Evaluation of MR imaging findings differentiating cavernous haemangiomas from schwannomas in the orbit

Abstract

Objective: It is important to distinguish between orbital cavernous haemangioma and schwannoma because the treatments of choice for the two tumours are different. The aim was to evaluate MR imaging findings distinguishing the two tumours.

Methods: Magnetic resonance imaging including T1- and T2-weighted imaging and contrast-enhanced MR imaging was performed in 43 patients with cavernous haemangiomas and 16 patients with schwannomas confirmed by pathology. Location, configuration, margins, signal intensity, homogeneity and enhancement pattern of the tumour were retrospectively evaluated.

Results: There was a significant difference between cavernous haemangiomas and schwannomas regarding the location, configuration and margins of the mass, signal intensity and homogeneity on T1- and T2-weighted imaging, the spread pattern of contrast enhancement, the enhancement pattern and the type of time-intensity curve (P<0.05). Markedly homogeneous hyperintensity signal on T2-weighted imaging and the spread pattern of the contrast enhancement favoured cavernous haemangioma rather than schwannoma (P<0.01).

Conclusion: Cavernous haemangiomas and schwannomas have different MR imaging features that could be helpful in the differentiation between the tumours. The spread pattern of the contrast enhancement on dynamic contrast-enhanced MR imaging is the most reliable finding distinguishing cavernous haemangiomas from schwannomas.

Fig. 1

A 54-year-old woman with a cavernous haemangioma. a Axial T1-weighted imaging demonstrated an oval intraconal isointense tumour relative to muscle. b The tumour appeared hyperintense (arrowhead) relative to muscle on axial T2-weighted imaging. c–e Dynamic MR images obtained at 25, 75 and 225 s, respectively, after administration of gadopentetate dimeglumine, showed enhancement starting from one point of peripheral portion of the tumour (arrowhead). f Post-contrast T1-weighted imaging with fat saturation showed further enlargement of enhancement regions (arrowhead)

Fig. 2

A 42-year-old man with a schwannoma. a Axial T1-weighted imaging showed an oval extraconal isointense tumour relative to muscle. b Axial T2-weighted imaging revealed that the tumour was isointense relative to muscle (arrowhead). c–e Dynamic MR images obtained at 25, 75 and 225 s, respectively, after administration of gadopentetate dimeglumine showed enhancement starting from wide areas of tumour (arrowhead). f Axial post-contrast T1-weighted imaging with fat saturation showed homogeneous enhancement of the tumour (arrowhead)

Fig. 3

A 47-year-old woman with schwannoma. a Obliquely sagittal T1-weighted imaging identified an irregular extraconal tumour with isointensity of the anterior portion of the tumour (arrow) and slight hypointensity of the posterior portion (arrowhead) relative to muscle. b Axial T2-weighted imaging showed isointensity of the anterior portion of the tumour (arrow) and hyperintensity of the posterior portion (arrowhead) relative to muscle. c Obliquely sagittal post-contrast T1-weighted imaging demonstrated enhancement of the anterior portion of the tumour (arrow) and no enhancement of the posterior portion (arrowhead)