UNIT 3: Lower Digestive Tract (Barium Enema) Large Intestine Flashcards
Large intestine is also known as the
Colon
Large intestines extends from the
ileo-cecal junction to anal canal
Large intestine structures
-Cecum
-Ascending Colon
-Transverse Colon
-Descending Colon
-Sigmoid Colon
-Rectum
Cecum
-Most proximal portion of colon
-RLQ
-Veriform Appendix attaches to cecum and is 2-6 inches long
Ascending Colon
Extends up the right side of the abdomen from cecum to right colic (hepatic) flexure
Hepatic or Right Colic Flexure
-Bends to the left joining ascending colon to transverse colon
-Attaches to underside of liver
-Lies posterior
Transverse Colon
-Extends across abdomen
-Most anterior portion of colon
-From hepatic flexure to splenic (left colic) flexure
Splenic or Left Colic Flexure
-Downward bend between transverse and descending colon
-Attaches to inferior surface of spleen
Hepatic vs Splenic Flexure
Hepatic flexure sits lower then splenic flexure because of the liver
Descending Colon
-Extends down left side of abdomen
-Splenic flexure to sigmoid colon
-Lies posterior
Sigmoid Colon
-S-Shape
-Extends from Iliac Crest to rectum
-Lies anterior
Rectum
-Most distal portion of large intestine
-Extends from level of S-3 to Anal Canal
Anal canal
-Distal 1-2 inches of rectum
-Regulated by 2 sphincters
Haustra
-Pouches produced from circular muscle fibers
Taenia Coli
longitudinal band of muscle fibers extending from apex to rectum
Large intestine radiograph labeled
Room Preparation
-Fluoroscopy room setup (make sure fluoro works)
-IV Pole
-Clamps
-Gel (Lubrication), Contrast Media Prepared
-Towels, Linens, Washcloths, and Chucks available
-Grid holder, Grid, IR available near by
-Check site protocol
Barium enema: single vs double contrast
-Single: Using RADIOPAQUE contrast media only
-Ex: Barium, Gastrografin
-Double: Using RADIOPAQUE and RADIOLUCENT contrast media
Radiopaque vs Radiolucent
-Radiopaque media uses barium or a type of water based iodinated CM
-Demonstrates anatomy & tonus
-Gastrografin may be used in cases of suspected bowel perforation or leaks
-Radiolucent uses gas to distend the bowel lumen
-Enables better bowel demonstration
Place enema bag on IV pole prior to start of exam:
-No higher than ___ inches above anus/Tabletop
-Remove the _______ from the tube prior to tipping
-24
-air
Patient Prep
-Low residue diet day prior to exam
-Laxative evening prior to exam
-NPO after midnight
-Cleansing enemas morning of exam
Prep Contraindications
-Colostomy Patients
-Prolonged diarrhea
-Hirschsprung’s Disease/ Megacolon
-Absence of neurons in the bowel wall; prevents relaxation of colon
-Abdomen distention, severe constipation, and recurrent fecal impactions
-Results in defective evacuation of rectum
-Treated surgically by removal of ganglion segment
-Severe rectal bleeding
Enema tips
Best position for enemas
Sims position
-Turn patient on left side
-Lean body forward
-Slightly bend top knee forward
-Position relaxes abdominal muscles
Barium enema: tube insertion
-Use lots of lubrication
-Direct tip anterior (towards umbilicus) and slightly superior
-Follow rectal curve
-DO NOT FORCE
-Once in place, balloon is inflated to hold tip in place
Barium enema: contrast administration
-Radiologist requests enema clip be released, barium flows into colon
-Patients may begin to feel uncomfortable and “full”
-Patient may be instructed to roll around table while tip is still in place
-You need to keep bag/ line clear of patient’s feet so it does not get tangled
Barium enema: Double Contrast Media Study
-Radiologist will ask you to place bag on floor to drain out barium. Be sure you have enough slack on line, you don’t want to pull on the inflated tip
-Rad will “puff” air into colon. Patient’s abdomen will become distended
-This is very uncomfortable for patients! Remind them to take slow, easy breaths
-Rad will instruct patient to roll around on table
Single and Double Contrast views
-Single:
-AP
-AP Axial
-RPO
-LPO
-Left Lateral Rectum
-Double:
-AP
-AP Axial
-RPO
-LPO
-PA
-Right & Left Lateral Decubitus
-Ventral Decubitus
-Cross- Table Lateral Rectum
Large Intestine: Supine, Prone, Upright/Erect
AP vs PA image, which is which?
-Image A: PA
-Image B: AP
AP/ PA Positioning
-PROJECTION: AP or PA
-IR SIZE: 14 X 17 (LW)
-S.I.D: 40”
-CR: Perpendicular to midpoint of IR & iliac crests
-PATIENT POSITION: Supine or Prone
-PART POSITION: MSP centered to midline of IR. Iliac crest to midpoint of IR
-Must include pubic symphysis
-RESPIRATION: Suspend on exhalation
AP/ PA Evaluation Criteria
-STRUCTURES DEMONSTRATED:
-PA or AP projection of entire colon
-EVALUATION CRITERIA:
-Entire colon including right and left colic flexures and rectum
-May need to use two IRs for hypersthenic patients
-Vertebral column centered to IR
-Descending and ascending colons visualized
PA Obliqe RAO Positioning
-PROJECTION: PA Oblique
-IR SIZE: 14 X 17 (LW)
-S.I.D: 40”
-CR: Perpendicular, entering 1-2 inches lateral to midline on elevated side at level of crest. Center of IR at level of crests.
-PATIENT POSITION: Prone
-PART POSITION:
• Right arm down by side, left hand by head, left knee flexed for stability
• Roll patient onto right hip, 35-45, RAO
• Patient’s body centered to midline of IR. Iliac crest centered to midpoint of IR
PA Oblique RAO Evaluation Criteria
STRUCTURES DEMONSTRATED:
-Best shows RIGHT COLIC (HEPATIC) FLEXURE
-Ascending colon
-Sigmoid portion of colon
EVALUATION CRITERIA:
-Entire colon
-Right colic flexure less superimposed or “open” as compared with PA
-Ascending colon, cecum & sigmoid colon
PA Oblique LAO Positioning
-PROJECTION: PA Oblique
-IR SIZE: 14 X 17 (LW)
-S.I.D: 40”
-CR: Perpendicular, entering 1-2 inches lateral to midline on elevated side at level of crest. Center of IR at level of crests.
-PATIENT POSITION: Prone
-PART POSITION:
-Left arm down by side, right hand by head, right knee flexed for stability
-Roll patient onto left hip, 35-45 degrees, LAO
-Patient’s body centered to midline of IR. Iliac crest centered to midpoint of IR
PA Oblique LAO Evaluation Criteria
-STRUCTURES DEMONSTRATED:
-Best shows LEFT COLIC (SPLENIC) FLEXURE
-Descending colon
EVALUATION CRITERIA:
-Entire colon
-Left colic flexure less superimposed or “open” as compared with PA
-Descending colon
Left Lateral (Robbin’s method) Positioning
-IR SIZE: 10X12 (LW)
-S.I.D: 40”
-CR: Perpendicular, entering the MCP at level of ASIS
-Lead strip placed posterior to the patient
-PATIENT POSITION: Left Lateral Recumbent
-May be done right lateral, check facility protocol
-PART POSITION:
-Place patient in true lateral position
-Center MCP longitudinally and ASIS laterally to IR
-Flex patient’s knees for stability with support placed between knees
-BREATHING: Suspend on exhalation
Lateral (Robbin’s method) Evaluation Criteria
-STRUCTURES DEMONSTRATED:
-Best shows rectum and distal sigmoid portion of colon
EVALUATION CRITERIA:
-Rectosigmoid area centered to IR
-No rotation
-Hips and femurs superimposed
Double contrast barium location in the large intestine
-SUPINE:
-Air fills anterior structures: Transverse & Sigmoid Colon
-Barium fills posterior structures: Ascending and Descending colon & rectum
-PRONE:
-Reverse from supine
-ERECT:
-Air rises to highest part of each portion of colon
-Air/ Fluid lines will be demonstrated
With the VENTRAL decubitus positions, the _____ portion of the colon is of primary importance and should not be penetrated during double contrast study
Air
In double contrast studies, what gaseous medium is usually used?
Air
What large intestine looks like from front, side, and back
AP oblique LPO positioning
Same as PA Oblique projection in RAO position:
-IR SIZE: 14 X 17 (LW)
-S.I.D: 40”
-CR: Perpendicular, entering 1-2 inches lateral to midline on elevated side at level of crest. Center of IR at level of crests.
EXCEPT:
-PATIENT POSITION: Supine
-PART POSITION:
-Left arm down by side, right arm across chest, right knee flexed for stability
-Roll patient onto left hip, 35-45 degrees, LPO
-May need to use a positioning sponge
AP Oblique LPO Evaluation Criteria
-Structures Demonstrated:
-Right Colic Flexure and Ascending and Sigmoid portions of the colon
-Evaluation Criteria:
-Entire Colon
-Right Colic Flexure less superimposed or open compared with AP projection
-Ascending colon, cecum, and sigmoid colon
-Penetration of the contrast medium
AP Oblique RPO Positioning
Same as PA Oblique projection in LAO position:
-IR SIZE: 14 X 17 (LW)
-S.I.D: 40”
-CR: Perpendicular, entering 1-2 inches lateral to midline on elevated side at level of crest. Center of IR at level of crests.
EXCEPT:
-PATIENT POSITION: Supine
-PART POSITION:
-Right arm down by side, left arm across chest, left knee flexed for stability
-Roll patient onto right hip, 35-45 degree, RPO
-May need to use a positioning sponge
-RESPIRATION: Suspend
AP Oblique RPO Evaluation Criteria
-Structures Demonstrated:
-Left Colic Flexure and descending colon
-Evaluation Criteria:
-Entire colon
-Left Colic Flexure and descending colon
-Penetration of the contrast medium
AP Axial Positioning
-PROJECTION: AP Axial
-IR SIZE: 14 X 17 (LW) or 10X12 (LW)
-S.I.D: 40”
-CR: 30-40 degrees cephalic entering at level of 2” below the level of the ASIS
-PATIENT POSITION: Supine
-PART POSITION: MSP centered to midline of IR. Iliac crest centered 2” above midpoint of IR
-RESPIRATION: Suspend
AP Axial Evaluation Criteria
-STRUCTURES DEMONSTRATED:
-Best shows rectosigmoid area of colon
-EVALUATION CRITERIA:
-Rectosigmoid area with less superimposition than AP
-Rectosigmoid area centered to IR
PA Axial Positioning
-PROJECTION: PA Axial
-IR SIZE: 14 X 17 (LW) or 10X12 (LW)
-S.I.D: 40”
-CR: 30-40 degree caudal exiting at the level of the ASIS
-PATIENT POSITION: Prone
-PART POSITION: Center MSP longitudinally to IR. Center IR at the level of the iliac crest
-RESPIRATION: Suspend
PA Axial Evaluation Criteria
-Rectosigmoid area with less superimposition than in PA projection because of angulation of the central ray
-Transverse colon and both flexures not always included
AP/PA Right Lateral Decubitus Positioning
-PROJECTION: AP or PA
-IR SIZE: 14X17 (LW)
-GRID: YES (BUCKY)
-S.I.D: 40”
-CR: Horizontal AND Perpendicular, entering the MSP at level of iliac crests
-PATIENT POSITION: Right Lateral Recumbent with back or abdomen in contact with IR
-Arms above head & knees bent for stability
-PART POSITION:
-Center MSP longitudinally to IR (use sponge to elevate pt or place IR below level of table)
-Center IR to level of iliac crests
AP/PA Right Lateral Decubitus Evaluation Criteria
-STRUCTURES DEMONSTRATED:
-AP or PA projection showing “up” medial side of ascending colon & lateral side of descending colon
-EVALUATION CRITERIA:
-Left colic (splenic) flexure to rectum
-No rotation as exhibited by ribs and pelvis
AP/PA Left Lateral Decubitus Positioning
-PROJECTION: AP or PA
-IR SIZE: 14X17 (LW)
-GRID: YES (BUCKY)
-S.I.D: 40”
-CR: Horizontal AND Perpendicular, entering the MSP at level of iliac crests
-PATIENT POSITION: Left Lateral Recumbent with back or abdomen in contact with IR
-Arms above head & knees bent for stability
-PART POSITION:
-Center MSP longitudinally to IR (use sponge to elevate pt or place IR below level of table)
-Center IR to level of iliac crests
AP/PA Left Lateral Decubitus Evaluation Criteria
-STRUCTURES DEMONSTRATED:
-AP or PA projection showing “up” lateral side of ascending colon & medial side of descending colon
-EVALUATION CRITERIA:
-Left colic (splenic) flexure to rectum
-No rotation as exhibited by ribs and pelvis
Rectum Cross-table Lateral Ventral Decubitus Positioning
-PROJECTION : Lateral
-IR SIZE: 10 X 12 (LW)
-GRID: STATIONARY GRID***
-S.I.D: 40”
-CR: Perpendicular to approx level of ASIS.
-PATIENT POSITION: Prone with right or left side against grid
-PART POSITION: Center mid-coronal plane to middle of grid/ IR
Rectum Cross-table Lateral Ventral Decubitus Evaluation Criteria
-STRUCTURES DEMONSTRATED:
-Rectum with air in most superior portion or “UP Side”
-EVALUATION CRITERIA:
-Recto-sigmoid area in centered on image
Defecogram
-AKA: Evacuation proctography or dynamic rectal examination
-For patients with defecation dysfunction:
-Prolapse Rectum
-Rectal Intussusception
-Rectocele
-Demonstrate rectal sphincter, post CVA (stroke)
-Functional study of anus and rectum during evacuation and rest phases of defecation
-Barium product instilled directly into rectum
-Patient seated on radiolucent commode in front of fluoroscopic unit for lateral projection
-Spot images or video recording is utilized to capture defecation process
-Anorectal angle and angle between the long axes of the anal canal and rectum are
evaluated
-Aqueous iodinated contrast may be instilled into vagina and bladder to assess changes in proximity between these structures and rectum during defecation
Pathology: Colitis
-Mucosal disease that effects mucosa and submucosa of rectosigmoid area
-May demonstrate loss of haustral sacculations
-“Hose Pipe” appearance
Pathology: Diverticulosis vs Diverticulitis
-DIVERTICULOSIS: Pouch created by herniation of mucous membrane through muscular coat
-DIVERTICULITIS: Inflamed diverticulae
Pathology: Obstruction
Mechanical pathology: Lumen of the bowel is occluded
Pathology: Volvulus
-Portion of bowel twisting or knotting on itself
-Commonly occurs in sigmoid colon
Pathology: Intussusception
-“Telescoping” of one part of bowel into lumen of adjacent part of bowel
-Causes obstruction
Pathology: Apendicitis
Inflammation of the vermiform appendix
Pathology: Neoplasm Polyp
benign adenomas and/ or carcinomas (malignancy)
Pathology: Neoplasm Apple-Core Carcinoma
Malignancy
Pathology: Chron’s disease
-Inflammatory bowel disease involving the intestinal wall
-Appears in small bowel and/or colon
If a polyp is seen on the LATERAL aspect of the DESCENDING colon, what position best shows this and why?
Right lateral decubitus because this position best shows the “up” MEDIAL side of ascending colon and the LATERAL side of the descending colon when it is inflated with air
Which projection does not require colic Flexure to be included in the image?
AP Axial and Lateral
If a polyp is seen on the LATERAL aspect of the ASCENDING colon, what position best shows this and why?
Left lateral decubitus because this position best shows the “up” LATERAL side of ascending colon and the MEDIAL side of the descending colon when it is inflated with air
Which projections best demonstrate the rectal-sigmoid area?
AP/PA Axial and Lateral
