孤立性肺结节PET-CT良恶性鉴别诊断

目录（contents）

1.
2. 3. 4. 5.
CT征象
钙化 大小 生长速度 形状 边界 充气支气管征 实性和磨玻璃成分 强化特征

1. 2. 3. 4. 5. 6. 7.
CT: benign versus malignant
Calcification Size Growth Shape Margin Air Bronchogram sign Solid and Ground-glass components Contrast enhancement
边缘


辐射冠征：绝大多数都为恶性（上图：恶性病灶 周围的辐射冠征--毛刺）。 病灶边缘呈分叶状的，可以是良性或恶性 边缘光滑，多为良性。
Margin



Corona radiata sign - highly associated with malignancy (figure) Lobulated or scalloped margins intermediate probability Smooth margins - more likely benign unless metastatic in origin
结节大小
结节大小与恶性可能性之间的关系



孤立性肺结节（SPN）定义：肺实质内小于等于3cm的病灶（需除外 肺不张和肿大的淋巴结）。大于3cm的病灶称为肿块（mass）。 之所以这样定义，是因为大于3cm的病灶多为恶性，而更小的病灶可 能是良心或恶性。 Swensen. et al 研究了SPN大小与恶性可能性之间的关系（上图）， 结论是小的结节，良性可能性大。超过2000例小于4mm的结节，无 一例属于恶性。


图中两个SPN，根据形态表现，哪个更像恶性的？ 左边的结节边缘呈毛刺状，内部有透亮区；右侧者呈分叶 状，边缘毛刺并与胸膜粘连，但是内部均质。 基于上面的表现，我们认为左侧者更像恶性的。最终证实， 左侧者为腺癌，右侧为真菌感染。


On the left two solitary pulmonary nodules. Based upon the morphology, which lesion has the most malignant features? The lesion on the far left has a spicuated margin and has lucencies within it. The lesion next to it is lobulated in contour and has some spicules radiating to the pleura. It is however homogeneous in attenuation. Based on these findings we should be most concerned that the lesion on the far left is malignant. It proved to be an adenocarcinoma, while the other one was a fungal infection. The lucencies and frank air bronchograms should not mislead you in thinking that it probably is infection.
生长速度

与以前的CT片进行比较，在结节定性方面 具有重要意义。超过2年无变化的结节多为 良性。
Growth

Comparison with prior imaging studies is often the most useful procedure to determine the importance of the finding of a SPN, since stability over 2 years is highly associated with benignity.
充气支气管征


最新研究表明，有充气支气管征的结节多为恶性。 主要见于BAC（细支气管肺泡癌）和腺癌。 上图显示充气的支气管呈线样（粗箭）或囊状 （细箭）透亮区，这是支气管走向不同造成的。
Air Bronchogram sign


Recent studies have showed that an air bronchogram is more commonly seen in malignant pulmonary nodules. It is most commonly seen in BAC (bronchoalveolar cell carcinoma) and adenocarcinoma. The case on the left shows an airbronchogram seen as a linear lucency (broad arrow) and as a more cystic lucency (small arrow) due to the fact that the bronchus is seen en face.
Calcification


Diffuse, central, laminated or popcorn calcifications are benign patterns of calcification. These types of calcification are seen in granulomatous disease and hamartomas. All other patterns of calcification should not be regarded as a sign of benignity. The exception to the rule above is when patients are known to have a primary tumor. For instance the diffuse calcification pattern can be seen in patients with osteosarcoma or chondrosarcoma. Similarly the central and popcorn pattern can be seen in patients with GI-tumors and patients who previously had chemotherapy.
孤立性肺结节的鉴别诊断，在临床 中经常遇到。根据结节的良恶性差 异，处理方法有很大差别。 在这篇文章中，我们主要探讨CT和 PET-CT的相关征象在孤立性肺结节 良恶性鉴别诊断中的意义。

The differential diagnosis of a solitary pulmonary nodule is broad and management depends on whether the lesion is benign or malignant. In this overview we will discuss some of the new features that can help to differentiate between benign and malignant nodules based upon CT and PET-CT findings
6.
7. 8.

PET-CT征象 结论
8.


PET-CT: benign versus malignant Conclusion
钙化
良性钙化征象：
弥漫性
中心性
层状
爆米花样


弥漫性、中心性、层状及爆米花样钙化多见于良性结节。 主要见于肉芽肿性疾病和错构瘤。 其他类型钙化多见于恶性结节，不应该认为属于良性表现。 在已知有原发肿瘤存在的情况下，其钙化类型不一定适用 此结论。例如：骨肉瘤或软骨肉瘤的病人，其钙化多表现 为弥漫性；同样的，中心性和爆米花样钙化也可见于胃肠 道肿瘤或接受过化疗的病人。
形状
左：横断图像；右：冠状重建图像。三维比值=（最大）横径/长径


日本的相关研究证实，多角形、三维比值大于1.78的结节，多为 良性。在肺的外围、胸膜下的结节也多为良性。 三维比值=（最大）横径/长径。大的三维比值说明病灶的形状是 扁平的（是“片”不是“块”），这是良性的特征。
Shape


Japanese screening studies showed that a polygonal shape and a three-dimensional ratio > 1.78 was a sign of benignity (2,3). A polygonal shape means that the lesion has multiple facets (multi-sided). A peripheral subpleural location was also a sign of benignity in this study. The three-dimensional ratio is measured by obtaining the maximal transverse dimension and dividing it by the maximal vertical dimension. A large three-dimensional ratio indicates that the lesion is relatively flat, which is a benign sign.
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Size


A solitary pulmonary nodule (SPN) is defined as a single intraparenchymal lesion less than 3 cm in size and not associated with atelectasis or lymphadenopathy. A lesion greater than 3 cm in diameter is called a mass. This distinction is made, because lesions greater than 3 cm are usually malignant, while smaller lesions can be either benign or malignant. Swensen et al studied the relationship between the size of a SPN and the chance of malignancy in a cohort at high risk for lung cancer (1). Their findings are listed in the table on the left. They concluded that benign nodule detection rate is high, especially if lesions are small. Of the over 2000 nodules that were less than 4 mm in size, none was malignant
实性和磨玻璃成分
一项研究表明：结节内含有磨玻璃样成分的， 更倾向于属于恶性。
孤立性肺结节 CT、PET-CT良恶性鉴别诊断
Solitary pulmonary nodule: benign versus malignant Differentiation with CT and PET-CT
Ann Leung and Robin Smithuis 原文地址：http://www.radiologyassistant.nl/en/460f9fcd50637