CT demonstration of a "halo sign" (ground-glass attenuation surrounding a nodule and representing hemorrhage) is suggestive of the diagnosis of angioinvasive aspergillosis in the right clinical setting. About half of patients develop cavitation at a mean of 15 days after development of the infection, when the neutrophil count rises above 1000 cells/mm3. The wall of the cavity is the site of angioinvasive aspergillosis. The dependent soft tissue mass that forms within the developing cavity represents necrotic lung and may be partially surrounded by an "air crescent sign" in the non-dependent portion of the cavity. In spite of the similar radiographic appearance, this is a completely different entity from mycetoma where there is fungal colonization in a preexistent cavity. Hemoptysis may occur with the onset of cavitation.
在 臨床診斷中CT出現「暈環徵」(結節周圍磨玻璃密度影,表示出血)常提示侵襲性麴黴菌病。 半數患者在感染15天後病灶形成空洞,伴中性粒細胞計數升高1000以上。 空洞壁即侵襲性麴黴菌病的部位。 壁內的軟組織腫塊代表壞死的肺組織。 部分患者可在病灶偏心位置出現「半月空氣徵」。 該徵象雖與「足分支菌病」相似,但病因卻完全不同,其是因為真菌在先前存在的空洞中繁殖導致。 侵襲性麴黴菌病在空洞形成的開始可能會有咯血的症狀。
Notes:
1. hemorrhage [ˈhɛmərɪdʒ] n.(尤指大量的)出血,失血; vi. 大出血
2. aspergillosis [ˌæspərdʒɪˈloʊsɪs] n. 麴黴病
3. crescent [ˈkrɛsənt] n. 新月,月牙; adj. 新月形的
4. mycetoma [ˌmaɪsə'toʊmə] n. 足分支菌病
來源:每天朗讀一段醫學影像學英語文章