J Korean Radiol Soc.  1999 Mar;40(3):577-584. 10.3348/jkrs.1999.40.3.577.

MR Imaging of Articular Cartilage: Comparison of Magnetization Transfer Contrast and Fat - Suppression inMultiplanar and 3D Gradient-Echo, Spin-Echo, Turbo Spin-Echo Techniques

• Lee YJ
• Joo EY
• Eun CK

• KMID: 2201049
• DOI: http://doi.org/10.3348/jkrs.1999.40.3.577

Abstract

PURPOSE: The purpose of this study was to evaluate the effects of magnetization transfer contrast(MTC) andfat-suppression(FS) in variable spin-echo and gradient-echo sequences for articular cartilage imaging and todetermine the optimal pulse sequences.
MATERIALS AND METHODS
Using variable 7-pulse sequences, the knees of 15pigs were imaged Axial images were obtained using proton density and T2-weighted spin-echo (PDWSE and T2WSE),turbo spin-echo (TSE), multiplanar gradient-echo (MPGR), and 3D steady-state gradient-echo (3DGRE) sequences, andthe same pulse sequences were then repeated using MTC. Also T1-weighted spin-echo(T1WSE) and 3D spoiledgradient-echo(3DSPGR) images of knees were also acquired, and the procedure was repeated using FS. For each knee,a total of 14 axial images were acquired, and using a 6-band scoring system, the visibility of and thevisibilities of the the articular cartilage was analyzed. The visual effect of MTC and FS was scored using a4-band scale. For each image, the signal intensities of articular cartilage, subchondral bone, muscles, and salinewere measured, and signal-to-noise ratios(SNR) and contrast-to-noise ratios(CNR) were also calculated.
RESULTS
Visibility of the cartilage was best when 3DSPGR and T1WSE sequences were used. MTC imaging increased the negativecontrast between cartilage and saline, but FS imaging provided more positive contrast. CNR between cartilage andsaline was highest when using TSE with FS(-3 5 1 . 1 +/-15.3), though CNR between cartilage and bone then fell to-1 4 . 7 +/-10.8. In MTC imaging using MPGR showed the greatest increase of negative contrast between cartilage andsaline(CNR change=-74.7); the next highest was when 3DGRE was used(CNR change=-34.3). CNR between cartilage andbone was highest with MPGR(161.9 +/-17.7), but with MTC, the greatest CNR decrease(-81.8) was observed. Thegreatest CNR increase between cartilage and bone was noted in T1WSE with FS. In all scans, FS provided acartilage-only positive contrast image, though the absolute value of CNR was lower than that of MTC imaging.
CONCLUSION
The most prominent effects of MTC and FS were seen in MPGR and T1WSE, respectively, though forcartilage, optimal high signal intensity and contrast can be achieved using 3DGRE with MTC, and 3DSPGR with FS.

Keyword

Knee, MR; Knee, ligaments, menisci, and cartilage; Magnetic resonance(MR), fat suppression; Magneticresonance(MR), magnetization transfer contrast

MeSH Terms

Cartilage
Cartilage, Articular*
Knee
Magnetic Resonance Imaging*
Muscles
Protons
Protons