医学英语教程:生物医学(学生用书)(附MP3下载)

　　Medical experts hoped that improved diagnostic imaging instrumentation， such as computed tomographic （CT） scanning and magnetic resonance imaging （MRI）， would make possible more precise diagnoses for most backpain patients. This promise has been illusory. One important reason is that， as in the x-ray studies， alarming abnormalities are found in pain-free people.　　Findings from various studies suggest that many red herrings confuse imaging interpretation'and that at least for some， spine abnormalities are purely coincidental and do not cause pain. Moreover， even the best imaging tests fail to identify the simple muscle spasm or injured ligament probably responsible for pain in a substantial percentage of back patients. All this imaging perplexity caused one orthopedic surgeon to remark， "A diagnosis based on MRI in the absence of objective clinical findings may not be the cause of a patient's pain， and an attempt at operative correction could be the first step toward disaster." In other words， the office examination is at least as important as the imaging test， and surgery for patients whose back pain is associated only with abnormal imaging results can be unnecessary if not down- right detrimental. Many physicians now advocate CT scans and MRI only for those patients who are already surgical candidates for other reasons.　　Complicating the situation still further is the fact that most patients with acute low-back pain simply get better - and quickly. A study comparing treatment outcomes found no differences in functional recovery times among patients who saw chiropractors， family doctors or orthopedic surgeons. Cost， on the other hand， varied substantially， with family doctors costing least and surgeons most. The Hippocratic admonition "First， do no harm" may be the most important counsel with regard to this condition - the favorable natural history of acute low-back pain is hard to beat.　　……