Large Intestine Pos 2 M4

Difference between the large intestine and the colon

Colon has 4 parts: ascending colon, transverse colon, descending colon, sigmoid colon

Large intestine includes all 4 parts but plus the cecum, rectum, & anal canal

Large intestine vs small intestine length

large: 5 feet

small: 23 feet

Large intestine

• larger diameter than small intestine

• 3 bands of muscle fibers: Teniae coli form haustra/haustrum (plural)

• located along the periphery of abdomen (outer areas)

Function of haustra

churning movement

Barium Enema (BE)

• single contrast (single column BE)

  • BaSO₄ or water soluble iodinated contrast

  • no air

• double contrast

  • both BaSO₄ and air

  • water soluble iodinated contrast can be used, but not really

  • carbon dioxide may be used (more readily absorbed than air)

  • uses less contrast than single column

Patient Prep BE

• dietary restrictions for a day before or more

  • light meal, clear liquids, no red metas

  • NPO 8 hrs before

  • no gum or smoking

• Bowel cleansing

  • intestinal cleaning kits

  • laxatives

  • cleansing enemas

• pregnancy check (10 day rule)

Barium prep

• powder contrast

  • mix w/ cool/cold water to produce anesthetic effect on colon & reduce spasm

  • NEVER use hot water; causes injury to intestinal tissue

• clamp tubing before pouring if using pre-mixed barium poured into enema bag

What does barium being a colloidal suspension mean?

• doesn’t dissolve/ insoluble

• settles to bottom

• barium particles uniformly dispersed

Barium Enema Tips

• single contrast: single lumen openings

• air contrast tips: double lumen openings ( contrast and air)

• retention tips: inflatable balloons at end

BE procedure

• ready enema bag & tip

• turn on flouro tower and IR

• move bucky to foot end of table

• patient in gown, no underwear

• patient history & explain procedures

• take scout film for doctor

• prep barium if scout is cleared

• tip patient

Tipping Tips

• SIMS position for pt. : on left side, right leg up & over

• gloves worn

• gown only opened for anal region (rest covered)

• explain everything

• run tiny barium amount into trash to remove air from tubing

• lubricate tip

• pt. takes deep breaths while you insert tip into anal canal (1.5” anterior toward umbilicus initially)

• follow curvature of rectum, direct tube superiorly & anteriorly (total insertion shouldn’t exceed 4”)

• inflate balloon, 1 puff of air, clamp

  • bulb should be filled to mac (2 puffs of air) under flouro

• cover pt. and have them turn on back

• DONT force tip (blockage or hemorrhoids)

Tech duties during BE

• introduce patient to radiologist

• assist radiologist

  • turn barium off/on (put barium bag on floor, gravity will do the rest)

• check on pt. during exam

• take overhead films after flouro quickly

• drain contrast after exam, remove tip, help pt. to bathroom

• clean room/table

• take post evacuation film

• remind pt. to drink water, drink laxative, & barium will come out white

AP/PA large intestine BE SID, Orientation, breathing instructions, pt. position

SID: 44”

LW (portrait)

end of expiration

supine

AP/PA large intestine BE CR

MSP & @ level of iliac crests (include symphasis)

AP/PA large intestine BE anatomy shown

• entire colon

• splenic flexure & rectum

• transverse colon filled w/ barium on PA

• transverse colon filled w/ air on AP (double contrast)

Axial AP Rectosigmoid Barium Enema SID, orientation, breathing instructions, pt. position

SID: 40”

LW (portrait)

expiration

supine

Axial AP Rectosigmoid CR & CR Angle

MSP & 2” inferior to ASIS

30-40 degrees cephalic

Axial AP Rectosigmoid anatomy shown

rectosigmoid area

RPO/LPO BE SID, orientation, breathing instructions

SID: 44”

LW (portrait)

expiration

RPO/LPO BE degree of obliquity for patient and patient positioning

35-45 degrees

bring arm across chest, flex knee

RPO/LPO BE CR

@ iliac crest & midway between MSP & ASIS on side up

(1” lateral to elevated side of MSP)

RPO/LPO BE anatomy shown

• entire colon

• LPO

  • right colic flexure (hepatic)

  • ascending colon

  • sigmoid colon

• RPO

  • left colic flexure (splenic)

  • descending colon

Left Lateral Rectum BE SID, orientation, breathing instructions, pt. positon, use what to absorb scatter?

SID: 40”

LW (portrait)

expiration

left lateral, knees on top of eachother & flexed, arms bent w/ hands near face

lead strip

Left Lateral Rectum BE CR

level of ASIS & midaxillary plane

(or little posterior to midaxillary plane)

Left Lateral Rectum BE anatomy shown

• rectum

• distal sigmoid portion of colon

• superimposed hips & femurs

AP/PA Decubitus BE SID, orientation, breathing instructions, grid?

SID: 44”

LW (portrait)

expiration

grid yes

Left Lateral Rectum BE patient position

• lateral recumbent

• build patient up w/ radiolucent support

• pt.s back (AP) or stomach (PA) in contact w/ grid

• mark side UP

Left Lateral Rectum BE CR

horizontal beam: midline of body & @ level of iliac crests

Left Lateral Rectum BE anatomy shown

• double contrast air-fluid levels

• large intestine

• upside area of interest

Scout KUB

• taken to ensure sufficient cleansing of large intestine

• KUB or abdomen positioning

  • CR: iliac crests & MSP

  • SID: 44”

  • shield males only

  • expiration

What is the AP Axial rectosigmoid aka

butterfly view due to appearance of elongated pelvis (wings)

PA Axial Rectosigmoid CR and CR angle

CR exits MSP & level of ASIS

30-40 degrees caudal

RAO BE degree of obliquity and CR

35-45 degrees oblique

iliac crest & 1” to left of MSP

RAO BE anatomy shown

• right colic flexure

• ascending & sigmoid colon are open

• large intestine

LAO BE patient obliquity and CR

35-45 degrees oblique

iliac crest & 1” to right of MSP

LAO BE anatomy shown

• left colic flexure & descending colon open

• large intestine

Post Evacuation Film (PA or AP)

• taken to ensure sufficient evacuation of barium from large intestine

• USE KUB positioning

  • SID: 44”

  • CR: iliac crest & MSP

  • expiration