences only and were discharged from further follow-up if there was no interval change. Follow-up imaging is behind schedule due to the study period covering much of the COVID-19 pandemic.
A total of 21 patients underwent local MRI thymus protocol in this period. Using primarily SII, 11 had benign thymic hyperplasia (SII >8.9%, CSR <0.85).
Other lesions included four cystic lesions,
two solid-looking thymic masses that went on to resection,
two vascular lesions, one biopsy-proven fibroadipose tissue, and no lesion identified on subsequent MRI in one patient. Only three patients have undergone follow-up MRI, all of which have remained unchanged/ undergone involution.
In this unit, SII alone is now used in the assessment of thymic masses. While both SII and CSR can be used, CSR is less reliable due to variations in adiposity of the reference paraspinal musculature [2].