Orthopaedics General e2b76a76 Which one of the following is the investigation of choice for evaluation of suspected Perthes' disease? A Plain X-ray B Ultrasonography (US) C Computed Tomography (CT) D Magnetic Resonance Imaging (MRI) High-Yield Explanation MRI is the investigation of choice as it can diagnose Perthes disease in early stages when X-ray is normal.