CT plays an important role in the diagnosis and staging of musculoskeletal tumors, but MRI offers several significant advantages.
MRI can provide superior soft tissue and marrow contrast and direct multiplanar images are routinely obtainable.
Previous MRI studies have utilized low field strength magnets with limited spatial resolution.
High field systems provide increased resolution and improved signal-to-noise ratios with the potential for hydrogen and phosphorus spectroscopy.
Using a 1.5 T scanner, we have imaged 30 patients with a variety of benign and malignant tumors.
Pulsing sequences (TR/TE) were used with Tl weighting (600 msec/25 msec) for marrow pathology and T2 weighting (2000 msec/25, 50, 75, 100 msec) for soft tissue pathology.
A rim of decreased signal intensity was often seen between benign lesions and normal marrow corresponding to reactive bone formation.
MRI was superior to CT in demonstrating extension of tumor across growth plates and in defining the relationship of tumors to vessels and joints.
Postoperative MRI studies showed less artifact from metallic implants than CT in the evaluation of tumor recurrence.
Although calcification could not be readily identified on MRI, fat and hemorrhage could often be specifically characterized.