Orientational dependence of intermolecular double quantum coherence (iDQC) signal from tendon tissue

Bahadir Ozus , Geoffrey D. Clarke , Stephen J. Dodd , Gary D. Fullerton

The proton signal changes as the long axis of tendon tissue is rotated with respect to the main magnetic field (B₀). The orientational changes in the tendon signal obtained using the correlation spectroscopy revamped by asymmetric z-gradient echo detection (CRAZED) sequence, which allows the effects of intermolecular dipolar interactions to be observed, were investigated and compared with the orientational changes of the signals produced using correlation spectroscopy (COSY), spin-echo (SE), and one-pulse sequences. The intermolecular double quantum coherence (iDQC) signal obtained using the CRAZED sequence showed a variation in the signal from tendon tissue, with sharper peaks and greater relative differences between minimum and maximum signal values compared to the variations in the signal obtained from the COSY, SE, and one-pulse sequences. This result is attributed to the orientational dependence of the transverse relaxation rate of single (SQC) and double (DQH) quantum coherences R₂ and R_2,2, respectively. Magn Reson Med 53:1183-1186, 2005. © 2005 Wiley-Liss, Inc.