Vascular Imaging

Draped aorta sign	Draped aorta sign: posterior wall of the aorta either is not identifiable or closely follows vertebral bodies
Hyperattenuation crescent sign	• Hyperattenuation crescent sign: welldefined peripheral crescent of increased attenuation within the thrombus of a large aneurysm indicates acute or impending rupture
loss of “wink” sign	Noncompressibility of vein (loss of “wink” sign) DVT
popliteal “dog-leg” sign (aCute bend in the lumen of the popliteal artery)	• Popliteal aneurysm: Most common peripheral arterial aneurysm. 50% of aneurysms are bilateral, and 80% are associated with aneurysm elsewhere. Commonly due to atherosclerotic disease or trauma. Angiography may show luminal dilatation or mural calcification. 25% of popliteal artery aneurysms may not be associated with visible arterial dilatation by angiography. In these cases, secondary signs such as the “dog-leg sign” (acute bend in lumen of the popliteal artery) may be helpful. Complications of aneurysm include distal embolization and thrombosis, resulting in ischemia. Rupture is uncommon.
Popliteal “dog-leg” sign (acute bend in the lumen of the popliteal artery)	• Popliteal aneurysms (if bilateral, 80% also have AAA) • Tortuous artery • Popliteal artery entrapment syndrome (accentuated arterial narrowing with passive dorsiflexion or active plantar flexion at arteriography) • Adventitial cystic disease (no flow on US) • Baker's cyst (no flow on US)
pseudovein” sign	Extravascular contrast extravasation is the hallmark of active bleeding. Accumulation in bowel lumen Gastric “pseudovein” sign (contrast between rugal folds) Filling of pseudoaneurysm or pooling upper gi hemorrhage
Vascular Complications of Ehlers-Danlos Syndrome CT Angiography and 3D mapping	Ehlers Danlos Syndrome EDS: group of clinically and genetically heterogeneous heritable connective tissue disorders; characterised by joint hypermobility, skin hyperextensibility, tissue fragility; six forms of EDS are currently recognised; disease related symptoms vary based on each EDS type Vascular EDS (type IV), AD; heterogeneous mutations in the COL3A1 gene and encoding for Type III procollagen; Excessive tissue fragility predisposing to premature arteria;, intestinal or uterine rupture 2 of 3 Major criteria: Thin translucent skin; Arterial, intestinal, uterine fragility or rupture; extensive bruising; characteristic facial appearance Minor criteria: Acrogeria (slender face, sunken cheeks, thin nose and lips); Hypermobility of small joints; tendon and muscle rupture; talipes equiovarus; anteriovenous, carotid-cavernous sinus fistula; pneumothorax, pneumohemothorax; gingival recession; positive family history, sudden death in close relative Patients deveop vascular lesions at a young age; aneurysms, dissection, occlusion, stenosis; lesions frequently involve multipe vascular segments; can be isolated to a single vascular segment; frequently involve abdominal viseral arteries; iliac arteries; thoracic and abdominal aorta Complications: Spontaneous aneurysm rupture; progression of pre-existing aneurysms; development of new aneurysms; dissection and vascular occlusions
Vascular sign	Vascular sign; acute embolus in a dilated vessel leading to apex of consolidation
Vessel cutoff sign rim sign on axial and tramtrack sign on long axis view	CT Pulmonary Angiography (CTPA) Direct findings of PE • Direct visualization of filling defect • Vessel cutoff sign: distal artery is not opacified due to occlusive embolus • Occluded artery is larger than the normal artery on the opposite side • Partial occlusion can cause rim sign on axial and tramtrack sign on long axis view Indirect findings of PE • Pulmonary hemorrhage; usually resolves in a week