Imaging Guidelines for Exostoses of the Proximal Tibia

Indications for MRI

The American College of Radiology recommends MRI for exostoses with concerning features for malignancy, such as new growth or pain after skeletal maturity, cartilage cap thickness concerns, or symptomatic complications, with a sensitivity of 61% and specificity of 95% for differentiating benign from malignant lesions 1, 2, 3, 4, 5
MRI is indicated for characterizing tissue composition, including cartilage cap thickness, which is critical for assessing malignant transformation risk, with MRI detecting marrow changes in 25% more cases than CT 1, 2, 3
The American College of Radiology suggests that MRI is superior to CT for detecting soft tissue extension, joint involvement, and neurovascular structure invasion, with CT being inferior to MRI for soft tissue evaluation, showing 31% better soft tissue involvement, 36% better joint involvement, and 15% better neurovascular assessment with MRI 1, 2, 3, 4
MRI is the preferred modality for staging bone tumors if malignancy is suspected, with the American College of Radiology recommending MRI without and with IV contrast for better characterization of cartilaginous tumors 1, 2, 3, 4, 5

MRI provides superior soft tissue contrast for evaluating the relationship to adjacent structures, with a sensitivity of 61% and specificity of 95% for differentiating benign from malignant lesions 1, 3, 4, 5
The American College of Radiology states that MRI can detect marrow changes in 25% more cases than CT, and is superior to CT for soft tissue evaluation, showing 31% better soft tissue involvement, 36% better joint involvement, and 15% better neurovascular assessment with MRI 1, 3, 4