Hahm J, Choe K, Joo S, Kim M
Department of Diagnostic Radiology, College of Medicine, Yonsei University, Seoul, Korea.
Yonsei Med J. 1995 May;36(2):175-86. doi: 10.3349/ymj.1995.36.2.175.
Contrast enhanced CT manifestations of 141 pulmonary nodules having internal density less than 40 HU were evaluated to study the prevalence of causative disease and their differential points. Tuberculosis (n = 79) was most common, active in 96%. There were 22 cancers, 10 abscesses, 9 paragonimiases, 8 cysts, 7 metastases, 4 aspergillomas without air meniscus sign, and so on. 35% of the benign lesions were greater than 3 cm in diameter and 67% of benign lesions did not show a smooth outer margin. Lung cysts and aspergillomas showed relatively thin peripheral enhanced rim (PER), sharp transitional zone (TZ), a smooth inner border (IB), and homogeneous low densities (LD). Tuberculous nodules tended to be smaller in size with thin PER and most had smooth IB and homogeneous LD. Paragonimiasis, abscess, and cancer tended to present with thick PER and lobulated IB. Lung abscess and paragonimiasis both showed homogeneous LD and narrow TZ. However, in paragonimiasis, multiple locules were seen. Lung cancer showed wider TZ and heterogeneous LD. The size and outer margin of pulmonary nodules as a diagnostic criteria is less useful in LD pulmonary nodule. Therefore, CT can be more useful in differentiating the benign from the malignant lesions by observing a more specific and characteristic pattern of peripheral enhanced rim, transitional zone, inner border, and homogeneity of low density area.
对141个内部密度小于40 HU的肺结节的增强CT表现进行评估，以研究致病疾病的患病率及其鉴别要点。肺结核（n = 79）最为常见，96%处于活动期。有22例癌症、10例肺脓肿、9例肺吸虫病、8例囊肿、7例转移瘤、4例无空气半月征的曲菌球等。35%的良性病变直径大于3 cm，67%的良性病变外缘不光滑。肺囊肿和曲菌球表现为相对较薄的周边强化边缘（PER）、锐利的过渡带（TZ）、光滑的内缘（IB）和均匀的低密度（LD）。结核结节往往较小，PER较薄，大多数有光滑的IB和均匀的LD。肺吸虫病、肺脓肿和癌症往往表现为较厚的PER和分叶状的IB。肺脓肿和肺吸虫病均表现为均匀的LD和狭窄的TZ。然而，肺吸虫病可见多个小腔。肺癌表现为较宽的TZ和不均匀的LD。肺结节的大小和外缘作为诊断标准在低密度肺结节中不太有用。因此，通过观察周边强化边缘、过渡带、内缘和低密度区均匀性的更具特异性和特征性的模式，CT在鉴别良性和恶性病变方面可能更有用。
