Pelvic lymph node visualization with MR imaging using local administration of ultra-small superparamagnetic iron oxide contrast.
OBJECTIVE
To determine if interstitial injection of iron oxide particles improves visualization of pelvic lymph nodes at magnetic resonance imaging (MRI) and to determine the effect of injection site on location of visualized nodes.


METHODS
In nine healthy volunteers, ferumoxtran-10 iron oxide (0.28 mg iron per kg) was injected into the anterior thigh (three subjects) or perianal (three subjects) or periprostatic tissues (three subjects). MRI at 1.5 T was performed before injection and one, three, and seven days after injection.


RESULTS
The mean of 30 nodes seen post-injection was greater than the mean of 5.8 seen pre-injection (P < 0.001). After thigh injection, a mean of three internal vs. 36 external nodes were seen. Compared with thigh injection, there was a higher fraction of internal nodes with perianal (mean of nine internal vs. 14 external, P < 0.001) and periprostatic injection (mean of 11 internal vs. five external, P < 0.001). More nodes were seen with gradient-echo sequences than with other sequences (P < 0.001).


CONCLUSIONS
Interstitial injection of iron oxide particles increases visualization of pelvic lymph nodes. Perianal and periprostatic injection increases the number of internal pelvic lymph nodes seen compared with thigh injection.
McCauley
Thomas R
TR
Albany Medical College, Department of Radiology, Albany, New York, USA. maccauley@biomed.med.yale.edu
Rifkin
Matthew D
MD
Ledet
Cheryl A
CA
D000328:Adult; D003287:Contrast Media / Q000008:administration & dosage; D003911:Dextrans; D052203:Ferrosoferric Oxide; D006801:Humans; D007501:Iron / Q000008:administration & dosage; D008198:Lymph Nodes / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D008297:Male; D010087:Oxides / Q000008:administration & dosage; D010388:Pelvis
D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; C097921:ferumoxtran-10; D007501:Iron; D052203:Ferrosoferric Oxide