孤立性肺结节PET-CT良恶性鉴别诊断

1、孤立性肺结节CT、PETCT良恶性鉴别诊断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 fe

2、atures that can help to differentiate between benign and malignant nodules based upon CT and PET-CT findings目录（contents）CT征象CT: benign versus1,钙化malianant乙大小1.Calcification3,生长速度2.Size4.形状3Growth5、边界4.Shape6.充气支气管征5.6.MarainAir Bronchoaram sian7.实性和磨玻璃成分7,Solid and Ground-alass8.强化特征com pon entsPET-

3、CT征象8Contrast enhancementPET-CT: benian结论versus malignant Conclusion钙化Diffuse Central Laminated Popcorn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。Calcification Diffus

4、皀，central, liminated or popcorn calcifications are benign patterns of calcification. These types of calcification are seen in grinulomitous disees皀 end hemertomes,All other patter ns of calcification should not be regarded as a sign of benignity. Th皀皀xception to th皀 rule ebov皀 is when patients &皀 kn

5、own to hev皀 a primary tumor；For instanc 皀 the d iff us 皀 celcificetion pattern cen be seen in patients with osteosarcoma or chondrosarcomaSimilarly the central and popcorn pattern can be seen in patients with G卜tumors and patients who previously had chemotherapy.结节大小Nodule SizeSizeTotalMalignancy 1.

6、78 was a sign of benignity (2,3)-ShapeA polygonal shape means that the lesion has multiple facets (multi-sided).A p皀riph皀謝 subpleural location wes also e sign of benignity in this study.The three-dimensional ratio is measured by obtaining the maximal transverse dimension and dividing it by the maxim

7、al vertical dimension.A large three-dimensional ratio indicates that the lesion is relatively flit, which is a benign sign.辐射冠征：绝大多数都为恶性（上图：恶性病灶 周围的辐射冠征一毛刺）。病灶边缘呈分叶状的，可以是良性或恶性Margin Corona radiata sign - highly associated with malignancy (figure) Lobulated or scalloped margins - in termediate probab

8、ility Smooth margins - more likely benign unless metastatic in origin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 comm

9、only seen in BAC (bronchoalveolar cell carcinoma) and adenocarcinoma The case on the left shows anairbronchogram 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.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

10、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 I皀sion on th皀 fer left hes e spicueted margin and has lucencies within it.The lesion next to it is lobulated in contour and

11、has som皀 spicul皀s ndieting to the pleura.It is however homogeneous in attenuation. Based on th皀s皀 findings we should be most concerned that the lesion on the far left ismelignent.It proved to be an adenocarcinorm引 while the other one was a fungal infection.The lucencies and frank air bronchograms sh

12、ould not mislead you in thinking that it probably is infection.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。结节内既含有部分实性成分，又含有磨玻璃成 分的，为恶性的可能性为63%O没有实性成分，只有磨玻璃成分的，恶性可能 性有18%。全部为实性成分的，恶性可能性为7%。Solid and Ground-glasscomponentsAnother result from screening studies is that no doles contai ning a grou ndglass comp

13、onent are more likely to be malig nant. Partly solid lesions with ground-glass components had a malignancy rate of 63%. Nonsolid only grounglass I皀sions had e malignency rate of 18%. Only solid lesions had a malignancy rate of only 7%.左侧者只有磨玻璃成分；右侧者既有磨玻璃成分 又含有实性成分。左侧者恶性可能性为1/5;右侧者恶性可能性为 2/3. On the

14、far left a lesion that only has a ground-glass appearanee and next to it a lesion that has both groundglass and solid comp on ents. The likelihood of malignancy is 1:5 for the lesion on the far left and 2:3 for the lesion with both ground-glass and solid comp on ents.强化特征增强扫描强化程度小于15HU的，有99%的可能性为良性。

15、 平扫后增强扫描，每一分钟扫描一次，连续4次。结节满足以下条件者，才能采用这种方法评价：结节5mnn相对呈球形内部均质，没有坏死、脂肪和钙化图像无明显伪影Contrast enhan ceme nt Contrast enhancement less than i5 HU has a very high predictive value for benignity (99%)_After a baseline scan, 4 consecutive scans at 1 minute interval are performed.This applies only for nodules wi

16、th the following selection criteria: Nodule 5mm Relatively spherical Homogeneous, no necrosis, fat or calcification No motion or beam hardening artifactsPET-CTPET-CT在实性结节评价方面起着越来越重要的作用。在进行PEPCT检查时，你必须意识到: PETYT敏感性高达95%,但特异性只有81%；肉芽肿性疾病可以呈假阳性；小于10mm的结节、良性肿瘤以及低度恶性的结节包括支气管肺 泡癌可以呈假阴性。上图为一例腺癌病人，结节并不显示为高代

17、谢状态，所以 呈假阴性。PETCT: benign versus malignant PETCT pleys en increasingly important role in the evaluation of solitary nodules, When you perform PET-CT, you have to realize the following: PET has a very high sensitivity 95%* but a lesser specificity of only 81% PET is false positive in granulomatous di

18、sease PET is usually false negative in size 10 mm and low-grade malignancy including bronchoalveolar carcinoma and carcinoid With these specificity numbers, there will be false oositi ves in about 20%# de pending on the Dackground prevalence of granulomatous disease. On th皀 I皀ft a patient with an adenocercinomaf that was not nypermetabolic on the PET； so it is afalse negative