Short-term repeatability of joint space width measurements using a magnetic resonance imaging compatible knee...

Area of Science:

• Radiology
• Orthopedics
• Medical Imaging

Background:

• Accurate joint space width (JSW) measurements are crucial for assessing knee joint health.
• Variability in JSW measurements can arise from differences in technologist positioning during MRI scans.
• Standardized positioning may improve the reliability of quantitative MRI assessments.

Purpose of the Study:

• To evaluate an MRI-compatible knee positioning device.
• To assess the device's ability to minimize intratechnologist and intertechnologist differences in minimum JSW measurements.
• To determine the impact of the device on scan-to-scan, intratechnologist, and intertechnologist repeatability.

Main Methods:

• Five subjects underwent MRI scans with and without an MRI-compatible positioning device.
• Two technologists performed scans, with repositioning between some scans.
• A semi-automated program calculated minimum JSW for tibiofemoral and patellofemoral joints.
• Scan-to-scan, intratechnologist, and intertechnologist repeatability were assessed.
• Root mean square (RMS) error was calculated for JSW measurements.

Main Results:

• Scan-to-scan and intratechnologist repeatability remained unchanged with the device.
• Intertechnologist repeatability for the tibiofemoral joint improved (0.70 to 0.42 mm).
• RMS error for the tibiofemoral joint significantly decreased (0.26 to 0.15 mm, P = 0.0006).
• Patellofemoral JSW measurement variability slightly increased but was not statistically significant.

Conclusions:

• The MRI-compatible positioning device effectively reduced JSW measurement variability for the tibiofemoral joint.
• Increased variability in patellofemoral measurements may relate to articular surface incongruities.
• The device shows potential benefit for quantitative, longitudinal knee joint health studies.