Magnetic resonance imaging of knee cartilage using a water selective balanced steady-state free precession sequence

✍ Scribed by Peter R. Kornaat; Joost Doornbos; Aart J. van der Molen; Margreet Kloppenburg; Rob G. Nelissen; Pancras C.W. Hogendoorn; Johan L. Bloem

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 342 KB
• Volume: 20
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.20194

✦ Synopsis

Abstract

Purpose

To compare an optimized water selective balanced steady‐state free precession sequence (WS‐bSSFP) with conventional magnetic resonance (MR) sequences in imaging cartilage of osteoarthritic knees.

Materials and Methods

Flip angles of sagittal and axial WS‐bSSFP sequences were optimized in three volunteers. Subsequently, the knees of 10 patients with generalized osteoarthritis were imaged using sagittal and axial WS‐bSSFP and conventional MR imaging techniques. We calculated contrast‐to‐noise ratios (CNR) between cartilage and its surrounding tissues to quantitatively analyze the various sequences. Using dedicated software we compared, in two other patients, the accuracy of cartilage volume measurements with anatomic sections of the tibial plateau.

Results

CNR~total~ eff (CNR efficiency between cartilage and its surrounding tissue) using WS‐bSSFP was maximal with a 20–25° flip angle. CNR~total~ eff was higher in WS‐bSSFP than in conventional images: 6.1 times higher compared to T1‐weighted gradient echo (GE) images, 5.1 compared to proton‐density (PD) fast spin echo (FSE) images, and 4.8 compared to T2‐weighted FSE images. The mean difference of cartilage volume measurement on WS‐bSSFP and anatomic sections was 0.06 mL compared to 0.24 mL for T1‐GE and anatomic sections.

Conclusion

A WS‐bSSFP sequence is superior to conventional MR imaging sequences in imaging cartilage of the knee in patients with osteoarthritis. J. Magn. Reson. Imaging 2004;20:850–856. © 2004 Wiley‐Liss, Inc.