The MR Signal Intensity Changes in the Muscles and Tendons of the Limbs of the Mongrel Dogs, and Rotator Cuffs of Adult Humans after Local Steroid Injection / 대한정형외과학회잡지

ABSTRACT

OBJECTIVE: The changes of magnetic resonance signal intensity after the local steroid injection in to the muscle and tendon in mongrel dogs and the subacromial spaces of patients were studied. MATERIALS AND METHODS: Local injection of the methylprednosolone acetate was performed in muscles and tendons of the limbs of ten mongrel dogs and rotator cuffs of patients. Normal saline was injected in to six muscles and tendons as a control. MR imaging was obtained before and after the local injection of methylprednisolone and the normal saline. RESULTS: After one week and two weeks after the injection, increased signal intensity on T2-weighted fast spin echo MR image was found in four and five of ten muscles and tendons respectively, to which methylpredisolone was injected. None of the muscles or tendons, to which normal saline was injected, showed increased signal intensity on follow-up MR imaging. The cases with increased signal intensity were interpreted as having a inflammation or injury. Moreover, in the clinical study, two of five patients who underwent local steroid injection showed an area of increased signal intensity on T2-weighted fast spin echo MR imaging. CONCLUSION: MR images after local steroid injection should be interpreted carefully with regard to the previous steroid injection.