Acute muscle injuries are of great importance in musculoskeletal (MSK) radiology due to their high prevalence in sports activities ^1,2. The most common injury is a muscle strain that results from indirect trauma during sprinting, stretching, or jumping movements. These injuries are frequently seen in football, Australian football (AFL), American football (NFL), rugby, and various athletic disciplines ^3-7. 

Acute muscle injuries can result in significant time loss from competition and an increased risk of re-injury. In many cases, clinical examinations alone are insufficient to obtain reliable results, making imaging techniques valuable for providing additional information ⁸. Since the grading of muscle injuries determines subsequent management, a reliable classification system is of great importance ^8-11.

In recent decades, various MRI-based classification systems have been proposed to grade acute muscle injuries ^8,9. The most commonly used ones include:

• The British athletics muscle injury classification (BAMIC) (2014) ¹²
• The Munich Consensus Injury Classification (2012) ¹³
• The Chan et al. Classification System (2012) ¹⁴

The objective of this study is to evaluate the interrater reliability of three MRI-based classification systems used for diagnosing acute muscle injuries.