Enhancement pattern of normal extraocular muscles in dynamic contrast-enhanced MR imaging with fat suppression.
OBJECTIVE
To evaluate the internal structure of normal extraocular muscles on fat-suppressed dynamic contrast-enhanced MR imaging.


METHODS
Ten subjects were examined using fat-suppressed dynamic contrast-enhanced MR imaging. We evaluated the enhancement pattern (C-shaped or ring-like) of extraocular muscles and quantified the maximum ratios of enhancement (Rmax) and maximum ratios of signal increase (Vmax). We also quantified Rmax and Vmax in the central and peripheral portions of medial rectus muscles.


RESULTS
In the early phase of dynamic contrast-enhanced MR imaging, a C-shaped or ring-like pattern was observed in 100% of inferior rectus, 95% of medial rectus, 55% of superior rectus, 20% of lateral rectus, and 15% of superior oblique muscles. Overall mean Rmax and Vmax values showed statistically significant differences to the temporal muscles. For the peripheral portion of medial rectus muscles, mean Rmax and Vmax values were greater than for the central portion.


CONCLUSIONS
Using fat-suppressed dynamic contrast-enhanced MR imaging, the C-shape or ring-like internal structure of the extraocular muscles could be visualized, and were considered to reflect their structure of orbital and global layers. Potential usefulness of the fat-suppressed dynamic contrast-enhanced MR imaging for detecting pathological status is suggested.
Taoka
T
T
Department of Radiology, Nara Medical University, Japan.
Iwasaki
S
S
Uchida
H
H
Fukusumi
A
A
Kichikawa
K
K
Nakagawa
H
H
Takayama
K
K
Sakamoto
M
M
Ohishi
H
H
D000273:Adipose Tissue; D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000033:anatomy & histology*; D009915:Orbit / Q000033:anatomy & histology; D013703:Temporal Muscle / Q000033:anatomy & histology
D003287:Contrast Media