File aortic disease

Contrast-enhanced CT• Cobweb sign: slender linear areas of low attenuation that occasionally appear in the false lumen the hematoma in the false lumen • Intimointimal intussusception

Imaging of Aorta disease

Nguyen Khoi Viet, MD

Department of Diagnostic Radiology

Bach Mai Hospital, Hanoi

The aorta is the largest artery

in the body and is the blood

vessel that carries oxygen-rich

blood away from the heart to

all parts of the body.

The section of the aorta that

called the thoracic aorta and,

as the aorta moves down

through the abdomen it is

called the abdominal aorta.

2

4

5

6

7

8

Mass, coracrtation

Aortic Dissection: Classification

Aortic Dissection: tear site

• Intimal tear sites (entry)

- Type A: 1 ~ 2 cm above the sino-tubular junction

involving right lat wall

- Type B: Distal to the origin of the left subclavian artery

Aortic Dissection : CT findings

Contrast-enhanced CT

• Cobweb sign: slender linear areas of low

attenuation that occasionally appear in the

false lumen

the hematoma in the false lumen

• Intimointimal intussusception : when one

lumen wraps around the other lumen in

aortic arch

Aortic Dissectionc; CT finding

Technical Factors

Excellent vascular enhancement is critical !!

- result in false-negative diagnosis.

insufficient scan delay time or delayed contrast enhancement:

- misinterpreted as thrombosis of the false

lumen

Improper timing of contrast material administration

B Streak Artifact

outside the patient

during imaging

C Periaortic Structures

• Superiror pericardial recess

• Left brachiocephalic vein

• Residual thymus

• Atelectasis

• Aortic arch braches,

• Mediastinal veins

• Plerual thickening or effusion

adjacent to the aorta

D Motion Artifact

• Aortic valve incompetency : AR

- ectasia of the aortic valve annulus

Aortic Dissection: Complications

• True lumen resembles a C-shaped envelope that is predominantly concave toward the false lumen

 true lumen collapse d/t high pressure of false lumen

• Tx; fenestration procedure

Dynamic Occlusion

Types of branch-vessel occlusion

• Intimal flap intersects or enters the branch-vessel origin

• Tx: intravascular stent

Types of branch-vessel occlusion

Static Occlusion

2008/08/08 CT angio + 3D coronary, aorta

M/48, abrupt onset of neck and back pain

Bãc t¸ch lo¹i IIIb theo De Bakey, bãc t¸ch vµo §M chËu gèc

• Spontaenous rupture of the vasa vasorum 

IMH (IntraMural Hematoma)

Schematic of aortic layers in IMH shows a hemorrhage

within the media but no intimal tear Red dots inside the

media represent the vasa vasorum

• “Hyperattenuating crescent” on precontrast CT

• No contrast enhancement, smooth margin

Intramural Hematoma ; CT findings

14/03/02 24/03/02 03/07/02

IMH vs Mural thrombus

M/68, Back pain

Penetrating Atherosclerotic Ulcer

PAU (Penetrating Atherosclerotic Ulcer)

Formation of extensive aortic atheroma confined to intimal layer, through lesion progression to deep ulceration of plaque with penetration into media,

to entrance of blood from aortic lumen into media and splitting of media with intramural hematoma

Plaque

ulceration Intimal plaque ulceration Medial hematoma pseudoaneurysm Adventitial Transmural rupture

PAU : Pathogenesis

PAU ; CT findings

CT findings (after CM): collection of contrast material is seen outside the aortic lumen (single or multiple); thickning aorta wall

Aortic Dissection vs PAU

 1. Atherosclerosis (73 - 80%): descending aorta

 2 Traumatic (15 - 20%): following transection

 3 Congenital (2%): aortic sinus, postcoarctation, ductus diverticulum

 4 Syphilis: ascending aorta + arch

 5 Mycotic = bacterial dissection

 6 Cystic media necrosis (Marfan / Ehlers-Danlos syndrome, annuloaortic ectasia)

 7 Inflammation of media + adventitia:

 Takayasu arteritis, giant cell arteritis, relapsing polychondritis, rheumatic fever, rheumatoid arthritis, ankylosing spondylitis, Reiter syndrome, psoriasis, ulcerative colitis, systemic lupus erythematosus, scleroderma, Behcet disease, radiation

 8 Increased pressure: systemic hypertension, aortic valve stenosis

 9 Abnormal volume load: severe aortic regurgitation

34

Aortic Aneurysm

Ph×nh xoang valsava (Marfan syndrome)

Ph×nh §MCB h×nh tói cã nhiÒu v«i ho¸ thµnh

§MC

Atherosclerotic Aneurysm

Ph×nh §MCB h×nh thoi

Rupture of Aortic Aneurysm

M/88, Pulasaging abdominal mass

Emegency repair of AAA

• Bacterial infection of a

diseased aortic wall

• Most often saccular with

focal dilatation

• Eccentric thrombus

• Focal calcification

Mycotic Aneurysm

Common site: aortic isthmus (between aortic arch and descending aorta)

Traumatic aortic injury

Review : Traumatic aortic dissection

• Location

– Aortic isthmus : 90%, just distal to the origin of left subclavian artery

– Ascending aorta : 5%, but 25% of autopsy

• Mechanism : desceleration or crush injuries (motor vehicle injury)

– Shearing stress to mobile aortic arch

– Bending stress as flexed over left main PA and bronchus

– Osseous pinch : squeeze between anterior bony structure and spine

– Torsion stress and water hammer effect to ascending aorta

Overview of traumatic injury of the thoracic aorta/Radiographics 1997;17:27-45

Aortic stenosis

• atherosclerosis

fibrosis

BN n÷, 48 tuæi, l©m sµng vµ siªu ©m doppler nghi hÑp t¾c m¹ch nhiÒu n¬i.

X¬ v÷a huyÕt khèi dµi lan to¶ §M chñ xuèng-chñ bông, cã

vÞ trÝ hÑp nÆng §MCB HÑp gèc §M thËn tr¸i do x¬ v÷a

Takayasus’ arteritis

• a primary arteritis of unknown origin that

• Incidence: 2-3 cases per year per million.

• Young women , M:F=1:10

cell infiltration) marked intimal proliferation and

fibrosis, media scarring & vascularization,

thrombosis, luminal narrowing

Radiographics, 1997:17:579-594

systemic or prepulseless phase

• CT scans: mural thickening and contrast enhancement

changes

(doubling pattern: low inside ring, high outside ring )

• Mural thickness decreases after steroid therapy

late or occlusive phase

• stenosis, occlusion, mural calcification, intraluminal thrombus,

Four kinds of stenosis

Type I- Classic pulseless type that involves the brachiocephalic trunk, carotid arteries, and

subclavian arteries

Type II- Combination of type I and III

Type III- Atypical coarctation type that involves the thoracic and abdominal aortas distal to the arch and its major branches

Type IV- Dilated type that involves extensive dilatation of the length of the aorta and its major

branches

M/54 chest pain

BN nữ, 24 tuổi, đo HA chênh lệch tay-chân, siêu âm doppler mạch cảnh có hẹp ĐM

d-ới đòn và cảnh gốc trái

VRT: Hẹp ĐM d-ới đòn và cảnh gốc trái từ gốc trên một đoạn dàI, bờ

đều.

Hẹp trung bình thân cánh tay

đầu, hẹp nhẹ gốc ĐMCG và d-ới

đòn phải

Cùng bệnh nhân

Hẹp nhẹ gốc ĐM thân tạng Tắc động mạch thận trái

Viêm động mạch

Takayasu

Coarctation of the Aorta

• Congenital obstructive anomaly of the aortic lumen

• Typically occurs in the aortic isthmus, between the

left subclavian artery and the ductus

• More than half of cases show tubular hypoplasia of

the transverse portion of the aortic arch with dilatation

of the supraaortic vessels

• Associated lesions :

– VSD, bicuspid aortic valve

– aneurysms of the ascending aorta, ductus, intercostal

arteries, and circle of Willis,

– stenosis of the left subclavian artery, and aberrant right

subclavian artery

RadioGraphics 2003; 23:S79–S91

M/27, chest pain

2009-01-26

M/54, Sudden abdominal pain

2008-1-17 2008-3-17

• Various pitfalls and artifacts are

potentially confusing the proper

diagnosis.

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