TEST 1 - CH 4,5,6,8

What lies in the retroperitoneum?

Suprarenal glands, AO + IVC, most of duodenum, pancreas, ureters, ascending/descending colon, kidneys, esophagus, rectum

Layers or the artery

Tunica intima (inner) - Endothelium that lines the lumen of all vessels

Tunica media (middle) - Smooth muscle cells and elastic fibers

Tunica adventitia (outer) - Collagen fibers

Proximal

When a structure is closer to the body midline or point of attachment to the trunk. For example, the knee is proximal to the ankle.

Distal

Farther from the midline or point of attachment to the trunk. For example, the ankle is distal to the knee

Cephalic/Superior/Cranial

Towards the head

Caudal/Inferior/caudad

Towards to the feet

Anterior/Ventral

The front (belly) surface of the body

Posterior/Dorsal

The back surface of the body

Medial

The superoinferior body axis that goes right through the midline of the body; Medial structures are those that are closer to the midline of the body than they are to another structure.

Ex) The aorta is medial to the kidneys

Lateral

Toward the side of the body; Ex) The ovaries are lateral to the uterus

Sagittal plane

Lengthwise plane running from front to back; Divides the body or any of its parts into right and left sides

Midsagittal plane

Divides the body into equal halves

Transverse plane

Divides the body or any of its parts into upper and lower portions

Coronal plane

Lengthwise plane that runs from side to side and divides the body into anterior and posterior portions

What are the abdominal regions?

From top to bottom:

Right Hypochondrium, epigastrium, Left hypochondrium

Right lumbar region, umbilical region, left lumbar region

Right iliac fossa, hypo-gastrium, left iliac fossa

What region of the abdomen is the liver in?

Right lobe - Majority is in the right hypochondrium and epigastrium

Left lobe - Left hypochondrium and epigastrium

• Gallbladder would also be in the right hypochondrium

Major organs in the epigastrium

Stomach and Pancreas

Major organs in the left hypochondrium

Spleen

Major organs in the right hypochondrium

Majority of right lobe of the liver and gallbladder

Major organs of the right lumbar region

Ascending colon, small intestine, and right kidney

Major organs of the umbilical region

Duodenum, small intestine, and transverse colon

Major organs of the left lumbar region

Descending colon, small intestine, and left kidney

Major organs of the right iliac fossa

Appendix, cecum, ascending colon, small intestine

Major organs of the hypo-gastrium

Bladder, sigmoid colon, small intestine and reproductive organs

Major organs or the left iliac fossa

Sigmoid colon, descending colon and small intestine

What is anatomic position?

Assumes that the body is standing erect, the eyers are looking forward, and the arms are at the sides with the palms and toes directed forward

The patient positions

What is the typical patient position for abdominal examination?

Supine

Parietal peritoneum

Outer layer that lines the abdominal wall

Visceral peritoneum

Inner layer that covers the abdominal organs

Artifacts

Anything that does not properly present the structures or motion imaged; Caused by some problematic aspect of the imaging technique; Some artifacts are helpful and should be used to the sonographer’s advantage but some hinder the diagnostic process.

Examples of artifacts are

Reverberation, mirror, side lobe, shadowing, and edge shadowing

Blood flow through the heart

Arteries carry blood away from the heart and veins carry blood to the heart and back from the tissues.

• Red = Oxygen

• Blue = No oxygen

What branches off of the aortic arch?

Brachiocephalic trunk (only on the right side of the aortic arch)

• Off the Brachiocephalic trunk are the Rt Subclavian and Rt Common Carotid Artery

  • Left common carotid artery

  • Left subclavian artery

What is another name for the brachiocephalic trunk?

Innominate

Anterior branches of the aorta

Celiac trunk, Common Hepatic Artery, SMA, IMA

Lateral branches of the aorta

Phrenic arteries, renal arteries, and gonadal arteries

What is the seagull sign

It is basically how the hepatic artery and splenic artery look in a TRV view

What is an aneurysm

A permanent localized dilation of an artery, with an increase in diameter greater than 1.5 times its normal diameter

What is a true aneurysm

A type of aneurysm that involves all three layers (intima, media, adventitia)

What percentage of aneurysms are infrarenal

95%

Types of aneurysms

Saccular - Bulges out on one side and the most common type of cerebral aneurysm

Fusiform - Bulges or balloons out on all sides of the blood vessel; Overall, most common type

What are risk factors of Abdominal Aortic Aneurysms (AAA)?

Tobacco

Hypertension

Vascular disease

Chronic obstructive pulmonary disease (COPD)

Genetics - Family history of AAA

Iliac and popliteal (behind the knee) aneurysm association

What are causes of AAA?

Atherosclerosis (plaque buildup) #1 cause

Trauma (after transection)

Congenital defect

Syphilis (involving the ascending aorta and arch)

Mycosis (fungal dissection)

Symptoms of AAA

Palpable abdominal mass, back pain, drop in hematocrit (rupture), may also be asymptomatic

Treatment for an aneurysm <4cm in diameter

Follow it every 6 months with intervention if the patient becomes symptomatic

Treatment for an aneurysm 4-5cm in diameter

Surgical intervention may be suggested if the patient is in good health

Treatment for an aneurysm >5-6cm in diameter

May benefit from a surgical repair, especially if the patient has other factors for rupture like hypertension, smoking, COPD

Treatment for aneurysms >6-7cm in diameter

Pose the greatest risk; Risk increases with age and other medical problems

Surgical intervention and AAA

• Suggested with associated rneal and iliac involvment

• Length of the infrarenal aortic neck is important to help determine the surgical approach

Endovascular Stent Grafts

Treatment for aneurysms that is less invasive; usually for infrarenal aneurysm

Basically, a large fabric-covered stent that is compressed and positioned through a catheter through the patient’s groin. Once in place, the graft is expanded to create a new path for blood flow.

What is the mortality rate if an aortic aneurysm ruptures?

50%

What are the most common locations for aneurysms

Infrarenal - Below the renal arteries

Suprarenal - Above the renal arteries

Juxtarenal - Just below the renal arteries

Types of Endoleaks

Type I - Gap between graft and vessel

Type II - most common, flow through branch vessels into aneurysm sac

Type III - Defect/misalignment of endograft materials

Type IV - Porous graft material

Type V (“endotension”) - No evidence of leak but continued enlargement of aneurysm

Pseudoaneurysm

A pulsative hematoma that results from the leakage of blood into the 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 bit is contained by the deeper layers of the aorta or by the adjacent tissue

When are pseudoaneurysms seen

After invasive procedures (often cardiac cath)

Why are pseudoaneurysms false?

They don’t involve all three layers of the artery

What is aortic dissection

A separation (tear) of the intima from the media of the aortic wall; Increased pressure on outer wall can eventually rupture; They can extend into the carotid arteries or down the aorta to the femoral arteries

High mortality risk

Where do aortic dissections usually originate?

Aortic arch in the thorax

What are the causes of aortic dissection

Marfan syndrome - connective tissue disorder

Chronic hypertension

AAA

Iatrogenic cardiac intervention - caused by medical treatment

Congenital heart anomalies

Coarctation of aorta

Trauma

What are symptoms of aortic dissection

Severe abdominal pain

Shortness of breath

Dizziness or fainting

Rapid, weak pulse

Heavy sweating

A significant difference in blood pressure on right and left side

Stroke-like symptoms can also occur

Example of aortic dissection on ultrasound (looks like cracks)

What is the origin of the IVC

Formed by the union of the common iliac veins posterior to the right common iliac artery at the level of the fifth lumbar vertebra; Ascends vertically through the retroperitoneal space on the right side of the AO, posterior to the liver and piercing the central tendon of the diaphragm at the level of the eighth thoracic vertebra to enter the right atrium of the heart

What is the most common origin of pulmonary emboli?

Venous thrombosis from the lower extremities

What are IVC filters?

AKA Greenfield Filter; Surgical and angiographic placement of transvenous filters into the IVC have been used to prevent recurrent embolization patients who cannot tolerate anticoagulants

Appearance of greenfield filter (always important to check medical records because they can look like clots)

What forms the portal vein

Formed posterior to the pancreas by the union of the SMV and splenic veins

How long is the portal vein trunk?

5-7cm in length

Where does the portal vein carry blood to

Carries blood from the intestinal tract to the liver by means of its two main branches: the right and left portal veins

Where does the portal vein drain blood from

Drains blood from the gastrointestinal tract; from the lower end of the esophagus to the upper end of the anal canal; and from the pancreas, gallbladder, bile ducts, and spleen

How do the Lt and Rt portal veins course through the liver

Transversely, so scans display their longest extent

SMV spatial relationship to the pancreas?

Anterior to the uncinate of the pancreas, and posterior to the neck

Characteristics of the splenic vein

A tributary of the portal circulation that begins at the hilum of the spleen, where it is formed by the union of several veins; Runs along the posteromedial border of the pancreas and anterior to the SMA to form the portal vein

What is the portal triad? Mickey Mouse Sign

Part of the portal system that contains a branch of the portal vein, hepatic artery, and bile duct contained within a connective tissue sheath. This gives the portal vein an echogenic wall

SMV location

Passes anterior to the third part of the duodenum and posterior to the neck of the pancreas where it joins the splenic vein to form the main portal vein

What small veins does the SMV also drain

• the middle colic vein (transverse colon), right colic vein (ascending colon), and pancreatic duodenal vein

Where does the SMV receive tributaries from?

Receives tributaries that correspond to the branches of the SMA where it is joined by the inferior pancreaticoduodenal vein to the right gastroepiploic vein from the right aspect of the greater curvature of the stomach

(Low) non-resistive vessels

Have a high diastolic component and supply organs that need constant perfusion

Ex) Internal carotid artery, hepatic artery, renal artery

(High) Resistive vessels

Have very little or even a reversed flow in diastole and supply organs that do not need a constant blood supply

Ex) External carotid artery and Iliac and brachial arteries

Low Resistance waveforms

More of a rounded systolic peak with significant flow during diastole and a noticeable end diastolic velocity

High Resistance waveforms

Sharp systolic peak and has a reversed diastolic flow due to resistance peripheral vascular bed.

Often triphasic

• Rapid systolic peak followed by a brief reversal of flow and then a smaller forward flow in diastole

Plug Flow

Typically seen in large arteries, in which most cells are moving at the same velocity across the entire diameter of the vessel; A clear window under systole is typical of plug flow

• When plug flow is present, the volume of blood flow can be calculated

Laminar flow

Smaller vessels and is bullet shaped

Turbulent flow

Basically, the blood is just going crazy and going in all types of directions. Happens with stenosis or in curved vessels.

Budd-Chiari Syndrome

Thrombosis of the haptic veins is present; Hepatic veins are small with echogenic material

• Presence of normal flow excludes Budd-Chiari syndrome

Triphasic

Waveform that touches the baselines three times

Biphasic

Waveform that touches the baseline twice

Monophasic

Waveform that doesn’t touch the baseline

Nutcracker syndrome

Occurs when the left renal vein is compressed between the SMA and the aorta.

Can cause:

Venous hypertension (collaterals)

Retrograde flow into gonadal veins (pelvic congestion)

May Thunder Syndrome (Iliac Vein Compression)

Compression of the left common iliac vein against the lumbar vertebrae by the overlying right common iliac artery. This increases the risk for deep vein thrombosis

Celiac Band Syndrome (Median arcuate ligament syndrome)

Compression of celiac axis by the median arcuate ligament of the diaphragm; Clinically an abdominal bruit is noted on expiration, but disappears with inspiration

Expiration - The MAL compresses celiac axis causing a “stenosis”

Inspiration - Celiac axis straightens and the “stenosis” disappears and velocities return to normal

What is the aortas waveform like

Triphasic, high resistance

What is the renal arteries waveform like

low resistance

What is the hepatic veins waveform like

Bidirectional, pulsatile due to tricuspid regurgitation

What is the portal veins waveform like

Hepatopedal (pedal toward the liver) and undulatory