Test 1 Workbook Review (Procedures 5)

For a vascular ultrasound contrast agent to be clinically useful, it should:

- be nontoxic - have microbubbles that are small enough to traverse the pulmonary capillary beds - be stable enough to provide multiple recirculation

Ultrasound contrast agents have shown the potential to improve the accuracy of hepatic sonography, including:

- enhanced detection of hepatic masses - enhanced characterization of hepatic masses - improved detection of intrahepatic and extrahepatic blood flow

Vascular ultrasound contrast agents can be useful in the evaluation of patients with suspected renal artery stenosis because they:

- increase the ability to visualize blood flow using color flow imaging - improve the intensity of spectral Doppler flow signals

Depending on the clinical application, vascular ultrasound contrast agents may be administered via:

- intravenous bolus injection - intravenous infusion

A high resistive index (RI) may indicate:

A high RI may indicate rejection, renal venous congestion, or chronic small vessel disease.

The national patient safety standards mandate that a timeout" be performed before beginning any procedure. Explain what a "timeout" is and what its purpose is.

A member of the biopsy team should ask the patient to recite his or her full name. The patient's ID or history number is confirmed, along with the type and location of the procedure. This is documented usually at the bottom of the consent form. The word "timeout" may also be typed on the screen and an image documented to be part of the ultrasound examination. This is helpful because there will be a preprocedural image; the "timeout" image, which documents date and time; and then needle tip documentation images.

___ renal vein thrombosis is an urgent finding, and the patient should undergo thrombectomy to avoid allograft loss

Acute

____ is sudden and most commonly caused from a drug-induced injury such as an acetaminophen overdose.

Acute liver failure

occurs 1 to 3 weeks following transplantation. If left untreated infarction may occur resulting from an autoimmune vasculitis.

Acute pancreatic transplant

As a sonographer, state what you should evaluate in the liver transplant patient.

Assess the size, echotexture, contour, biliary tree, and vasculature, and look for any masses, fluid collections, or ascites.

Describe the sonographic evaluation of the pancreatic transplant:

Assessing the echotexture, vasculature, and looking for any masses, fluid collections, or ascites is important.

Most of the research and development of ultrasound contrast agent has centered on creating agents that can:

Be administered intravenously

____ complications taken as a whole are the second most common cause of allograft dysfunction following rejection

Biliary

What is the most common complication of renal biopsy?

Bleeding

Hepatitis ____ virus reinfection occurs in nearly all patients who receive a liver transplant for HCV cirrhosis

C

What are the causes for renal graft rejection?

Causes of graft dysfunction include rejection, acute tubular necrosis (ATN), and drug nephrotoxicity.

List other liver diseases that can cause the liver to fail, resulting in the need for transplantation:

Chronic hepatitis B, and autoimmune hepatitis, Nonalcoholic steatohepatitis, hemochromatosis, Wilson disease, Budd-Chiari, biliary diseases, hepatocellular carcinoma (HCC), hepatoblastoma, and cholangiocarcinoma

Major long-term cause of graft failure after the first 6 months occur in 4 to 10% of patients. Results in fibrosis and atrophy of the pancreas.

Chronic pancreatic transplant

CFI

Color flow imaging

Identify the contraindications of a biopsy

Contraindications may include an uncorrectable bleeding disorder, lack of a safe needle path, and an uncooperative patient.

CES

Contrast enhanced sonography

Identify the benefits of using a needle guide on the transducer:

Faster learning curve, faster placement of the needle, and assurance that the needle is going through the anesthetized area when multiple passes are required

FNA

Fine needle aspiration

In this mode, the ultrasound system is configured to receive only echoes at the second harmonic frequency, which is twice the transmit frequency.

Harmonic imaging

The most common vascular complication of liver transplantation is ____ thrombosis

Hepatic artery

The most common reason for transplantation in the United States is cirrhosis due to chronic ____ followed by ___ abuse

Hepatitis C, alcohol abuse

rare, occurs immediately post operative and causes thrombosis and graft loss

Hyperacute pancreatic transplant

List some conditions that can lead to renal failure and a need for transplantation:

Hypertension and renal artery stenosis or renal vein thrombosis; diabetes mellitus; urinary tract obstruction; inherited kidney disease such as polycystic kidney disease; glomerulonephritis; interstitial nephritis; hemolytic uremic syndrome, systemic lupus erythematosus; scleroderma; vasculitis; toxins such as alcohol, cocaine, or heavy metals; recurrent kidney infection; medication therapy used for other diseases; severe dehydration

Index that defines the low acoustic output power that can be used to minimize the destruction of microbubbles by energy in the acoustic field

Mechanical index

Describe how tissue-specific ultrasound contrast agents differ from vascular agents.

Microbubbles of tissue-specific agents are removed from the blood pool and are taken up by, or have an affinity toward, specific tissues or thrombus. Over time, the presence of contrast microbubbles within or attached to the tissue changes its sonographic appearance. By changing the signal impedance (or other acoustic characteristics) of normal and abnormal tissues, these agents improve the detectability of abnormalities and permit more specific sonographic diagnoses. Tissue-specific ultrasound contrast agents are typically administered by IV injection. Some tissue-specific agents also enhance the sonographic detection of blood flow and therefore are potentially multipurpose. Vascular, or blood pool, UCAs enhance Doppler (color and spectral) flow signals by adding more and better acoustic scatterers to the bloodstream. In general, after IV administration, blood pool UCAs are contained exclusively in the body's vascular spaces, and when a vascular agent's microbubbles are ruptured or otherwise destroyed, microbubble shell products are metabolized or eliminated by the body, and the gas is exhaled.

Initially used to predict death within 3 months in patients who had a transjugular intrahepatic portosystemic shunt (TIPS) performed. The MELD score is a mathematical calculation based on lab values of bilirubin (measurement of bile pigment), creatine (kidney function), and international normalized ratio (INR) (blood clotting ability)

Model of End-Stage Liver Disease (MELD)

Describe how to see the needle in ultrasound

Move the needle up and down in a bobbing motion. Bob or jiggle the stylet inside the needle. Angle the transducer in a superior and inferior motion. This is helpful when the needle is bent out of the plane of the sound beam. Use harmonics or compound imaging. A last resort is to remove the needle and start again, while closely watching displacement of the tissue as the needle advances.

Intraluminal thrombus is identified filling the vessel with ___ color Doppler flow.

No

For an agent to be clinically useful, it should have these three characteristics:

Nontoxic, have microbubbles or microparticles that are small enough to traverse the pulmonary capillary beds (i.e., less than 8 micrometers in size), and are stable enough to provide multiple recirculations

List the limitations of ultrasound guidance

Not all masses can be visualized with ultrasound because they may be isoechoic to normal tissue. In the abdomen, bowel gas may move in and obscure the mass before or even during the procedure; overlying bowel may not be able to be displaced. The needle tip may be difficult to see or may deviate from the projected path because of bending or deflection of the needle. Other disadvantages of using ultrasound to guide procedures include the inexperience of ultrasound personnel, the comfort level of the radiologist and/or sonologist with other imaging modalities, and the need to use fixed angles when needle guides are used on the transducers.

Organ allocation process

Organ Procurement and Transplantation Network (OPTN)

Posttransplant lymphoproliferative disorder (PTLD)

PTLF

Laboratory tests that can be used to evaluate the effects of heparin, aspirin, and antihistamines on the blood-clotting process by detecting clotting abnormalities of the intrinsic and common pathways

Partial thromboplastin time (PTT)

Which laboratory test is used to evaluate the effects of heparin, aspirin, and antihistamines on the blood-clotting process?

Partial thromboplastin time (PTT)

For children under 12 years of age

Pediatric end stage liver

Complications from an ultrasound-guided biopsy are usually minor and may include _____, _____ reactions, and ______.

Post procedural pain or discomfort, vasovagal, and hematomas

One of the most severe complications found in both solid organ and stem cell transplantations is ____

Posttransplant lymphoproliferative disorder (PTLD)

Simultaneous pancreas-kidney transplant

SPK

Some risk factors of thrombosis include:

Severe pancreatitis, arterial wall injury, or superior mesenteric and splenic arterial and venous stump thrombus

What are the limitations of sonographic detection of blood flow?

Sonographic detection of blood flow is limited by many factors, including the depth and size of a vessel, the attenuation properties of intervening tissue, and low-velocity flow. Limited sensitivity of ultrasound equipment may also negatively influence the results of a vascular examination.

Renal artery ___ is one of the most common vascular complications and usually occurs within the first year following transplantation.

Stenosis

Why is Doppler critical for the renal transplant evaluation?

The Doppler portion is crucial for the transplanted kidney. Venous and arterial color and spectral Doppler needs to be obtained to look for any signs of thrombus or stenosis. Color Doppler and power Doppler should be used to judge adequate perfusion throughout the kidney.

What is a common indirect Doppler technique to evaluate the arterial and venous flow?

The arcuate arteries within the parenchyma are evaluated in the upper, mid, and lower poles to obtain an RI measurement using the peak systolic and end diastolic velocities.

What are the current limitations for ultrasound imaging and Doppler blood flow detection?

The clinical use of contrast-enhanced sonography (CES) has been shown to reduce or eliminate some of the current limitations of ultrasound (US) imaging and Doppler blood flow detection. These include limitations of spatial and contrast resolution on gray-scale US and the detection of low-velocity blood flow and flow in very small vessels using Doppler flow detection modes, including color flow imaging (CFI) and pulsed Doppler with spectral analysis.

Discuss the main advantage of using ultrasound for biopsy guidance

The main advantage of using ultrasound for guidance is continuous real-time visualization of the biopsy needle, which allows adjustment of the needle as needed. Moreover, as the biopsy specimen is being obtained, the needle tip can be watched in real-time to ensure that it does not slip outside the mass. Ultrasound also has the advantage of allowing different patient positions and approaches to be considered for safest access to the mass. Subcostal approaches can allow the use of steep angles with the needle directed cephalad, which can help reduce the risk of a pneumothorax or bleeding from an injury to an intercostal artery. Another benefit is the ability to comfort and reassure the patient, as the sonologist, sonographer, and nurse are all near the patient during the procedure. Other advantages include the ability to perform the biopsy in a single breath hold, portability, lack of radiation, decreased costs, and shorter procedure times.

Describe what structures the sonographer should evaluate in a renal transplant patient:

The renal transplant is evaluated as a native kidney and renal artery examination would be, assessing the size, echotexture, and vasculature, and looking for hydronephrosis, masses, fluid collections, or ascites.

Thrombosis of the PV occurs in about 3% of liver transplants. List the common causes:

This commonly results from mismatched caliber differences in the vessels, stretching of the PV near the anastomotic site, slow portal inflow, or hypercoagulable states.

Type of contrast agent whose microbubbles are removed from the blood and are taken up by specific tissues in the body.

Tissue-specific ultrasound contrast agent

True or False Eocal pyelonephritis can be an isolated area of increased or decreased echogenicity with nonspecific findings

True

Maintains a centralized computer networking system for all organ procurement organizations and transplant centers while seeking to be fair and effective in selecting transplant candidates

United Network for Organ Sharing (UNOS)

List the urgent finding immediately post renal transplant:

Urgent findings include: (1) RA severe stenosis or kinking of vessel affecting the flow within the renal parenchyma; (2) RA, RV, CFA, iliac artery or vein thrombus or occlusion; or (3) an identified source of active bleeding.

Segmental infarction with the transplant is a result of:

Vascular thrombosis, hyperacute rejection, kinking of the artery, dissection, or anastomotic occlusion

Why is Doppler crucial for the transplanted liver patient?

Venous and arterial color and spectral Doppler needs to be obtained to look for any signs of thrombus or stenosis. It is critical to angle correctly in the left, right, and main hepatic arteries with pulse-wave Doppler to accurately assess for stenosis. The sonographer will need to measure the peak systolic and end diastolic velocities to obtain the resistive index (RI) measurement.

Intrahepatic ____ are localized fluid collections of necrotic inflammatory tissue that contain purulent material and an infectious organism

abscesses

AE

acoustic emission

Occurs when an appropriate level of acoustic energy is applied to the tissue; the microbubbles first oscillate and then rupture

acoustic emission

Vascular ultrasound contrast agents enhance Doppler flow signals by:

adding more and better acoustic scatters to the bloodstream

AFP

alpha-fetoprotein

The microbubbles of tissue-specific ultrasound contrast agents:

are taken up by or have an affinity toward specific tissue

Bioposies are used to confirm if a mass is ___, ___, or ____

benign, malignant, or infectious

Bile leaks seep into the peritoneal cavity and may form a contained perihepatic collection or

biloma

The most common site of obstruction is at the site of ureteral implantation into the _____

bladder

The transplanted pancreas will appear different from the native organ; typically, it has a(n) ____ appearance, and the border can be difficult to visualize at times.

blob

Renal transplant recipients are at a higher risk for developing urinary ___

calculi

When insonating microbubble-based ultrasound contrast agents, the energy present within the acoustic field:

can have a detrimental effect on the contrast microbubbles

With chronic PV thrombosis ____________ can occur with the hepatic artery.

cavernous transformation

The most common cause for requiring a renal transplant is ___ end-stage renal disease or renal failure

chronic

Defect in blood-clotting mechanisms

coagulopathy

The spectral waveform of the portal vein (PV) has ___ flow with minimal respiratory changes.

continuous

Agent used to reduce or eliminate some of the current limitations of ultrasound imaging and Doppler blood flow detection color flow imaging

contrast-enhanced sonography

A(n) ____ uses an ultrasound-automated spring-loaded device, termed a biopsy gun, to provide a core of tissue for histologic analysis

core-biopsy

The most common cause for hepatic artery stenosis is postoperative ____

edema

Postoperative edema can create ___ blood flow velocities within the hepatic arteries (HAs) or venous system

elevated

Postoperative edema can create ____ blood flow velocities within the renal artery (RA) or renal vein (RV), and the arcuate arteries may have an elevated RI and may demonstrate little or no diastolic flow.

elevated

agents containing room air are commonly referred to as _____ contrast agents, whereas agents containing heavy gasses are referred to as ______ agents

first generation, second generation

Agents containing room air

first-generation agents

Following pancreatic transplantation, _______________ has been reported in as many as 30% of cases.

fistulas or leakage

____ collections are the most common complication following pancreatic transplantation, with the most common being a hematoma

fluid

One method of ultrasound-guided intervention is called the ______ technique and is performed without the use of a needle guide on the transducer.

free-hand

Method of performing an ultrasound guided procedure without the use of a needle guide on the transducer

freehand technique

Portal venous ___ is a common finding on ultrasound during the early postoperative period following transplantation

gas

High blood ___________ can lead to many complications such as amputations, heart disease, stroke, vascular disease, blindness, nerve damage, or kidney damage

glucose

Allows detection of contrast-enhanced blood flow and organs with grayscale ultrasound

gray scale harmonic imaging

GSHI

gray scale harmonic imaging

Some vascular agents also improve ultrasoung visualization of flowing blood and demonstrate changes to the _______ of tissue

gray-scale echogenicity

HI

harmonic imaging

On gray-scale imaging, the transplanted liver parenchyma should appear smooth and ____ being isoechoic relative to the right renal cortex

homogenous

Decreased systolic and diastolic blood pressure below normal

hypotension

Diminished blood volume

hypovolemia

After the injection of the tissue -specific ultrasound contrast agents (UCA) sonazoid, the reflectivity of the contrast containing tissue increase; when the right level of acoustic energy is applied to tissue, the contrast microbubbles eventually rupture, resulting in random Doppler shifts; these shifts appear as a transient mosaic of colors on the color Doppler display; masses that have destroyed or replaced normal Kupffer cells will be displayed as color free areas

induced acoustic emission

IAE

induced acoustic emission

More than 80% of renal transplant recipients develop at least one _____ within the first year.

infection

INR

international normalized ratio

Method developed to standardize prothrombin time (PT) results among laboratories by accounting for the different thromboplastin reagents used to determine PT

international normalized ratio

Hypodermic injection into a vein for the purpose of injecting a contrast medium

intravenous injection

hepatic ultrasound blood flow studies are limited by _______ velocity blood flow

low

The most common site of hepatocellular carcinoma (HCC) recurrence is the ____, followed by the liver.

lung

The most common complication of venovenous bypass during liver transplantation is a(n) ____

lymphocele

The most common peritransplant fluid collect is a(n) ____

lymphocele

The most common indication for a biopsy is to confirm ___ in a mass

malignancy

MI

mechanical index

The rupture of ____ results in random Doppler shifts appearing as a transient mosaic of colors on a color Doppler display.

microbubbles

Agents include Optison, Definity, Imagent, Levovist, and SonoVue

molecular imaging agents

The most common biliary complication is ____ which is usually caused from a stricture at the anastomosis but may also be secondary to choledocholithiasis.

obstruction

When in harmonic imaging mode, the ultrasound system is configured to receive

only echoes at the second harmonic frequency, which is twice the transmit frequency

When using a microbubble-based ultrasound contrast agent, the microbubbles ____ (that is, they get larger and smaller) when subjected to the acoustic energy present in the ultrasound field with gray-scale ultrasound.

oscillate

____ is the second most common complication following transplantation

pancreatitis

For all spectral Doppler, the angle should be _______________ with the vessel that is sampled and less than 60 degrees to ensure accurate velocity measurements.

parallel

PTT

partial thromboplastin time

Wideband gray-scale harmonic imaging provides a way to better differentiate areas with and without contrast and has the potential to demonstrate real-time gray-scale blood pool imaging, or ____ imaging

perfusion

Hematomas are most common along the ____ spaces and near the vascular and biliary anastomosis sites

perihepatic

Collection of air or gas in the pleural cavity

pneumothorax

PDI

power Doppler imaging

Laboratory test that measures levels of this antigen in the body, elevated levels of which could indicate prostate cancer

prostate-specific antigen

PSA

prostate-specific antigen

PT

prothrombin time

A(n) ___ is a focal disruption of the artery with no direct communication with a vein and can occur in any vessel

pseudoaneurysm

On ultrasound ____ appears as a round cystic structure that demonstrates disorganized "yinyang" color flow within

pseudoaneurysm

The most common cause for liver transplant failure is ____

rejection

The patients own kidney is removed from the retroperitoneum and reimplanted into the iliac fossa

renal autotransplantation

It is important to determine how much that mass moves with ____ and also how well and how long the patient can hold his or her breath

respiration

currently, tissue specific agents that are taken up by the _________ system appear to be most useful in the assessment of pt with suspected liver abn, including the ablitly to both detect and characterize liver tumors using contrast enhanced sonography.

reticuloendothelial

The patient must be informed of the potential ___, the alternate methods of obtaining the same information, and what the course of the disease would be if the biopsy were not performed and the correct treatment could not be planned.

risk

What type of substances does the microbubbles of a "first-generation" ultrasound contrast agent contain?

room air

patients may be marked for a thoracentesis or may have the procedure under sonographic guidance. Patients should be scanned in the ____ position that the procedure will be performed in, which is usually in an upright position, through the back.

same

Vascular or blood pool ultrasound contrast agents enhance Doppler (color and spectral) flow signals by adding more and better acoustic ____ to the bloodstream.

scatters

In harmonic imaging mode, the ultrasound system is configured to receive only echoes as the ____ harmonic frequency, which is twice the transmit frequency.

second

Agents containing heavy gases

second generation agents

____________ are clear serous fluid collections that are usually found within the first few days after transplantation.

sexomas

In the harmonic imaging mode, the echoes from the oscillating microbubbles have a higher ____ ratio than would be provided by using conventional ultrasound so that regions with microbubbles are more easily appreciated visually.

signal-to-noise

although ultrasound is usually sensitive for the detection of medium to large hepatic lesions it is limited in its ability to detect _____. iscoechioc, and or peripherally located lesions, particularly in obese patients or patients with diffuse liver disease

small

Thrombosis and ____ occur most commonly at anastomosis sites due to size discrepancy between the native and transplant vessels or suprahepatic caval kinking.

stenosis

Whenever possible, a(n) ____ approach should be used to prevent the possibility of a pneumothorax or damage to the intercostal arteries.

subcostal

Any peritransplant fluid collection should be considered infected in the ___________ patient.

symptomatic

FNA uses a(n) _____ needle to obtain cells from a mass.

thin-gauge

Surgical puncture of the chest wall for removal of fluids; usually done by using a large-bore needle

thoracentesis

Slow flow, extrinsic compression, or a narrowing at the anastomosis may be a precursor to developing ___

thrombus

UCA

ultrasound contrast agent

Agents that can be administered intravenously to evaluate blood vessels, blood flow, and solid organs

ultrasound contrast agents

Typically, the ____ pole of the kidney is biopsied to prevent possible lacerations of the main renal vessels are ureter.

upper

Type of ultrasound contrast agent whose microbubbles are contained in the body's vascular spaced

vascular ultrasound contrast agents

Concerning the action of stimuli from the vagus nerve on blood vessels; vasovagal syncope is a brief loss of consciousness caused by a sudden drop in heart rate and blood pressure, which reduces blood flow to the brain

vasovagal

___ thrombosis is the second most common cause of allograft failure and typically is seen within the first 6 weeks following transplantation

venous