The researchers from Stanford University retrospectively analyzed 13 pediatric cancer patients and young adults with 12 bone sarcomas and one desmoid tumor. The patients had undergone whole-body MRI scans one hour, 24 hours, or 48 to 120 hours after intravenous injection of ferumoxytol (Feraheme, Amag Pharmaceuticals).
One hour after ferumoxytol administration, the researchers observed no enhancement of joint effusions and no significant difference in signal-to-noise ratio (SNR). More than 24 hours after contrast injection, four patients showed significantly increased SNR values (p = 0.002) of the effusion compared with muscle. The other three scans at more than 24 hours, however, did not show significant enhancement of the effusion and showed no joint infiltration on histology.
"The purpose of this study was to elucidate the underlying pathological mechanisms that lead to the observed ferumoxytol-induced indirect arthrography effect," wrote study co-author Dr. Ashok Joseph Theruvath, a postdoctoral research fellow at Stanford University School of Medicine, and colleagues in the abstract. "We observed a surprising marked T1-enhancement of the joint effusion in some patients and not others."
The researchers recommended additional studies to validate the findings in a larger sample of patients.
