فهرست نشریات علمی دسترسی آزاد ایران

Background: Larger pores in human cortical bone (> 30 m) have essential role in its mechanical competence, suggesting to quantify such proton pools as a reliable measure of cortical bone porosity and thus, cortical bone quality. Signal from such pores can be captured using short echo time (STE) pulse sequence with echo-time in the range of 0.51 ms. Since T1-relaxation increases with the porosity volume; in the first step we have quantified T1 values as a reliable measure of cortical porosity employing the dual-TR technique. Objectives: Results show that the T1 values quantified by this method are accurately close to the ones reported in the ultra-short echo time (UTE) literature. Such T1 values can be used in the quantification process of cortical bone porosity to discriminate osteoporotic bone from normal. Results: Results for quantitative measurement of T1-values were shown in eight and five healthy volunteers using STE pulse sequence at 1.5 and 3 T respectively. Measurements were performed for both genders, resulting in the mean T1-values of about 202.81 ms and 238.56 ms for human cortical pore water at 1.5T and 3 T respectively. Such T1 quantities are in a good agreement with the values reported in the UTE literature (380-775 ms and 200-400 ms at 4.7T and 3T, respectively). Conclusions: Results show that quantifying T1-relaxivity of the cortical bone using STE-MRI is feasible with the similar accuracy of UTE imaging. Such pulse sequences are available on commercial MRI magnets in everyday clinics, save money and time to half of what UTE needs; meaning that STE pulse sequence can be utilized as a proper alternative in quantifying cortical bone parameters in-vivo.