Bone mineral imaged in vivo by 31P solid state MRI of human wrists

✍ Scribed by Yaotang Wu; Timothy G. Reese; Haihui Cao; Mirko I. Hrovat; Steven P. Toddes; Rostislav A. Lemdiasov; Jerome L. Ackerman

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 511 KB
• Volume: 34
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.22637

✦ Synopsis

Abstract

Purpose:

To implement solid state ^31^P MRI (^31^P SMRI) in a clinical scanner to visualize bone mineral.

Materials and Methods:

Wrists of seven healthy volunteers were scanned. A quadrature wrist ^31^P transmit/receive coil provided strong B~1~ and good signal‐to‐noise ratio (SNR). A ^1^H‐^31^P frequency converter was constructed to enable detection of the ^31^P signal by means of the ^1^H channel. Data points lost in the receiver dead time were recovered by a second acquisition with longer dwell time and lower gradient strength.

Results:

Three‐dimensional ^31^P images, showing only bone mineral of the wrist, were obtained with a clinical 3 Tesla (T) scanner. In the best overall case an image with isotropic resolution of ∼5.1 mm and SNR of 30 was obtained in 37 min. ^31^P NMR properties (resonance line width 2 kHz and T~1~ 17–19 s) of in vivo human bone mineral were measured.

Conclusion:

In vivo ^31^P SMRI visualization of human wrist bone mineral with a clinical MR scanner is feasible with suitable modifications to circumvent the scanners' limitations in reception of short‐T~2~ signals. Frequency conversion methodology is useful for implementing ^31^P SMRI measurements on scanners which do not have multinuclear capability or for which the multinuclear receiver dead time is excessive. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.