How Is A Chest MRI Process Done?

Hello. I hope there s a radiologist or doctor around and can help me ease my doubts and fears. I ve been suffering for months from chest pain, or better, the pain is on the left side, feels like a heart pain and by pressing all around the area it gets worse. I had been having low grade fever since then and two outbursts, one the first time I started to feel this, of very high fever, 39°C. Long story short, my rheumatologist believes is something rheumatic so he ordered me to do a chest MRi specifyng for evaluation of sternoclavicular and chondrosternal joints . So I do the MRi, they made me lay on my stomach, put something very heavy on my back, I supposed those were the coils, and the whole thing took 20 minutes. The result was negative. Now I would like to know, is it normal that I was asked to lay on my stomach? Because everywhere I read it says that chest MRi requires you to lay on your back, if possibile, by lifting your arms and putting them next to your head for a better acquisition of immages and you ll be asked to hold your breath a few times. Nothing of that happened. Also, while trying to book the appointment for the MRi, one hospital let me speak with a radiologist and he told me this exam was completely pointless. I was taken aback. Truth to be told, looking at my report, it only mentions the situation of my bones. No mention of the anatomy and fuction of the heart and its component structures (valves, etc.), blood flood dynamics in the vessels and heart chambers, display lymph nodes and blood vessels and so on which you expect from a chest MRi. Help me understand. Was the exam done wrong? Pointless? Was the radiologist right? Should my rheumatologist not had written any specifycation and just let me do a classic chest MRi? Thanks for any reply.