RDSC 233
Bontrager pp. 98-116
Anatomy seen on the plain abdomen radiograph
Radiographic anatomy
Positioning of:
Plain film abdomen (KUB), flat and:
Upright abdomen
Left lateral decubitus abdomen
Dorsal recumbant (Rt or Lt)
Maternal abdomen
Exposure Factors
What in the World?
Miscellaneous, but significant, odds and ends

Atlas of Human Anatomy
Third edition (260)
+
Four quadrants intersect umbilicus
(RUQ, LUQ, RLQ, LLQ)
Nine regions
Right hypochondriac
Right lumbar
Right inguinal (iliac)
Epigastric
Umbilical
Pubic (hypogastric)
Left hypochondriac
Left lumbar
Left inguinal (iliac)

Atlas of Human Anatomy
Third edition (260)
Seven landmarks
Iliac crest
Anterior superior iliac spine (ASIS}
Pubic symphysis
Greater trochanter
Xiphoid tip (T9-T10)
Inferior costal margin
Ischial tuberosity
+

Atlas of Human Anatomy
Third edition (245)
Peritoneum
Falciform ligament
Diaphragm
Transversus abdominis M.
*
Internal & external oblique M.
*
* Muscles of the flank stripe

Atlas of Human Anatomy
Second edition (266)
Abdominal viscera
Kidneys
Adrenal (suprarenal) glands
Pancreas (head, body, tail)
Duodenum
Rectum
Bladder
Esophagus
Aorta (left sided)
Inferior vena cava (right sided)

Atlas of Human Anatomy
Second edition (301)
Liver
Gallbladder & bileducts
Stomach
Colon (parts of covered in colon unit)
Spleen
Jejunum and ileum (not shown)
Portal vein

What is normally visible
Conditions
1. Spleen Y
2. Gallbladder N
3. Stomach Y with gas
4. Veins N
5. Arteries N if calcified
6. Small bowel N gas is pathological
7. Colon (gas) Y with gas
8. Bladder Y with urine
9. Pancreas N
10. Ureters N
11. Kidneys Y
12. Adrenal glands N
13. Flank stripes Y
14. Liver Y

Radiographic Anatomy of the plain film abdomen
A radiograph of the kidneys, ureters, and bladder (KUB) demonstrates the:
1. Size
2. Shape
3. & Position of some, but not all the organs in the abdominal & pelvic cavities.
Why (in two words or less,) is it difficult to differentiate abdominal organs, and not possible to visualize others at all?
Subject Contrast
An old term was
“flat plate of the abdomen”

Radiographic Anatomy of the plain film abdomen
What is normally visible
1. Liver
2. Spleen
3. psoas muscles
4. kidneys
5. flank stripes
6. bone (like crazy)
7. Calcifications
What is sometimes visible
1. Stomach and colon (gas)
2. Bladder (urine filled)
3. Arteries (calcified aorta)
What is not visible
1. Gallbladder
2. Pancreas
3. Small bowel (unless pathological, with gas)
4. Ureters
5. Adrenal glands
6. Veins
7. Everything else

Radiographic Anatomy of the plain film abdomen
Liver (homogeneous shadow in RUQ)
Spleen
Stomach (c gas)
Parts of colon (c gas) hepatic flexure transverse colon cecum & ascending colon
Gas, though natural, is a negative contrast media . In the history of radiography, gas (air) was injected in the bladder and ventricles of the brain.
Carbonated soda is given to children to create a
“window” to the kidneys

Radiographic Anatomy of the plain film abdomen
More Gas
Patterns
Entire colon, from cecum to sigmoid, filled with gas.
Unless obstructed , distention of this degree should be relieved by flautulence
A child’s stomach and colon filled with gas and feces, (speckled appearance).
Note how the hepatic flexure and transverse colon define the liver
Gas filled transverse colon demonstrating haustrations.

Detail of liver in RUQ Radiographic Anatomy of the plain film abdomen
Detail of spleen in LUQ

Detail of flank stripe Detail of urine filled bladder Radiographic Anatomy of the plain film abdomen
Flank stripes are not always seen due to lack of contrast or clipping on larger persons.
When visible, bowing of the stripes may be a sign of a mass .
The bladder is often seen, if contrasted by urine.
Gas in the sigmoid colon may obscure it

Radiographic Anatomy of the plain film abdomen
Kidneys
Subject contrast of the kidneys is enhanced by the perirenal fat capsule. They are best seen in the asthenic body habitus
= Psoas muscles
Placement of Rt marker is less than desirable

Radiographic Anatomy of the plain film abdomen
Calcifications can form in various tissues, and especially fluid filled organs where minerals consolidate. In the plain film abdomen those seen are:
Large gallstone in RUQ
If not in the RUQ, where else could it be?
* gallstones (calcium not cholesterol)
* kidneystones
* bladderstones
* arteriosclerosis
(mostly of abdominal aorta)

Where is it, or, at least, where should it be?

Radiographic Positioning of the Abdomen

Positioning of:
AP KUB (flat plate of the abdomen)
Upright abdomen seated or standing
Left lateral decubitus including
Review the ARRT Standard Terminology for Positioning and Projections

Standard KUB Positioning
1. Put the tube in detent
And leave it alone
2. Align the tube to the bucky
(longitudinally)
And leave it alone*
3. Put a film in the bucky, mark it, close the tray
And leave it alone
4. To position, float the table, move the patient, but don’t disturb steps 1-3
5. Shield
When positioning in lab, follow these steps. Someone will critique your efficiency
*If views in a routine require angles, do them last if possible.

Standard Abdomen Positioning
Preparation
1. Evaluate the order
2. Greet the patient
3. Take History
Plain film radiography of the abdomen may be used to diagnose acute abdomen , or provide preliminary information for further studies.
Pertinent Hx includes:
Abdominal pain: chronic or acute , location (quadrant or region). Times?
(i.e. after eating). Previous hx? Known cause? Bloating, constipation, diarrhea.
4. Remove jewelry, check attire, snaps, pins, NG tubes , etc.
5. Explain the exam in layman’s terms
6. Questions?
7. Set technique before positioning

Routine KUB Positioning
1. 40” SID (relatively standard)
2. Reciprocating bucky
12:1, 16:1 grid
3. 70-80 kVp range
4. 14” x 17” film, lengthwise
5. ID marker at bottom
6. Rt marker above ID marker

Routine KUB Positioning
1. CR to iliac crest
2. Entire spine straight
3. No rotation on hips
(check ASIS)
4. Arms away from sides (with sheet covering patient, watch for wandering hands)
5. Exposure at end of respiration (hold it)

* Patient ID
* Rt/Lt, special marker
* Contrast & density
* Motion *
* Artifacts
Clipping: Superior ramus and pubic symphysis must be included.
Rotation: Ala of ilium are symmetrical. Vertebral bodies are vertical (no side bending) and not rotated.
* Peristalic activity may create motion of the gas pattern.

KUB Positioning: 2 films method
When the patient is tall, two films used lengthwise may be necessary.
When the patient is wide, two transverse.
Note the overlap as evidenced by the iliac crest
Take first exposure of the pelvis.
After changing films, place finger on top of light field, float table top to the the upper abdomen collimated field overlaps the previous field by
3” or 4” inches.

N on routine positions:
Upright abdomen
Left lateral decubitus
Dorsal recumbant decubitus

Routine Upright Positioning
Same as supine, expect upright .
And, patient must be in position for at least 5 minutes prior to exposure. Bring by WC if possible
4.
1. Same as KUB, but center top of film to axilla.

Residual barium x 3 weeks
3. Ptosis (Change in position)
Might a change in technique be called for on the upright?
Standard Upright Abdomen Positioning
What (else) does the upright demonstrate?
1. Air-fluid levels in the bowel
2. Free air in the abdomen
(peritoneal cavity) under the diaphragm

Standard Upright Abdomen Positioning
Criteria: In addition to the criteria for a supine KUB, the upright film must demonstrate lung tissue above the diaphragms and plenty of it. Visualizing the pelvic cavity to the symphysis is not criteria

Standard Left Lateral Decubitus Positioning
The left lateral decubitus film is done
Flash marker when the patient is unable to stand or sit.
Sponge
Set up/Positioning
Same as for the upright, except the grid film is in a film holder
(not a reciprocating bucky)
Check the patient’s measurement. Too many double bacon cheeseburgers may make it like this
Lt flank
Rt flank
A horizontal beam projection to demonstrate free air , and air fluid levels .
A left lateral, and only a left lateral , is the decubitus position because of the air bubble that is normally in the stomach

Standard Left Lateral Abdomen Positioning
What’s the big deal with the stomach bubble?
To evaluate free air, it is important to not have the stomach bubble under the flank stripe.
Rt side
Criteria:
Mid portion of the abdomen, along the flank (not symphysis or diaphram) visible.
Iliac crest
Stomach bubble

Dorsal decubitus (Rt or Lt) Abdomen Positioning
The dorsal decubitus film is done when that
Flash marker position is all the patient is able to tolerate, or for evaluation of the aorta in arteriography
CR
Sponge
Set up/Positioning
Same as for the decubitus
A horizontal beam projection to demonstrate free air , and air fluid levels .
In the dorsal decubitus position free air layers out under the anterior abdominal muscles. Air fluid levels, and the abdominal aortic aneurysms may be seem, but due to part thickness, this projection is not optimal.

On all films
Patient ID
Rt or Lt marker
The KUB film must demonstrate all anatomy within the abdominal cavity
Contrast & density
Motion
Artifacts
The upright, left lateral decubitus, and dorsal decubitus positions demonstrate free air, and air-fluid levels.
The upright also demonstrates ptosis of the abdominal organs.

Exposure Factors
From the “Rules of Thumb”
Based on: 3 phase, 100 RS film, 12:1 grid, 40” SID
Abdomen/Pelvis
Frontal
(2 x cm) + 35 =kVp @ 50 mAs
Lateral (4x frontal)
(AP + 10 kVp @ 100 mAs
Oblique
(AP + 40% - 60% of frontal technique

Exposure Factors
From the “Rules of Thumb”
Based on: 3 phase, 100 RS film, 40” SID
Maternal Abdomen
On occasion a radiograph of the pregnant abdomen is ordered during labor, to check for a breech presentation.
Every radiology department should have at least one high speed film/screen system for this purpose.
What is required in terms of kVp and mAs?
High kVp (110 or higher), low mAs.

Exposure Factors
From the “Rules of Thumb”
Based on: 3 phase, 400 RS film, 40” SID
Calculate a maternal abdomen technique for a 35 cm measurement
1. (2 x 35) + 35 = 105 kVp @ 50 mAs
2. 40 mAs / 4 = 12.5 mAs (film speed)
3. 15% of 105 = 16.5 =
Answer 121 kVp @ 6 mAs
Critique critera: For presentation, only gross anatomy need be visualized.
Maternal abdomen films are rarely repeated.

Significant Pathologies or Pathologic Indicators of the abdomen and their
Radiographic Appearances
Mass
Institutional colon
Pneumoperitoneum
Ascites
Ileus

An example of how the knowledge of the normal size, shape, and position of abdominal anatomy is used to diagnose disease on a KUB.
This film demonstrates a bowing of the right psoas muscle, and increased opacity. The diagnosis was abdominal aortic aneursym (AAA), unusual in that it is on the right, rather than the left, where the aorta is.

Another example: size, shape, or position.
10 cm mass on the right of midline
In the right lumbar region

Normal variants
If a mass is not pathologic, it may be an anomaly.
The detail in this LUQ shows anatomy not normally seen there. Lateral to the kidney, only the stomach, spleen, and colon are expected possibilities.
The radiologist determined this to be the
“tongue” of the liver (long tip of left lobe), interposed between the spleen and splenic flexure

Institutional Colon
Fecal stasis or fecal impaction are terms that describe what is commonly called constipation.
Institutional colon in found in bedridden, elderly patients, whose eliminations have not been monitored

Pneumoperitoneum
Diaphragm
Air in the abdominal cavity,
(outside of the alimentary tract) comes from perforated viscus, a puncture wound, or recent surgery.
Gastric or duodenal ulcers can perforate and allow air and stomach contents to escape, leading to peritonitis
Liver
Stomach
In the upright position free air layers out under the diaphragm. Large quantities may be obscured if the top of the film is not high enough.
Free air
Stomach bubble

Ascites
Fluid accumulation in the abdominal cavity, secondary to serious disease.
Ascites creates a gray, low contrast effect, and as in this film, may make gas in the bowel look trapped, or encased by the extrinsic pressures from the fluid.

Ileus x
An ileus is a failure of intestinal contents to move through the bowel, for reasons catagorized as
Mechanical ileus: caused by a physical obstruction such as a tumor, adhesions , volvulus
(twisting) intussusception
(telescoping), or hernia .
Dynamic ileus: muscular constriction
Adynamic ileus: lack of motility , paralytic
Gallstone ileus
Postoperative ileus
High grade mechanical obstruction. Gas avoids pelvis indicating possible mass.
Gas in the stomach, normal from aerophagia , is relieved by eructation . Gas in the colon, normal from the action of e-coli, is relieved by flatulence . Gas in the small intestine is pathological.

Ileus
Gas in the colon, normal from the action of e-coli, is relieved by flatulence .
Gas in the small intestine is pathological.
Mild to moderated ileus. In addition to distention of the colon, note the gas pattern in the small bowel

What in the World?
Miscellaneous, but significant, odds and ends

What in the World?
Identifying ingested or inserted foreign bodies are another use for the KUB film

What in the World?
Badmitton champion presents with abdominal pain.
This Greenfield caval filter is in the inferior vena cava for the purpose of catching clots from leg veins. If the filter were not present, clots would travel to the right heart, pulmonary artery, and the arterioles of the lungs, causing pulmonary embolism.
(Kidding about the badmitton)

What in the World?
There is something odd about the gas pattern
In the area of the sigmoid colon
And it’s shaped like a tooth brush holder

What in the World?
Is this Melvin the
Moonman, or...
A Cheese Whiz jar UTB

What in the World?
Illustration from “The Compete
Idiot’s Guide to Home Medical
Treatment,” or what?

The End

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What can be visualized
10. Spleen
11. Gallbladder
12. Adrenal glands
13. Stomach
14. Veins
15. kidneys
16. Colon (gas)
17. bladder
18. Pancreas
19. Ureters
Y ( if needed to see) or N
Gas? Urine?
Liver Y N N
Sm. Bowel Y Y N