CT characteristics of Morel-Lavallée lesions: an under-recognized but significant finding in acute trauma imaging.
OBJECTIVE
To highlight the significance and imaging characteristics of Morel-Lavallée (ML) lesions, which have been well characterized on MRI, but are potentially under-recognized on CT.


METHODS
Twenty-eight Morel-Lavallée lesions were identified in 18 patients and were all clinically or surgically confirmed. Lesions were grouped into acute (<3 days), subacute (3-30 days), and chronic (>30 days) at the time of CT imaging. Charts were reviewed to gather patient characteristics, injury patterns, radiologist interpretation, treatment, and outcomes.


RESULTS
Sixteen male and 2 female patients with a mean age of 50 years (range 19-80) at the date of their initial evaluation were identified. All patients had significant trauma that accounted for 28 ML lesions, all of which were in a characteristic subcutaneous location overlying the muscular fascial plane. Lesions on CT went through an evolution from hyperdense, poorly or moderately marginated without a pseudocapsule to being hypodense, with internal fat globules or septations and well marginated with a complete enhancing pseudocapsule. Only 1 (4 %) of the ML lesions was suggested and 7 (25 %) lesions were not commented on at all by the interpreting radiologist.


CONCLUSIONS
Morel-Lavallée lesions are post-traumatic closed, internal, soft-tissue, degloving lesions that are potentially underrecognized on CT. Most acute ML lesions are nonspecific, resembling simple hematomas or contusions. ML lesions evolve as they age with subacute and chronic lesions demonstrating the known features described on MR imaging that should allow for an accurate imaging diagnosis.
Department of Radiology, Mayo Clinic, Rochester, MN, USA.
Gavin A
GA
McKenzie
Department of Radiology, Mayo Clinic, Rochester, MN, USA.
Blake D
BD
Niederhauser
Department of Radiology, Mayo Clinic, Rochester, MN, USA.
Mark S
MS
Collins
Department of Radiology, Mayo Clinic, Rochester, MN, USA. howe.benjamain@mayo.edu.
Benjamin M
BM
Howe
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000069836:Degloving Injuries / Q000000981:diagnostic imaging*; D005260:Female; D006406:Hematoma / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D055815:Young Adult
Chronic hematoma; Closed degloving injury; Floating fat; Morel-Lavallée