Contrast Media and Urinary System Flashcards
The tissue density and composition of the organs in the abdomen are very ________ as well as the thickness of these organs.
similar
The liver, pancreas, spleen, stomach, kidneys, and bowel will display a low amount of
subject contrast
is the radiographic contrast caused by the difference in the composition of the patient’s body tissues.
Subject contrast
The organs of the digestive system, urinary system and cerebrovascular system have similar densities and atomic numbers and will therefore absorb nearly the same amount of radiation and therefore have
Low subject contrast
Are diagnostic agents that are introduced into the body orifices or injected into the vascular system, joints, and ducts to enhance subject contrast in anatomic areas where low subject contrast exists
Contrast media
The ability of the contrast media used in radiographic procedures to enhance subject contrast depends greatly on
The atomic number of the element used in a particular medium and
The concentration of atoms of the element per volume of the medium
Contrast media are generally classified as
negative or positive contrast agents.
Negative contrast agents are (radiolucent or radiopaque?)
radiolucent
Positive contrast agents are (radiolucent or radiopaque?)
radiopaque
The specialty contrast agent for MRI is:
IV contrast agent gadolinium diethylenetriaminepentaacetic acid (gadolinium-DTPA).
Metalic and magnetic agent that affects signal intensity.
The specialty contrast agent for Ultrasound is:
Gas-filled microbubbles that affect the sound wave to enhance ultrasound contrast
Physical properties of negative contrast agents:
Composed of elements with low atomic numbers
Administered as:
Gas (air)
Carbon dioxide
Tablets, crystals, soda waterWhy is oxygen rarely used alone as a contrast agent?
Cells absorb oxygen quickly.
What is the most common negative contrast agent?
Room air.
A negative contrast agent may be combined with a positive contrast agent to produce a
double contrast effect.
In a double contrast barium enema, barium is the ______ contrast agent and air is the ______ contrast agent.
positive, negative.
An example of a discontinued exam using negative contrast media is:
Pneumoencephalography
The uses of negative contrast media are limited because
they may not provide sufficient contrast of a structure when used alone.
Why must negative contrast agents never be injected intravenously?
serious or fatal consequences can result
Three characteristics of positive contrast agents:
Are radiopaque
Composed of elements with high atomic numbers
Absorbs more x-rays and appears bright on a radiograph
Positive contrast agents absorbs about ___ times more x-rays than bone and ___ times more x-rays as soft tissues.
3 and 5.
Two examples of positive contrast agents:
- Barium (Z# 56)
- Iodine (Z#53)
Each of these elements has a much higher atomic number and mass density than does soft tissue (Z# 7.4)
What is the atomic number of Gadolinium?
64
Two popular types of positive contrast media:
- Barium Sulfate
2. Iodinated Compounds:
Barium sulfate is a heavy metal element with the atomic number:
56
Barium sulfate is an inert powder composed of crystals that is used for
examination of the digestive system
What is barium sulfate comprised of?
The element barium is combined with oxygen and sulfate to form the inert compound barium sulfate.
What is the chemical formula of barium sulfate?
BaSO4
Barium sulfate is commonly referred to as:
Barium
A mixture of barium sulfate and water forms a
colloidal suspension, NOT a solution.
Barium sulfate never dissolves in water.
Depending on the environment of the barium sulfate, such as acid within the stomach, the powder has a tendency to clump and come out of suspension. This is called
FLOCCULATION
Stabilizing agents, such as _____ or _____ are used to prevent flocculation.
sodium carbonate, sodium citrate.
Barium flocculates in the presence of _____, producing fine flocculation in the proximal loops where _________
mucus, the pH is low.
Definition of enteral:
within, or by way of, the intestine or gastrointestinal tract.
Barium sulfate is used for examination of the entire ________ ________, and can be a relatively thin or thick mixture.
alimentary canal.
What are some forms barium sulfate comes in?
Barium sulfate can come in paste, liquid, powder and tablet form & can be purchased in premixed liquid form or in powder form.
Because of its inability to be absorbed by the body, barium sulfate cannot be used
intravascularly or intrathecally.
Definition of Intrathecal:
– introduced into or occurring in the space under the arachnoid membrane of the spinal cord or brain.
When is barium contraindicated?
in the case of a suspected perforation in the alimentary canal (organs of digestion) as barium is not absorbed naturally by the body.
What contrast agent must be used when patient presents with a history of suspected perforation?
a water-soluble iodine contrast agent is recommended (brand name examples: Gastrografin, Gastroview or Hypaque)
If barium enters the peritoneal or pelvic cavity, it can cause
peritonitis and must be surgically removed.
What are the adverse reactions to barium sulfate?
Obstruction/constipation Extravasation Vaginal Rupture Hypervolemia Allergic Reactions aspiration of barium by sedated or mentally handicapped patients Barium in appendix
Why should patients be instructed to drink plenty of fluids after receiving barium sulfate?
All barium transits the colon. One function of the colon is to absorb water from waste. Barium sulfate residue in the colon can dry and cause patient to become constipated.
Extravasation definition:
leakage from a vessel into the tissue.
A complication related to administration of barium during a BE is
perforation of the colon with extravasation into the abdominal cavity
Extravasation can lead to
peritonitis.
Who are at increased risk of a colon perforation during a BE?
Elderly patients or those receiving long term steroid medication are at increased risk for colon perforation because of atrophic tissue. Also at risk are patients with diverticulitis or ulcerative colitis. These diseases result in inflammation and degradation of the intestine.
Patients who have had a recent biopsy of the colon should not have a BE until
the area heals.
Barium tip or retention catheter can be a source of colon perforation. How can this risk be reduced?
The balloon should not be overinflated.
Vaginal Rupture- is a rare complication of barium sulfate administration. It is due to
misplacement of the catheter before lower GI examinations.
How can vaginal rupture be avoided?
Female patients should be asked whether they feel the enema tip in the rectum.
Hypervolemia definition:
a blood disorder consisting of an increase in the volume of circulating blood
Hypervolemia can occur when:
water from the cleansing enema or barium enema is shifted from the colon into the circulatory system with a resulting increase in blood volume
Consequences of hypervolemia are:
pulmonary edema, seizures, coma or even death.
Table salt is an ingredient that is added to the barium sulfate solution by the manufacturer to:
reduce the possibility of hypervolemia.
Allergic reactions to barium sulfate are possible but are usually due to:
the preservatives in the barium sulfate preparation OR to the latex in the barium enema catheters.
Why should sedated patients not undergo an upper GI exam?
Swallowing reflex diminished; increases chances of aspiration resulting in barium pneumonia
Mentally handicapped and persons with altered mental status due to age or disease is also at risk for aspiration
What type of complications can occur from barium in the appendix?
No directly related complications have resulted from this occurrence.
What are the two types of iodinated compounds?
Oil based and water-soluble.
Iodine’s atomic number is:
53
Iodine is almost as radiopaque as:
barium.
Advances in imaging techniques and improvement in contrast agent technology have rendered oil-based contrast agents nearly obsolete. They may still be used infrequently for
lymphangiograms and bronchograms
Use of oil based contrast media in radiography is relatively
limited.
In the past, oil-based iodinated contrast media were routinely used for myelograms, bronchograms, hysterosalpingograms, sialograms, and dacryocystograms, but have been replaced by
water-soluble iodinated contrast media
Because oil-based contrast media are not miscible with blood,
it should NEVER be injected intravenously or intraarterially.
Oil based contrast media are made from
fatty acids
An ethyl group takes the place of the alcohol chemical group usually found in fatty acids. These chemical manipulations change the fatty acids into
esters.
Iodine atoms are added at certain areas of the ester molecules. The result is
iodinated ethyl esters of fatty acids
When the esters are exposed to light, heat, or air,
they decompose.
Any oil based contrast media that has darkened in color from the original pale amber color:
should not be used. The dark color indicates that the media has decomposed.
Plastic syringes should not be used for injection of oil-based iodine contrast media because
toxic substances from the plastic can dissolve into the media.
The main disadvantage of oil-based iodine contrast media is
that they persist in the body because they are insoluble in water
Adverse Reactions to oil-based iodinated contrast media:
Any iodine-containing contrast agent may provoke an anaphylactoid (allergic-like) reaction although this is rare.
Anaphylactic shock (anaphylaxis) is
the result of an exaggerated hypersensitivity reaction (allergic reaction) to an antigen that was previously encountered by the body’s immune system.
When Anaphylactic shock occurs:
histamine and bradykinin are released, causing widespread vasodilation, which results in peripheral pooling of blood.
This response is accompanied by contraction of nonvascular smooth muscles, particularly the smooth muscles of the respiratory tract.
Anaphylactic shock can cause:
shock, respiratory failure, and death within minutes after exposure to the allergen.
Usually, the more abrupt the onset of anaphylaxis,
the more severe the reaction.
The most common causes of anaphylaxis are __________________. The path of entry may be ___________________.
medications, iodinated contrast agents, and insect venoms. through the skin, respiratory tract, or gastrointestinal tract, or through injection.
Water soluble contrast media may be described as either
Ionic iodinated contrast media or nonionic iodinated contrast media
Water soluble contrast media has relatively low
toxicity.
Water soluble contrast media generally absorbed by the body and excreted by the kidneys within:
24 hours of intravascular administration
Intrathecal versus intravenous:
Intrathecal is introduced into or occurring in the space under the arachnoid membrane of the spinal cord or brain. Intravenous is introduced within a vein.
The labels of “ionic” or “nonionic” refer to
the structural composition of the molecules contained in the contrast agent not whether or not it has iodine in it.
The primary difference between the ionic and nonionic solutions rests with
the physiologic interaction within the body.
Ionic media dissociate into two molecular particles in
water or blood plasma.
IONIC Iodine Contrast Media are ionic because:
one particle has a negative charge called an anion, and the other particle has a positive charge called a cation.
The anion part of the ionic iodine contrast media molecule begins with a six-carbon bonded hexagon called a
benzene ring.
A carbon atom occupies each corner of the benzene ring but is not usually drawn because
the molecular diagram would look cluttered.
Every other carbon bond site of the benzene ring is bonded to an
iodine atom, which makes the contrast medium tri-iodinated.
There are 3 remaining carbon bond sites that are not bonded to an iodine atom.
Of those 3 remaining sites, one is occupied by
a negatively charged acid group.
It is at this acid group site in the molecule of ionic iodine contrast media that
the anion and cation separate on injection
The 2 carbon bond sites on the ionic iodine contrast molecule—R2 and R3—are occupied by
chemical structures that increase the solubility or the excretion rate of the contrast by the body
It is the two carbon bond sites (R2 and R3) that result in the different result in the different classes of ionic media:
Diatrizoate—with the trade name hypaque
Metrizoate—with the trade name isopaque
Iothalamate—with the trade name conray
The CATION (positively charged) part of the ionic iodine contrast molecule are salts. The salts most commonly used are
derivatives of sodium, calcium, and meglumine (methylglucamine)
Once injected, the CATION will dissociate or separate from the parent ANION and
create 2 separate ions in the blood.
The separation of the cation from the anion creates an increase in the blood plasma osmolality called
a hypertonic condition
Osmolality definition:
refers to the concentration or number of particles (anions and cations) in the solution per kilogram of water and is directly related to the occurrence of adverse reactions.
A contrast agent with high osmolality has
an increased number of particles and more osmoles in the solution.
An increase in osmolality can cause
vein spasm, pain at the injection site and fluid retention.
Most importantly, ionic contrast agents may increase the probability that a patient will
experience a contrast media reaction.
Increasing the number of ions in the plasma can
disrupt homeostasis and create a reaction
There is LESS chance of interruption of homeostasis if osmolality of the injected contrast
closely resembles that of BLOOD PLASMA which is about 300 osmol/kg.
On average, the osmolality of ionic iodinated contrast agents ranges from
1000 to 2400 osmol/kg
The osmolality of nonionic iodinated contrast agents is around
750 osmol/kg which is much closer to blood plasma.
most water based ionic iodinated contrast media are referred to as
high osmolality contrast media or HOCM
Water based iodinated nonionic contrast media are referred to as
low osmolality contrast media (LOCM) and are better tolerated by the body
Research indicates that patients are less likely to have contrast media reactions OR more likely to have less severe reactions or side effects when ________ are used.
nonionic contrast agents
LOCM are __ times more expensive than HOCM.
20
Why was nonionic iodinated contrast media developed?
to reduce the side effects of the ionic iodine contrast media.
Nonionic iodinated contrast media molecules ____________ so that hypertonicity is avoided.
molecules do not dissociate or separate in solution
The molecular structure of NONIONIC Iodine Contrast Media is a tri-iodinated benzene ring that
does not carry an acid group.
NONIONIC Iodine Contrast Media (LOCM):
Many __________ surround the benzene rings
oxygen-hydrogen hydroxyl groups
The hydroxyl groups in nonionic iodine contrast media increase
the solubility of the media in blood plasma
Both ionic and nonionic iodine media have physiologic effects on the body, but IONIC agents are _________ and therefore have shown greater effects and adverse reactions.
higher osmolality contrast agents
Viscosity of water based iodinated contrast media is influenced by
the concentration and size of the molecule and affects the injectability of the media.
Heating the media to body temperature reduces _______ and facilitates the ability for rapid injection.
viscosity
When plasma water is displaced by contrast particles, water from body cells
move into the vascular system (through osmosis)
Water from body cells moving into the vascular system results in:
in hypervolemia and blood vessel dilation, with pain and discomfort
hypervolemia definition:
a blood disorder consisting of an increase in the volume of circulating blood
With the use of water soluble iodinated contrast media:
Blood pressure may decrease because of ________, or it may increase because of _________
vessel dilation, hypervolemia and the effects of hormones in the kidneys.
Allergic reactions to water-soluble iodinated contrast media resemble allergic reactions to
foreign substances, such as pollen grains.
Concerning water soluble iodinated contrast media, reactions of typical allergic patients may be:
minor such as urticaria (hives)
Reactions such as wheezing and edema in the throat and lungs with accompanying bronchospasm and nausea and vomitting are thought to be caused by
the release of histamine from certain cells found in the lungs, stomach, and lining of blood vessels.*
Sometimes pre-medication with steroids and antihistamines can reduce or eliminate
allergic effects of water soluble iodinated contrast media.
Injection of contrast media results in dilation and then constriction of the renal arteries. The end result is
diminished blood supply to the kidneys.
Osmotic effects are also presumed to cause an increase in the amount of
molecular substances that cannot be reabsorbed by the renal tubules.
This results in an increased secretion of urine with dehydration.
BUN (blood urea nitrogen) and creatinine (waste product of metabolism) levels are indicators of kidney function and is a good indicator for
possible contrast media-induced renal effects.
Normal creatinine levels for the adult are
0.6 to 1.5 mg/dl (mg/100ml)
BUN levels should range between
8 to 25 mg/100 ml
Blood urea nitrogen (BUN) – This lab test checks
the metabolic function of the liver and excretory function of the kidneys.
Abnormal BUN values may indicate
CHF, renal disease, renal failure, myocardial infarction, dehydration
Serum creatinine—This lab test checks
renal excretory function.
Abnormal values of serum creatinine may indicate
dysfunction of the kidneys and/or dehydration.
IV fluid given before and during procedures can
reduce the severity of renal effects in those with renal disease or diabetes and older patients.
The urinary system eliminates _______ and maintains ________ .
organic wastes, the water and electrolyte balance of the body.
The urinary system consists of:
2 kidneys
2 ureters
1 urinary bladder
1 urethra
Kidneys and ureters are ______ structures.
retroperitoneal
Kidneys lie
on either side of the vertebral column in the most posterior part of the abdominal cavity
The latin designation for kidney is ____ and renal is a common adjective referring to ______.
ren, kidney.
Right kidney is more inferior than the left kidney because of
the liver.
On the upper medial border of each kidney is the
suprarenal (adrenal) gland
The suprarenal glands (adrenal glands) are part of the ______ system and have no functional relationship with the kidneys
endocrine
Each kidney connects to the urinary bladder by a
ureter
The bladder _______ until it can be eliminated.
stores urine
Urine is eliminated from the body via
the urethra
Most of each ureter lies ______ to its respective kidney
anterior
The ureters follow the natural curve of
the vertebral column curving forward following the lumbar lordotic curve and then curves backward on entering the pelvis.
The ureters enter the _______ aspect of the bladder.
posterolateral
The urethra is
the connection of the bladder to the exterior
The urethra exits from the body inferior to
the pubic symphysis
Retroperitoneal structures of the urinary system:
Kidneys and ureters
Infraperitoneal structures of the urinary system:
Distal ureters
Urinary bladder
Urethra
Each kidney is arbitrarily divided into an upper part and a lower part—called
the “upper pole” and the “lower pole”
Dimensions of the average kidney:
4-5 inches long, 2-3 inches wide, 1 inch thick. About the size of a bar of soap.
The angle of the psoas muscles causes the longitudinal plane of the kidneys to form a vertical angle of about ___ degrees with the MSP where the ____ POLE is closer to the vertebral column than its ____ POLE
20, upper, lower.
The kidneys are rotated ___ degrees from the coronal plane with the lateral border ______ to the medial border
30, posterior.
A 30º LPO will position the _____ kidney parallel to the IR.
A 30º RPO will position the _____ kidney parallel to the IR.
Right, left.
Most abdominal radiographs are performed on (breathing instruction) with patient _____.
This allows kidneys to lie ________________.
expiration, supine. High in the abdominal cavity.
The kidneys are somewhat higher in individuals of _______ habitus and somewhat lower in those of ______ habitus.
hypersthenic, asthenic.
Kidneys normally lie about halfway between
xiphoid process and iliac crest.
Top of left kidney is usually at level of
T11-T12.
Bottom of right kidney most often level with upper part of
L3
When one inhales deeply or stands upright, the kidneys will drop about
one lumbar vertebrae, or 5 cm (2 inches).
If the kidneys tend to drop more than 2 inches from the supine to upright position than a condition termed _______ exists.
nephroptosis
Sometimes in very thin patients and in older patients, the kidneys could drop dramatically and end up within the pelvis which could create problems from
a “kinking” or twisting of the ureters.
During the production of urine, the kidneys:
(1) Remove waste products from the blood
(2) Regulates water levels in the body
(3) Regulate acid-base balance and electrolyte levels of the blood
Nitrogenous waste products (urea and creatinine) are formed during the normal metabolism of proteins.
Build up of nitrogenous wastes in blood results in
uremia and may indicate renal dysfunction
uremia:
the presence of excessive amounts of urea and other nitrogenous waste products in the blood, as occurs in renal failure.
How much of blood pumped from the heart with each beat passes through the kidneys?
25%
The average water intake for humans during each 24-hour period is about
2.5 L, which eventually ends up in the bloodstream. The kidneys are the filters for the circulatory system.
At rest, more than ____ of blood flows through the kidneys every minute.
1 L
From the large amount of blood flowing through the kidneys daily, the kidneys normally excrete about ____ of urine per day
1.5 L
renal cortex
the outer, smooth-textured reddish area
renal medulla
the deep, reddish-brown region that consists of 8-18 cone shaped renal pyramids.
The apex of the renal pyramids are also known as:
renal papilla.
The portions of the renal cortex that extend between the renal pyramids are called
renal columns.
Together, the renal cortex and renal pyramids of the renal medulla make up the
functional portion or parenchyma of the kidney
The term renal parenchyma is a general term used to describe _______________, such as those visualized during an early phase of an IVU procedure.
the total functional portion of the kidneys,
The essential microscopic components of the parenchyma of the kidney are called
nephrons.
Each kidney has about _____ nephrons.
1 million
Urine formed by the nephrons drain into large ________ which extend through the renal papillae of the pyramids
papillary ducts
Nephrons are involved in 3 basic processes:
- Filtering blood
- Returning useful substances to the blood so they aren’t lost from the body
- Removing substances from the blood that aren’t needed
The individual nephron is composed of
renal corpuscle and a renal tubule
The renal corpuscle consists of a double-walled membranous cup called the ____________ and a cluster of blood capillaries called the ___________.
glomerular capsule (Bowman’s capsule), glomerulus (=little ball)
The vessel entering the glomerular capsule (Bowman’s capsule) is called the ____________.
afferent arteriole
The vessel leaving the glomerular (Bowman’s) capsule is the
efferent arteriole.
After exiting the glomerular capsule, the efferent arteriole ultimately reunite and continue on to communicate with the
renal vein.
The glomerulus serves as a filter for the blood, permitting water and finely dissolved substances to:
pass through the walls of the capillaries into the capsule.
From the glomerular (Bowman’s) capsule the filtered fluid from the plasma passes into the second part of the nephron, the
renal tubule.
Each renal tubule contines from a glomerular capsule in the _____ of the kidney and then travels in a circuitous path through the _____________________.
cortex, cortical and medullary substances.
The renal tubule consists of three parts:
the proximal convoluted tubule, the nephron loop (loop of Henle) and the distal convoluted tubule
The renal pyramids within the medulla are primarily a collection of
collecting ducts (tubules).
The filtrate is termed urine by the time it reaches the
minor calyx.
Between the glomerular capsule and minor calyces, more than of the filtrate is reabsorbed into the kidney’s venous system.
99%
Part of the renal pelvis, the calyces, and branches of the renal blood vessels and nerves lie in a cavity within the kidney called the
renal sinus.
The ureters vary in diameter from _____to_____.
1 mm to almost 1 cm.
Each ureter is _____ long
10 to 12 inches
Each ureter descends behind the _________ and in front of the _________________.
peritoneum, psoas muscle and the transverse processes of the lumbar vertebrae
The ureters enter the __________ portion of the bladder.
posterolateral
As the urinary bladder fills with urine, pressure within it compresses:
the openings into the ureters and prevents the reflux. (backflow of urine into the kidney)
Normally, 3 constricted points exists along the course of each ureter, which are:
1) the ureteropelvic junction or UPJ. This is the point the renal pelvis funnels down into the small ureter
2) where the ureters join the bladder. where the iliac blood vessels cross over the ureters
3) where the ureters join the bladder. This is called the ureterovesical junction or UVJ.
ureterovesical junction or UVJ.
where the ureters join the bladder.
Ureteropelvic junction or UPJ:
the point where the renal pelvis funnels down into the small ureter.
Most kidney stones passing down ureter tend to hang up at the:
UVJ.
When the volume of urine reaches about 250 mL,
the desire for micturition occurs
The total capacity of the bladder varies from
350 to 500 mL
As the bladder becomes more and more full, the desire to void becomes more and more urgent.
If the internal bladder pressure rises too high,
involuntary micturition occurs.
Dysuria =
pain during urination.
Anuria =
absence of urine formation
Polyuria =
Passage of large volume of urine in relation to fluid intake during a given period; common symptom of diabetes
Diuresis =
increased excretion of urine
The urethra is
a narrow, musculomembranous tube with a sphincter type of muscle at the neck of the bladder and extends about 1 ½ inches in the female and 7 to 8 inches in the male
The male urethra extends from the bladder to the end of the penis and is divided into _______________ portions.
prostatic, membranous, and spongy
The male urethra is about The male urethra is about _____ in length
7” to 8”
Prostatic portion of the male urethra:
about 1 inch in length, reaches from the bladder to the floor of the pelvis and is completely surrounded by the prostate
Membranous portion of male urethra:
passes through the urogenital diaphragm and is about ½ inch long
Spongy portion of urethra
passes through shaft of penis, extending from floor of pelvis to external urethra orifice.
The length of the male urethra acts as a natural barrier to external bacteria and the urine remains
sterile
The prostate is
a small glandular body surrounding the proximal part of the male urethra and is situated just posterior to the inferior portion of the pubic symphysis.
True or false: The renal veins are anterior to the renal arteries.
True
Which of the following structures is most anterior in the female pelvis? Rectum Urinary bladder Uterus Ovaries
Urinary bladder
The urinary bladder is located in the _______ compartment of the peritoneum.
Infraperitoneal
Retroperitoneal
Intraperitoneal
Rectouterine
Infraperitoneal
Radiographic examination of the urinary system in general is termed
urography
Contrast may be ______ into the bloodstream by an ___________ or some sort of __________ may be required so that the contrast medium can be delivered directly into structure being studied.
injected, intravenous injection, catheterization
Venipuncture and contrast media injection are considered
delegated medical arts
Radiographers must be certified competent in venipuncture after:
attending an organized training program.
Annual recertification is required.
Before withdrawing contents from any vial or bottle confirm:
Correct contents of container
Route of administration
Amount to be administered
Expiration date
Iodinated contrast agents may be administered by either:
bolus injection or drip infusion
Bolus injections:
provide a rapid introduction of contrast agent into the venous system at one time. This method is typical for maximum contrast enhancement
The rate of bolus injection is controlled by:
Gauge of needle or connecting tubing Amount of contrast agent injected Viscosity of contrast agent Stability of vein Force applied by individual performing injection
Drip Infusion
Method where contrast media is introduced into venous system by connective tubing attached to IV site.
Rate of drip infusion:
May be gradual or rapid depending on study
Controlled by clamp
The radiographer must have all necessary materials ready before injecting contrast media. Room must be prepared, including
emergency cart stocked with epinephrine or Benadryl in event of adverse contrast reaction
Equipment and Materials for Injection
Sharps container Tourniquets Alcohol pads Cotton balls or gauze Tape or Tegaderm Gloves Contrast media Various sizes of butterfly and over-the-needle catheter Syringes IV tubing Arm board
Why is a consent form required when injections of contrast media are made?
Venipuncture is an invasive procedure and carries the risk of complication when contrast agents are injected
Whose responsibility is it to make sure the consent form for contrast injection is signed?
It is the radiographers responsibility to ensure the patient is aware of potential risks and that the informed consent form is signed.
If patient is child, procedure needs to be explained to child and parent or guardian and the parent/guardian signs the informed consent form
For most IVUs, veins in the __________ are recommended and include:
antecubital fossa (“in front of the elbow”)
Median cubital
Cephalic
basilic
Veins in this region are generally large, easy to access, and durable enough to withstand a bolus injection of contrast agents without extravasation
the antecubital fossa
Other veins that may be selected for injection of contrast include
cephalic vein of lateral wrist and veins on posterior hand or lower forearm such as cephalic or basilic
DO NOT inject contrast media directly into
a shunt, central line, or vascular catheter unless it has been manufactured for contrast injections or under direction of a physician
What size needle is most commonly used for bolus injections of 50 to 100 mL (cc) of contrast solution on adults?
an 18- to 20- gauge butterfly needle. For pediatric patients a smaller 23- to 25 gauge needle is often used.
It is recommended that IV access be maintained until
imaging procedure is completed in the event that treatment for an adverse contrast reaction becomes necessary
Expected outcome (typical feelings during injection) of injected contrast media:
Temporary hot flash
Metallic taste in mouth
Usually pass quickly
Discussing these with patient reduces anxiety and prepares patient psychologically.
Questions to ask patient when taking patient’s history:
- Are you allergic to anything?
- Have you ever had hay fever asthma, or hives
- Are you allergic to any drugs or medications?
- Are you allergic to iodine?
- Are you allergic to any foods
- Are you currently taking metformin, Glucophage, Glucovance, Avandamet, Fortamet, Riomet, Actosplus, Met, Diabex, or Metaglip?
- Have you ever had an x-ray exam that required an injection into an artery or vein?
Normal Creatinine level (adult)
0.6 to 1.5 mg/dl
Normal BUN levels (adult)
8 to 25 mg/100 ml
Elevated levels of either creatinine or BUN levels may indicate
indicate acute or chronic renal failure, tumor, or other conditions of the urinary system.
Patients with elevated blood levels have a greater chance of
experiencing adverse contrast media reaction
Combination of iodinated contrast media and metformin may increase risk for
contrast media-induced acute renal failure and/or lactic acidosis
ACR recommends that metformin be withheld
for 48 hours after the procedure and resumed only if kidney function is determined to be within normal limits.
Radiographer must review chart and ask the patient whether he/she is taking metformin. If patient says yes – inform radiologist before injection. Why?
Current kidney function must be verified
Referring physician is notified to check kidney function 48 hours after procedure before medication is resumed
When preparing for an injection of contrast media, what should be done with the empty container of contrast?
Empty container should be shown to radiologist or person who is making actual injection. Empty contrast container should be kept in exam room until procedure is complete and patient dismissed
Who is responsible for ensuring emergency cart is stocked and available in room during injection procedures?
the radiographer.
Patients who have a history of hay fever, asthma, food allergies, or previous contrast media reaction may be candidates for the pre-medication procedure. What is one common pre-medication protocol?
Give combination of Benadryl and prednisone over a period of 12 or more hours before the procedure.
Categories of Contrast Media Reactions
- Mild
- Moderate
- Severe
- Organ specific
Mild reactions to contrast media:
Nonallergic reaction does not typically require drug intervention or medical assistance.
Treatment of mild reactions to contrast media:
includes having patient breath slowly, providing cool cloth, reassuring patient. Continue to observe and monitor to ensure that symptoms do not advance into more serious condition
Symptoms of mild reaction to contrast media:
Anxiety Light-headedness Nausea Vomiting Metallic taste (common side effect) Mild erythema Warm, flush sensation during injection (common side effect) Itching
Moderate reaction to contrast media:
A true allergic reaction (anaphylactic reaction)
Symptoms of a moderate reaction to contrast media:
Urticaria (moderate to severe hives) Possible laryngeal swelling Bronchospasm Tachycardia (100 beats per minute) Bradycardia (60 beats per minute) Angioedema Hypotension
Treatment for moderate reaction to contrast media:
Moderate reaction may lead to life-threatening, medical assistance must be provided without delay. Treatment: often drug intervention to counter effects of reaction
Severe reaction to contrast media:
Life-threatening reaction known as vasovagal reaction. (From the book) Introduction of contrast media stimulates the vagus nerve, which may cause heart rate to drop and blood pressure to fall dangerously low. Fast and prompt response from medical team is required.
Symptoms of severe reaction to contrast media:
Hypotension (systolic blood pressure 80 mm Hg) Bradycardia (50 beats/min) Cardiac arrhythmias Laryngeal swelling Possible convulsions Loss of consciousness Cardiac arrest Respiratory arrest No detectable pulse
Treatment of severe reaction to contrast media:
Medical emergency must be declared immediately
Emergency cart available with oxygen and suction apparatus
Hospitalization is eminent
Organ-specific reaction to contrast media:
Specific organs are affected by the contrast media injection.
Organ specific symptoms of reaction to contrast media include:
Cardiac system—pulseless electrical activity
Respiratory system—pulmonary edema
Vascular system—venous thrombosis
Nervous system—seizure induction
Renal system—temporary failure or complete shutdown
Extravasation—leakage of contrast media outside of the vessel into the surrounding soft tissues
Organ specific reaction follows contrast media injection and may not be identifiable for up to ___ hours after the study has been completed.
48
Treatment of organ specific reactions includes:
monitoring, possible hydration, administration of Lasix (diuretic), interventional cardiac medications, antiseizure medications, and renal dialysis
Because reaction type occurs after urographic procedure has been completed patient should be instructed to
alert the physician of any difficulties producing urine or other unusual symptoms.
Suggested treatment of extravasation:
Notify department nurse and/or physician.
Elevate affected extremity above heart to decrease capillary pressure and promote reabsorption of extravasated contrast media.
Use cold compress followed by warm compresses first to relieve pain and then to improve resorption of contrast media.
Document the incident.
Excretory or intravenous urography (IVU) :
Common radiologic exam of the urinary system.
Often referred to as an IVP or intravenous pyelogram.
Pyelo refers only to
the renal pelves. Excretory or intravenous urogram normally visualizes more anatomy than just the renal pelvis so the term IVP is not accurate.
The IVU visualizes:
the minor and major calyces, renal pelves, ureters, and urinary bladder after injection of a contrast medium.
The IVU is a functional test because
contrast medium molecules are removed from the bloodstream and excreted completely by the normal kidneys.
Purpose of IVU:
- Visualize the collecting portion of the urinary system
- Evaluate kidney function
- Evaluate urinary system for pathology or anatomic anomalies
Contraindications to IVU:
Hypersensitivity to iodinated contrast media Anuria Multiple myeloma Diabetes Severe hepatic or renal disease Congestive Heart Failure Pheochromocytoma
Pheochromocytoma
Usually benign tumor of the adrenal medulla. Over-secretion of epinephrine and/or norepinephrine by the tumor cells is associated with hypertension.
Diuretic-
An agent that increases excretion of urine
Lasix
Brand name for a diuretic
Lithotripsy
Therapeutic technique that uses acoustic (sound) waves to shatter large kidney stones into small particles that can be passed
Oliguria
excretion of a diminished amount of urine in relation to fluid intake (hypouresis or oliouresis
Urinary reflux
backward or return flow of urine from bladder into ureter and kidney; also called vesicoureteral reflux; common cause of pyelonephritis, in which backflow of urine may carry bacteria that can produce infection in the kidney
Urinary Tract Infection (UTI):
infection caused by bacteria, viruses, fungi, or certain parasites; commonly caused by urinary reflux
Patient Preparation for an IVU
Light evening meal prior to the procedure
Bowel-cleansing laxative
NPO after midnight (minimum of 8 hours)-not dehydrated
Enema on the morning of the examination
Voiding prior to procedure.
Why is voiding prior to an IVU important?
Bladder that is too full could rupture
Urine present in bladder dilutes contrast media
Pregnancy precautions for IVU:
IVUs may be performed to rule out urinary obstruction
Radiologist determines routine to reduce # of radiographs
Higher kV with lower mAs reduces patient exposure
Bowel preparation is not attempted in infants and children getting an IVU. What is recommended instead?
It has been recommended by some that infants and children be given a carbonated soft drink to distend the stomach with gas.
How does distending the stomach with gas help see the urinary system during a pediatric IVU?
the gas-containing intestinal loops are usually pushed inferiorly and the upper urinary tracts, particularly those on the left side of the body, are then clearly visualized through the outline of the gas-filled stomach.
To fully inflate the stomach of a child undergoing an IVU, at least __ ounces of a carbonated soft drink should be given to a newborn infant, and _____ ounces are required for a child 7 or 8 years old.
2, a full 12
Supplies needed for an IVU
Correct type and amount of contrast Empty container of contrast media Selection of needles Alcohol wipes Procedure gloves Tourniquet Support for elbow Sharps container Male gonadal shield Emesis basin Epinephrine or benadryl Ureteric compression (if used) Cold towel (or warm towel) Operational and accessible oxygen and suction devices
Ureteric Compression:
Enhances filling of pelvicalyceal system and proximal ureters
Allows renal collecting system to retain contrast longer
Where are the paddles of the ureteric compression device placed?
Should be positioned over the point where the ureters cross the psoas muscles
Once contrast media is introduced with ureteric compression device in place,
the paddles are inflated and remain in place until post-compression images are ready to be obtained.
Contraindications to Ureteric Compression
Possible ureteric stones Abdominal mass Abdominal aortic aneurysm Recent abdominal surgery Severe abdominal pain Acute abdominal trauma
Alternative to ureteric compression:
Position the pt trandelenburg. Head end of the table is lowered 15 degrees.
Purpose of the scout film for an IVU:
Verifies patient prep
Determines acceptable exposure factors
Verifies positioning
Detects abnormal calcifications
What is usually the first thing done when performing an IVU?
Patient history taken.
When does the radiologist see the scout film for an IVU?
Prior to injection.
If the pt is catheterized for the IVU:
clamp before injection.
Timing for entire IVU series is based on
start of injection. Exact time and length of injection should be noted
Injection usually takes
between 30 seconds and 1 minute
Most reactions (for IVU)occur within first __ minutes following injection—though delayed reactions occur
5.
Patient is observed for signs and symptoms indicating a reaction to the contrast during an IVU. What should be noted?
Chart the amount and type of contrast given to patient
According to the preference of the radiologist, ______ of contrast agent is used for adults
30 to 100 ml
The dosage administered to infants and children is regulated according to
age and weight.
After full injection at start of IVU procedure:
radiographs are taken at specific time intervals. Each image marked with lead numbers to indicated time interval when radiograph was taken
The initial contrast “blush” of the kidney is termed the
nephron phase
After the nephron phase, as kidneys continue to filter and concentrate the contrast medium, it is directed to the
pelvicalyceal system.
During an IVU, depending on patient’s hydration status and the speed of the injection, the contrast agent normally begins to appear in the pelvicalyceal system within
2-8 minutes.
The greatest concentration of contrast medium in the kidneys, during an IVU, normally occurs
15 to 20 minutes after injection.
Common basic IVU routine:
- Nephrogram or Nephrotomogram
- 5-Minute image
- 10- to 15- Minute image
- 20-Minute obliques
- Postvoid
Nephrogram or Nephrotomogram
Taken immediately after injection (or 1 min. after start of injection)
Captures early stages of entry of contrast media into collecting system
5-Minute image & 10- to 15- Minute image
Full KUB to include entire urinary system Usually supine (AP)
20-Minute obliques
LPO and RPO-Upside kidney parallel to IR and projects downside ureter away from spine
Postvoid
AP, PA or erect AP
What is a Postrelease or “Spill” Procedure with Ureteric Compression?
Full size radiograph taken after compression has been released
Used to assess for asymmetric renal function
How is a Postrelease or “Spill” Procedure with Ureteric Compression performed?
Compression applied immediately after 5 minute radiograph
Removed immediately before 15-minute radiograph
Erect Position for Bladder: For what exam is it taken and why?
Radiograph taken before voiding during an IVU: Prolapse of bladder
Enlarged prostate
Delayed Radiographs: for what reason would they be taken?
Filling of involved ureter is often slow in patients with urinary calculi
Patient may be brought back to department on a 1 to 2 hour basis
Why would Prone Radiographs be taken?
May be recommended for demonstration of the ureteropelvic region and for filling the obstructed ureter in patients with hydronephrosis.
The ureters fill better in the prone position because it reverses the curve of their inferior course
Hydronephrosis
distention of the renal pelvis and calyces of the kidneys as a result of some obstruction of the ureters or renal pelvis.
Causes of hydronephrosis:
It may be present in both kidneys in a female when the ureters are compressed by the fetus.
Other more common causes are calculi (stones) in the renal pelvis or ureter, tumors, and structural or congenital abnormalities.
The supine position allows the more ______ placed upper calyces to fill more readily and the ____________________ fill more in the prone position.
posteriorly, anterior and inferior parts of the pelvicalyceal system
Why would 14x17 Upright Radiographs be taken?
Demonstrates mobility of the kidneys and determines if the kidney’s mobility is beyond normal limits. (also provides information as described in erect position of bladder)
Nephron phase is
a blush of the entire kidney substance.
Blush results from contrast throughout nephrons
When is a Nephrogram image obtained?
1 minute after start of injection. Ureteric compression can prolong nephron phase to as long as 5 minutes in the normal kidney
If the nephrogram is taken with tomography it is called a
nephrotomogram. 3 tomograms and 3 focal levels
Centering and IR size confined to kidneys
Usually midway between iliac crest and xiphoid
One method to determine initial fulcrum level for nephrotomogram:
measure thickness of mid-abdomen with calipers and then divide that number by 3.
A 24 cm abdomen would require an 8 cm cut a 7 cm cut and a 6 cm cut
Timing during an IVU is critical, so exposure must be made exactly ________ after start of injection
60 seconds.
Table, IR and control panel must be set before injection is begun
Injection sometimes takes nearly 60 seconds to complete
Examinations of Urinary System:
- Intravenous Urography (Excretory Urography)
- Hypertensive Intravenous Urography
- Retrograde Urography
- Retrograde Cystography
- Voiding Cystourethrography
- Retrograde Urethrography
Purpose of a Hypertensive IVU
IVU for patients with high blood pressure
Determines whether kidneys are cause of hypertension
Suggested protocol for a hypertensive IVU:
Radiographs taken every minute for up to 5 minutes
After 5-minute IR, standard IVU routine
Check with radiologist to determine additional images to be taken.
True or false: Hypertensive IVU’s are a common procedure today.
False
Retrograde Urography: Indications and contraindications:
The retrograde urogram is indicated for evaluation of the collecting system in patients who have renal insufficiency or who are allergic to iodinated contrast media.
Under what conditions is a retrograde urography performed?
Performed in surgery-patient sedated or anesthesized
STERILE. Contrast media delivered to pelvicalyceal system retrograde through catheter by urologist
What is a retrograde urography and what is its purpose?
Nonfunctional exam of urinary system
Determines location of calculi or other type of obstruction
How is the pt positioned for a retrograde urography?
The patient is placed on the cystoscopic table in a modified lithotomy position.
Once the pt is positioned for a retrograde urography, what happens?
The patient is then sedated or anesthesized
Patient is draped appropriately
The urologist inserts a cystoscope through the urethra and into the bladder
Retrograde Urography: After the urologist examines the bladder,
ureteral catheters are inserted into one or both ureters.
The tip of each ureteral catheter is placed at the level of the renal pelvis
Retrograde Urography: What is performed After catheterization?
Scout film. Radiographer checks technique and positioning. Urologist checks placement of the catheter.
Retrograde Urography: Once the Urologist checks placement of the catheter,
he/she then injects 3 to 5 ml of contrast through the catheter into the renal pelvis of one or both kidneys.
What is the second radiograph of the retrograde urograph?
The pyelogram. Respiration is suspended after the injection. This demonstrates the renal pelvis and major and minor calyces.
Retrograde urography: The THIRD and final radiograph is the:
ureterogram. The head of the table may or may not be elevated.
Retrograde urography: After the third radiograph, the urologist withdraws the catheters and
simultaneously injects contrast medium in one or both ureters.
For all radiographs taken during retrograde urography, exposure is made after:
anesthesist suspends respiration if the patient is under general anesthesia.
Retrograde Urography: Who generally indicates when to make exposure?
The urologist.
Retrograde Cystography: How is the contrast media delivered?
Catheter.
Retrograde Cystography: How much contrast media is used?
150-500 cc
Retrograde Cystography: How is the procedure viewed?
The gravity flow of the contrast media is viewed via fluoro with AP and AP obliques. Introducing the contrast too quickly could result in rupture of the bladder.
Retrograde Cystography: Purpose
NONFUNCTIONAL radiographic exam of the urinary bladder after iodinated contrast media has been introduced by a catheter.
The cystogram is a common procedure performed to rule out
trauma, calculi, tumor, and inflammatory disease of the urinary bladder
This is or is not, a surgical procedure and is carried out in the fluoroscopy room?
Is NOT. Cystoscopy is not required
Retrograde cystography: Pt prep:
There is no patient preparation but patient should empty bladder before catheterization.
Retrograde Cystography: After catheterization under aseptic conditions, the bladder is:
drained of any residual urine.
Retrograde Cystography: Filling the bladder may require :
150 to 500 cc and is filled under fluoroscopic guidance
Radiologist may take spot films
Voiding Cystourethrography: Purpose:
Functional study of the bladder and urethra
Performed after routine cystogram
Voiding Cystourethrography: Pathologic Indications:
Trauma or incontinence are common pathologic indications for a VCU exam.
Voiding Cystourethrography: Procedure:
The voiding phase of the examination is done under fluoroscopy
Procedure is performed with patient supine.
Voiding Cystourethrography: How is female pt viewed compared to male pt?
The female is examined in the AP or slight oblique position.
The male is best examined in a 30 degree AP oblique projection—RPO position
Where to center for Voiding Cystourethrography?
symphysis pubis
Retrograde Urethrography: Purpose:
Nonfunctional radiographic study of the male urethra
Basics of Retrograde Urethrography:
Retrograde injection of contrast media
Use of Brodney clamp
Patient in 30° RPO position
Rarely performed
Retrograde Urethrography: Pathologic Indications:
Trauma or obstruction of the urethra
How is contrast media delivered for an IVU?
intravenous injection: antegrade flow of media through superficial vein in arm.
How is contrast media delivered for retrograde urography?
retrograde injection through ureteral catheter by a urologist as a surgical procedure
How is contrast media delivered for retrograde cystography?
retrograde flow into the bladder through ureteral catheter driven by gravity.
How is contrast media delivered for VCUG?
retrograde flow into the bladder through ureteral catheter , followed by removal of catheter for imaging during voiding.
How is contrast media delivered for Retrograde Urethrography on a male?
retrograde injection through Brodney clamp or special catheter.
Pediatric Applications for urinary system exams:
Preparation for IVU for infant and young child must be monitored carefully-can’t restrict fluids for long period of time
Increased use of US for urinary conditions-no radiation
Geriatric applications for urinary system exams:
May be affected negatively by change in diet and food intake before IVU
Must be carefully monitored during procedure
Many have clinical history of diabetes
Alternative modalities and procedures for urinary system:
CT, MRI, Nuclear Med, Ultrasound
Renal cysts and/or adrenal masses may be demonstrated during this phase of IVU:
Nephrotomogram or nephrogram
RPO and LPO Positions: IVU: What is shown?
Trauma or obstruction to downside ureter
AP Projection: IVU - Postvoid: Pathology Demonstrated:
Enlarged prostate (possible BPH) or prolapse of bladder nephroptosis
AP Projection: IVU—Ureteric Compression: Pathology Demonstrated:
Pyelonephritis and other conditions involving the collecting system
Cystography: AP/LPO and RPO and Lateral (special): Pathology demonstrated:
Signs of cystitis Obstruction Vesicoureteral reflux Bladder calculi Lateral projection will demonstrate possible fistulas between bladder and uterus or rectum
Cystography: AP: Central Ray
2 inches (5 cm) superior to pubic symphysis with 10° to 15° caudad tube angle Projects pubic symphysis inferior to bladder
Cystography: Posterior Obliques position:
45° to 60° body rotation.
Visualizes posterolateral aspect of bladder, especially UV junction
Cystography: Posterior Obliques Central ray:
2 inches (5 cm) superior to pubic symphysis and 2 inches (5 cm) medial to ASIS To demonstrate urinary reflux, center higher at level of iliac crest
Cystography: Lateral: Central Ray
Perpendicular
Center 2 inches (5 cm) superior and posterior to pubic symphysis
Voiding Cystourethrography: Pathology demonstrated
Determines causes of urinary retention
Evaluates for possible vesicoureteral reflux
