Abdominal X-Ray

- Bowel obstruction

- Abdominal distention

- r/o foreign body

AXRs are pretty out dated because we have better imaging, but there are some indications including...

CXR

What should be ordered in patient with suspected pneumoperitoneum?

AXR

The chest region has more air. The abdomen has more organs. Therefore, you need more radiation for an AXR.

Is there greater radiation exposure when performing an AXR or CXR?

Supine

AXR view that displays the overall appearance of the gas pattern.

Upright/erect

AXR view that displays free air in the peritoneal cavity, used to show air fluid levels in obstruction or ileus. Diaphragm, liver and spleen tend to become more visible because fluid moves down into pelvis. Remaining mid and lower abdominal contents tend to become less visible.

Left lateral decubitis

AXR view that is used to look for free air on the outside edge of the liver.

- View, age, sex, date

- Technically satisfactory

- Overall gas patterns

- Extraluminal air

- Abnormal calcifications

- soft tissues outline size and shape

- other incidental findings

Framework for assessment and presenting the AXR...

black: gas

white: calcified structures

grey: soft tissues

darker grey: fat

intense white: metallic objects

the 5 densities on AXR are...

black: ______

white: _______

grey: _______

darker grey: ______

intense white: ________

11th thoracic spinous process

A "Technically Satisfactory" AXR extends superiorly to the ______

obturator foramen (ischial tuberosity, greater trochanter too)

A "Technically Satisfactory" AXR extends inferiorly to the ______

Lateral rib margins and iliac crest

A "Technically Satisfactory" AXR extends laterally to the _________.

look for clear bone edges of lumbar spine

How to assess penetration of AXR...

Coverage

Penetration

Rotation

Things to assess for technical satisfaction...

Supine AP

in a ______ AXR, fluid lies posteriorly within the gut and the gas in the bowel will float anteriorly on top of it.

Erect

in a ___ AXR, fluid lies inferiorly and te bowel will have an air fluid level.

intraluminal

gas inside the bowel

Stomach

____ almost always has intraluminal air.

small bowel

____ has 2-3 loops of air

extraluminal

____ air is never normal. This is air outside the bowel lumen.

Bowel distension

bowel filled with air within normal limits.

Bowel dilation

bowel filled beyond its normal capacity, usually indicative of a bowel obstruction.

centrally

small bowel is located _____

peripherally

large bowel is located _____

2.5 cm

normal size of the small bowel is less than _____

6 cm

normal size of the large bowel is less than _____

valvulae conniventes

folds of the small bowel are called ______. These are coiled spring shaped folds, 1-2 mm thick that appear like stacked coins, and completely traverse the width of the colon.

Haustra

folds of the large bowel are called ____ and only partially traverse the bowel.

Small bowel

there is often very little ____ gas seen on plain films.

stool

___ may be present in the large bowel, will appear as multiple small bubbles within soft-tissue type of structure.

Normal AXR

Large Bowel Distension

no dilation, less than 6cm

Small bowel obstruction

Large bowel obstruction

Aerophagia

patient swallows a lot of air, excess gas diffusely, but air in rectum is present so no obstruction

- Functional ileus

- Mechanical obstruction

Ogilvie syndrome

causes of intraluminal gas

- pneumoperitoneum

- abcesses

causes of extraluminal air

Functional ileus

one or more loops of bowel lose their ability to propagate peristaltic waves, causing a functional "obstruction" proximally, seen as gas-filled loops of bowel.

localized ileus

occurs when part of a bowel is aperistaltic (usually due to irritation). Affected small bowel usually remains persistently dilated on subsequent images. Some gas continues to pass through the affected bowel because there is not a true obstruction, so there is visible air in the rectum.

generalized adynamic ileus (Paralytic Ileus)

generalized dilation of the small and large bowel. Entire bowel is aperistaltic. Most often seen postoperatively. Air visible in the rectum/sigmoid since this is not a mechanical obstruction.

proximal

d/t the Law of the Gut, ____ to an obstruction becomes dilated because of swallowed air.

Distal

d/t to the Law of the Gut, ____ to an obstruction shows absence of air.

irritation

localized ileus is most commonly due to _____

postoperatively

generalized adynamic ileus is most commonly due to ______

Localized ileus

Generalized Adynamic ileus

Ogilvie's Syndrome

acute intestinal pseudo obstruction commonly of the right colon that affects older immobile patient on medications.

Ogilvie's Syndrome

older immobile patient on medications

Small Bowel Obstruction

manifested by dilated centrally lcoated bowel greater than 3 cm in diameter, high pitched hyperactive bowel sounds, visible valvulae conniventes, stepladder configuration on erect view, no gas distally

adhesions

History of abdominal surgery

number one cause of small bowel obstruction

Small Bowel Obstruction

SBO

SBO with Step ladder appearance on erect AXR

large bowel obstruction

persistent dilation of a bowel segment in the periphery. Few or no air fluid levels in upright film because most contents of this bowel are solids. Cuf off point due to passage of gas and feces distal to blockage. Visible haustra. No air in rectum

Cancer

number one cause of Large Bowel Obstruction.

LBO

LBO

Colonic Volvulus

the twisting of the colon upon itself. Occurs when part of the colon twists on its mesentery, resulting in acute, subacute, or chronic colonic obstruction. Colon is distended with gas and has an inverted U appearance.

Cecum

frequently has the largest diameter of the large intestine

coffee bean sign

Colonic Volvulus may appear as the __________

Cecum

this Coffee bean sign would be indicative of a Volvulus of the _____.

Sigmoid

this Coffee bean sign would indicative of a Volvulus of the _____.

Sigmoid colon (most commonly)

Cecum

Colonic most commonly occurs at the...

Sigmoid Volvulus

Pneumoperitoneum

free intraperitoneal gas that indicates perforated viscus. Most common causes include perforated peptic ulcer, rupture of an air containing loop of bowel, and trauma. Recognizable on imaging via air beneath diaphragm in upright film, falciform ligament sign, Rigler's sign

CT scan

choice of study for diagnosis of pneumoperitoneum.

Pneumoperitoneums

Rigler's sign

pneumoperitoneum

Rigler's sign

ability to see both sides of the bowel wall. Requires a large amount of air to present in order to visualize.

Chilaiditi's Syndrome

asymptomatic interposition of the bowel between the liver and the right hemidiaphragm. Usually an incidental findings that may look like pneumoperitoneum.

Chilaiditi's syndrome

Psoas

muscle that is almost always seen on AXR when exposure is technically adequate.

Psoas muscle

Liver

soft tissue structure that normally displaces all bowel gas from the RUQ

12th rib

the spleen usually doesn't project below the _____

4 lumbar vertebrae

the kidneys are approximately the height of ______

uterus

____ if seen sits on top of and may indent the bladder. It is often not seen on plain films.

Prostate

___ sits deep in the pelvis, usually only seen if calcified.

Splenomegaly

bladder

Phleboliths

normal findings

Calcified mesenteric Lymph nodes

normal finding

Costal cartilage, phleboliths, prostate gland, mesenteric lymph nodes

normal calcifications that can be seen on AXR

Abnormal calcifications

finding on AXR that can indicate underlying pathology. Can actually be pathology themselves.

- Rimlike (AAA, porcelain GB)

- Linear

- Lamellar (renal calculi, gallstones)

- Cloudlike/popcorn (Chronic pancreatitis, uterine fibroids)

Patterns of Calcifications on AXR...

Abdominal Aortic Aneurysm

Ultrasound

the study of choice when asymptomatic pulsatile abdominal mass is palpated.

CT scan

defines the absolute size of AAA, extent of mural thrombus and presence of dissection.

Porcelain Gallbladder

inflammatory scarring of the wall of the gallbladder, along with dystrophic calcification within the wall. Increased incidence of GB cancer.

Porcelain gallbladder

Bladder calculi

gallstones

gallstones on CT scan

nephrolithiasis

nephrolithiasis on CT scan

chronic pancreatitis

- feces

- iatrogenic (surgical clips, IUDs, stents)

- Accidental (bullets, per rectum objects)

- Projectional findings (pajama buttons, coins, body piercings)

Incidental findings on AXR include...

stool

fluffy mid-density material throughout the abdomen, multiple small bubbles of gas, mottled appearance.

stool

stool

constipation

lots of stool backed up