Objective       To evaluate the CT and MRI features of solitary fibrous tumor (SFT) in the orbit.      Methods       CT and MR images of 5 patients with pathologically identified SFT were retrospectively reviewed. Two of these patients underwent CT scanning

2 underwent MR imaging

and 1 underwent both examination. They were inpatients of optical ward from two hospitals of the authors during 2004 to 2009

3 female

2 male

age from 33 to 54 (median age 46). The imaging findings on the location

size

margin

CT density

MRI signal intensity

and pattern of enhancement of the lesion were analyzed.      Results       All 5 lesions were

found as a well-defined mass

ranging from 2.1 to 3.5 cm in size. Three tumors were located in the extraconal space

and the left 2 in the intraconal space. CT scan showed that 3 lesions were of isodensity or slightly high density

and punctate calcification was found in one of them. MRI showed 3 lesions were of homogeneous isointense or slightly low signal intensity on T

1

WI and heterogeneous mixed signal intensity on T

2

WI. One lesion showed isointense signal intensity mainly but mixed with hyperintense and hypointense signal intensity on T

2

WI. The other 2 lesions showed evident hyperintense signal intensity mainly but mixed with hypointense signal intensity plaque on T

2

WI. All 5 lesions showed marked heterogeneous enhancement.      Conclusion       Orbit SFT demonstrates some characteristic MRI features and might be included in the differential diagnosis of soft tissue masses in the orbit.