Large Bowel

Question 1

Anatomy of the Colon

• 4 sections
• 2 flexures

Answer 1

Ascending, transverse, descending and sigmoid colon

Hepatic or right colic flexure and splenic or left colic flexure

Question 2

Barium Enema Contraindications

Answer 2

Possible perforation of the bowel or possible blockage of the bowel

Question 3

Indications for a Barium Enema

Answer 3

Neoplasms 
Intusseseption 
Colitis 
Ulcerative colitis
Diverticulitis 
Volvulus

Question 4

Barium Enema Patient Preparation

Answer 4

2 days of clear liquid diet
Laxatives or a cleansing maybe necessary
NPO from midnight the night before the exam
Colon must be empty as residual matter may appear as an abnormality such a small tumour or polyps

Question 5

Scout or preliminary image

Answer 5

Taken to ensure the bowel is empty prior to barium enema

Question 6

Technologists responsibility during enema

Answer 6

Interview patient, patient assessment/history, provide exam explanations and post procedural instructions
Organize supplies required for exam (towels, linens)
Rely relevant info to the Rad and confirm exam type double vs single
Assist and support patient during the exam

Question 7

Room Prep for exam

Answer 7

Have sponges, lead gloves, compressions paddles, face cloths
Have contrast agents ready and all enema tips
Have the table in the correct position based on patients mobility and not rads preference

Question 8

Types of enema tips

Answer 8

Plastic disposable (no balloon)
Plastic disposable with retention (balloon) used in single contrast studies
Plastics disposable air-contrast retention balloon - has a separate tube to inject air where it mixes with the barium for double contrast

Question 9

Tip Insertion

Answer 9

Little or no air in enema tube
Place patient in the sims positions on their left side w/ knees bent (meant to relax abdominal muscles)
Inform patient that the tube is cold and wet and give breaking instructions
Re enforce tip securely through the instructions tape and additional equipment - shouldn’t exceed 1 1/2 inches into the body

Question 10

Medications given for cramping during the exam

Answer 10

Glucagon and Buscopan can be given to relax peristaltic action of the bowel during the exam is the patient it experiencing painful cramps

Question 11

Single contrast Routine views

Answer 11

AP or PA 
LPO 
RPO
Sigmoid/axial 
Lateral rectum 
Post evac

Question 12

Double Contrast Routine Views

Answer 12

AP or PA
RLD and LLD
Oblique views
Sigmoid/axial 
Lateral rectum 
Post evac

Question 13

Large bowel filling supine vs prone

Answer 13

Supine - transverse and sigmoid air filled and ascending and descending barium filled
Prone - transverse and sigmoid barium filled and ascending and descending and parts of sigmoid are air filled

Question 14

RAO and LPO obliques

Where the CR is and the anatomy demonstrated

Answer 14

RAO - CR 2-2.5cm left of MSP on the level of the crests
LPO - CR 2-2.5cm lateral to elevated side of the MSP at the level of the crests
Best demonstrate the right colic or hepatic flexures and the ascending and sigmoid portions of the colon
The entire colon should be included in the image

Question 15

LAO and RPO

Where the CR is and what anatomy is best demonstrated

Answer 15

LAO - CR about 2-2.5cm to the right of MSP on the crests
RPO - CR about 2-2.5cm lateral to the elevated side of the MSP at the level of the crests
Best demonstrates the left colic or splenic flexure and the descending colon
And the entire colon should be included

Question 16

Posterior obliques positioning

Answer 16

LPO and RPO patient rotated 35-45 degrees and center at L4 and 5 cm lateral to the upside of the MSP

Question 17

Anterior Oblique Positioning

Answer 17

RAO and LAO
Patient rotated 35-45 degrees and center at L4 and 5 cm to the left of the MSP for a RAO and 5cm right of the MSP for a LAO

Question 18

Right Lateral Decubitus

Answer 18

CR at the iliac crests along the MSP (CR horizontal and perpendicular to IR)
Entire colon must be demonstrated in the image
Barium is gravitated to the right side
Air rises and delineates the medial wall of the ascending colon and lateral wall of the descending colon
Be sure to use a grid

Question 19

Left Lateral Decubitus

Answer 19

CR at the iliac crests (CR horizontal and perpendicular to IR)
Include the entire colon in the image
Demonstrates the lateral side of the ascending colon and the medial side of the descending colon
Be sure to use a grid

Question 20

Why is double contrast better than single contrast

Answer 20

Double contrast is better b/c the air expands the colon and the barium coats the intestines, shows air fluid levels
Single only coats the intestines

Question 21

Sigmoid view

AP Axial projection

Answer 21

Angle 30-40 degrees cephalad along the MSP
Center about 5cm below the level of the ASIS
Elongated views of the rectosigmoid segments with less overlapping
A lot of pathologies begin in the sigmoid colon

Question 22

Sigmoid View

Pa axial projection

Answer 22

Angle 30-40 degrees caudad
CR to exit the level of the ASIS and to MSP
Elongated view of the rectosigmoid segments with less excessive superimposition
Only interest in the sigmoid colon with this view, don’t want the entire colon

Question 23

Additional Sigmoid views

LPO axial oblique

Answer 23

CR 10 cm inferior and 10 cm medial to the right ASIS
The view provides more elongation and less superimposition of the rectosigmoid segments of the large bowel
Not usually part of protocol and will be specifically requested by rad
Not common

Question 24

Lateral Rectum

Answer 24

Done in ventral decubitus use a horizontal beam and CR on the level of the ASIS OR Left lateral CR to the level of the ASIS
A horizontal beam is used to demonstrate air filled posterior rectum
Includes rectum and distal sigmoid portion of the colon

Question 25

Post Evacuation

Answer 25

CR perpendicular to the IR and centered to the iliac crests and MSP
Can be done PA or AP but PA if perferred because the patients body weight spreads apart the bowel and less dose
Entire large intestine is included on the image
Demonstrates the mucosal pattern of large intestine with residual contrast media after the patient has emptied their bowels

Question 26

3 types of contrast media

Answer 26

Barium - positive agent, can be in paste, powders, liquid and paste
Air or gas - negative agent, provided in pill or granule form, CO2, nitrogen or room air can also be used
Water soluble - positive agent provided in liquid form (Conray or gastrografin) also used when the patient is going for surgery or has a possible perforation

Question 27

Barium Enema Procedure

Answer 27

Barium preparation - room temp barium should be used
Cuff inflators and clamps should all be in place ready to go
Rad comes in after tip insertion, using Fluoro barium if run and air is gently pumped into the bowel and images are taken
Tech assist patient to move during exam ensure tube and barium are not in the way or hindering movement
After Fluoro, a few overheads may be taken by the tech
Once the exam is completed the barium is drained out through the tube and enema tip is removed and patient escorted to the washroom

Question 28

Room Prep for enema

Answer 28

Have auxillary equipment ready - sponges, lead gloves, compression paddle, face cloths and linens
Have contrast agent ready
Table should be in the correct position based on the patients mobility

Question 29

Disadvantages vs. Advantages of water soluble contrast

Answer 29

Doesn’t coat the bowel as well
Fast transit time
Dehydrates people more
Bitter taste
Used if the patient is going for surgery
Used to check to see if the bowel is voided
Used if the patient cannot hold the contrast in the bowel
Used if the patient has a bowel perforation or obstruction

Question 30

AP or PA position

Answer 30

AP - barium filled transverse colon
PA - air filled transverse colon
The entire colon must be included on the image