Optimization of Gray/White Matter Contrast with Fast Inversion Recovery for Myelin Suppression: A Comparison of Fast Spin-Echo and Echo-Planar MR Imaging Sequences
Leo J. Wolansky
,a,
Steven G. Findena,
Janet Chena,
Rafik Hannaa,
Andrei I. Holodnya,
Imtiaz Ahmada,
Wen Ching Liua and
Sohail Contractora
a From the Department of Radiology, University of Medicine and Dentistry of New Jersey (UMDNJ).
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FIG 1. Comparison of BW-constant FIRMS and EP-FIRMS sequences (axial sections).
A and B, Basal ganglia level: FIRMS (A) and EP-FIRMS (B).
C and D, Brain stem level: FIRMS (C) and EP-FIRMS (D).
Although EP-FIRMS has a greater C/N value, subjectively the images are comparable in quality at superior levels (A, B) with minimal geometric distortion. Inferior levels show severe geometric distortion due to the proximity of sphenoidal sinus air, evident at the anterior margin of the pons in the EP-FIRMS image (arrowhead, D), with no artifact in the FIRMS image (C).
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FIG 2. A and B, Magnified axial MR images of the basal ganglia and thalamus obtained with BW-optimized FIRMS (A) and EP-FIRMS (B) sequences show superior contrast of FIRMS over EP-FIRMS. Note the insula (arrowheads): the gray/white matter is clearly delineated with FIRMS while poorly visualized with the much noisier EP-FIRMS
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FIG 3. A and B, Axial MR images at the level of the midbrain obtained with BW-optimized FIRMS (A) and EP-FIRMS (B) sequences. FIRMS image has superior C/N values as compared with EP-FIRMS image. The EP-FIRMS image has no significant geometric distortion at this superior level
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