(HealthDay News) — A new type of whole-body magnetic resonance imaging (MRI) may allow detection and staging of tumors in children and young adults, without exposure to ionizing radiation, according to research published online Feb. 19 in The Lancet Oncology.

Christopher Klenk, MD, of Stanford University in California, and colleagues performed whole-body diffusion-weighted MRI scans, using the iron supplement ferumoxytol as a contrast agent, and standard clinical 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) scans. Participants included 22 children and young adults with malignant lymphomas and sarcomas.

The researchers found that, compared with zero exposure to radiation for the whole-body MRI scans, exposure to ionizing radiation from the PET/CT scans averaged 12.5 mSv.

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For whole-body diffusion-weighted MRI scans, compared with PET/CT scans, sensitivity was 90.8% versus 93.7%, specificity was 99.5% versus 97.7%, and diagnostic accuracy was 98.3% versus 97.2%.

Tumor staging results showed good agreement between the two imaging modalities.

“Ferumoxytol-enhanced whole-body diffusion-weighted MRI could be an alternative to 18F-FDG PET/CT for staging of children and young adults with cancer that is free of ionising radiation,” the researchers wrote. “This new imaging test might help to prevent long-term side-effects from radiographic staging procedures.”

In an accompanying editorial, Thomas C. Kwee, MD, PhD, cautioned against immediate application of the study results to clinical practice.

“Although the technical feasibility and potential diagnostic value of using ultrasmall superparamagnetic iron oxide particles in a whole-body diffusion-weighted MRI protocol has been shown in these patients, further work is needed before it can become a clinical alternative to 18F-FDG-PET/CT,” Kwee wrote.

One author disclosed financial ties to the biomedical industry.


  1. Klenk C, Gawande R, Uslu L, et al. Ionising radiation-free whole-body MRI versus 18F-fluorodeoxyglucose PET/CT scans for children and young adults with cancer: a prospective, non-randomised, single-centre study. Lancet Oncol. 2014; doi:10.1016/S1470-2045(14)70021-X.
  2. Kwee TC. Can whole-body MRI replace 18F-fluorodeoxyglucose PET/CT?. Lancet Oncol. 2014; doi:10.1016/S1470-2045(14)70037-3.