Splenic imaging with ultrasmall superparamagnetic iron oxide ferumoxtran-10 (AMI-7227): preliminary observations.
OBJECTIVE
Ferumoxtran-10 (ultrasmall superparamagnetic iron oxide; Combidex, AMI-7227) is a long-circulating MR contrast agent with reticuloendothelial uptake known to enhance tissue T1 and T2 relaxation rates. The purpose of this study was to assess the effect of ferumoxtran-10-enhanced MRI in evaluating focal splenic lesions.


METHODS
Eighteen patients underwent MR evaluation of the spleen. Two of these patients with exophytic normal splenic tissue (splenules) and 13 of these patients with 24 focal splenic lesions (7 cysts, 2 hemangiomas, 7 metastases, 1 infarct, 7 lymphoma) were assessed by T1-weighted gradient echo and T2-weighted fast SE MRI following intravenous administration of ferumoxtran-10 (1.1 mg of Fe/kg). Qualitative analysis involving improved lesion detection and/or characterization, additional information from postcontrast images affecting staging, and patient management was performed. Quantitative measurements of lesion-to-spleen contrast-to-noise ratio were also performed.


RESULTS
Additional information was provided by ferumoxtran-10-enhanced images in 15 of 18 patients. In 8 of 15 (53%) patients, improved lesion detection (i.e., number of lesions) was obtained on contrast-enhanced images. Improved lesion visualization (i.e., conspicuity) was noted in 11 of 15 (73%) of patients. In 10 of 15 (67%) patients, postcontrast imaging provided additional information leading to lesion characterization. Staging of disease and patient management were affected in 5 of 15 (33%) and 6 of 15 (40%) patients, respectively.


CONCLUSIONS
Ferumoxtran-10 is a promising contrast agent for the evaluation of focal splenic lesions.
Harisinghani
M G
MG
Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA. mharisinghani@partners.org
Saini
S
S
Weissleder
R
R
Rubin
D
D
deLange
E
E
Harms
S
S
Weinreb
J
J
Small
W
W
Sukerkar
A
A
Brown
J J
JJ
Zelch
J
J
Lucas
M
M
Morris
M
M
Hahn
P F
PF
D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics*; D003911:Dextrans; D005260:Female; D052203:Ferrosoferric Oxide; D006801:Humans; D007501:Iron / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008279:Magnetic Resonance Imaging / Q000379:methods; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D010087:Oxides / Q000008:administration & dosage / Q000493:pharmacokinetics*; D012680:Sensitivity and Specificity; D013154:Spleen / Q000473:pathology*; D013158:Splenic Diseases / Q000473:pathology*; D014018:Tissue Distribution
D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; C097921:ferumoxtran-10; D007501:Iron; D052203:Ferrosoferric Oxide