Real-time magnetic resonance imaging (MRI) during active wrist motion--initial observations.

Area of Science:

• Musculoskeletal imaging
• Orthopedic biomechanics
• Advanced MRI techniques

Background:

• Dynamic wrist instability is a complex condition impacting musculoskeletal medicine.
• Non-invasive Magnetic Resonance Imaging (MRI) allows evaluation of wrist anatomy without ionizing radiation.
• Assessing dynamic instability requires imaging during joint motion.

Purpose of the Study:

• To develop an MRI protocol for evaluating the wrist during continuous active motion.
• To demonstrate the feasibility of dynamic wrist imaging.
• To enable measurement of metrics for dynamic wrist instability.

Main Methods:

• A 3-Tesla active-MRI protocol using a bSSFP sequence (475 ms temporal resolution) was developed.
• Fifteen wrists of 10 volunteers were scanned during various active wrist movements.
• Physicians evaluated distal radioulnar joint congruity, extensor carpi ulnaris tendon translation, and joint angles.

Main Results:

• The distal radioulnar joint subluxation ratio varied with pronation/supination.
• Extensor carpi ulnaris tendon subluxation was observed in most wrists during supination.
• Scapholunate interval increased during a clenched-fist maneuver, and joint angles were measurable.

Conclusions:

• Active-MRI demonstrates initial feasibility for in vivo dynamic wrist instability investigation.
• This technique may offer a new approach to diagnosing complex wrist conditions.
• Further research can refine active-MRI for clinical application in dynamic instability.