不要混淆：空气新月征与Monod征
医学影像专业平台，影像学习小宝库
从开始学习医学影像学以来，我们学过非常多的影像学征象。一部分征象具有较高特异性，我们可以对疾病进行精准诊断，我们称为Aunt minnie；而大多数的影像征象对疾病的鉴别诊断具有重要意义。今天我们要讲的两个征象，非常熟悉，但一直被大家混淆应用，部分教材及书籍也使用了不恰当的描述。
AirCrescent Sign（空气新月征）：The air crescentsign has been described as a complete or partial ircumferential rim of radiolucent airspace within a parenchymal consolidation ornodular opacit. It has classically been associated with invasiveaspergillosis and can be visualized in chest radiographs as well as CT scans.The aspergillus hyphae invade the pulmonary vasculature and cause arterialthrombosis, pulmonaryinfarction, and surrounding hemorrhage.The air crescent isformed as a result of separation of the devitalized necrotic center from thesurrounding opaque rim of hemorrhagic tissue. Clinically, in an appropriatesetting, presence of an air crescent marks the recovery phase of the diseaseand portends a favorable prognosis. The air crescent sign can be seen in otherconditions such as pulmonary TB, pulmonary abscess, and bronchogenic carcinoma.
空气新月征：肺内空洞或空腔内的球形病灶与洞壁之间形成的新月形透亮影称为“空气新月征”。该征象通常与侵袭性曲霉菌病有关。新月征可以在胸部X光片和CT扫描中看到。曲霉的菌丝侵入肺血管，导致动脉血栓形成，引起肺部梗塞，以及梗死周边出血。空气新月形成主要是中央坏死区收缩与周围的不透明的边缘出血组织分离形成了间隙。临床上，新月征的出现标志着疾病的恢复期，预示预后良好。空气新月征也可见于如肺结核，肺脓肿和支气管源性肺癌等其他疾病。
Monod sign（Monod征）： first described by Pesle and Monod in 1954,refers to air surrounding a fungal ball in a preexisting pulmonary cavity that falls to a gravity-dependent location of the cavity. It is an important sign that helps distinguish a “mass within a preexisting cavity” such as an aspergilloma vs a “cavitary mass”.
Monod征：由Pesle和Monod在1954年首次提出Monod征，特点是：空洞或空腔内的霉菌球随着体位的变动，始终因为重力作用位于最低位。这个重要征象用于鉴别曲霉球与“空腔肿块”。
鉴别诊断：
参考文献：CHEST 2017：151(6)