Fast quantitative 3D ultrashort echo time MRI of cortical bone using extended cones sampling

Area of Science:

• Biomedical Imaging
• Materials Science

Background:

• Quantitative 3D ultrashort echo time (UTE) MRI is crucial for assessing cortical bone properties.
• Optimizing UTE imaging parameters is essential for clinical efficiency and accuracy.

Purpose of the Study:

• To evaluate the impact of extended sampling window durations on quantitative 3D UTE MRI biomarkers of cortical bone at 3 Tesla.
• To determine if longer sampling windows introduce significant quantification errors in UTE-MRI.

Main Methods:

• Cortical bone samples (bovine and human) were imaged using 3T MRI with radial and spiral Cones sampling trajectories.
• Quantitative UTE-MRI biomarkers (T1, T2*, MTR, MT modeling) were acquired with varying sampling window durations.
• Errors in biomarkers were assessed relative to a reference radial sampling window.

Main Results:

• No significant differences in UTE biomarkers (T1, T2*, MTR, MT modeling) were found for spiral sampling windows from 992 µs to 1600 µs compared to a 688 µs radial window.
• These findings held true for both bovine and human cortical bone samples.

Conclusions:

• Quantitative 3D UTE-MRI of cortical bone can be significantly accelerated by using longer sampling windows.
• Accelerated UTE-MRI techniques maintain accuracy, with quantification errors below 5% and reduced scan times by up to 76%.