Table 1.
Comparing quantitative MRI techniques for bone imaging.
| UTE MRI technique | Quantification | Scan time-efficiency | Predicted bone characteristics | |
|---|---|---|---|---|
| Cortical bone | Basic UTE (+ phantom imaging) (37–45) | Total water proton density | High | - Significantly correlated positively with cortical bone porosity and negatively with BMD (μCT) (44, 45) |
| IR-UTE (+ phantom imaging) (41–44, 46) | Bound water proton density | Moderate | - Significantly correlated positively with cortical bone stiffness, strength, and toughness to fracture (47, 48) | |
| DAEF-UTE (+ phantom imaging) (41, 47) | Pore water proton density | Moderate | - Significantly correlated positively with bone porosity (μCT) and negatively with stiffness, strength, and toughness to fracture (47, 48) | |
| IR-UTE and UTE subtraction (+ phantom imaging) (38, 44, 49) | Pore water proton density | Moderate | - Significantly correlated positively with cortical bone porosity and negatively with BMD (μCT) (44) | |
| Bicomponent UTE fitting (12, 16, 50–52) | T2*s of bound and pore water, as well as bound water to total water ratio | Low | - Pore water fraction was significantly correlated positively with cortical bone porosity (μCT and histomorphometry) and negatively with BMD, stiffness, and strength (negatively) (16, 50, 51, 53). Correlations of bound water fraction were inverse. | |
| Tricomponent UTE fitting (53, 54) | T2*s of bound, pore water and fat, as well as bound and fat to total water ratios | Low | - Pore water fraction was significantly correlated positively with cortical bone porosity (μCT) and negatively with BMD, stiffness, and strength (53, 54). Correlations of bound water fraction were inverse. | |
| UTE to IR-UTE signal fraction (40) | Total and bound water ratio | Moderate | - Significantly correlated positively with cortical bone porosity (μCT) and age (40). | |
| Dual TE signal fraction (55, 56) | Pore and total water ratio | High | - Significantly correlated positively with cortical bone porosity (μCT) and donor age and negatively with mechanical stiffness and collagen estimation from near infrared spectroscopy (55, 56). | |
| Basic UTE signal decomposition model (57) | Bound and pore water ratio | High | - Pore water fraction was significantly correlated positively with subject age (57). Correlations of bound water fraction were inverse. | |
| UTE-MT modeling (44, 51, 58–62) | Macromolecular proton to total proton ratio | Low | - Significantly correlated negatively with cortical bone porosity (μCT and Histomorphometry) and positively with BMD, stiffness, and strength (44, 51, 58, 61). | |
| UTE-MT modeling and Basic UTE (+ phantom imaging) (44) | Macromolecular proton density | Low | - Significantly correlated negatively with cortical bone porosity (μCT) and subject age (44). | |
| UTE QSM (63, 64) | Magnetic susceptibility (BMD estimation) | Low | - Significantly correlated negatively with cortical bone porosity (μCT) and positively with BMD (64) | |
| Basic UTE at 31P frequency (42, 43, 65, 66) | Phosphorous content (BMD estimation) | Moderate | - Feasibility studies were performed (66). | |
| Trabecularbone | SPIR UTE (67) | Bound water T2* | Moderate | - Correlated positively with cortical bone porosity (μCT) (67) |
| IR-UTE (68) | Bound water content | Moderate | - Feasibility studies were performed (68). |