Dynamic wrist imaging using four-dimensional CT: current concepts, clinical applications, and future perspectives.

Area of Science:

• Orthopedics
• Radiology
• Biomechanics

Background:

• Carpal instability is a dynamic disorder often missed by static imaging (radiography, CT, MRI).
• Delayed diagnosis can lead to progressive instability and degenerative changes.
• Conventional imaging lacks the ability to visualize in vivo wrist kinematics during motion.

Purpose of the Study:

• To introduce and evaluate the utility of four-dimensional CT (4D CT) for dynamic carpal instability assessment.
• To demonstrate 4D CT's capability in identifying abnormal wrist motion patterns and subluxations.
• To explore 4D CT's role in clinical applications and preoperative/postoperative assessment.

Main Methods:

• Acquisition of sequential volumetric datasets during active wrist motion using 4D CT.
• Dynamic, in vivo visualization and quantitative analysis of wrist kinematics.
• Comparison with the contralateral wrist for physiological reference.

Main Results:

• 4D CT enables visualization of abnormal intercarpal coordination and subluxations not detectable with static imaging.
• Identifies altered carpal kinematics in conditions like Kienböck disease.
• Provides objective evaluation of wrist motion for surgical planning and assessment.

Conclusions:

• 4D CT offers functional insights into wrist biomechanics, complementing conventional imaging and arthroscopy.
• It is valuable for diagnosing dynamic carpal instability when static imaging is inconclusive.
• Advancements in 4D CT are expected to enhance its clinical applicability and integration into practice.