Article Category: Research Article
Online veröffentlicht: 10. Aug. 2021
Seitenbereich: 268 - 273
Eingereicht: 29. Dez. 2020
Akzeptiert: 16. Feb. 2021
DOI: https://doi.org/10.2478/raon-2021-0018
© 2021 Tajda Srot Volavc, Mitja Rupreht, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Introduction
The aim of the study was to review the appearances of Morel-Lavallée (ML) lesions on magnetic resonance imaging (MRI).
Patients and methods
14 patients diagnosed with the ML lesion on MRI were analysed retrospectively (mean age = 35 years). Mechanism of injury, time frame from injury to MRI, location, shape, T1 and proton-density fat-suppression (PDFS) signal intensity (SI), presence of a (pseudo)capsule, septations or nodules within the collection, mass effect and fluid-fluid levels were analyzed. The Mellado and Bencardino classification was utilized to classify the lesions.
Results
In most cases, mechanism of injury was distortion. Mean time frame between the injury and MRI was 17 days. Lesions were located around the knee in 9 patients and in the peritrochanteric region in 5 patients. Collections were fusiform in 12 patients and oval in 2 patients. 9 collections were T1 hypointense and PDFS hyperintense. 4 collections had intermediate T1 and high PDFS SI. 1 collection had intermediate T1 and PDFS SI. (Pseudo)capsule was noted in 3 cases. Septations or nodules were found in 4 cases. According to the Mellado and Bencardino, collections were classified as seroma (type 1) in 9, subacute hematoma (type 2) in 1 and chronic organizing hematoma (type 3) in 4 cases.
Conclusions
Characteristic features of ML lesion include a fusiform fluid collection between the subcutaneous fat and the underlying fascia after shearing injury. Six types can be differentiated on MRI, with the seroma, the subacute hematoma and the chronic organizing hematoma being the commonest.