CH.3 ABDOMEN Flashcards
Acute Abdominal Series
supine KUB, upright AP or decubitus abdomen, and PA or AP chest
Certain acute or emergency conditions of the abdomen may develop from conditions such as
bowel obstructions
perforations
abdominal masses
most important Abdominal Muscles in radiographic imaging?
right and left hemi-diaphragm
right and left psoas major and minor muscles
where are the important abdominal muscles located?
The right hemi-diaphragm is attached anteriorly to the fifth rib and posteriorly at the level of the tenth rib. The left hemi-diaphragm is located near the first intercostal space.
The psoas major muscles are located laterally to the lumbar vertebrae.
Abdominal Organ Systems
digestive system, urinary system, and reproductive system
Digestive System
- Oral cavity
- Pharynx
- Esophagus
- Stomach
- Small intestine
- Large intestine
The digestive system accessory organs?
liver, gallbladder, pancreas
- Oral cavity
the mouth
- Pharynx
a passageway in the head and neck that is part of both the digestive system and the respiratory system
- Esophagus
The esophagus is located in the mediastinum of the thoracic cavity.
- Stomach
The stomach is the first organ of the digestive system that is located entirely within the abdominal cavity. The stomach is an expandable reservoir for swallowed food and fluids
- Small intestine
The small intestine continues from the stomach as a long, tubelike convoluted structure about 15 to 18 feet (4.5 to 5.5 m) in length. The three parts of the small intestine, as labeled in descending order.. duodenum, jejunum, ileum
- Large intestine
The sixth and last organ of digestion is the large intestine, which begins in the right lower quadrant at the junction of the small intestine and the ileocecal valve.
What are the three digestive organs within the abdominal cavity?
Stomach, small intestine, large intestine
What is the primary function of the stomach?
Expandable reservoir for swallowed food and fluids
What does the combining form ‘gastro’ refer to?
Relationship to the stomach
What is the gastrointestinal (GI) tract?
Entire digestive system starting with the stomach and continuing through the small and large intestines
How long is the small intestine?
About 15 to 18 feet (4.5 to 5.5 m)
What are the three parts of the small intestine?
- Duodenum
- Jejunum
- Ileum
What is the length of the duodenum?
About 10 inches (25 cm)
What shape does the duodenum resemble when filled with contrast medium?
The letter C
What drains into the duodenum to aid in digestion?
Ducts from the liver, gallbladder, and pancreas
What is the ileocecal valve?
The orifice (valve) between the distal ileum and the cecum portion of the large intestine
What is the first portion of the large intestine called?
Cecum
Where does the large intestine begin?
In the right lower quadrant at the junction of the small intestine and the ileocecal valve
What are the alternative names for the colic flexures?
- Hepatic (right) flexure
- Splenic (left) flexure
What is the final 6 inches (15 cm) of the large intestine called?
Rectum
What is the terminal opening of the large intestine known as?
Anus
How does the shape and location of the large intestine vary?
It varies greatly with different body habitus
Fill in the blank: The vertical portion of the large bowel above the cecum is called the _______.
Ascending colon
True or False: The small intestine is wider in diameter than the duodenum.
False
What is the spleen and its significance in the circulatory system?
The spleen is part of the lymphatic system and circulatory system, located posterior and to the left of the stomach in the left upper quadrant.
Where is the spleen located in the body?
It occupies a space posterior and to the left of the stomach in the left upper quadrant.
What happens to the spleen during trauma?
The spleen is a fragile organ and may be lacerated during trauma to the lower left posterior rib cage.
Name the three accessory organs of digestion.
- Pancreas
- Liver
- Gallbladder
What is the function of accessory organs of digestion?
They aid in digestion via the materials they secrete into the digestive tract.
Describe the pancreas in terms of its location and size.
The pancreas is an elongated gland located posterior to the stomach and near the posterior abdominal wall, averaging about 6 inches (12.5 cm) in length.
What is the relationship between the pancreas and the duodenum?
The head of the pancreas is nestled in the C-loop of the duodenum.
What are the two secretion systems of the pancreas?
- Endocrine (internal) secretion system
- Exocrine (external) secretion system
What hormone does the endocrine portion of the pancreas produce?
Insulin
How much digestive juice does the pancreas produce daily?
About 1½ quarts (1500 mL) daily.
What is the largest solid organ in the body?
The liver.
What is one of the functions of the liver?
Production of bile that assists in the emulsification of fats.
Where is the gallbladder located?
Posterior and inferior to the liver.
What happens to bile when it is not needed for fat emulsification?
It is stored and concentrated in the gallbladder.
What hormone stimulates the gallbladder to release bile?
Cholecystokinin.
What is cholelithiasis?
The presence of one or more calculi (gallstones) in the gallbladder.
What are the two types of gallstones?
- Cholesterol-based gallstones
- Pigment-based stones
Which population is more likely to have cholesterol-based gallstones?
Populations within the United States (80%).
What percentage of gallstones contain enough calcium to allow visualization on an abdominal image?
About 20%.
What imaging modality is better for detecting radiolucent gallstones?
Diagnostic ultrasound.
What anatomical relationships do CT images demonstrate?
Anatomic relationships of the digestive organs and their accessory organs, in addition to the spleen.
At what level of the thoracic vertebra are the CT images taken to visualize the upper abdomen?
At the level of T10 or T11.
Where is the spleen visualized in relation to the stomach on an axial view of the upper abdomen?
Posterior to the stomach in the left upper quadrant.
What anatomical structures are seen in the mid-abdomen CT image at the level of L2?
- Abdominal aorta
- Inferior vena cava
- Kidneys
What indicates the patient’s position during the CT scan of the mid-abdomen?
The dark air-filled portion of the transverse colon indicates that the patient was lying in a supine position.
What are the main components of the urinary system?
- Two kidneys
- Two ureters
- One urinary bladder
- One urethra
The urinary system is crucial for waste elimination and urine storage.
What is the function of the kidneys in the urinary system?
Eliminate waste materials and excess water from the blood
The kidneys filter blood to remove waste and regulate water balance.
Where are the kidneys located in relation to the lumbar vertebral column?
On either side of the lumbar vertebral column
The right kidney is typically situated a little more inferior than the left due to the liver.
What is the role of the ureters?
Transport urine from the kidneys to the urinary bladder
Each kidney has its own ureter that drains urine.
What is the position of the urinary bladder?
Superior and posterior to the symphysis pubis
The bladder stores urine until it is excreted.
What is the name of the examination used to visualize the urinary system with contrast medium?
Excretory or intravenous urogram (IVU)
This examination allows visualization of the hollow organs of the urinary system.
True or False: The term intravenous pyelogram (IVP) is currently the correct term for the examination of the urinary system.
False
The correct terms are excretory urogram (EU) and intravenous urogram (IVU).
What are the labeled structures in a sectional CT image of the urinary system?
- Inferior lobe of liver
- Ascending colon
- Right kidney
- Right ureter
- Right psoas major
- L2–L3 vertebra
- Left kidney
- Left ureter
- Descending colon
- Loops of small intestines (jejunum)
These structures help identify the anatomical relationships within the abdomen.
What major blood vessels are seen in the sectional image of the abdomen?
- Abdominal aorta
- Inferior vena cava
These vessels are critical for blood circulation in the abdominal region.
Fill in the blank: The stored urine passes to the exterior environment via the _______.
urethra
The urethra is under voluntary control for urine excretion.
What is the term for the large serous, double-walled, saclike membrane covering the abdominal cavity?
Peritoneum
The total surface area of the peritoneum is approximately equal to the total surface area of the skin that covers the entire body.
What are the two types of peritoneum?
- Parietal peritoneum
- Visceral peritoneum
Parietal peritoneum adheres to the abdominal cavity wall, while visceral peritoneum covers the organs.
What is the space between the parietal and visceral peritoneum called?
Peritoneal cavity
This space is normally filled with various organs and some serous lubricating-type fluid.
What condition is characterized by an abnormal accumulation of serous fluid in the peritoneal cavity?
Ascites
What structures are referred to as retroperitoneal?
- Ascending colon
- Descending colon
- Aorta
- Inferior vena cava
These structures are only partially covered by the visceral peritoneum.
What is mesentery?
A double fold of peritoneum that connects the small intestine to the posterior abdominal wall
Mesentery binds the abdominal organs to each other and contains blood and lymph vessels, as well as nerves.
What does the term omentum refer to?
A specific type of double-fold peritoneum extending from the stomach to another organ
The lesser omentum connects the stomach to the liver, while the greater omentum connects the stomach to the transverse colon.
What is the function of the greater omentum?
It serves as a layer of insulation and drapes over the small bowel
The greater omentum can be referred to as the ‘fatty apron’ due to the fat deposited in it.
Fill in the blank: The _______ is the double fold of peritoneum that extends from the stomach to the liver.
Lesser omentum
True or False: The greater omentum is the first structure encountered beneath the parietal peritoneum when dissecting the abdomen.
True
What is the role of the serous lubricating-type fluid in the peritoneal cavity?
Allows organs to move against each other without friction
What is the mesocolon?
The peritoneum that attaches the colon to the posterior abdominal wall
The prefix meso- refers to mesentery-type folds from which other abdominal organs are suspended.
How many forms of mesocolon exist and what are they named?
Four forms:
* ascending
* transverse
* descending
* sigmoid or pelvic
Each form is named according to the portion of the colon to which it is attached.
What are the two parts of the peritoneal cavity?
Greater sac and lesser sac
The greater sac is commonly referred to as simply the peritoneal cavity, while the lesser sac is also known as the omentum bursa.
What is considered a retroperitoneal organ?
Structures closely attached to the posterior abdominal wall
Examples include kidneys, ureters, adrenal glands, pancreas, C-loop of duodenum, ascending and descending colon, upper rectum, abdominal aorta, and inferior vena cava.
What is the definition of infraperitoneal organs?
Organs located under or beneath the peritoneum
Examples include lower rectum, urinary bladder, and reproductive organs.
What qualifies an organ as intraperitoneal?
Organs partially or completely covered by visceral peritoneum
Examples include liver, gallbladder, spleen, stomach, jejunum, ileum, cecum, transverse and sigmoid colon.
True or False: The lower aspect of the peritoneum is a closed sac in females.
False
In females, the uterus, uterine tubes, and ovaries pass directly into the peritoneal cavity.
What is a key difference between male and female peritoneal enclosures?
The lower peritoneal sac is closed in males but not in females
In males, it lies above the urinary bladder, separating reproductive organs from those within the peritoneal cavity.
What are the intraperitoneal organs?
Liver, Gallbladder, Spleen, Stomach, Jejunum, Ileum, Cecum, Transverse colon, Sigmoid colon
Intraperitoneal organs are those completely surrounded by peritoneum.
What are the retroperitoneal organs?
Kidneys, Ureters, Adrenal glands, Pancreas, C-loop of duodenum, Ascending and descending colon, Upper rectum, Major abdominal blood vessels (aorta and inferior vena cava)
Retroperitoneal organs are located behind the peritoneum.
What are the infraperitoneal (pelvic) organs?
Lower rectum, Urinary bladder, Reproductive organs (Male—closed sac, Female—open sac including uterus, tubes, and ovaries)
Infraperitoneal organs are located below the peritoneum.
How is the abdomen divided into four quadrants?
By two imaginary perpendicular planes at the umbilicus
One horizontal and one vertical plane create the four quadrants.
What are the names of the four abdominal quadrants?
Right upper quadrant (RUQ), Left upper quadrant (LUQ), Right lower quadrant (RLQ), Left lower quadrant (LLQ)
These quadrants help in localizing organs and describing abdominal pain.
What structures are located in the right upper quadrant (RUQ)?
Liver, Gallbladder, Right colic (hepatic) flexure, Duodenum (C-loop), Head of pancreas, Right kidney, Right suprarenal gland
RUQ contains major digestive organs and parts of the urinary system.
What structures are located in the left upper quadrant (LUQ)?
Spleen, Stomach, Left colic (splenic) flexure, Tail of pancreas, Left kidney, Left suprarenal gland
LUQ contains organs associated with digestion and filtration.
What structures are located in the right lower quadrant (RLQ)?
Ascending colon, Appendix (vermiform), Cecum, 2⁄3 of ileum, Ileocecal valve
RLQ is significant for appendicitis and other digestive issues.
What structures are located in the left lower quadrant (LLQ)?
Descending colon, Sigmoid colon, 2⁄3 of jejunum
LLQ is important for bowel-related conditions.
How is the abdominopelvic cavity divided into nine regions?
Using two horizontal planes (transpyloric and transtubercular) and two vertical planes (right and left lateral)
This division provides a more detailed anatomical reference.
What are the names of the nine abdominal regions?
Right hypochondriac, Epigastric, Left hypochondriac, Right lateral (lumbar), Umbilical, Left lateral (lumbar), Right inguinal (iliac), Pubic (hypogastric), Left inguinal (iliac)
These regions help in the precise identification of organ locations.
True or False: The four-quadrant system is used most frequently in imaging for localizing organs.
True
It is easier to describe locations of pain or symptoms using this system.
What are the seven palpable landmarks of the abdomen?
- Xiphoid process
- Inferior costal margin
- Iliac crest
- Anterior superior iliac spine
- Greater trochanter
- Symphysis pubis
- Ischial tuberosity
These landmarks are critical for positioning and locating organs within the abdomen.
What is the xiphoid process and its significance in abdominal positioning?
The xiphoid process is the most inferior process of the sternum, located at the level of T9–T10. It approximates the superior anterior portion of the diaphragm, but is not a primary landmark for positioning due to body type variations.
It is palpated by pressing gently on the abdomen below the distal sternum.
At what vertebral levels is the inferior costal margin located?
L2–L3
This landmark is used to locate upper abdominal organs, such as the gallbladder and stomach.
How can the iliac crest be palpated?
The iliac crest can be palpated by pressing inward and downward along the mid-lateral margin of the abdomen.
It corresponds approximately to the mid-abdominopelvic region and is often used for abdominal imaging.
What is the anterior superior iliac spine (ASIS) and how is it located?
The ASIS is located by palpating the iliac crest and then moving anteriorly and inferiorly until a prominent projection is felt.
It is more prominent in females and is used for positioning pelvic and vertebral structures.
What is the greater trochanter and its palpation technique?
The greater trochanter is a landmark that can be palpated more easily on thin patients by feeling the movement while rotating the leg.
It serves as a secondary landmark for abdominal positioning.
What anatomical feature does the symphysis pubis represent?
The symphysis pubis is the anterior junction of the two pelvic bones and corresponds to the inferior margin of the abdomen.
Palpation may be uncomfortable for some patients.
What is the ischial tuberosity and its role in abdominal positioning?
The ischial tuberosity can be palpated to determine the lower margin on a PA abdomen projection.
It is located about 0.4 to 1.5 inches below the symphysis pubis and may be uncomfortable for the patient.
True or False: Palpation of abdominal landmarks should be performed firmly and quickly.
False
Palpation must be performed gently to avoid discomfort, and the patient should be informed of the purpose beforehand.
Fill in the blank: The iliac crest corresponds approximately to the level of the _______.
[umbilicus]
This is true for most people and is significant for imaging.
What is the primary concern when imaging pediatric patients?
Motion prevention and short exposure times
Pediatric patients require special considerations to minimize repeat exposures.
For children younger than 13 years, what adjustments are needed based on measured part thickness?
Reduction in kVp and mAs
Confirmed technique factors should always be available to minimize repeat exposures.
When is it unnecessary to use grids in pediatric abdominal radiographic procedures?
If measured thickness is less than 10 cm
This simplifies the imaging process in certain cases.
What additional care is often needed for geriatric patients during radiographic procedures?
Extra care and patience in explaining procedures
This includes careful breathing instructions and assistance in positioning.
What measures can enhance comfort for thin geriatric patients during supine abdomen radiographic procedures?
Extra radiolucent padding and blankets
These measures help keep patients warm and comfortable.
How is the positioning of bariatric patients for abdomen projections similar to that of sthenic patients?
Similar positioning techniques are applied
However, challenges arise in palpating bony landmarks.
What may need to be moved to locate bony landmarks on morbidly obese patients?
Folds of adipose tissue and skin
This can lead to embarrassment for the patient.
What landmarks may be used to determine the upper margin of the IR for bariatric patients?
Xiphoid process (T9–T10) or lower costal margin (L2–L3)
The ASIS may also be used for the lower abdomen margin.
Why might using the umbilicus as a landmark for the iliac crest be inaccurate?
Due to extension of the abdomen, skin folds, and possible past surgeries
This can complicate accurate imaging.
What is critical to image in bariatric patients to ensure complete abdominal visualization?
The entire abdomen to the skin margins
This is necessary because the large intestine often extends the abdomen’s width.
How should two exposures of the abdomen be taken for comprehensive imaging?
With landscape alignment and slight overlap of 1 to 2 inches
The first projection images the upper abdomen, and the second captures the lower abdominopelvic structures.
What is the recommended top and bottom placement of the IR for the first and second projections in a supine abdomen study?
Top at the xiphoid process and bottom at the symphysis pubis
This ensures visualization of all abdominal anatomy.
What is the first guideline for digital imaging of the abdomen?
Four-sided collimation to the body part being imaged and accurate centering are most important.
What does the ALARA principle stand for?
As low as reasonably achievable.
What exposure factors should be used in digital imaging of the abdomen?
The lowest exposure factors required to obtain a diagnostic image, including the highest kVp and the lowest mAs.
What should be checked after the processing of a digital image?
The exposure indicator on the final processed image.
Why is it important to verify the exposure factors used in digital imaging?
To ensure optimal quality with the least amount of radiation to the patient.
Fill in the blank: The guidelines for digital imaging emphasize the importance of _______.
four-sided collimation.
True or False: The highest mAs should always be used in digital imaging to ensure image quality.
False.
What should the technologist assess after each image in digital imaging?
The exposure factors and exposure indicator.
What is the purpose of an AP supine image of the abdomen (KUB)?
To evaluate and diagnose diseases and conditions involving abdominal organ systems
This is typically done before introducing contrast medium.
What is the acute abdomen series primarily used to evaluate?
Conditions or diseases related to bowel obstruction or perforation
It requires visualization of air-fluid levels and possible intraperitoneal free air.
Define ascites.
An abnormal accumulation of fluid in the peritoneal cavity of the abdomen
Usually caused by chronic conditions like cirrhosis or metastatic disease.
What does pneumoperitoneum refer to?
Free air or gas in the peritoneal cavity
It may require surgery if caused by perforation of a gas-containing viscus.
What is dynamic bowel obstruction?
The complete or nearly complete blockage of the flow of intestinal contents
It can be caused by fibrous adhesions, Crohn’s disease, or intussusception.
What is the most common cause of mechanical bowel obstruction?
Fibrous adhesions
These are fibrous bands of tissue that create a blockage in the intestine.
What is Crohn’s disease?
A chronic inflammation of the intestinal wall that results in bowel obstruction
Most common in young adults, affecting the terminal ileum and proximal colon.
What is intussusception?
The telescoping of a section of bowel into another loop, creating an obstruction
Most common in children and requires treatment within 48 hours.
What is the radiographic appearance of ascites?
General abdominal haziness
Seen in an acute abdomen series.
Fill in the blank: Pneumoperitoneum appears as a _______ under the dome of the right hemidiaphragm.
Thin, crest-shaped radiolucency
What appearance is associated with Crohn’s disease on an acute abdomen series?
Distended loops of air-filled small intestine with a cobblestone appearance
This is due to the inflammation of the intestinal wall.
What is volvulus?
The twisting of a loop of intestine, creating an obstruction
It may require surgery for correction.
What characterizes ileus as a nonmechanical obstruction?
Lack of intestinal motility, often seen postoperatively
It is categorized as adynamic or paralytic ileus.
What severe complication can arise from ulcerative colitis?
Toxic megacolon
This extreme dilation of a segment of colon may lead to perforation.
True or False: Barium enema is contraindicated in patients with toxic megacolon.
True
What is the radiographic appearance of an ileus?
Large amounts of air in the dilated small and large intestine with visible air-fluid levels
There is no distinct point of obstruction.
What is the clinical indication for an AP projection of the abdomen (KUB)?
Pathology of the abdomen, including bowel obstruction, neoplasms, calcifications, ascites, and scout image for contrast media studies of abdomen
What is the minimum SID for an AP projection of the abdomen?
40 inches (100 cm)
What is the recommended IR size for an AP projection of the abdomen?
14 × 17 inches (35 × 43 cm), portrait
What is the kVp range for an AP projection of the abdomen?
70–85
What is the purpose of shielding in an AP projection of the abdomen?
Shield radiosensitive tissues outside region of interest
Describe the patient position for an AP projection of the abdomen.
Supine with midsagittal plane centered to midline of table or IR, arms at sides, legs bent with support under knees
What is the proper part position for the IR in an AP projection of the abdomen?
Center of IR to level of iliac crests, with bottom margin at symphysis pubis
How should the CR be directed for an AP projection of the abdomen?
Perpendicular to and directed to center of IR (to level of iliac crest)
What is the recommended collimation for an AP projection of the abdomen?
14 × 17 inches (35 × 43 cm), collimate on four sides to anatomy of interest
When should the exposure be made during an AP projection of the abdomen?
At end of expiration
What should be done to account for involuntary motion of the bowel during exposure?
Allow about 1 second delay after expiration
True or False: A tall hyposthenic or asthenic patient may require two images placed portrait.
True
For a broad hypersthenic patient, how should the IRs be placed?
Two 14 × 17-inch (35 × 43-cm) IRs placed landscape, with one centered lower and the second for the upper abdomen
What should be checked to ensure proper positioning of the pelvis and shoulders?
Check that both ASIS are the same distance from the tabletop
Fill in the blank: The bottom margin of the first IR for a tall patient should be at the _______.
symphysis pubis
Fill in the blank: The top margin of the second IR for a tall patient should be at the _______.
xiphoid
What is the purpose of bending the legs with support under the knees during positioning?
To lessen lordotic lumbar curvature
What are the clinical indications for the PA projection in the prone position of the abdomen?
Pathology of abdomen, including bowel obstruction, neoplasms, calcifications, ascites, and scout image for contrast medium studies of abdomen
Why is the PA projection less desirable than the AP projection if the kidneys are of primary interest?
Increased object–image receptor distance (OID)
What is the benefit of using the PA projection in terms of exposure?
Helps to lower exposure due to tissue compression, leading to reduced part thickness
List the special abdominal projections.
- PA prone
- Lateral decubitus (AP)
- AP erect
- Dorsal decubitus (lateral)
- Lateral
What is the minimum SID for the PA projection of the abdomen?
40 inches (100 cm)
What is the recommended IR size for the PA projection of the abdomen?
14 × 17 inches (35 × 43 cm), portrait
What is the kVp range for the PA projection of the abdomen?
70–85
What should be done to protect radiosensitive tissues during the PA projection?
Shield radiosensitive tissues outside region of interest
Describe the patient position for the PA projection of the abdomen.
Prone with midsagittal plane of body centered to midline of table or IR, legs extended with support under ankles, arms up beside head
What is the correct CR direction for the PA projection of the abdomen?
Perpendicular to and directed to center of IR (to level of iliac crest)
What is the recommended collimation size for the PA projection of the abdomen?
14 × 17 inches (35 × 43 cm), field of view or collimate on four sides to anatomy of interest
When should the exposure be made during the PA projection of the abdomen?
At the end of expiration
True or False: Tall, asthenic patients may require two images placed portrait.
True
What anatomy should be demonstrated in the PA projection of the abdomen?
- Outline of liver
- Spleen
- Kidneys
- Psoas muscles
- Air-filled stomach and bowel segments
- Arch of the symphysis pubis for the urinary bladder region
What are the criteria for evaluating the position in the PA projection?
- No rotation
- Iliac wings appear symmetric
- Sacroiliac joints and outer lower rib margins should be the same distance from spine
- Collimation to area of interest
What indicates proper exposure in the PA projection of the abdomen?
- No motion
- Ribs and all gas bubble margins appear sharp
- Sufficient exposure (mAs) and long-scale contrast (kVp) to visualize psoas muscle outlines, lumbar transverse processes, and ribs
- Margins of liver and kidneys visible on smaller to average-sized patients
What is the clinical indication for using the Lateral Decubitus Position (AP Projection) of the abdomen?
Demonstrates abdominal masses, air-fluid levels, and possible accumulations of intraperitoneal air.
What is the best method to demonstrate small amounts of free intraperitoneal air?
Using chest technique on erect PA chest.
How long should the patient be in the lateral decubitus position before exposure?
A minimum of 5 minutes; 10 to 20 minutes is preferred.
Which position best visualizes free intraperitoneal air in the area of the liver?
Left lateral decubitus position.
What are the special projection types for the abdomen?
- PA prone
- Lateral decubitus (AP)
- AP erect
- Dorsal decubitus (lateral)
- Lateral
What is the minimum SID for the Lateral Decubitus Position?
40 inches (100 cm).
What is the size of the IR used for the Lateral Decubitus Position?
14 × 17 inches (35 × 43 cm), landscape.
What is the kVp range recommended for the Lateral Decubitus Position?
70–85.
What should be done for shielding during the Lateral Decubitus Position?
Shield radiosensitive tissues outside the region of interest.
Describe the patient positioning for the Lateral Decubitus Position.
- Lateral recumbent on radiolucent pad
- Firmly against table or vertical grid device
- Knees partially flexed
- Arms up near head
What is the CR direction for the Lateral Decubitus Position?
CR horizontal, directed to center of IR, at about 2 inches (5 cm) above level of iliac crest.
What is the recommended collimation size for the Lateral Decubitus Position?
14 × 17 inches (35 × 43 cm), or collimate on four sides to anatomy of interest.
When should the exposure be made during the Lateral Decubitus Position?
At the end of expiration.
What anatomy should be demonstrated in the Lateral Decubitus Position evaluation?
- Air-filled stomach
- Loops of bowel
- Air-fluid levels where present
- Bilateral diaphragm
What indicates proper positioning in the Lateral Decubitus Position?
- No rotation
- Iliac wings appear symmetric
- Outer rib margins equal distance from spine
True or False: The spine should be straight and aligned to the center of the IR.
True.
What is the exposure criteria for the Lateral Decubitus Position?
- No motion
- Ribs and gas bubble margins sharp
- Sufficient exposure to visualize spine and ribs
What is the clinical indication for an erect abdominal image?
Abnormal masses, air-fluid levels, and accumulations of intraperitoneal air under diaphragm
When should the erect abdominal image be performed?
If the patient comes to the department ambulatory or in a wheelchair in an erect position
What are the special views for abdomen imaging?
- PA prone
- Lateral decubitus (AP)
- AP erect
- Dorsal decubitus (lateral)
- Lateral
What is the minimum SID for erect abdominal imaging?
40 inches (100 cm)
What is the size of the IR used for erect abdominal imaging?
14 × 17 inches (35 × 43 cm), portrait
What is the kVp range for erect abdominal imaging?
70–85
What type of marker should be included on the IR?
Erect marker
What is the recommended shielding for erect abdominal imaging?
- Shield radiosensitive tissues outside region of interest
- Use gonadal shields on male patients
Describe the patient position for erect abdominal imaging.
- Upright
- Legs slightly spread apart
- Back against table or grid device
- Arms at sides away from body
- Midsagittal plane centered to midline
What should be done regarding the rotation of the pelvis or shoulders?
Do not rotate pelvis or shoulders
Where should the center of the IR be positioned relative to the iliac crest?
Approximately 2 inches (5 cm) above iliac crest
What is the CR orientation for erect abdominal imaging?
CR perpendicular to center of IR
What is the recommended collimation for the field of view?
14 × 17 inches (35 × 43 cm), collimated on four sides to anatomy of interest
When should the exposure be made during respiration?
At end of expiration
How long should the patient be upright before exposure?
Minimum of 5 minutes; 10 to 20 minutes is desirable
What should be done if a patient is too weak to maintain an erect position?
Perform a lateral decubitus
What is the anatomy demonstrated in an erect abdominal image?
- Air-filled stomach and loops of bowel
- Air-fluid levels where present
- Bilateral diaphragms
- As much of lower abdomen as possible
- Small free intraperitoneal crescent-shaped air bubble if present under right hemidiaphragm
What are the criteria for evaluating position in erect abdominal imaging?
- No rotation; iliac wings symmetric
- No tilt; spine straight and aligned with center of IR
- Collimation to area of interest
What are the exposure criteria for erect abdominal imaging?
- No motion; ribs and gas bubble margins sharp
- Sufficient exposure to visualize spine and ribs
- Slightly less overall density than supine abdomen preferred
What is the Dorsal Decubitus Position used for?
It is used for evaluating the abdomen, particularly for detecting abnormal masses, gas accumulations, aneurysms, calcification of vessels, and umbilical hernias.
The position can be right or left lateral.
List the clinical indications for using the Dorsal Decubitus Position.
- Abnormal masses
- Accumulations of gas
- Air-fluid levels
- Aneurysms
- Calcification of aorta or other vessels
- Umbilical hernia
Aneurysms refer to the widening or dilation of the wall of an artery, vein, or the heart.
What are the special projection types for the abdomen?
- PA prone
- Lateral decubitus (AP)
- AP erect
- Dorsal decubitus (lateral)
- Lateral
These projections help in various abdominal evaluations.
What is the minimum SID for abdominal imaging?
40 inches (100 cm)
SID stands for Source-to-Image Distance.
What is the standard IR size for the Dorsal Decubitus Position?
14 × 17 inches (35 × 43 cm), landscape
IR stands for Image Receptor.
What is the kVp range recommended for abdominal imaging?
70–85
What should be done for shielding during abdominal imaging?
Shield radiosensitive tissues outside the region of interest and use gonadal shields on male patients.
Describe the patient positioning for the Dorsal Decubitus Position.
Supine on radiolucent pad with side against the table or grid device; secure cart to prevent movement.
A pillow under the head and support under partially flexed knees may enhance comfort.
How should the IR and CR be positioned for abdominal imaging?
Center of IR and CR should be at the level of iliac crest or 2 inches (5 cm) above it to include diaphragm.
What should be ensured regarding the rotation of the patient during positioning?
No rotation of pelvis or shoulders; both ASIS should be the same distance from the tabletop.
What is the recommended collimation for abdominal imaging?
Collimate to upper and lower abdomen soft tissue borders.
Close collimation is crucial due to increased scatter from exposed tissue outside the area of interest.
When should the exposure be made during respiration?
At the end of expiration.
True or False: The Dorsal Decubitus Position can be taken as a right or left lateral.
True
Appropriate R or L lateral markers should indicate the side closest to the IR.
What anatomy should be demonstrated in abdominal imaging?
- Diaphragm
- Lower abdomen
- Air-filled loops of bowel
- Soft tissue detail in anterior abdomen and prevertebral regions
This ensures comprehensive evaluation of the abdominal area.
What are the evaluation criteria for positioning in abdominal imaging?
- No rotation (superimposition of posterior ribs and iliac wings)
- No tilt (symmetric appearance of intervertebral foramen)
- Proper collimation
Correct positioning is vital for accurate imaging results.
What exposure criteria should be met during abdominal imaging?
- No motion (sharp rib and gas bubble margins)
- Lumbar vertebrae may appear underexposed
- Soft tissue detail visible in anterior abdomen and prevertebral region
This ensures high-quality diagnostic images.
What are the clinical indications for a lateral position abdomen exam?
Abnormal soft tissue masses, umbilical hernia, possible aneurysms of aorta or calcifications, localization of foreign bodies
These indications help determine the necessity of imaging in specific abdominal conditions.
What are the special views used for an abdomen exam?
- PA prone
- Lateral decubitus (AP)
- AP erect
- Dorsal decubitus (lateral)
- Lateral
These views provide comprehensive imaging of the abdomen in various positions.
What is the minimum SID required for a lateral position abdomen exam?
40 inches (100 cm)
The Source-to-Image Distance (SID) is critical for image quality and radiation dose.
What is the standard IR size for a lateral position abdomen exam?
14 × 17 inches (35 × 43 cm), portrait
This size is commonly used for adult abdomen imaging.
What is the recommended kVp range for a lateral position abdomen exam?
70–85
This range helps achieve optimal contrast and detail in the images.
What shielding measures should be taken during a lateral position abdomen exam?
Shield radiosensitive tissues outside region of interest; use gonadal shields on male patients
Shielding is important to minimize radiation exposure to sensitive areas.
Describe the patient position for a lateral recumbent abdomen exam.
Patient in lateral recumbent position on right or left side, pillow for head, elbows flexed, arms up, knees and hips partially flexed, pillow between knees
Proper positioning ensures a true lateral view and reduces discomfort.
What is the correct alignment for the midcoronal plane during the exam?
Align midcoronal plane with CR and midline of table; ensure pelvis and thorax are not rotated
Correct alignment is crucial for accurate imaging and diagnosis.
Where should the CR be centered for a lateral position abdomen exam?
CR perpendicular to table, centered at level of the iliac crest to midcoronal plane
Centering the CR properly ensures that the area of interest is captured in the image.
What is the recommended collimation for a lateral position abdomen exam?
Collimate closely to upper and lower IR borders and to anterior and posterior skin borders
Proper collimation helps minimize scatter and enhances image quality.
What is the correct breathing instruction for patients during a lateral position abdomen exam?
Suspend breathing on expiration
This instruction helps reduce motion and improve image clarity.
What anatomy should be demonstrated in a lateral position abdomen exam?
- Diaphragm and as much of lower abdomen as possible
- Air-filled loops of bowel with soft tissue detail visible in prevertebral and anterior abdomen regions
Clear visibility of these structures is essential for accurate assessment.
What indicates no rotation in a lateral position abdomen exam?
Superimposition of posterior ribs and posterior borders of iliac wings, bilateral ASIS
Proper alignment is confirmed through these visual markers.
What exposure criteria should be met in a lateral position abdomen exam?
- No motion; rib and gas bubble margins appear sharp
- Lumbar vertebrae may appear about 50% underexposed with soft tissue detail visible
Sharpness and detail are critical for accurate interpretation of the images.
What are the three projections typically included in an Acute Abdominal Series?
AP supine abdomen, AP erect abdomen, PA chest
The routine may vary depending on the institution.
Why is the PA chest included in the acute abdomen series?
It allows free intraperitoneal air under the diaphragm to be visualized
The erect abdomen also helps visualize free air if centered high enough.
What is the recommended routine for acute abdomen series in pediatric patients?
AP supine abdomen and one horizontal beam projection
A left lateral decubitus may be difficult for patients younger than 2 or 3 years.
What are the specific clinical indications for performing an Acute Abdominal Series?
- Ileus (nonmechanical small bowel obstruction)
- Mechanical ileus (obstruction from hernia, adhesions)
- Ascites (abnormal fluid accumulation)
- Perforated hollow viscus
- Intra-abdominal mass (neoplasms)
- Postoperative conditions
These indications guide the necessity for imaging.
What should be done if the patient comes to the department in an erect position?
Perform erect images first
This ensures optimal visualization of free air.
What are the breathing instructions for the chest and abdomen projections?
Chest projections on full inspiration; abdomen on expiration
This technique helps in obtaining clearer images.
Where should the CR be positioned for supine and erect radiographs?
CR to level of iliac crest on supine; 2 inches above crest on erect
This positioning helps include the diaphragm.
What is the significance of the left lateral decubitus position?
It replaces the erect position if the patient is too ill to stand
This position is also useful for visualizing air-fluid levels.
How long should a patient be in the left lateral decubitus position before exposure?
Minimum of 5 minutes; 10 to 20 minutes preferred
This allows for better demonstration of intraperitoneal air.
Fill in the blank: The acute abdomen series typically includes an AP supine abdomen, an AP erect abdomen, and a _______.
PA chest
