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182 Cards in this Set
- Front
- Back
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Why do you need to know the vascular structures within the abdomen? |
Landmarks Abnormalities |
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What is the function of the vascular system? |
Transport gases and nutrient materials to tissues Transport waste products from cells to appropriate sites for excretion |
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What three layers comprise the arteries and veins? |
Tunica intima Tunica media Tunica adventitia |
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What three layers comprise the layers of the tunica intima? |
A layer of endothelial cells lining the arterial passage A layer of delicate connective tissue An elastic layer made up of a network of of elastic fibers |
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What comprises the tunica media? |
Smooth muscle fibers with elastic and collagenous tissue |
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What comprises the tunica adventitia? |
Loose connective tissue with bundles of smooth muscle fibers and elastic tissue |
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What is the vasa vasorum? |
Tiny arteries and veins that supply the walls of blood vessels |
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What are arteries? |
Hollow elastic tubes that carry blood away from the heart Enclosed within a sheath that includes a vein and nerve |
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What do smaller arteries contain compared to larger arteries? |
Less elastic tissue More smooth muscle |
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Will the AO change in diameter with respiration? |
No |
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What are veins? |
Hollow collapsible tubes with diminished tunica media Carry blood toward the heart Have larger total diameter than arteries Contain special semilunar valves that prevent backflow |
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Does the IVC change in diameter with respiration? |
Yes, it will dilate slightly |
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What aides venous return? |
Muscle contraction Valves Overflow from capillary beds Force of gravity Suction from negative thoracic pressure |
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What are arterioles? |
Small diameter arteries in the microcirculation Branches out from arteries and leads to capillaries |
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What are capillaries? |
Minute, hair-sized vessels connecting the arterial and venous systems Their walls have only one layer |
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What is the principle artery in the body? |
The AO |
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What are the five sections of the AO? |
Root Ascending Descending Abdominal Bifurcation into iliac arteries |
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What is the measurement of the AO? |
Men: 20.2 +/- 2.5 Women: 17.0 +/- 1.5 |
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What is the measurement of the CIA? |
Men: 13.2 +/- 2.0 Women: 12.0 +/- 1.3 |
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What is the measurement of the CFA? |
Men: 10.9 +/- 1.5 Women: 9.6 +/- 1.0 |
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What is the root of the aorta? |
Arises from the left ventricle Comprised of three semilunar valves |
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What do the semilunar valves of the aortic root do during ventricular systole? |
Open to allow blood to be ejected into ascending aorta |
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What do the semilunar valves of the aortic root do during ventricular diastole? |
Close to prevent blood flowing back into left ventricle |
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Where do the coronary arteries arise? |
Superiorly from the right and left coronary valves |
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What is another word for valve? |
Leaflet Cusp |
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Where does the ascending aorta start? |
Ascends a short distance from the ventricle and arches superiorly to form aortic arch |
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Which branches arise from the aortic arch? |
Brachiocephalic (right innominate) Left common carotid Left subclavian |
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Which arteries supply blood to the head, neck, and upper extremities? |
Brachiocephalic (right innominate) Left common carotid Left subclavian |
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Where does the descending aorta flow to? |
Posterior to the heart and through the thoracic cavity, where it pierces the diaphragm |
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Where does the abdominal aorta flow to? |
Anteriorly to the vertebral column to the fourth lumbar vertebrae |
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Where does the aorta bifurcate into the right and left common iliac arteries? |
The level of the fourth lumbar vertebrae |
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Which vessels arise from the abdominal aorta? |
Phrenic arteries Celiac trunk SMA Renal arteries IMA |
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Where does the Phrenic artery arise from and what does it supply? |
Arise from the lateral walls of aorta Supplies the undersurface of the diaphragm |
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What surrounds the celiac trunk? |
Liver Spleen IVC Pancreas |
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What does the celiac trunk branch into? |
Common hepatic Left gastric Splenic |
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What are the anterior branches of the abdominal AO? |
Celiac trunk Common hepatic Gastroduodenal Right and left gastric Splenic |
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Where does the gastroduodenal artery arise from? |
Common hepatic artery |
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Where does the right gastric artery arise from |
Hepatic artery proper Common hepatic artery (less common) |
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What five branches of the SMA supply the small bowel? |
Inferior pancreatic Duodenal Colic Ileocoloc Intestinal |
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What part of the small bowel do the branches of the SMA supply? |
Cecum Ascending colon Transverse colon Small intestine |
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What is the path of the SMA? |
Posterior to the neck of the pancreas and anterior to the uncinate proces Branches into the mesentery and colon |
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What do the renal arteries branch into? |
Anterior branch Inferior suprarenal ateries |
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What is the path of the right renal artery? |
Posterior to the IVC to the right kidney |
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Where do the renal arteries enter the kidneys? |
Posterior to the renal veins |
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Where does the gonadal artery arise from? |
Inferior to the renal arteries |
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What is the path of the gonadal artery? |
Courses along psoas muscle to respective gonadal area |
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At what level of the spine does the IMA arise? |
L3 to L4 about 3-4 cm to aortic bifurcation |
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What are the main branches of the IMA? |
Left colic Sigmoid Superior rectal |
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What do the branches of the IMA supply? |
Left transverse colon Descending colon Sigmoid colon Rectum |
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What do the common iliac arteries divide into? |
Internal and external iliac arteries |
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What do the branches of the internal iliac artery supply? |
Pelvic viscera Peritoneum Buttocks Sacral canal |
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What does the internal iliac artery branch into? |
Anterior and posterior branches |
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What branches come off the external iliac artery before it becomes the femoral artery? |
Inferior epigastric Deep circumflex iliac |
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What is the artery posterior to the knee called? |
Popliteal artery |
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Where does the popliteal artery arise from? |
Femoral artery |
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What does the popliteal artery branch into? |
Anterior and posterior tibial arteries |
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What are the three anterior tributaries of the IVC? |
hepatic veins |
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What are the three lateral tributaries of the IVC? |
Right suprarenal vein (left suprarenal drains into left renal) Renal veins Gonadal vein |
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What are the five lateral abdominal tributaries of the IVC? |
Inferior phrenic vein 4 lumbar veins |
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What are the three veins of origin for the IVC? |
2 common iliac veins Median sacral vein |
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What vessels form the portal vein? |
SMV Splenic |
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Where does the portal vein form? |
Posterior to the pancreas |
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How long is the trunk of the portal vein? |
5-7 cm |
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What does the portal vein branch into? |
Right and left branches |
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Where does the portal vein drain blood from? |
GI tract Lower end of esophagus to upper end of anal canal Pancreas Gallbladder Bike ducts Spleen |
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What gives the portal vein an echogenic wall? |
A connective tissue sheath |
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What is the splenic vein? |
A tributary of the portal circulation |
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What vessels join the splenic vein? |
Short gastric vein Left gastroepiploic vein |
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What is the path of the splenic vein? |
Along the posteromedial border of the pancreas |
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What are the tributaries of the portal vein? |
Pancreatic Left gastroepiploic Short gastric |
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Where does the portal vein drain blood from? |
Stomach Spleen Pancreas |
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What is the path of the SMV? |
Anterior to the third part of duodenum and posterior to neck of pancreas where it joins splenic vein to form MPV |
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What veins drain into the SMV? |
Middle colic vein Right colic vein Pancreatic duodenal vein |
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Where does the IMV drain blood from? |
Left third of the colon and upper colon |
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Where does the IMV ascend to? |
Retroperitoneally along the left psoas muscle |
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Where does the IMV begin? |
Midway down the anal canal as the superior rectal vein |
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What are the tributaries of the IMV? |
Left colic Sigmoid Superior rectal |
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Where do the renal veins originate? |
Anterior to the renal arteries At level of L2 |
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Which renal vein is larger? |
Left renal vein |
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What vessels drain into the left renal vein? |
Left adrenal Left gonadal Lumbar |
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So any vessels drain into the right renal vein? |
No |
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Why is the aorta examined? |
To document the presence of aneurysmal dilation |
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When is the aorta considered aneurysmal? |
With a diameter > 3 cm With focal dilation of the vessel |
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When are the iliac considered aneurysmal? |
With a diameter > 2 cm |
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What are the clinical reasons for a sonographic evaluation of the AO? |
Pulsatile abdominal mass Abdominal pain radiating to the back Abdominal bruit Hemodynamic compromise in the lower legs |
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What conditions can affect the arterial system? |
Atheroma Aneurysm Connective tissue disorder Rupture Thrombosis Infections |
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What are some possible sonographic findings of the AO? |
Normal AO Ectasia Tortuous AO Aneurysm |
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What is the protocol for a vascular scan? |
NPO for at least 6 hours 4, 3, 2.5 KHz Supine or decubitus position |
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At what level is the AO proximal? |
Level of the celiac trunk, celiac artery, and SMA |
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At what level is the AO mid? |
Half way between proximal and distal Inferior to renal arteries |
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At what level is the AO distal? |
Above bifrucation |
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At what level should TRV scans of the AO be taken? |
At diaphragm superior to the renal arteries Inferior to the renal arteries At the bifurcation |
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Where do lymph nodes lie? |
Anterior to the vessels |
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How is the IVC imaged compared to the AO? |
Anteriorly |
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What is an aneurysm? |
A permanent localized dilation of an artery A diameter > 1.5 times its normal diameter |
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What are the types of aortic aneurysms? |
Bulbous Saccular Dumbbell |
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What is a true aneurysm? |
Forms when the tensile strength of the wall decreases Secondary to underlying diseases |
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What are some underlying diseases of a true aneurysm? |
Morgan syndrome Ehlers-Danlos syndrome Familial aortic dissection Annuloaortic ectasia Intimomedial mucoid degeneration |
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What is a pseudoaneurysm? |
A pulsatile hematoma that results from the leakage of blood into soft tissue abutting the punctured artery With subsequent fibrous encapsulation and failure of the vessel wall to heal Blood escapes through a hole in the intima of the vessel wall but is contained by the deeper layers of the AO or by adjacent tissue |
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What percentage of aneurysms are infrarenal? |
95% |
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What condition is common with a larger aneurysm? |
Mural thrombus |
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What is a pseudoaneurysm the result of? |
Trauma |
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What is a mycotic aneurysm the result of? |
Infection |
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When is surgery considered for an aneurysm? |
When the diameter is > 5 cm |
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What is a berry aneurysm? |
A small spherical aneurysm of 1-1.5 cm Looks like a berry Seen mostly in the brain |
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What is a saccular aneurysm? |
Aneurysm connected to vascular lumen by a mouth that may be as large as an aneurysm Spherical and large 5-10 cm Partially or completely filled with thrombus |
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What is a fusiform aneurysm? |
Most common Gradual dilation of vascular lumen May be eccentric so one aspect of wall is more severely affected |
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What are the risk factors of aortic aneurysms? |
Tobacco Hypertension Vascular disease COPD Family history for AAA |
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What are the factors which predispose an aneurysm? |
Arteriosclerosis Trauma Congenital Smoking Obesity High blood pressure High cholesterol Mycotic Cystic medial necrosis Inflammation of media or adventitia Abnormal volume load |
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What are the causes of AAA? |
Atherosclerosis Trauma Congenital defects Syphilis Mycosis Cystic medial necrosis Inflammation of media and adventitia |
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What is arteriosclerosis? |
Most common cause of aneurysms (97%) Above age 50 5:1 men to women Involvement of aorta and/or common iliacs Sometimes involves ascending and descending AO Usually begins below renal arteries and extension to bifurcation |
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What are the symptoms of AAA? |
Palpable abdominal mass Back pain Drop in hematocrit (rupture) May be asymptomatic |
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What are the growth patterns of an AAA? |
Normal lumen diameter > 3 cm US 98.8% accurate in detecting aneurysms < 6 cm patients are assessed at yearly intervals |
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What do doctors do with aneurysms > 4 cm in diameter? |
Followed every 6 months with intervention of patient becomes symptomatic |
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What do doctors do with aneurysms 4-5 cm in diameter? |
Surgical intervention may be suggested if the patient is in good health |
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What do doctors do with an aneurysm > 5-6 cm in diameter? |
May benefit from surgical repair, especially if patient has other factors for rupture |
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When are patients considered at higher risk with AAA? |
Aneurysms > 6-7 cm in diameter Risk increases with age and other medical problems |
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What are the survival rates of AAA? |
75% of patients have 1 year survival if < 6 cm 50% of patients have 1 year survival if > 6 cm 25% of patients have 1 year survival if > 7 cm 75% risk of fatal rupture is present if > 7 cm 1% risk of rupture is present if < 5 cm Operative mortality rate before rupture is 5%, but with surgery after rupture, mortality rate increases to 50% |
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When is surgical intervention suggested for an aneurysm? |
When associated with renal and iliac involvement |
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What are endovascular stent grafts? |
A less invasive approach to the repair of an aneurysm |
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What are some other masses that can simulate an abdominal mass? |
Retroperitoneal tumor Huge fibroid uterus Para-aortic nodes |
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What is the mortality rate of an aortic aneurysm rupture? |
50% |
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What are the symptoms of an aortic aneurysm rupture? |
Excruciating abdominal pain Shock Expanding abdominal mass |
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What are the sonographic findings for an aneurysm? |
Increased aortic diameter > 3 cm Focal dilation Lack of normal tapering dismally Presence of thrombus |
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How does a thrombus appear on US? |
Usually along anterior or anterolateral wall Old clot is easier to see Calcifications appear as thick, echogenic, sometimes with shadowing |
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What does US of a pseudoaneurysm show? |
Communication between artery and vein |
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What is an aortic dissection? |
A year in the wall of the aorta that causes blood to flow between the layers of the wall of the aorta and force the layers apart |
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How does an aortic dissection appear in US? |
A flap Intimal tear found in ascending portion of arch in 90% Usually within 100 if aortic valve Extends proximally toward heart Sometimes extends dismally to iliac and femoral arteries |
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What are the CF for an aortic dissection? |
Ages 40-60 Males more common Hypertensive |
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What is a type I aortic dissection? |
Originates in ascending AO Propagates at least to aortic arch and often beyond it distally |
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What is a type II aortic dissection? |
Originates in and is confined to the ascending AO |
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What is a type III aortic dissection? |
Originates in descending AO Rarely extends proximally |
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What is an arteriovenous fistula? |
An abnormal connection or passageway between an artery and vein A majority are acquired secondary to trauma Some may develop as a complication of arteriosclerotic aortic aneurysm |
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What are the clinical and US findings of an AVF? |
Lower trunk and leg edema Dilated IVC Vein is distended (if fistula is large) Right-sided heart disease or failure |
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What is the normal measurement of the IVC? |
< 2.5 cm |
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What are some common abnormalities of the IVC? |
Congenital: Double IVC Intrahepatic interruption of the IVC Acquired: IVC dilation IVC tumor IVC thrombosis |
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What is the incidence of a double IVC? |
< 3% |
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What is intrahepatic interruption of the IVC? |
The intrahepatic segment of the IVC is absent Hepatic veins drain directly into right atrium Venous blood flow from lower body is directed from IVC into azygos system at level of renal veins Dilation of azygos and hemiazygos veins occurs |
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What IVC disorder can be mistaken for an aortic pathology? |
Intrahepatic interruption of the IVC |
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What are the clinical and US findings of intrahepatic interruption of the IVC? |
Ages 30-40th Portal hypertension Obstruction at the diaphragm Dilation of azygos system IVC dilation |
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What is the most common origin of pulmonary emboli? |
Venous thrombosis from lower extremities |
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What procedures can be used to prevent recurrent embolization in patients who cannot use anticoagulants? |
Surgical and angiographic placement of transvenous filters into the IVC |
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What is a nonresistive waveform? |
High diastolic component Supplies organs that need constant perfusion |
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What is a resistive waveform? |
Have very little or reversed flow in diastole Supplies organs that do not need constant blood supply |
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Explain the x, y, and z axes for spectral display? |
X: time Y: Doppler shift frequency Z: Gray scale (quantity of RBCs at given velocity) |
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What is plug flow? |
Pattern of flow, typically in large arteries, in which most cells are moving at the same velocity across entire diameter of vessel A "clear window" under systole Allows for volume to be calculated |
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What are the Doppler flow patterns of the AO? |
Flow varies at different levels Proximal AO has high systolic and low diastolic flow Distal AO has triphasic flow (reversal component present) |
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What are the Doppler flow patterns of the celiac trunk? |
Some spectral broadening Unchanged after meals |
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What are the Doppler flow patterns of the splenic artery? |
Very turbulent flow pattern Prone to aneurysm |
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What are the Doppler flow patterns of the SMA? |
Highly resistive in fasting patient Nonresistive in nonfasting patient |
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What are the Doppler flow patterns of the hepatic artery? |
Spectral broadening Crucial in heart transplants |
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What are the Doppler flow patterns of the renal arteries? |
Nonresisitve Spectral broadening |
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What are the Doppler flow patterns with renal artery stenosis? |
Difficult to demonstrate Collaterals may form |
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What are the Doppler flow patterns with renal hydronephrosis? |
Doppler needed to rule out prominent vessels |
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What are the Doppler flow patterns with renal transplants? |
Turbulence near anastomosis Renal artery stenosis develops in 12% Occlusion is easier to diagnose in native kidney |
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What are the Doppler flow patterns with Renal transplant rejection? |
Normal flow is 30-50% of diastolic flow Impedance increases |
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What are the Doppler flow patterns of the renal veins? |
Variable flow like the IVC Evaluated with transplants |
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What are the Doppler flow patterns of the IVC and hepatic veins? |
Varies with respiration Flows above and below baseline (reflux from right atrium) |
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What are the Doppler flow patterns of the portal vein? |
Hepatopetal flow Continuous flow pattern Varies slightly with respiration |
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What is Budd-Chiari syndrome? |
Thrombosis of hepatic veins present Hepatic veins are small with echogenic material |
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What are the US findings of cavernous transformation of the portal vein? |
Chronic portal vein obstruction Extrahepatic portal vein not visualized Echogenic area produced by fibrosis present in porta hepatis Periportal collaterals present in porta hepatis |
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What are the US findings of portal venous hypertension? |
Determination of hepatopetal versus hepatofugal flow Dilated portal, splenic, superior mesenteric veins Dilated hepatic and splenic arteries Splenomegaly Low velocity in portal vein Patent umbilical vein Loss of respiratory variation Varices Ascites Small liver with irregular surface or large liver with abnormal texture |
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What are the Doppler flow patterns with cavernous transformation of the portal vein? |
Hepatopetal, continuous, low velocity flow |
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What is the cause of portal vein hypertension? |
Obstruction of portal vein, hepatic vein, or IVC by fibrosis or regenerating nodules Prolonged CHF Cirrhosis |
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Is respiratory variation of vessel lost with portal hypertension? |
No collapse of veins exists |
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What are the four types of spontaneous shunting? |
Coronary gastroesophageal Paraumbilical Hemorrhoidal anastomoses Retroperitoneal anastomoses |
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What is coronary gastroesophageal shunting? |
Most common Lower esophageal varices occur where esophageal branches of left gastric vein form anastomoses with branches of azygos and hemiazygos veins in submucosa of lower esophagus |
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What is paraumbilical vein shunting? |
Appears as continuation of left portal vein and extends down anterior abdominal wall to the umbilicus |
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What is hemorrhoidal anastomoses shunting? |
Occurs between superior and middle hemorrhoidal veins |
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What is retroperitoneal anastomoses shunting? |
Vascular structures within lesser omentum may cause thickening of omentum (especially in children) Small vessels seen around pancreas Doppler is useful |
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What is aliasing? |
Most common artifact with Doppler US Indicates improper representation of information that has been sampled insufficiently |
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What is the Nyquist limit? |
The minimum number of samples required to avoid aliasing The upper limit to Doppler shift that can be detected properly by pulses instruments |
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When does temporal aliasing occur? |
If Doppler-shift frequency exceeds 1/2 PRF |
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Which Doppler instruments do not experience aliasing? |
Continuous-wave |
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How can aliasing be reduced? |
Increase PRF* Shift baseline* Increase Doppler angle Use lower operating frequency Use continuous wave device |
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Why does aliasing occur with a pulses system? |
Because it is a sampling system |
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What can increasing the PRF cause? |
Range ambiguity |
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What is range ambiguity? |
Occurs when a pulse is emitted before all the echoes from the previous pulse have been received Early echoes from the last pulse are received simultaneously with late echoes from the previous pulse |
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When can a mirror image of a Doppler spectrum occur? |
When Doppler gain is set too high |
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When does internally generated electronic noise appear? |
When Doppler gain is set too high |
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What is clutter? |
Results from tissue, heart wall or valve, or vessel wall motion |
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What is a "twinkling" artifact? |
Observed at strongly reflecting scattering surface |
