Longitudinal In Vivo Assessment of Tibia Bone Porosity in T1DM Rabbits Using Ultrashort Echo Time MRI

Area of Science:

• Orthopedics
• Radiology
• Endocrinology

Background:

• Type 1 diabetes mellitus (T1DM) is associated with an increased risk of fractures.
• Longitudinal changes in cortical porosity during diabetes progression remain poorly understood.

Purpose of the Study:

• To evaluate cortical porosity and geometric alterations in a T1DM rabbit model using ultra short echo time MRI (UTE-MRI).
• To correlate UTE-MRI findings with micro-CT (μCT) and bone remodeling biomarkers.

Main Methods:

• A longitudinal study utilizing a T1DM rabbit model (n=28) with 3T 3D dual-echo UTE and IR-UTE MRI sequences.
• Assessment of porosity index (PI), suppression ratio (SR), and cortical thickness via UTE-MRI, compared with μCT and bone remodeling markers at 24 weeks.

Main Results:

• T1DM rabbits exhibited significantly higher UTE-MRI-measured cortical porosity and lower cortical thickness compared to controls, consistent with μCT findings.
• PI positively correlated with μCT-measured porosity and pore diameter.
• Early increases in PI were observed from week 12 in T1DM rabbits, with negative correlations to osteoblast and osteoclast markers.

Conclusions:

• UTE-MRI is a promising tool for longitudinal monitoring of cortical porosity and geometric changes in T1DM.
• This technique can identify early, potentially reversible, bone alterations associated with diabetes.