CT and MR Imaging in a Large Series of Patients with Craniofacial Fibrous Dysplasia

Abstract

SummaryBackgroundIn this retrospective review of patients with craniofacial fibrous dysplasia (FD), the clinical and radiological findings of CT and MR scan were analyzed.Material/MethodsThe study material included 32 patients, at 9 to 68 years of age that were directed for differential diagnostics of several disorders in the head. We recorded CT and MRI data related to the lesion number, location, sidedness, appearance, and sex of the cases with craniofacial FD.ResultsOf 32 patients involved in this study, 17 had monostotic and 15 had polyostotic involvement pattern. Bones most commonly involved by monostotic involvement in females were, in descending order, mandibular, maxillary, and sphenoid bones, while the sphenoid bone was involved the most in males. Leontiasis ossea was observed in 2 patients. Sclerotic and mixed lesion types were more common in both females and males. In T1- and T2-weighted MRI sequences, hypointensity was more common compared to hyperintensity or heterogeneous intensity. The type of enhancement of lesions was found similar after contrast medium administration.ConclusionsIn the presence of craniofacial FD during CT or MRI imaging of the head, a detailed description of FD lesions may provide an important clinical benefit by increasing radiological experience during the diagnostics of this rare disorder.

Magnetic resonance imaging features of craniofacial fibrous dysplasia

“…CFD lesions are not composed solely of homogeneous fibrous tissue but can also contain hyaline cartilage [12,14], bone matrix of variable mineralisation, fatty tissue [11], necrosis, and areas of cystic degeneration [13]. Nearly 90% of the CFD lesions evaluated in our study were iso- to hypointense to skeletal muscle in T1w images, which is again consistent with published findings [7,11,15]. Low T1w signal intensities may indicate fibrous tissue [13,16], calcifications, hyaline cartilage, collagenous matrix, or necrotic parts [13].…”

“…As the number of MR examinations has increased in recent years, reliable detection and detailed characterisation of incidentally detected bone lesions have become important tasks for radiologists [10]. Our study expands the present knowledge of CFD and the ground glass phenomenon in MRI based on one of the largest study groups of CFD in MRI published to date [7,11]. In summary, our study confirms reliable detectability of CFD in MRI and typical features of CFD in general, such as young patient age, expansive nature of the lesion, and local alteration of bone, cortex, and especially the bone marrow [2].…”

“…in 2013, and Atalar et al . in 2015 [7,15,17]. However, high T2w signal intensity of FD lesions was observed by Utz et al .…”

“…Ground glass areas show a homogeneous greyish appearance due to the presence of woven bone components with a variable amount of mineralisation. The magnetic resonance imaging (MRI) appearance of CFD lesions has only been reported in small study populations, and investigators have not specifically addressed the ground glass phenomenon [7].…”

Fibrous dysplasia for radiologists: beyond ground glass bone matrix

“…All lesions showed some degree of enhancement on post-contrast T1-WI. Active lesions show avid enhancement, while inactive lesions show milder enhancement [ 8 ]. The enhancement pattern may be patchy central, rim, homogeneous or a combination.…”