Chronic shoulder pain. Would be useful.

My wife is 36 years old and has had persistent right-sided pain for more than 10 months. The pain starts near the lower part of the right shoulder blade and spreads upward toward the neck and into the right arm. We have not received a clear diagnosis yet. We would like a specialist evaluation to understand whether the pain could be related to the cervical spine, nerve irritation/compression, shoulder-blade muscles, upper back, or shoulder joint. We are considering an MRI, but would prefer advice on the most appropriate targeted scan rather than a whole-body MRI. Please also advise whether neurological examination, nerve-conduction studies, X-ray, physiotherapy assessment, or other tests would be useful.