X-rays should be obtained for persons over age 50, in whom metastatic tumors are more likely, and those under age 20, in whom symptomatic congenital or developmental anomalies may be present.

• 年龄超过50岁，很可能是转移性肿瘤，而年龄在20岁以下者同可能有闰状性的先天性或发育性异常常存在，故应作X线检查。