Anatomy and Procedures of the Large Intestine Flashcards
Begins at junction of small intestine and ends at anus
Large Intestine
Forms an arch around the loops of small intestine
Large intestine
Four main parts of the large intestine:
*cecum
*colon
* rectum
*anal canal
How long is the large intestine
approx 5 feet long
series of pouches along large intestine
Haustra
Muscular bands that form haustra
Taeniae coli
Pouchlike portion below the junction of the ileum and colon
cecum
What is the right colic flexure?
hepatic colic flexure (liver)
What is the left cotic flexture known as?
Splenic left colic flexture (spleen)
Which colic flexture sits higher?
The left colic flexture sits higher because the right has the presence of the liver
Colon has four portions:
*ascending
*transverse
*descending
*sigmoid
Vermiform appendix attached to:
posteromdedial side of cecum
Sharp angle at ascending and transverse
right colic flexure
sharp angle at junction of transverse and descending
left colic flexure
Rectum extends from:
sigmoid to anal canal
Forms S shaped loop and ends at rectum at level of third sacral segmant
sigmoid portion
Anal canal terminates at the:
Anus
Function of the large intestine :
-reabsorption of fluids
-elimination of waste products
Large intestine is also known as the
colon
the types of contrast used for examination methods for large intestine
-single contrast
-double contrast
two-stage examination required what:
with barium first, then air or other gas after barium is evacuated
why is air needed for large intestine
to really see the polyp if suspected
Bowel cleansing methods
*complete intestinal cleansing kit
*Gi lavage
*cleansing enema
For Large intestine why must the pt. be completely emptied
Retained fecal matter can simulate small masses
What also may be used for contrast media of the large intestine
Carbon dioxide
*more rapidly absorbed
whose role is it to tip the pt
technologist can but if having a problem go to radiologist
Preparation for the large intestine include:
-laxatives
-dietary restrictions
-cleansing enemas
Always start off your barium edema study with what type of image?
Scout image to make sure the abdomen is clean
Barium edema is considered what type of study?
retrograde study
Whose role is it to put the barium and air in the pt
Radiologist
What temperature do we want our barium to be for a BE?
85 to 90 degrees
-temperature of suspension should be lower than body temperature
*can cause injury if too warm
*higher temperature uncomfortable for pt and decrease retention
how is the parts of the BE apparatus
*disposable soft plastic enema tips
*disposable enema bags
*balloon cuff (balloon inflated with air after insertion)
*special tip for double contrast to be able to insert air as well
* small tips if needed for younger pt. , or for pt that have strictures, fissures, inflamed hemorrhoids
Instruct patient on ways to minimize
discomfort during filling.
Relax abdomen
Deep oral breathing
Communicate cramping so that filling may be
slowed or stopped
How high should the IV bag be?
18 to 24 inches
-no higher than 24 inches
What position is the patient placed for BE?
Sim’s position
What is the main reason we run the barium all the way to the tube or basin?
to remove air from tubing
Steps for enema tip insertion:
pt on left side
*roll forward 35 to 40 degrees and rest on flexed right knee above and in front of left knee
*adjust height of bag
*expose anal region
*run barium into basin to remove air from tubing
*lubricate enema tip
*instruct pt to take deep breaths
How far should the tip go in?
4 inches no more than 4
When should you inflate the ballon?
Once the tip has been inserted
Who’s in charged of putting the air?
the doctor
if barium is in the fundus how is the pt positioned
AP
if air is in the pyloric how is the pt positioned
Supine
what is the cecum connected to regarding the colon
ascending
roles of technologist during enema
*be control of the clamp
* watch the tubing
*assist radiologist as needed
* help pt position
when removing enema tube what should be done first
**deflate the balloon!!
*you can also put the bag on the floor below pt to release some of the barium so its less tension for pt before going to the bathroom
if evacuation is inadequate at the end, what might help
pt may be given a hot beverage for stimulation
After pt evacuates stool what do you do next
another radiograph is taken to check mucosa
what type of system is the contrast BE
Closed system
-does not require removal and reinsertion of enema tip
*patient remains on table for entire procedure
essential projections for large intestine
-PA
-PA axial
-PA oblique (RAO or LAO)
-Lateral
-AP
-AP axial
-AP oblique (RPO) (LPO)
Anything that is PA is a form of ?
compression
Yout must include the entire bowl or colon on what projection?
PA and AP
AP oblique projections for large intestine
RPO or LPO
AP or PA essential projections for large intestine for decub
-right lateral decubitus position
-left lateral decubitus position
why does the right clic flexure usually sit lower than the left
bc of the liver
CR for PA or AP large intestine
perp to center of IR
enters MSP at level of iliac crest
part position for AP or PA large intestine
MSP centered to midline
IR centered at level of iliac crests
the entire colon is best demonstrated on what projections?
PA and AP
pt position for PA axial large intestine
prone
part position for PA axial large intestine
MSP in midline
IR at level of iliac crests
cr for pa axial large intestine
angled 30 to 40 degrees caudad
enters msp at level of anterior superior iliac spine
criteria for PA axial large intestine
*No rotation
* Rectosigmoid area centered
* Rectosigmoid demonstrated with less
superimposition than PA
* Transverse colon and flexures not
necessarily included
criteria for AP/PA large intestine
*No rotation
* Vertebral column centered so that ascending
and descending portions included
* Entire colon, including flexures and rectum
* 2 IRs may be needed for tall or hypersthenic
patients
* Exposure technique that shows the anatomy
patient position for ap axial large intestine
supine
what is the PA axial large intestine view for
rectosigmoid area
part position for ap axial large intestine
*msp aligned to midline of grid
*IR centered to 2 inches below iliac crests
cr for ap axial large intestine
angle 30 to 40 degrees cephalic
criteria for ap axial large intestine
*Rectosigmoid area centered
* Rectosigmoid area with less superimposition
than in AP because of CR angle
* Transverse colon and flexures not
necessarily included
*Exposure technique that shows the anatomy
patient position for PA oblique large intestine
*35 to 45 degrees RAO or LAO
Which oblique best demonstrates right colic flexure, ascending colon and sigmoid
RAO
which oblique best demonstrates the left colic flexure and descending colon
LAO
part position for PA oblique large intestine
Supported by flexed
knee and arm of
elevated side
MSP centered to
midline
IR centered to level of
iliac crests
criteria for PA oblique large intestine
RAO
Entire colon
Right colic flexure
with less
superimposition
than PA
Ascending colon,
cecum, and
sigmoid colon
CR for PA oblique large intestine
Perpendicular to IR
Enters 1 to 2 inches
(2.5 to 5 cm) lateral to
midline of body on
elevated side at level
of iliac crests
criteria for PA oblique large intestine
LAO
Entire colon
Left colic flexure
with less
superimposition
than PA
Descending colon
Patient position for AP oblique large intestine
35 to 45 degrees LPO or RPO
which oblique demonstrates right colic flexure and ascending and sigmoid colon
LPO
Which oblique demonstrates left colic flexure and descending colon
RPO
part position for AP oblique large intestine
MSP centered to midline
Sponge supporting elevated side
Dependent knee flexed for support
IR centered to level of iliac crests
CR for AP oblique large intestine
Perpendicular to IR
Enters patient 1 to 2 inches (2.5 to 5 cm) lateral to
midline of MSP on elevated side at level of iliac
crests
Criteria for RPO large intestine
Entire colon
Left colic flexure and descending colon
Criteria for LPO large intestine
Entire colon
Right colic flexure less superimposed or open as
compared with AP
Ascending colon, cecum, and sigmoid colon
what position must the pt be in for cross table rectum
prone
CR for for lateral large intestine
perp to IR
enters MCP at level of ASIS
criteria for lateral large intestine
Rectosigmoid area in
center
Superimposed hips
and femurs
Superior portion of
colon not necessarily
included when
rectosigmoid of
primary interest
for double contrast studies for right or left lateral decubitus what is the side of interest
air or side “up”
what decubitus position demonstrates medial side of ascending colon and lateral side of descending colon
right lateral decubitus
CR for AP/PA large intestin R or LF lateral decubitus
Horizontal and perpendicular to IR
Enters midline of body at level of iliac crests
part position for AP/PA Large Intestine
Right or Left Lateral Decubitus
Body elevated on
radiolucent support
to center MSP to
midline of grid
IR centered to level
of iliac crests
what decubitus position demonstrates lateral side of ascending colon and medial side of descending colon
left lateral decubitus
patient position for AP/PA Large Intestine
Right or Left Lateral Decubitus
Recumbent lateral
Back or abdomen in
contact with grid
criteria for Left/Right Lateral Decubitus Position
Large Intestine
Area from the left colic flexure to the rectum
No rotation; evidenced by symmetry of the
ribs and pelvis
Single-contrast: barium penetrated
Double-contrast: air side of interest and
should not be overpenetrated
Overhead lateral shows what
no lines
straight lines show you what
air and fluid levels
decub
Rectosigmoid is best demonstrated with what views:
-PA axial
-AP axial
-Lateral projection
What oblique shows the right colic flexure and ascending colon
PA oblique RAO or LPO
What oblique shows the left colic flexture and descending colon
PA oblique LAO or RPO
Axial views are for what?
the rectum and sigmoid
What views show the rectum and sigmoid?
-lateral
-lateral decub
-axial views
Axial view how do you angle for PA
PA angle down 30 to 40 degrees caudad
Axial view how do you angle for AP
AP angle up 30 to 40 degrees cephalic
Do not need to get flictures on
lateral rectum and axial views
side with air is being best demonstrated
decub
A right lateral decub show
air going to the medial aspect of ascending colon and the lateral aspect of the descending colon
A left lateral decub show
air goes to the lateral aspect of the ascending colon and medial aspect of the descending colon
After done with image you might do an upright for what
mobility
Post evac is usually what
the whole abdomen AP or PA
