What Causes Acute Ribs Pain?

Sir, I have been recommended a Bone Scan test for pain in the 8th and 9th rib on my left back side. Kindly suggest which hospitals does this scan. I am under Dr.Vinod Agarwal's (Orthopeadic Surgeon-at Santacruz )treatment for this pain since the last 2 yrs. MRI and CT scan results r normal. But the pain in the ribs r unbearable, hence doc recommended a Bone scan. A bone density test was also done, which did not show any significant results. Pls advise.