Table 1.

Strengths and limitations of radiography and magnetic resonance imaging

	Radiography	Magnetic resonance Imaging
Strengths	• Inexpensive • Widely available • Short examination time	• Sensitive to change • Specific because it directly shows cartilage • Positioning is not an issue, since cartilage can be directly visualized • Treats the joint as a whole organ
Limitations	• Not sensitive to change: minimal progression is not identifiable, so large patient sample size and lengthy studies are required • Not specific: meniscal extrusion and damage may account for joint space narrowing • Change in positioning is problematic in multicenter and long-term studies • Does not show other important structures that account for pain in osteoarthritis	• Expensive • Limited availability • Long examination time • Requires expert knowledge (that is, input of radiologist is essential) for choice of appropriate pulse sequences and imaging protocol • Difficulties with repositioning • Challenges of imaging obese patients who do not fit the coil • Images with identical pulse sequences may not be obtained across all sites in multicenter magnetic resonance imaging studies