课件：晕轮征-中文版.ppt

影像学晕轮征的诊断学意义,晕轮征-Halo sign,晕轮-自然界常见现象,概述,CT晕轮征：在胸部HRCT上围绕结节影的磨玻璃影。 最初主要用于描述免疫受损患者侵袭性肺曲霉菌病的HRCT特征。 除了感染性曲霉菌病以外，许多肿瘤性及炎症性疾病也可能引起晕轮征。因此，晕轮征本身并无诊断特异性，但结合临床，该征象对诊断有帮助。,机理,晕轮征产生通常意味着是出血性结节，出血的机制包括出血性梗塞、血管炎、新生血管组织、支气管动脉瘘及坏死。 晕轮征也可以由肿瘤细胞或炎症细胞浸润肺实质引起。,感染性疾病与晕轮征,免疫受损患者的侵袭性肺曲霉菌病是最常见的产生CT晕轮征的原因。 CT晕轮征也可以出现在毛霉菌引起的肺侵袭性真菌病。 肺念珠菌及球孢子菌病也可以出血晕轮征。,感染性疾病,CT晕轮征可以产生于诸如肺隐球菌病、疱疹病毒肺炎及巨细胞病毒肺炎导致的肺部炎症细胞浸润。 其他少见的感染也可以导致CT晕轮征：非典型分支杆菌感染、立克次氏体肺炎、粘病毒肺炎及脓毒性肺栓塞。,侵袭性肺曲霉菌病与晕轮征,病理特征为肺部梗塞灶周围的肺泡出血。 曲霉菌血管侵袭性生长导致中小肺血管血栓形成，导致肺实质坏死。,IPA and halo sign,病理与影像学关联：病灶中心坏死部分在CT上表现为结节影，病灶周围的出血灶或出血性梗塞灶在CT上表现为磨玻璃晕轮。 IPA的CT特征为早期多个13cm大小的结节影，周围有晕轮现象。 后期，结节影增大并最终形成表现为新月征的空洞。,IPA and halo sign,IPA患者早期晕轮征比例相当高，晚期则较少见。 在一组25例IPA患者系列CT研究发现，晕轮征在第1天高达96%，而第14天仅有19%患者出现晕轮征。,IPA and halo sign,因此，在抗生素治疗无效的发热粒缺患者中，如果早期CT检查发现晕轮征，高度提示有侵袭性曲霉肺。CT晕轮征甚至出现在检测真菌的血清学阳性之前。,Invasive pulmonary aspergillosis in a 39-year-old man with acute myelogenous leukaemia and neutropenia. Thin-section CT at the level of the lung apex shows multiple nodules surrounded by a halo of ground glass opacity in both upper lobes.,Angioinvasive aspergillosis in a 42-year-old man with acute myelogenous leukemia. (a) Chest CT scan (lung window) reveals a 2-cm nodular lesion with a wide halo of ground-glass attenuation representing adjacent hemorrhage. (b) Photograph of a cut section of the lung demonstrates a rounded tan nodule, a finding that is consistent with pulmonary infarction. (c) Low-power photomicrograph (original magnification, x40; hematoxylin-eosin stain) shows vascular invasion by Aspergillus species (arrows).,Journal of Computer Assisted Tomography Issue: Volume 23(4), July/August 1999, pp 622-626,Invasive pulmonary aspergillosis,毛霉菌与晕轮征,毛霉菌病是一种严重的致死性的机会感染，主要出现在免疫受损患者及伴有糖尿病和肾脏病基础病的患者。这类患者常可出现晕轮征。,念珠菌和球孢子菌病与晕轮征,念珠菌和球孢子菌病较少出现晕轮征 肺念珠菌病通过血源播散形成弥漫性小脓肿、感染栓子及出血性梗塞。 此类念珠菌感染常表现为播散性粟粒样结节影，结节影直径一般小于1cm，这些特点与IPA不同。,隐球菌病,部分免疫受损患者肺隐球菌病可以出现有晕轮征的结节影。 组织学上显示晕轮区域的磨玻璃影代表肉芽肿性炎症反应。,单纯疱疹病毒及CMV肺炎与晕轮征,HSV与CMV肺炎是导致免疫受损宿主死亡的重要原因。 胸部CT表现为间质肺炎样改变、出血性结节影、弥漫性肺损伤及广泛的或者局限性磨玻璃影，少部分患者可出现有晕轮征的结节影。,Cytomegalovirus pneumonia in a 45-year-old woman with rapidly progressive glomerulonephritis. Thin-section CT of the right lung base demonstrates multiple tiny nodules (arrows) with the CT halo sign in the right lower lobe.,肿瘤性疾病,血管肉瘤、绒毛膜癌、骨肉瘤及黑素瘤等富含血管的肿瘤肺转移时可以出现晕轮征结节影，磨玻璃样的晕轮主要是肿瘤新生血管出血导致。,肺卡波西肉瘤,典型的肺卡波西肉瘤CT表现为围绕支气管血管束分布的边界欠清的结节影。少部分患者CT表现为晕轮的结节影。,Kaposi sarcoma in a 29-year-old woman with a history of renal transplantation. Thin-section CT at the level of the carina shows multiple nodules with a surrounding halo of ground glass opacity in both lungs, which are dissimilar to flame-shaped lesions, the classic findings of Kaposi sarcoma.,Cutaneous Kaposi sarcoma in a 34-year-old homosexual man with AIDS. Thin-section CT scan shows multiple hemorrhagic pulmonary nodules with an associated halo sign. Radiographics. 2001;21:825-837.,肺癌,部分肺部鳞癌患者CT也可出现晕轮征结节影。 肺泡细胞癌、肺淋巴瘤及部分转移性肺癌也可以出血CT晕轮征。,Air-Space Pattern in Lung Metastasis from Adenocarcinoma of the GI Tract,Journal of Computer Assisted Tomography Issue: Volume 20(2), March/April 1996, pp 300-304,Bronchioloalveolar carcinoma,BAC常可表现为结节影周围磨玻璃影，文献报告一组22例BAC患者中有2例出现晕轮征。 文献报告BAC更容易在免疫功能正常的患者中出现晕轮征。,BAC与晕轮征,BAC形成磨玻璃影的机制与BAC形成病理方式有关。BAC细胞一般沿着肺泡壁和间隔生长，一般较少向肺泡腔内生长，故不填充肺泡腔。表现为肺泡壁和间隔增厚，形成CT上的磨玻璃影。,BAC,BAC患者在CT上可以出现假空洞样改变，组织学上表现为结节的中心部位肺泡腔内仍然含气，未被肿瘤组织填充。 如果在假空洞的周边出现晕轮征，则高度提示是BAC。,Journal of Computer Assisted Tomography Issue: Volume 23(4), July/August 1999, pp 622-626,Bronchioloalveolar carcinoma,Bronchioloalveolar carcinoma in a 60-year-old woman. Thin-section CT obtained at the level of the bronchus intermedius shows a peripheral pulmonary nodule with the CT halo sign.,淋巴细胞增殖性疾病,肺淋巴细胞增殖性疾病主要表现为肺部多发或者单发结节影。 结节影边缘可以出现肿瘤细胞浸润形成磨玻璃晕轮征。,患者，男，29岁，体检发现肺部病变9月入院，开胸肺活检病理诊断淋巴瘤样肉芽肿病。,其他疾病晕轮征,CT晕轮征也可以在韦格纳肉芽肿、肺部子宫内膜异位症及肺部包囊虫病。,Wegeners granulomatosis,韦格纳肉芽肿可以在肺部形成出血性结节影，表现为晕轮征改变。,Wegeners granulomatosis in a 70-year-old woman. Thin-section CT shows a pulmonary nodule with the CT halo sign in the left lower lobe (thick arrow). Note another nodule in the right middle lobe but without surrounding ground glass opacity (thin arrow) (Courtesy of Kyung Soo Lee, MD, Samsung Medical Center, Seoul, Korea).,Eosinophilic lung diseases,肺部嗜酸细胞疾病（寄生虫相关肺嗜酸细胞增多、特发性嗜酸细胞综合征）可以形成CT晕轮征。 病理组织学改变为中心嗜酸细胞脓肿，外周肺泡腔及间质内炎症细胞浸润。,Simple pulmonary eosinophilia (Loeffler syndrome) in a 42-year-old man with peripheral eosinophilia (53.5% of eosinophils in the peripheral blood). Thin-section CT shows multiple small nodules (arrows) with a surrounding halo of ground glass opacity in the right lower lobe.,Journal of Computer Assisted Tomography Issue: Volume 23(4), July/August 1999, pp 622-626,A pulmonary nodule with halo sign is usually seen in patients with eosinophilic lung diseases including simple pulmonary eosinophilia,Journal of Computer Assisted Tomography Issue: Volume 23(4), July/August 1999, pp 622-626,Parasitic infection,Hypers