MR imaging of the knee: preliminary results with a 3DFT GRASS pulse sequence.
The knees of 17 patients (18 extremities) with possible meniscal, cruciate ligament, and articular cartilage abnormalities were examined with a three-dimensional Fourier transform (3DFT), gradient-refocused acquisition in a steady state (GRASS) pulse sequence. Arthroscopic confirmation was available in all cases and was the standard for comparison. Thirteen of these extremities were also examined by using a two-dimensional Fourier transform spin-echo pulse sequence with a 2000-msec repetition time and 20- and 80-msec echo time. In these 13 cases, both pulse sequences correctly identified seven of eight meniscal abnormalities. However, interpretation of the 3DFT GRASS images resulted in fewer false-positive meniscal tears (three vs six). Cruciate ligament tears were detected more readily on the 3DFT GRASS images (six vs three with two possible tears on the spin-echo images). These preliminary findings suggest that the overall accuracy of MR imaging of the knee could be improved by including 3DFT gradient-refocused pulse sequences.
Spritzer
C E
CE
Department of Radiology, Duke University Medical Center, Durham, NC 27710.
Vogler
J B
JB
Martinez
S
S
Garrett
W E
WE
Johnson
G A
GA
McNamara
M J
MJ
Lohnes
J
J
Herfkens
R J
RJ
D000293:Adolescent; D000328:Adult; D001182:Arthroscopy; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis; D007718:Knee Injuries / Q000175:diagnosis; D007719:Knee Joint / Q000033:anatomy & histology / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged