Dist. Ct. did not err in granting defendants-prison doctors’ motion for summary judgment in section 1983 action by plaintiff-prisoner alleging that defendants were deliberately indifferent to his medical needs by failing to order MRI to address and diagnose pain in his shoulder. Defendant-physician held belief that plaintiff’s pain stemmed from arthritis, such that MRI would not assist him in diagnosis and treatment of plaintiff. Moreover, plaintiff could only potentially show that physician’s treatment of him was negligent, which is insufficient to establish instant 8th Amendment claim. Plaintiff also failed to show that medical standards called for use of MRI to determine whether diagnosis of arthritis based on x-ray films may be mistaken.