MRI combined with PET in diagnosis of primary lymphoma of bone / 中国医学影像技术

ABSTRACT

Objective To observe the imaging features of primary lymphoma of bone (PLB) on MRI and PET, and to assess the value of MRI combined with PET for PLB. Methods Sixteen patients with pathologically confirmed PLB were collected, and the MRI and PET appearances were analyzed retrospectively. Results Single bone infiltration was detected in 15 patients (5 in femurs, 3 in vertebro, 3 in right iliums, 2 in tibias, 1 in radius and 1 in maxillae), while multiple bones infiltration were noticed in 1 patient (lesion located in manubrium sterni and the 7th right rib). MRI demonstrated heterogeneous focal-lamellar or diffuse signal intensity within marrow, isointense or hypointense on T1WI and slightly hyperintense on T2WI with homogeneous or heterogeneous enhancement. Severe soft tissue mass was seen in all 16 patients, the range of soft tissue mass was larger than osseous lesion in 15 patients and equal to osseous lesion in 1. Most PLB were homogeneous isointense or slightly hypointense on T1WI and homogeneous or heterogeneous slight-hyperintense on T2WI with slightly or moderately homogeneous or heterogeneous enhancement, while in 3 patients showed single vertebral compression fracture with local epidural- and/or paravertebral-soft tissue, and the range of soft tissue larger than the pathologic vertebrae. PET was performed before operation in 13 patients, showing local increasement of glycometabolism and uptake of radioactive nuclide without abnormality for other sites. For three patients of primary lymphoma of vertebrae underwent PET after operation, and recurrence was detected in 1 patient after 2 months. Conclusion Large soft mass with small osseous destruction and relatively hypointensity on T2WI is somehow characteristic for PLB. PET features of PLB are not specific, but has some advantages in determining the nature of lesion, differentiating lesions and follow-up after operation. MRI combined with PET is an appropriate imaging method for PLB.