Iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) for evaluation of early bone mass changes in ageing osteoporosis patients

This study explored the application value of iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) technology in the early diagnosis of ageing osteoporosis (OP). 172 participants were enrolled and underwent magnetic resonance imaging (MRI) examinations on a 3.0T scanner. 100 cases were included in the normal group (50 males and 50 females; mean age: 45 years; age range: 20-84 years). 33 cases were included in the osteopenia group (17 males and 16 females; mean age: 55 years; age range: 43-83 years). 39 cases were included in the OP group (19 males and 20 females; mean age: 58 years; age range: 48-82 years). Conventional T₁WI and T₂WI were first obtained, followed by 3D-IDEAL-IQ-acquisition. Fat fraction (<i>FF</i>) and apparent transverse relaxation rate (<i>R</i> ₂ ^∗) results were automatically calculated from IDEAL-IQ-images on the console. Based on T₁W and T₂W-images, 300 ROIs for each participant were manually delineated in L₁-L₅ vertebral bodies of five middle slices. In each age group of all normal subjects, each parameter was significantly correlated with gender. In male participants from the normal, osteopenia, and OP groups, statistical analysis revealed <i>F</i> values of 11319.292 and 180.130 for comparisons involving <i>FF</i> and <i>R</i> ₂ ^∗ values, respectively (all <i>p</i> < 0.0001). The sensitivity and specificity of <i>FF</i> values were 0.906 and 0.950, 0.994 and 0.997, 0.865 and 0.820, respectively. For <i>R</i> ₂ ^∗, they were 0.665 and 0.616, 0.563 and 0.519, 0.571 and 0.368, respectively. In female participants from the normal, osteopenia, and OP-groups, statistical analysis revealed <i>F</i> values of 12461.658 and 548.274 for comparisons involving <i>FF</i> and <i>R</i> ₂ ^∗ values, respectively (all <i>p</i> < 0.0001). The sensitivity and specificity of <i>FF</i> values were 0.985 and 0.991, 0.996 and 0.996, 0.581 and 0.678, respectively. For <i>R</i> ₂ ^∗, they were 0.698 and 0.730, 0.603 and 0.665, 0.622 and 0.525, respectively. Significant differences were indicated in the quantitative values among the three groups. <i>FF</i> value had good performance, while <i>R</i> ₂ ^∗ value had poor performance in discriminating osteopenia and OP-groups. Overall, the IDEAL-IQ technique offers specific reference indices that enable noninvasive and quantitative assessment of lumbar vertebrae bone metabolism, thereby providing diagnostic information for OP.