[2D-SPLASH spectroscopy to determine the fat/water ratio in the muscle of the rotator cuff].
OBJECTIVE
The degree of fatty infiltration of the rotator cuff is an important factor for the prognosis of an operative reconstruction afterrotator cuff tear. The aim of this work was to develop a method using a clinical MR scanner that allows the quantification of the fat/water ratio with the necessary spatial resolution.


METHODS
A SPLASH sequence consisting of 19 complex 2D-FLASH images was implemented on a clinical 1.5 T MR scanner. The echo time was gradually increased from 5.0 ms to 50.0 ms. A spatial in plane resolution of 1.17 mm, a spectral resolution of 0.33 ppm and a spectral width of 6.25 ppm were achieved in a total acquisition time of about 3 min. The quantitative evaluation of the spectra in arbitrarily shaped regions of interest (ROIs) was obtained using a home-built reconstruction program and the time domain fit program AMARES.


RESULTS
Phantom studies show a linear relation of the concentration determined by SPLASH spectroscopy (r = 0.997). Because of the high spatial resolution and the possibility to evaluate arbitrarily shaped ROIs, the determination of the fat/water ratio in single muscles in the shoulder has been possible.


CONCLUSIONS
By the use of the 2D-SPLASH sequence the degree of fatty infiltration in the rotator cuff can now be determined quantitatively for the first time.
Köstler
H
H
Institut für Röntgendiagnostik der Universität Würzburg, Germany. herbert.koestler@mail.uni-wuerzburg.de
Kenn
W
W
Hümmer
C
C
Böhm
D
D
Hahn
D
D
D000273:Adipose Tissue / Q000473:pathology*; D001284:Atrophy; D001834:Body Water / Q000378:metabolism*; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D018482:Muscle, Skeletal / Q000473:pathology*; D019047:Phantoms, Imaging; D011379:Prognosis; D017006:Rotator Cuff / Q000473:pathology* / Q000601:surgery; D000070636:Rotator Cuff Injuries; D012984:Software