外科感染通常分为哪两大类?临床上各常见于哪些疾病?
下列哪种方法不能矫治散光() ["A.硬性角膜接触镜","B.表面角膜镜片术","C.准分子激光角膜切削术","D.准分子激光角膜原位磨镶术","E.白内障摘除人工晶状体植入术"]
囊肿的声像图特征是() ["A.边界回声不定","B.外形不定","C.内部无回声","D.后方回声衰减","E.侧缘声影不定"]
简述血管瘤的临床类型及其特点。
下列哪种介质中,超声难以传播() ①空气 ②骨骼 ③硫酸钡 ④肝 ["A.①","B.①②","C.①②③","D.①④","E.①②③④"]
简述何谓Clark分级法。