Inferior Vena Cava

Hepatic

Portal Vein Non-traumatic Splenic Vein Superior Mesenteric Vein Venous Emergencies Renal Vein

of the Abdomen Inferior Mesenteric Vein

Vinit Baliyan, Anushri Parakh, Sandeep Hedgire, Anand Prabhakar Iliac Vein

*All illustrations by author Ilio-caval Cases Bland IVC in setting of Leiomyosarcoma (*) of the IVC May-Thurner Syndrome inherited hypercoagulopathy with with secondary bland thrombus (arrow) (MTS) thrombus extending above the filter IVC filter (yellow)

*

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Causes Clinical Implications Imaging • Duplex US for DVT in lower extremities 1) Inherited 1) (pulmonary) • CT and/or MR venography 2) Acquired coagulopathy 2) Chronic stasis i. Immobility i. Varices 1) Differentiate acute vs chronic ii. Malignancy ii. Dermatitis and ulcers i. Acute-expanded vein, wall enhancement, iii. Myeloproliferative disorders iii. Male infertility due to stranding iv. Recent surgery ii. Chronic-eccentric thrombus, narrow vessel 3) Local tumor invasion 3) Extension to visceral caliber, calcifications, webs, collaterals / varices i. Renal / hepatic cancers tributaries ii. Primary IVC leiomyosarcoma Management 2) Bland vs Tumoral thrombus 4) Compression syndromes 1) Anticoagulation, IVC filter i. Tumor thrombus-greater degree of venous 1) May-Thurner (MTS) 2) Mechanical thrombectomy expansion, thrombus vascularity, diffusion Pubic Varices 3) Venous stenting/bypass-MTS restriction, metabolically active on PET Visceral Caval Tributary Thrombosis Cases Renal Vein Thrombosis in Budd Chiari Syndrome with hepatic vein attenuation (yellow), reduced peripheral Behçet Syndrome enhancement (purple), increased central enhancement (*) and ascites

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Causes Clinical Implications Imaging General 1) Inherited coagulopathy Budd Chiari Budd-Chiari- Multiphase CT and/or MR 2) Acquired coagulopathy 1) Hepatic dysfunction, hepatic failure i. Acute-Venous occlusion, hepatosplenomegaly, ascites, i. Dehydration 2) Cirrhosis, regenerative nodules, hepatocellular decreased peripheral parenchymal and increased central ii. carcinoma parenchymal enhancement 3) Local tumor invasion 3) Portal and its sequelae ii. Subacute/chronic-Atrophy with caudate hypertrophy, i. Renal / hepatic cancers arterialized peripheral blood flow, collaterals, Specific Renal Vein Thrombosis regenerative nodules, venous calcifications 1) Budd Chiari Syndrome – Congenital 1) Acute renal failure (webs), myeloproliferative disorder, 2) Renal atrophy Renal vein thrombosis- Doppler, CT/MR angiography local tumors and abscesses 3) Papillary necrosis i. Acute-Nephromegaly, reversal of diastolic arterial flow, 2) Renal Vein Thrombosis – nephrotic increased RI, vein thrombus, venous infarction, persistent syndrome, sickle cell, renal abscess cortical enhancement and reduced/lack of enhancement ii. Chronic-Atrophy, collaterals, venous calcifications Porto-splanchnic Thrombosis Cases SMV thrombus with Secondary venous gas due IMV thrombosis (purple) secondary to bowel ischemia to bowel ischemia sigmoid diverticulitis (yellow)

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Causes Clinical Implications Imaging Superior mesenteric vein (SMV) 1) Inherited coagulopathy • Multiphase CT and/or MRI 2) Acquired coagulopathy 1) Mesenteric congestion and bowel wall SMV thrombosis i. Idiopathic i. Acute – Venous occlusion, bowel wall thickening, ii. Cirrhosis 2) Bowel ischemia dilation, mesenteric fat stranding, ascites and hyper- iii. Pancreatitis enhancement. Bowel infarction with pneumatosis, iv. Myeloproliferative disorders venous luminal air and lack of enhancement v. Abdominal surgery 1) Findings of SMV thrombosis ii. Subacute/chronic –Recanalization of vessel, collateral 3) Local tumor invasion 2) Splenic congestion formation, venous calcifications i. HCC* 3) Porto-systemic collaterals Portal vein thrombosis *Tumor thrombus- vein expansion i. Acute –thrombosis, splenomegaly, vein thrombus, Splenic vein thrombosis greater degree, thrombus vascularity, absent/decreased flow diffusion restriction, hot on PET 1. Isolated splenomegaly with ii. Chronic- Cavernoma, venous calcifications, Porto- systemic collaterals Variceal Hemorrhage Cases Peristomal venous hemorrhage in with dilated anterior abdominal (yellow) and dilated SMV tributary

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CECT-Ven CECT-Ven (MIP) (MIP) CECT-Arterial CECT-Ven Causes Clinical Implications Imaging • Multiphase CT and/or MRI Esophageal/gastric varices are Esophageal varices commonly seen in the setting of chronic 1) Life threatening hemorrhage portal hypertension. These can bleed. Esophageal varices Serpiginous vessels around gastroesophageal Stomal varices junction. Additional collaterals at porta hepatis, Variceal hemorrhage is a life threatening 1) Rare entity emergency and imaging is not typically perisplenic, periumbilical and perirectal 2) Bowel ostomies recruit mesenteric vasculature locations. In active hemorrhage, brisk performed in patients with suspected (branches of SMV) in close proximity with systemic variceal bleed. extravasation is seen on venous/delayed veins in the abdominal wall. Therefore, in long phases that is absent on arterial phase standing cases, this is a potential site for Stomal varices Variceal hemorrhage is rarely seen on development of portosystemic shunts cross sectional imaging. Serpiginous vessels around the stoma with 3) Peristomal varices are a rare cause of stomal site dilated anterior abdominal wall collaterals and bleed dilated adjacent SMV tributary @baliyan_vinit Pitfalls and Artifacts @AnushriParakh

Case: Apparent filling defect in intrahepatic IVC (black) due to admixing of unenhanced blood from infrarenal IVC (yellow) and enhanced blood from renal veins (purple).

Clinical Implication: May be falsely called as thrombus

Mitigate: By performing delayed imaging, typically at 2 minutes, to CECT-Ven CECT-Ven differentiate from true thrombosis

Case: ; Post renal vein bypass. Apparent thrombosis of a large gonadal vein (purple) on venous phase CT, that is bright on T2W. Delayed phase MR post contrast CECT-Ven administration demonstrates enhancement.

Mitigate: Additional delayed phases in a setting of a large venous channel fed by a small organ/territory. CECT-Ven T2W CE-MR Thank You [email protected]; [email protected]