Those indentations on your back is your scapula(shoulder blade) maybe request a scapula X-ray or shoulder X-ray. I am an X-ray tech and look for that indentation on everybody for one of the shoulder X-rays, everybody has that indentation. Go back and ask them to look at your shoulder blade.
I had chest x-ray and chest CT done and all read as "normal", despite having an indent and my heart being compressed as shown on CT. The radiologist was looking for a pulmonary embolism (blood clot in lung), but should have noted the obvious defect of the chest wall and heart. Once I got my consultation at Mayo in Phoenix it was re-examined by their radiologist and correctly diagnosed. Ask your doctor to re-look as the actual image, and not go off the radiologist's report.