【单选题】超短半衰期放射性核素是天然的还是()制备的。
【简答题】句型转换。 1. He looks like his mother. (改为同义句) He and his mother ________ ________ ________. 2. He took good care of his dog.(改为同义句) He ________ ________ his dog________. 3. I'm not healthy. (改为同义句) I'm...
【简答题】CT最早用于颅脑检查,对颅脑疾病具有很高诊断价值。适用于颅脑外伤、脑血管意外、脑肿瘤、新生儿缺氧缺血性脑病、颅内炎症、脑实质变性、脑萎缩、术后和放疗后复查以及先天性颅脑畸形等。扫描基线有听眦线、听眉线和听眶线。颅脑增强扫描分为平扫后增强扫描和直接增强扫描两种方法。平扫后增强扫描是在乎扫基础上加做的增强扫描。直接增强扫描是注入对比剂后的逐层连续扫描。关于颅脑扫描基线和应用,错误的是A、听眦线是外耳孔...