Skeletal Radiology

, Volume 31, Issue 10, pp 574–580

MR imaging of knee cartilage with FEMR

  • Shreyas S. Vasnawala
  • John M. Pauly
  • Dwight G. Nishimura
  • Garry E. Gold
Article

DOI: 10.1007/s00256-002-0562-4

Cite this article as:
Vasnawala, S.S., Pauly, J.M., Nishimura, D.G. et al. Skeletal Radiol (2002) 31: 574. doi:10.1007/s00256-002-0562-4

Abstract

Objective. Fluctuating equilibrium magnetic resonance (FEMR) is a rapid three-dimensional (3D) imaging sequence with high signal-to-noise ratio (SNR). FEMR may be useful for detecting cartilage defects in the knee. At 1.5 T, FEMR uses a TR with odd multiples of 2.2 ms for fat/water separation. With a TR of 6.6 ms, high-resolution 3D imaging of cartilage is possible.

Design and patients. The knees of 10 volunteers and two patients were imaged on a GE Signa 1.5 T scanner using an extremity coil. Scans were preceded by a shimming sequence optimizing linear terms. Subjects were imaged with FEMR, proton-density fast spin-echo (PD-FSE), T2-weighted fast spin-echo (T2-FSE), and 3D fat-suppressed spoiled-gradient-recalled echo (3D-SPGR).

Results. SNR and contrast-to-noise efficiency measurements for cartilage using FEMR were superior to those using PD-FSE, T2-FSE, and 3D-FS-SPGR. FSE images showed bright synovial fluid with limited cartilage detail. 3D-SPGR had comparable resolution to FEMR but suboptimal cartilage/fluid contrast and longer scan times (8 min versus 2 min). Cartilage surface detail, outlined by bright synovial fluid, was best seen on the FEMR images.

Discussion. FEMR obtains high-resolution 3D images of the entire knee in 2 min with excellent cartilage/fluid contrast. FEMR is sensitive to field inhomogeneity and requires shimming. Surface defects are outlined by bright synovial fluid, and cartilage has higher signal-to-noise efficiency compared with PD-FSE, T2-FSE, and 3D-SPGR techniques.

Cartilage MRI Steady-state Fast Lipid suppression

Copyright information

© ISS 2002

Authors and Affiliations

  • Shreyas S. Vasnawala
    • 1
  • John M. Pauly
    • 2
  • Dwight G. Nishimura
    • 2
  • Garry E. Gold
    • 1
  1. 1.Department of Diagnostic Radiology, Stanford University, Stanford, CA 94305, USA
  2. 2.Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, CA 94305, USA
  3. 3.VA Rehabilitation Research and Development Service, Palo Alto VA Health Care System, Palo Alto, CA 94304, USA
  4. 4.Packard EE Building Room 222, Stanford, CA 94305-9510, USA