Superparamagnetic Particles as Oral Contrast Medium in MR Imaging of Malignant Lymphoma

Abstract

Non-biodegradable superparamagnetic particles, in plain and viscous aqueous suspensions, were used as an oral contrast medium in 34 patients with known or suspected malignant lymphoma. The contrast effect, the occurrence of artifacts, and the distribution were evaluated in the plain and the viscous aqueous suspensions, and the diagnostic information received from abdominal MR examinations performed without bowel contrast medium was compared with that of post-contrast examinations. Magnetic particles in the concentration of 0.5 gil displayed a good contrast effect at 0.5 T, and helped in differentiating the intestine from adjacent tissues, resulting in increased diagnostic information in abdominal MR imaging. In the patients given the viscous aqueous suspension the occurrence of artifacts caused by the magnetic particles decreased considerably, and the distribution was homogeneous and improved compared with that in patients given the plain aqueous suspension.

The value of hyoscine butylbromide in abdominal MR imaging with and without oral magnetic particles

“…Superparamagnetic oral contrast agents may not be ideal to visualize the bowel wall because susceptibility artifacts can obscure structures adjacent to the opacified lumen of the GI tract [4,6,15]. OMP has been formulated to provide SE images with very few metallic artifacts [4].…”

“…OMP has been formulated to provide SE images with very few metallic artifacts [4]. As a result, conspicuity of the bowel wall was not impaired on postcontrast scans.…”

“…On the basis of data from animal studies and clinical trials [4,5,11], the present investigation was approved by the Institutional Ethical Committee.…”

“…One approach to overcome this limitation is the injection of hypotonic agents [3]. When negative MR bowel contrast agents were employed, investigators have found that peristalsis-related artifacts did not present a problem [4][5][6][7]. However, pharmacological motion suppression with glucagon has successfully been used to image the bowel wall after oral administration of the diamagnetic negative contrast agent perfluoroctylbromide (PFOB) [8,9].…”

“…It was not our purpose to investigate the overall efficacy of OMP. Therefore, proton density and T2-weighted images, which are of great value after administration of OMP [4][5][6][7]10], were not included in the evaluation of hyoscine butylbromide.…”