Cavernous hemangiomas of the orbit: MR imaging

To describe the MR imaging findings in eight patients with cavernous hemangioma of the orbit.

CT, MR imaging and echographic studies of eight patients with cavernous hemangioma localized in the orbit were reviewed. All patients presented with a progressive symptomatology: in seven cases with a painless proptosis, in one case with a failing of visual acuity of the concerned eye. The patients were examined with T2- and T1-weighted spin echo sequences, before and after intravenous administration of Gadolinium*, in axial, coronal and sagittal planes. In seven patients, a fat saturation prepulse was given after the Gd-enhanced study. Two patients were also examined with CT scan, with and without intravenous contrast administration. Three patients underwent a Doppler color-coded transorbital sonography. The analyzed criteria were: location, form, margins, size, signal or density. Seven patients underwent surgery with pathologically proved cavernous hemangioma. In one patient, therapy was conservative, because of the absence of significant clinical complaints.

In all cases, MRI showed a well-defined intraconal mass. The lesions were homogeneous, isointense to muscle on the T1-weighted sequence and hyperintense to muscle on the T2-weighted sequences. In five cases, a peripheral rim, hypointense to the mass on the T1- and T2-weighted sequences could be observed. After Gadolinium*, six lesions showed initial central patchy enhancement. On the three following T1-Gadolinium* sequences, these lesions showed total and homogeneous filling. In two patients, the lesions showed immediate homogeneous enhancement. On CT, the orbital masses were spontaneously hyperdense, with associated focus of microcalcifications. On echography, the lesions appeared hyperechogenic, heterogeneous, with individualization of small areas of very slow flow.

From the analysis of the MR appearance of an intraconal, well-defined mass, associating homogeneous signal, isointense to muscle on T1-weighted sequence, hyperintense on T2-weighted sequence, and especially progressive filling on Gd-enhanced sequences, the diagnosis of cavernous hemangioma may be highly suggestive, in a patient presenting a painless progressive proptosis.