STATIC, DYNAMIC AND FIRST-PASS MR-IMAGING OF MUSCULOSKELETAL LESIONS USING GADODIAMIDE INJECTION

Forty-five patients with known or suspected musculoskeletal tumors wer e examined with static and dynamic MR imaging to evaluate the safety, tolerability and diagnostic utility of gadodiamide injection and to as sess the diagnostic value of dynamic MR imaging and parametric ''first -pass'' (FP) images. The proportion of patients presenting more diagno stic information on the contrast-enhanced compared to the precontrast spin-echo examinations was determined. The dynamic enhancement charact eristics were evaluated with time-intensity curves and parametric imag es of the FP enhancement rate. The tolerance of gadodiamide injection was good. Contrast enhancement was useful for delineating tumor from m uscle, and differentiating viable from necrotic tissue and cystic from solid lesions. Malignant tumors showed a significantly higher slope v alue, earlier onset of enhancement, and higher maximum enhancement tha n benign lesions. However, slope values could not be used to predict t he malignant potential of a lesion. due to overlap between highly vasc ular benign and low vascular malignant lesions. By displaying highly v ascular areas, parametric FP images provided useful information on the most active part in a tumor before biopsy and for assessing the incor poration of bone-chip allografts. Static, dynamic and FP MR imaging us ing gadodiamide injection appears safe and provides useful information for diagnosis, biopsy and follow-up of musculoskeletal lesions.