Program including abstracts as pdf available here

P 47
Title
uSEFuLNESS OF IDEAL IN ORAL AND MAXILLOFACIAL MR IMAGING -PHANTOM STuDy-
Authors
S. MuRAKAMI 1 , y. FuJINAMI 1 , N. KAKIMOTO 1 , H. SHIMAMOTO 1 , M. KATAOKA 1 , S. TOMITA 1 ,
A. NAKATANI 1 , y. uCHIyAMA 1 , T. SASAI 1 , I. SuMIDA 1 , T. TSuJIMOTO 1 , S. FuRuKAWA 1
Affiliations
1 Osaka University Graduate School of Dentistry - Department of Oral and Maxillofacial Radiology,
Osaka, JAPAN
Body
PURPOSE:
To compare the effectiveness of T2-weighted magnetic resonance (MR) imaging using iterative
decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL)
with that of a conventional MR imaging protocol in minimizing metallic artifacts and fat suppression
in a phantom simulating the oral and maxillofacial region.
MATERIALS AND METHODS:
Chemical shift-selective fat saturation (CHESS) and IDEAL were used to obtain coronal T2weighted
MR images of 6 kinds of dental metals, i.e. Au, Ag, Ti, Al, Co-Cr alloy, and Ag-Au-
Pd alloy, in a water bath containing tubes filled with air, water, oil, and diluted gadolinium
contrast medium.
The artifact size was quantitatively measured according to the ASTM F2119-01 recommendation,
and the degree of fat suppression was qualitatively analyzed.
RESULTS:
The sizes of the artifacts caused by Ti and the Co-Cr alloy were markedly decreased in the
IDEAL T2-weighted images (P < .001). In addition, fat suppression was hardly observed in the
CHESS T2-weighted image when Ti or the Co-Cr alloy was set in the tubes. In the case of Au,
Ag, Al, and the Ag-Au-Pd alloy, large artifacts did not appear in both CHESS and IDEAL images.
CONCLUSION:
Compared with CHESS T2-weighted MR imaging, IDEAL T2-weighted MR imaging effectively
reduced the degree of tissue-obscuring artifacts produced by magnetic metals and improved
image quality.
Keywords
artifact,dental metal,fat suppression
162