试述管饲法的定义及分类。
营养素
男，35岁，胸部外伤，CT图像如图，最可能的诊断为() ["A．支气管囊肿并感染","B．畸胎瘤","C．右侧气胸","D．右侧液气胸","E．右侧脓胸"]
男，28岁，胸闷1周，胸部CT如图，最可能的诊断为() ["A．间皮瘤","B．肺癌","C．包裹性积液","D．肺炎性假瘤","E．肺肉瘤"]
男，32岁，被车撞伤后1小时，请结合影像图像选择其最可能的诊断为() ["A．右侧气胸","B．右肺不张","C．右侧气胸并皮下纵隔气肿","D．右侧肺大疱并皮下纵隔气肿","E．支气管断裂"]
食欲
