Spatial variation of T2 in human articular cartilage.

Abstract

There is a reproducible pattern of increasing T2 that is proportional to the known spatial variation in cartilage water and is inversely proportional to the distribution of proteoglycans. The authors postulate that these regional T2 differences are secondary to the restricted mobility of cartilage water within an anisotropic solid matrix.

Combined T1‐T2 mapping of human femoro‐tibial cartilage with turbo‐mixed imaging at 1.5T

“…These relaxation values confirm the dominant effect of the administered gadolinium, since the T1 relaxation value without gad- olinium is reported in the literature to be around 770 msec (15). For T2, our reported T2 relaxation values (with a mean T2 relaxation value of 34 msec) apparently are lower than those found in the literature (2,3,12,16,17). However, these results should be interpreted in the light of a recent study by Goodwin et al (17), in which they evaluated the relationship between T2 relaxation values and the cartilage matrix architecture.…”

“…Two MRI techniques that have demonstrated promise in this regard are quantitative T2 mapping and T1 mapping after Gd-DTPA administration, known as delayed gadolinium-enhanced MRI of cartilage (dGEMRIC). Current research suggests that these techniques are complementary, with T2 mapping providing information on structural integrity of the collagen matrix (1)(2)(3)(4), and dGEMRIC identifying regions of proteoglycan loss (5-7). The major disadvantages in the application of both techniques are the total length of the scan time needed (approximately 18 minutes) and the geometric mismatch between the acquired images.…”

Effect of multislice acquisition on T1 and T2 measurements of articular cartilage at 3T

“…In previous studies, multislice MSE acquisition for T 2 mapping of articular cartilage has been used for clinical evaluations (9,14,15). However, it is known that there is a possible negative MT effect on the accuracy of T 2 measurement when multislice acquisition is used for cartilage T 2 mapping (19).…”

“…Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) is a qualitative MRI technique that can evaluate the concentration of GAG in cartilage (6,7). Transverse relaxation time (T 2 ) mapping is an MRI technique that can evaluate the integrity of the collagen network structure and water content in cartilage (8,9). These two MRI techniques have had their capacities validated in basic studies (6,8,10,11) and have been used for clinical evaluations (12)(13)(14)(15).…”

“…There are several kinds of pulse sequences for T 1 or T 2 measurements. Fast-spin-echo inversion-recovery (FSE-IR) sequence and multi-spinecho (MSE) sequence have been commonly used for T 1 measurement and T 2 measurement of articular cartilage, respectively (7,9,(12)(13)(14)(15). The main reason to use these sequences for clinical evaluation is that they offer acceptable calculation accuracy and reproducibility in a suitable acquisition time.…”