Vascular Dilatation or Inflammation

KEY FACTS

• Intravascular papillary endothelial hyperplasia

Organizing thrombus with excessive reactive papillary endothelial proliferation

Predilection for subcutaneous tissues of extremities, particularly upper limbs

Focal vascular dilatation with intraluminal mass

– Hypoechoic compared with subcutaneous fat

– Hyperechoic septum (70%)

– Little or no color flow (30%); moderate (40%); high color flow (30%)
• Superficial thrombophlebitis

Thrombosed vein surrounded by halo of hyperechoic edematous subcutaneous fat; ± perivascular hyperemia
• Venous varix

Focal dilatation of vein
• Intravascular organized hematoma

Focal hypoechoic to hyperechoic lesion within lumen

– i.e., hematoma-like lesion within vein

– No flow on color Doppler imaging
• Pseudoaneurysm

Hypoechoic or anechoic perivascular mass

– Neck connects pseudoaneurysm lumen to artery

– Characteristic to-and-fro flow pattern at neck of pseudoaneurysm

– Characteristic yin-yang sign within pseudoaneurysm sac

– Thrombus or slow flow within pseudoaneurysm sac also occasionally seen
• Kimura disease

More common in Asians

Fusiform-shaped hypoechoic tumor of arterial wall

– Variable intratumoral hyperemia

• US is best imaging modality for all focal vascular abnormalities, provided vessel accessible

• Intravascular papillary endothelial hyperplasia (IPEH) : Masson tumor, Masson hemangioma, intravascular angiomatosis, vegetant intravascular hemangioendothelioma
• Pseudoaneurysm : False aneurysm

• IPEH

Organizing thrombus with excessive reactive papillary endothelial proliferation
• Superficial thrombophlebitis

Inflammation of superficial vein
• Venous varix

Focal dilatation of vein
• Intravascular organized hematoma

Organized hematoma within vessel, usually vein
• Pseudoaneurysm

Luminal outpouching of artery with

– Defect in tunica intima and media and preservation of tunica adventitia

– Or full-thickness wall defect with bleeding contained by hematoma and surrounding soft tissues
• Kimura disease

Inflammatory response associated with self-limiting allergic or autoimmune reaction to unknown stimulus

• IPEH

T1WI: Isointense mass with node-like hyperintense foci

T2WI: Heterogeneous hyperintense mass with node-like hypointense foci
• Intravascular organized hematoma

Signal intensity depends on age of hematoma
• Pseudoaneurysm

T1WI

– Pseudoaneurysm luminal flow void

– High signal in methemoglobin-containing portions of surrounding hematoma

MRA

– Contrast-enhanced MRA preferred to time-of-flight or phase-contrast technique because of superior signal:noise ratio

– Double to triple dose gadolinium typically used

Apr 9, 2020 | Posted by admin in MUSCULOSKELETAL IMAGING | Comments Off