Ultrashort echo time bi‐component analysis of cortical bone—a field dependence study

Abstract

Ultrashort echo time bi-component analysis provides consistent bound and free water fractions at 1.5 T and 3 T, thereby allowing field-independent comparisons.

Bi‐component T2* analysis of bound and pore bone water fractions fails at high field strengths

“…The measured short‐ T 2 * component fractions of 69.6% and 68.1% at 1.5 and 3 T, respectively, are nearly identical to the 68.5% and 69% measured by Li et al . in bovine bone, but are slightly lower than the 74.4% and 75.9% measured in human bone at these same field strengths. The ages and pore volume fractions of the human bones studied by Li et al ., however, are unknown.…”

A realistic phantom for validating MRI‐based synthetic CT images of the human skull

“…We attribute the significant change in T Ã 2 measurements of the skull between pre-and postfilling scans to the perfusion of contrast solution within the porous layers of the skull, which were encompassed within the ROIs. The results from dry bone, however, were comparable to what was previously reported in the literature (250-330 ls 30,31 ).…”

Assessment of different fitting methods for in-vivo bi-component T2* analysis of human patellar tendon in magnetic resonance imaging

“…However, changes in T2 and T2* are nonspecific and can be caused by multiple factors including hydration, macromolecular content, and tissue anisotropy with comparable changes occurring in disparate settings [5][6][7][8][9] . Bi-component T2 and T2* mapping techniques have been used to improve the specificity of T2 analysis by assessing the individual water components of musculoskeletal tissues [10][11][12][13][14][15][16][17][18][19][20][21][22] . Bi-component T2 and T2* mapping methods have measured two distinct T2 components in cartilage assumed to represent short relaxing water bound to the macromolecular matrix and long relaxing bulk water [12][13][14]21,22 .…”

“…Bi-component T2 and T2* mapping methods have measured two distinct T2 components in cartilage assumed to represent short relaxing water bound to the macromolecular matrix and long relaxing bulk water [12][13][14]21,22 . Bi-component T2* mapping methods have been used in cortical bone to differentiate between water bound to the organic matrix and free water in the Haversian systems [15][16][17] , Bi-component T2 and T2* mapping methods have also been used in the meniscus to differentiate between macromolecular bound water and bulk water [18][19][20] . In tendon, recent studies using bi-component T2* mapping techniques have measured two distinct T2 components representing short relaxing water bound to the highly organized collagen fibers and long relax-…”