Work

Quantifying temperature-dependent T1changes in cortical bone using ultrashort echo-time MRI

Year: 2015

Type: article

Abstract: PURPOSE: To demonstrate the feasibility of using ultrashort echo-time MRI to quantify T1 changes in cortical bone due to heating. METHODS: Variable flip-angle T1 mapping combined with 3D ultrashort echo-time imaging was used to measure T1 in cortical bone. A calibration experiment was performed to detect T1 changes with temperature in ex vivo cortical bone samples from a bovine femur. Ultrasound heating experiments were performed using an interstitial applicator in ex vivo bovine femur specimens, and heat-induced T1 changes were quantified. RESULTS: The calibration experiment demonstrated that T1 increases with temperature in cortical bone. We observed a linear relationship between temperature and T1 with a linear coefficient between 0.67 and 0.84 ms/°C over a range of 25-70°C. The ultrasound heating experiments showed increased T1 changes in the heated regions, and the relationship between the temperature changes and T1 changes was similar to that of the calibration. CONCLUSION: We demonstrated a temperature dependence of T1 in ex vivo cortical bone using a variable flip-angle ultrashort echo-time T1 mapping method.

Source: Magnetic Resonance in Medicine

DOI: 10.1002/mrm.25994