MR imaging of the knee with a 0.064-T permanent magnet.
Magnetic resonance (MR) imaging has proved beneficial in the evaluation of internal derangements of the knee. A limitation to general acceptance of MR imaging of the knee has been availability and cost. The recent introduction of low-field-strength MR imaging has shown promise in decreasing the cost and increasing the availability of this modality. High-resolution (pixel size, 0.7 mm2), three-dimensional Fourier transform (3DFT), thin-section (3.5 mm) imaging performed on a 0.064-T permanent magnet was used to evaluate 117 knees in 114 consecutive patients. The appearance of normal anatomy and internal derangements of the knee at low-field-strength imaging is described. Arthroscopic correlation was available for 28 knees. Findings from low-field-strength MR imaging and arthroscopy agreed in 79% of cases in the determination of meniscal tears. Partial-flip-angle techniques with 3DFT produced thin-section images of the knee of diagnostic quality. The authors conclude that in patients with internal derangements of the knee, low-field-strength (0.064-T) MR imaging may provide useful information.
Rothschild
P A
PA
Radiologic Imaging Laboratory, University of California, San Francisco 94080.
Domesek
J M
JM
Kaufman
L
L
Kramer
D M
DM
Dye
S F
SF
Anderson
L J
LJ
Lewis
J L
JL
Gon
M K
MK
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; 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 / Q000295:instrumentation; D008297:Male; D008875:Middle Aged