主动脉急症的CT诊断.ppt

1、急诊室经常遇到的急性主动脉疾病,内容,急性主动脉综合征 主动脉夹层（AD） 壁内血肿（IMH） 穿透性溃疡（PAU） 主动脉瘤 胸，腹破裂和即将破裂的迹象,Acute Aortic Syndrome - Aortic Dissection (AD) Intramural Hematoma (IMH) Penetrating Atherosclerotic Ulcer (PAU) Aortic Aneurysm Thoracic, Abdominal Rupture and Impending Rupture Signs,AORTIC DISSECTION主动脉夹层,Most common ca

2、use of acute aortic syndrome (70%) An intimal tear with separation of the aortic media into two layers 急性主动脉综合征最常见的原因（70%） 主动脉壁内膜被分离成两层,Classification 分类,Type A Dissection,Type B Dissection,Type A: 90% die within 3 months if not treated urgent operation Type B: medications or interventional treatmen

3、t,A型：如不紧急手术治疗，三个月内死亡率大于90%； B型：药物或介入治疗,60%70%,30%40%,Chest Radiographic Findings胸片表现,normal in 10-40% widened mediastinum 61.1% displacement of aortic calcification 14.1% abnormal cardiac contour 25.8%,正常10-40% 纵隔增宽61.1% 主动脉钙化14.1% 心脏异常轮廓25.8%,Role of MDCT angiography动脉CTA作用,(1) Sites of primary ent

4、ry and re-entry; (2) Intimomedial flap, false and true lumen; (3) Extent of the dissection (4) Evidence of rupture; (5) Involvement of the aortic branches; (6) Abdominal aortic branch patency and evidence of end-organ malperfusion; (7) Morphology and diameter of the aorta along with the patency, siz

5、e and tortuosity of the iliac and femoral arteries (useful for endovascular treatment planning),(1) 破裂入口和出口; (2) 内膜片，真假腔 (3) 夹层的程度 (4) 破裂的证据； (5) 主动脉分支受累； (6) 腹主动脉分支通畅和终末器官灌注不良的证据； (7) 沿着通畅主动脉的形态和直径，髂动脉和股动脉的大小和扭曲（有助于血管内治疗计划）,Unenhanced CT 平扫,Unenhanced CT: - internal displacement of intimal calcific

6、ations Contrast-enhanced CT:- intimal flap that separates the true lumen from the false lumen,CT平扫钙化内膜内移 增强CT内膜片分离出真假腔,Classification： Stanford type A,Stanford type B,False lumen Larger cross sectional area ( Pfalse Ptrue ) Delayed enhancement/ thrombosis Beak sign；Cobweb sign True lumen: its contin

7、uity with an undissected portion of the aorta,Cobweb sign,Beak sign,假腔 截面积大 ( 假腔 真腔 ) 延迟强化/血栓形成 Beak sign；Cobweb sign 真腔: 一直延续,Complications of Thoracic AD并发症,Acute aortic regurgitation Major arch vessel obstruction, coronary artery involvement,Aortic rupture pericardium tamponade, left pleural cavi

8、ty, mediastinum,急性主动脉瓣关闭不全 主动脉弓阻塞 冠状动脉受累,主动脉破裂 心包填塞，左胸腔、纵隔,Complications of Abdominal AD并发症,Main abdominal arterial branch involvement Aortic rupture: hemoperitoneum,1主腹动脉分支受累2主动脉破裂腹腔积血,Malperfusion灌注不良,Mortality 死亡率: 3850% Incidence Main coronary artery 4.77% 主冠状动脉 Carotid 6.628% 颈动脉 Subclavian art

9、ery 5.617% 锁骨下动脉 SMA2.311.9% 肠系膜上动脉 Renal artery 3.212.4% 肾动脉 Intercostal a. for spinal circulation 1.86.8% 肋间动脉如脊髓循环 Iliofemoral artery 13.230% 髂股动脉,Branch Vessel Obstruction分支血管阻塞,Static Occlusion: Intimal flap enters the branch vessel origin Thrombus formation in the false lumen Dynamic Occlusion

10、: Intimal flap covers the vessel origin like a curtain Artery arising from the true lumen is compromised,静态闭塞：内膜片进入分支血管的起始处，血栓形成在假腔 动态闭塞：内膜片像窗帘覆盖血管起始处，起源真腔的动脉受到损害,Dynamic occlusion:动态闭塞 - true lumen resembles a C-shaped envelope that is predominantly concave toward the false lumen - treated with a f

11、enestration procedure,Types of branch-vessel occlusion分支血管闭塞的类型,Static occlusion:静态闭塞 - intimal flap intersects or enters the branch-vessel origin - treated locally with an intravascular stent,Types of branch-vessel occlusion,陷阱Pitfalls of MDCT,Non ECG-gated CT: motion artifact pericardial recess mu

12、ral thrombus in a fusiform aneurysm Periaortic fibrosis or mediastinal, pulmonary, or retroperitoneal tumors,Pericardial Recess,ECG-gated Vs. Non- ECG-gated,Management of acute aortic dissection,How to write report,Extent of dissection Location of intimal tear Identification of true/false lumen Malp

13、erfusion : side branch involvement Associated findings,INTRAMURAL HEMATOMA壁间血肿,Spontaneous rupture of the vasa vasorum in the aortic wall A blood collection within the aortic wall with restricted flow / “dissection with restricted flow”,Precontrast CT, narrow window “Hyperattenuating crescent” on pr

14、econtrast CT No contrast enhancement, smooth margin 30% rate of progression to overt aortic dissection,Acute Intramural Hematoma急性壁间血肿,Subacute Intramural Hematoma亚急性壁间血肿,Subacute and chronic IMH ( 1 week after the onset of symptoms ) Decreased attenuation (identical to that in intraluminal blood),D

15、ifferentiation of acute IMH from mural thrombus or thrombosed false lumen seen in AD,Mural thrombus: more irregular lumen, non-displaced intimal calcification, more common in abdominal aorta, associated with aneurysm 附壁血栓： 更不规则腔，非移位性内膜钙化，更常见于腹主动脉， 合并动脉瘤,IMH,AD w/ thrombosed false lumen,Mural thrombu

16、s,AD false lumen thrombosis: multilayered pattern of increasing attenuation intimal flap (when you scroll up and down.),RadioGraphics 2009; 29:791804,AD,Natural history of IMH,10%,16-47%,20-45%,Can resolve：followed 2 months.,(a) Unenhanced axial CT image obtained at presentation depicts a type B aor

17、tic intramural hematoma (arrow). (b) Contrastenhanced axial CT image obtained 1 month later shows an enhancing ulcerlike projection (arrow), a finding suggestive of a new intimal tear. (c) Contrastenhanced axial CT image obtained 2 months later shows overt dissection(arrow).,Can progress to dissecti

18、on with ulcer like projection and dissection,Can progress to fusiform aneurysm 可进展为梭形动脉瘤,(a, b) Unenhanced axial CT images obtained at presentation depict a type B hematoma. (c) Contrast- enhanced axial CT image obtained 2 years later shows a fusiform aneurysm at the site of the initial aortic intra

19、mural hematoma.,F/70 acute chest and upper back pain,2008-02-18 CT Angiography,Observation acute chest pain,2008-04-26 CT Angiography,Differential Diagnosis鉴别诊断,Pericaridal recess Aortitis: diffuse, circumferential involvement Retroperitoneal fibrosis or periaortic lymphoma Thickened aortic wall enh

20、ances More commonly involve abdominal aorta Circumferential,Retroperitoneal fibrosis,Pericardial Recess,pericaridal隐窝 主动脉炎：弥漫，环周受累 腹膜后纤维化或腹主动脉旁淋巴 主动脉壁增厚 更常见的涉及腹主动脉环,F/23 palpitation, HA,2010-07-07 CT Angiography,40HU,75HU,Takayasus arteritis,Type B IMH Primarily conservative Surgery or stent-graft i

21、f recurring, refractory chest pain, evidence of increasing extent and diameter Type A IMH Emergency operation if there is cardiac tamponade, impending rupture, or rupture Conservative treatment,How to write report,Extent of IMH: type A or B Presence/absence of PAU or intimal tear If present, locatio

22、n of PAU or intimal tear Signs of rupture/ progression,PENETRATING AORTIC ULCER穿透性溃疡,Ulceration of atherosclerotic plaque - Disruption of the aortic media - Medial hematoma formation, localized - Potential for rupture - False aneurysm formation Mid-thoracic or distal descending aorta,Definition: ulc

23、eration of an aortic atherosclerotic plaque penetrating through the internal elastic lamina into the media。主动脉粥样斑块溃疡穿透内弹性膜进入管腔,Plaque ulceration 斑块溃疡,Adventitial pseudoaneurysm 血管外膜假性动脉瘤,Transmural rupture 透壁破裂,Intimal plaque ulceration 内膜斑块溃疡,Medial hematoma 内侧血肿,Penetrating Atherosclerotic Ulcer穿透

24、性溃疡,Natural history of PAU,Initial diameter 20mm or depth 10mm,CT Findings,Focal contrast-material-filled pouch communicating with the aortic lumen but extending outward beyond its expected aortic wall boundaries,M/88 acute Lt. chest pain, underlying AGC,2005-05-06 Chest CT,42/51,DDx of Aortic Ulcer

25、ation,Atheromatous Ulcer No extension beyond expected margin of aortic wall No hematoma PAU Acute, life threatening Sometimes with IMH, hematoma or soft tissue infiltration Irregular margin IMH Concentrically located collection of blood within media smoothly AD Intimal flap extends across aorta Leng

26、th more extensive,Aortic Aneurysm,Thoracic aortic aneurysm Permanent abnormal dilation of the aorta 1.5 more than normal diameter 5cm in diameter Normal value: Asc TA 3cm in diameter,46/65,Aortic Aneurysm,Causes Atherosclerosis Marfans Aortitis Takayasus Behcets Giant cell Mycotic Syphylitic Traumat

27、ic True vs. pseudo Fusiform vs. Saccular,47/51,Abdominal Aortic Aneurysm,Op indication Diameter over 5.5 cm Rapid size increase 7mm/6month 10mm/1 year Annual risk of rupture 8 cm 40-60%,48/51,Impending Rupture,Pain Growing: 1cm/ 6mo Perianeurysmal hemorrhage Hyperdense cresent IMH or intrathrombic h

28、emorrhage Density heterogeneity of intramural thrombi Eccentric lumen with thin wall Focal discontinuity of cal. Rim Recently abrupt break,Findings of Impending Rupture,Increased aneurysm size ：diameter 7cm + acute symptoms（TAA 6 cm, AAA 7.2 cm ） Thrombus and calcifications : thrombus to lumen ratio

29、 decreases as aneurysm increase； thick circumferential thrombus is protective against rupture Hyperattenuating crescent sign : acute or impending rupture ( refer to PRECONTRAST CT! ) Draped aorta sign : contained rupture,Findings of Aneurysm Rupture动脉瘤破裂表现,TAA: Hemopericardium, Hemomediastinum, Hemo

30、thorax (Lt)心包、纵膈、胸腔积血 Aortobronchial, Aortoesophageal fistula AAA: Retroperitoneal hematoma ( Periaortic blood extending into the perirenal, pararenal space or psoas muscles ) Aortoenteric fistula Extravasation: immediate or delayed findings Focal discontinuity in circumferential calcifications unst

31、able or ruptured aneurysm,51/51,Impending Rupture 先兆破裂,M/70,Aneurysm rupture in a 65-year-old man. Nonenhanced CT scan shows a ruptured atherosclerotic aneurysm of the descending thoracic aorta. Note the high-attenuation fluid in the left pleural space, a finding that represents acute hemothorax.,Ao

32、rtobronchial fistula 主动脉支气管瘘,Aortoesophageal fistula 食管主动脉瘘,2011-11-07 outside CT,M/73 Hemoptysis,Aortoenteric fistula,59/51,Infrarenal AAA,Hyperdense crescent rim vs. Acute IMH高密度新月形边缘与急性IMH,Histologically, hyperdense crescent rim seen at CT in large abdominal aortic aneurysm is caused by fresh blo

33、od that first insinuates itself into the mural thrombus and later penetrates into the aortic wall IMH is caused by hemorrhage within the aortic wall AAA is more commonly associated with a chronic IMH than with an acute or subacute one Hyperattenuating crescent in association with fusiform aneurysm i

34、s discordant with subacute or acute IMH,Impending rupture；Increased size of infrarenal AAA6.5cm - 7.1cm.,M/68 abdominal pain,2008-11-27 CT Angiography,Impending rupture. Contained rupture cases Increased size of infrarenal AAA 6.5cm - 7.1cm.,How to write report,Extent of aneurysm Serial change of an

35、eurysm size Proximal neck length (from left renal artery: AAA) Feature of impending rupture Associated findings,Infected (Mycotic) Aneurysm感染（真菌）动脉瘤,most often pseudoaneurysm, prone to rupture (53-75%) endocarditis related septicemia / direct propagation from adjacent vertebral OM, renal or psoas mu

36、scle abscess. Findings saccular shape, lobular contours, eccentric thrombus periaortic inflammation, abscess, and mass periaortic gas and adjacent vertebral body abnormalities due to the spread of infection fast expansion over time,39067380 F/73 For fever focus w/u,2010-01-28 Abdomen CT,SUV 3.8,2010

37、-03-11 CT Angiography,42231815 M/71 chest pain,2011-09-12 outside Chest CT,HU 20,2011-10-13 CT Angiography,Traumatic Aortic Injury (TAI)外伤性主动脉损伤,Severe deceleration High speed motor vehicle accident Fall from a great height Immediate death in 80-90% Untreated: 1% per hour for 48 h,Two Theory,Shear btw fixed arch/mobile descending aorta,Osseous pinch btw spine/anterior bony complex,RadioGraphics 1997;27,Traumatic Aortic Injury,Traumatic Aortic Injury (TAI)外伤性主动脉损伤,Most common sites Aortic isthmus (