Evaluation of trabecular and subentheseal bone volume density in calcaneus with dual-echo ultrashort echo time magnetic resonance imaging: In vivo feasibility study

Abstract

Trabecular and entheseal bone quantity in the calcaneus may relate to general bone health and physical activity levels of patients. Magnetic resonance imaging (MRI) has been increasingly used for bone evaluation, to avoid ionizing radiation and enable simultaneous evaluation of surrounding soft tissue. A rapid quantitative MRI-based method to estimate bone volume to total volume (BV/TV), ^{without re}solving ^{trabecular-level f}eatures, has been developed utilizing a dual echo ultrashort echo time (UTE) sequence that can directly acquire bone and free water signal for further quantification. This ^{study i}nvestigated the feasibility of using dual echo UTE for trabecular and subentheseal BV/TV evaluation in the calcaneus. Ankle joints of 32 healthy subjects (12 women and 20 men, 35.0 ± 6.8 years old) were scanned in the sagittal plane using dual echo UTE ^{(TE=0.03 and 2.2 ms) on a clinical 3T MRI scanner} with 3 min scan time. BV/TV was measured in four regions of interest (ROIs); proximal calcaneal crescent (ROI 1), plantar calcaneal crescent (ROI 2), deep calcaneal bone (ROI 3), and subentheseal bone (ROI 4). Differences were examined with Kruskal Wallis test. Spearman's correlations of BV/TV with age, weight, height, and BMI were calculated. BVTV was significantly different (p < 0.05) between regions (mean ± SD of 42.8 ± 4.3, 41.7 ± 3.2,38.4 ± 3.3, and 37.8 ± 3.2 for subentheseal bone, proximal calcaneal crescent, plantar calcaneal crescent, and deep trabecular regions, respectively). BV/TV showed significant positive correlations with age and weight in all regions. This study highlights the ^feasibility of dual echo UTE technique for rapid MRI-based evaluation of BV/TV in patients.