[In vitro imaging of magnetite particles].
OBJECTIVE
To find an optimal imaging modality for the assessment of magnetite agglomerations used as the heating sources during magnetic thermoablation of tumors.


METHODS
1 to 107 mg of coated (starch) magnetite particles were directly administered to an in vitro tumor model (swine lymph nodes) and investigated immediately (radiography) or after being embedded within a 4 % agar-phantom (sonography). T1-weighted MR images (TR = 400 ms, TE = 14 ms) were acquired from lymph nodes containing 0.5 to 25 mg magnetite.


RESULTS
All investigated magnetite masses were qualitatively detectable by radiography. Sonographically, only mass agglomerations containing 107 mg magnetite were appropriately discernible. MRT images revealed distinct susceptibility artifacts.


CONCLUSIONS
Based on the investigated imaging modalities, radiography is the method of choice for assessment of magnetite agglomerations using relevant dosages for magnetic thermoablation of tumors.
Hilger
I
I
Institut für Diagnostische und Interventionelle Radiologie des Klinikums der Friedrich-Schiller-Universität Jena, Germany. ingrid.hilger@med.uni-jena.de
Hofmann
F
F
Reichenbach
J R
JR
Bergemann
C
C
Hiergeist
R
R
Andrä
W
W
Hergt
R
R
Kaiser
W A
WA
D000818:Animals; D016477:Artifacts; D003952:Diagnostic Imaging; D017352:Echo-Planar Imaging; D052203:Ferrosoferric Oxide; D006979:Hyperthermia, Induced / Q000295:instrumentation*; D066298:In Vitro Techniques; D007501:Iron; D008198:Lymph Nodes / Q000473:pathology; D009374:Neoplasms, Experimental / Q000473:pathology*; D010087:Oxides; D019047:Phantoms, Imaging; D013552:Swine; D014463:Ultrasonography
D010087:Oxides; D007501:Iron; D052203:Ferrosoferric Oxide