Effectiveness of a silicone device for foot MRI in order to obtain homogeneous fat suppression images.
BACKGROUND
Incomplete fat suppression induced by magnetic field inhomogeneity is difficult to compensate for with hardware magnetic-field shimming.


OBJECTIVE
To evaluate the effectiveness of a silicone device used to obtain homogeneous fat suppression during 3T magnetic resonance imaging (MRI) scans of the foot.


METHODS
Thirty-eight healthy volunteers were enrolled and examined twice, before (group A) and after (group B) the application of a silicone device. Fat-saturated, T2-weighted, fast spin-echo images were acquired using the same scanning protocol at both examinations. Signal- and contrast-to-noise ratios (SNR and CNR) were calculated and compared in the four regions of interest (ROIs). ROI 1 and 2 were selected from toe-side bone and soft tissue, while ROI 3 and 4 were selected from proximal bone and soft tissue. Qualitative analysis using a four-point scale was performed for three categories. The categories are as follows: the overall image quality, homogeneity of the first phalange and metatarsal bone, respectively.


RESULTS
The SNR and CNR in ROI 1 and 2 were significantly higher in group A than in group B (SNR; P < 0.001, CNR; P < 0.001), and there were no significant difference in ROI 3 and 4. The qualitative score of the overall fat suppression in group B was significantly higher than that in group A (P < 0.001). Homogeneity of the first phalange in group B was also significantly higher than that in group A (P < 0.001). On the other hand, the homogeneity of the metatarsal bone was not significantly different in the two groups.


CONCLUSIONS
The use of a silicone device provides homogeneous fat suppression in 3T MRI of the foot and can significantly improve image quality.
Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
Dae Keon
DK
Seo
Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
Sara
S
Na
Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
Jung-Hoon
JH
Park
Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
Kwan Woo
KW
Choi
Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
Ho Beom
HB
Lee
Department of Radiological Science, College of Health Sciences, Eulji University, Gyeonggi-do, Republic of Korea handk@eulji.ac.kr.
Dong-Kyoon
DK
Han
D000273:Adipose Tissue / Q000166:cytology*; D000293:Adolescent; D000328:Adult; D004867:Equipment Design; D005260:Female; D005528:Foot / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D059629:Signal-To-Noise Ratio; D012828:Silicones; D013382:Subtraction Technique / Q000295:instrumentation*; D055815:Young Adult
D012828:Silicones
Fat suppression; contrast-to-noise ratio; homogeneity; magnetic resonance imaging; signal-to-noise ratio; silicone