Measuring Knee Bone Marrow Perfusion Using Arterial Spin Labeling at 3 T.

Area of Science:

• Biomedical Engineering
• Radiology
• Physiology

Background:

• Bone perfusion is crucial for assessing bone health and viability.
• Arterial spin labeling (ASL) offers a non-invasive method for perfusion imaging without contrast agents.
• Assessing knee bone marrow perfusion is important for diagnosing skeletal conditions.

Purpose of the Study:

• To evaluate the feasibility of ASL for imaging knee bone marrow perfusion in the distal femur at 3T.
• To assess the impact of imaging parameters like post-bolus delay and labeling size on ASL quality.
• To explore the potential of ASL in detecting perfusion changes in patients with juvenile osteochondritis dissecans (JOCD).

Main Methods:

• ASL imaging was performed using a flow-sensitive alternating inversion recovery (FAIR) method with a single-shot fast spin echo sequence.
• Quantitative ASL imaging of knee bone marrow was conducted on healthy volunteers and JOCD patients.
• Studies investigated the effects of prolonged post-bolus delay and varied labeling size on perfusion signals.

Main Results:

• ASL imaging was successfully performed in all healthy volunteers.
• Prolonged post-bolus delay led to signal decay and reduced image quality.
• Bone marrow perfusion signal varied with labeling size, indicating flow association. Mean blood flow was 38.3 ± 5.2 mL/100g/min.
• JOCD patient imaging suggested ASL can detect disease-related perfusion alterations.

Conclusions:

• ASL imaging of knee bone marrow in the distal femoral condyle at 3T is feasible.
• Optimizing imaging parameters like post-bolus delay is crucial for maintaining signal quality.
• ASL shows promise as a tool for evaluating bone marrow perfusion and diagnosing conditions like JOCD.