Purpose or Case Report: Background & Purpose:

Fractures on MRI can be difficult to see, particularly if they are small or surrounded by edema and other heterogeneous signal changes. This is made more challenging if an x-ray is not available for review when reading an MRI, or if the injury on x-ray is subtle. The purpose of this exhibit is to review the different appearances and types of fractures by MRI, including avulsion, acute osteochondral, physeal related, and stress fractures, and help the learner develop a pattern-based approach when reviewing an MRI, in order to improve detection and confidence.

Learning Objectives:

1. Recognize the different ways an acute fracture can appear by MRI, including understanding mechanisms of injury and any associated ligamentous or tendinous involvement.
2. Learn to approach each MRI the same way, with a careful assessment of bone marrow edema heterogeneity, joint fluid heterogeneity, and articular surfaces.
3. Develop awareness of subtle, small, or unusual fractures that may be hiding amidst edema or fluid.

Content:

This exhibit will portray and explain the imaging appearances of different fractures on MRI including: incomplete, avulsion, acute osteochondral, physeal related, and stress fractures. Different joint centered abnormalities will be emphasized, particularly the knee, shoulder, and pelvis. A pattern based approach will be reviewed in order to avoid missing subtle findings. This will include:
1. Searching within the heterogeneity of marrow edema patterns on both T1 and T2 weighted sequences to find linearity, subtle cortical depressions, or incomplete fracture lines.
2. Looking for healing or more chronic changes, including periosteal reaction by MRI.
3. Following articular cartilage and the physis to make sure they have normal contours and are smooth.
4. Examining joint fluid for avulsed joint bodies, with attention to any linear appearing signal changes in the dependent recesses of joints.
Methods & Materials:
Results:
Conclusions: Through a comprehensive and structured approach, this pictorial overview of fracture appearances on MRI will help the learner to recognize and be more comfortable with identifying different types of fractures on MRI, as well as their associated injuries.