Presentation on theme: "Radiography of the GI System"— Presentation transcript:
1Radiography of the GI System Chapter 17Radiography of the GI System
2Anatomy Of Digestive System Alimentary CanalMouthPharynxEsophagusStomachSmall / Large Intestine
3Anatomy Of Digestive System Accessory glandsLiverGallbladderSalivary glandsPancreas
4EsophagusLong muscular tube carries food and saliva from laryngopharynx to stomachApproximately 10 in. long in adultLies in midsagittal plane
5Esophagus Originates around C-6 In thorax, it is anterior to spine, posterior to trachea and heartPasses through diaphragm through esophageal hiatus
6Esophagus Inferior to diaphragm curves sharply left Increases in diameterJoins stomach at esophagogastric junctionAt level of xyphoid tip4 layers of the esophagusOutermost - fibrousMuscularSubmucosalInnermost - Mucosal
7Stomach Dilated saclike portion of digestive tract Composed of same 4 layers as esophagusOutermost - fibrousMuscularSubmucosalInnermost - Mucosal
8Stomach (cont’d) Divided into 4 parts CardiaFundusBodyPyloric portionEntrance to stomach is cardiac orificeControlled by cardiac sphincterExit is the pyloric orificeControlled by pyloric sphincter
9Stomach (cont’d) Body Begins at cardiac notch Contains rugae Terminates at angular notchPyloric portionConsists of pyloric antrum and canal(antrum: cavity or chamber)
10Body Habitus - Effect On Positioning HypersthenicHorizontal and superiorDependent portion above umbilicusAsthenicVertical and inferiorSthenicGenerally found between xyphoid process and iliac crest
11Functions Of Stomach Breaks down food chemically Broken down material is called?chymeA storage area for further digestion
12Small Intestine Extends from pyloric sphincter to ileocecal valve Joins large intestine at right angleDigestion and absorption of food occur in small intestineApproximately __ feet in length in adult22
13Small Intestine Contains same four layers as stomach and esophagus Mucosa contains projections called villi to facilitate digestion and absorptionDivided into 3 parts:DuodenumJejunumIleum
14Duodenum Contains 4 regions 8 - 10 inches in length Widest portion of small intestineFollows a C-shaped courseContains 4 regionsSuperior, descending, horizontal, ascending
15Jejunum And Ileum Jejunum Ileum Upper remaining 2/5 of small bowelIleumTerminates at ileocecal valveBoth are gathered into freely movable loops (gyri)Attached to posterior abdominal wall by mesentary(the double layer of peritoneum)
16Valvulae conniventesMuscular bands encircling small bowel usually seen to traverse bowel wall at right angles to long axis of the bowel
17Large Intestine What is the main purpose? Reabsorbs fluids and eliminate waste productsAbout _____ feet in length in adult5Greater in diameter than small intestineContains same four layers as esophagus, small intestine, and stomachWhich are?
18Portions Of Large Intestine CecumAscendingJoins transverse colon at right colic flexureTransverseDescendingJoins transverse colon at left colic flexureSigmoidRectumAnal canal
19Large IntestineThe muscular portion contains external bands of muscle known as taeniae coliThese bands create a series of pouches known as?haustra
23Contrast Media Barium sulfate Water insoluble Iodinated contrast media Water solubleHorrible tasteDoes not adhere to wall of alimentary tractIndicated in case of perforation
24Contrast Media Air Considered a negative contrast Generally administered by carbon dioxide crystal ingestionBarium and Air are often used as a double contrast agent
25Preparing pt. for GI study Have contrast agents mixed and ready to goExplain exam to pt.Ensure pt. has followed preparation instructions!
26Preparation cont’d Ensure that footboard is securely on table! Use short exposure timesUse high kVp to penetrate bariumTake exposures end of full expiration!
27Radiography Of Esophagus Can use double or single contrastBarium should flow to sufficiently coat esophagusCan be done upright or recumbentExam will usually be started with fluoroscopy
28AP or PA Projection Pt. supine or prone Center midsagittal plane to cassetteBottom of cassette should be placed just below tip of xyphoidPt. drinks contrast before exposure and continues drinking during exposureShield!
29RAO or LAO Positions Pt should be rotated 35 - 40 degrees Center about 2 inches lateral to MSPBottom of cassette below xyphoid
30RAO or LAO Positions Pt must drink before and during exposure Use shielding!
31Lateral Projection Place pt in lateral position Center midcoronal plane to cassetteBottom of cassette below xyphoid processPt must drink continuously before and during exposureUse shielding!
32Structures Shown/Film Evaluation Entire barium filled esophagus from lower neck to stomachBarium should be sufficiently penetratedSurrounding structures should be visible, not overpenetratedNo rotation on AP, PA, or lateral projectionsEsophagus should be displayed between heart and spine on oblique projections
33What is the Valsalva Maneuver? Useful in demonstrating esophageal varicesHave pt. first deeply inspireSwallow contrastBear downRecumbent position
34Esophageal varicesExtremely dilated sub-mucosal veins in the lower esophagusMost often a consequence of portal hypertension, commonly due to cirrhosisPts with esophageal varices have a strong tendency to develop bleeding
35Radiography Of The Stomach Upper GI SeriesGenerally consists of fluoroscopy and serial radiographsSingle or double contrastPt. should follow a low residue diet for 2 days prior to examPt. must be NPO after midnightAP scout generally obtained prior to exam
36UGI Positioning - AP Projection SupineCRMSP at L1-L2Between MSP and left side if using small filmAt MSP if using 14 X 17StructuresBarium filled fundic portionHiatal hernias, if present
37Single v. Double Contrast Single ContrastShows size, shape, and position of stomachExamines changing contour of stomach during peristalsisObserve filling and emptying of duodenal bulb
38Double Contrast Mucosal lining is well visualized Small lesions are less easily obscured
41UGI Study - PA Projection Prone PositionCenter at MSP if using 14 X 17CRPerpendicular to plane of film at level of L1-L2
42UGI study - PA Projection Structures shown?Size, shape, and relative position of stomachEvaluation:All pertinent anatomyNo rotationExposure sufficient to penetrate bariumSurrounding structures visible
43UGI Positioning - PA Oblique Projection RecumbentBody rotated degreesHypersthenic patients require more rotationCRPerpendicular to L1-L2Between vertebral column and elevated lateral border of the abdomen
44UGI Positioning - PA Oblique Projection StructuresEntire duodenal loopBest image of pyloric canal and duodenal bulbEvaluationAll pertinent anatomyNo superimposition of pylorus and duodenal bulbDuodenal bulb and loop in profile
45UGI Positioning - AP Oblique Projection SupineRight side elevated degreesAverage about 45 degreesCRBetween vertebral column and left lateral border at L1-L2StructuresFundic portion of stomach filled with bariumEvaluationAll pertinent anatomyNo superimposition of pylorus and duodenal bulbBarium filled fundus
46Lateral Projection Position Lateral recumbent - right side CR Level of L1-L2Between midcoronal and anterior of abdomen
47Lateral ProjectionStructuresPyloric canal and duodenal bulb in hypersthenic patientsEvaluationNo rotationAll pertinent anatomy
48Small Bowel Follow Through PreparationLow residue diet for 2 days prior when possibleNPO after midnight before examExamination ProcedureScout film obtainedPatient drinks bariumImages obtained in prone or supine positionImages begin 15 minutes after barium ingestedBarium usually reaches ileocecal valve in about 2 -3 hours
49Radiography Of Small Intestine Contrast administration 3 WaysOrallyRetrogradeReflux filling via barium enemaDirect injection of contrast through NG tubeEnteroclysis (Radiocontrast is infused through tube inserted through nose to duodenum, and images are taken in real time as contrast moves through)
50Small Bowel - AP/PA Projection Patient supine or proneCR centered to level of L2 for early filmsIliac crest for later filmsContinue taking radiographs until barium reaches terminal ileumFluoroscopic spot films may be taken of terminal ileum
51Small Intestine Follow Through 15 minutesImmediate
55Preparation of Colon Pt must take laxative on day prior to exam Pt may have clear liquid day prior to examNPO after midnightCleansing enemas may also be indicated
56Pt. Preparation Explain exam fully to pt. Use care when inserting enema tip!Retention-type balloon tips should only be inflated under fluoroscopic controlBarium should only be administered under fluoroscopic control by radiologist
57Single or double contrast Single demonstrates anatomy and tonus (contraction) of colon, along with most abnormalitiesFeces
58Double ContrastDouble allows visualization of lumen along with any polyps or lesions
59AP Projection - Barium Enema SupineMSP centered to cassetteCR at iliac crestEntire colon must be includedTwo cassettes are sometimes necessary
60PA Projection - Barium Enema Pt. proneMSP centered to filmCR at iliac crestEntire colon must be visualizedBarium should be sufficiently penetrated with surrounding structures visible
61PA Axial Projection - BE Pt. proneMSP centered to IRCR directed degrees caudal to ASISDemonstrates rectosigmoid area of colonArea must be centered to IR
63AP Oblique Projection - BE Pt. SupineBody rotated degreesCR in. lateral to midline at iliac crest
64AP Oblique Projection - BE LPO - Right colic flexure, ascending and sigmoid portions of colonRPO - Left colic flexure, descending colonMust demonstrate entire colonWhich oblique is this?
65PA Oblique Projection (RAO)- Barium Enema Pt. proneLeft side elevated degreesCR at iliac crest, 1 -2 inches lateral to midline of body
66PA Oblique Projection (RAO)- Barium Enema Best demonstrates hepatic flexureAscending and sigmoid portionEntire colon must be visualizedWhat projection is this similar to?
67PA Oblique (LAO) - BE Pt. prone Right side elevated 35 - 45 degrees CR to iliac crest, inches lateral to midline
68PA Oblique (LAO) - BE Demonstrates descending portion of colon Entire colon must be visualizedWhat flexture doe this best demonstrate?(splenic)What projection is it comparable to?
69Lateral Projection - Barium Enema Lt. or Rt. lateral recumbent positionCenter midcoronal plane to filmCR enters midcoronal plane at level of ASIS
70Lateral Projection - Barium Enema Best demonstrates rectum and distal sigmoid portions of colonRectosigmoid area should be centered, no rotation
71Lateral Decubitus Positions - BE AP or PA projection
72Left Lateral Decubitus Positions - BE Up side is air-filledMust include entire colonAir-filled portion must not be overpenetrated
73Upright Position - Barium Enema Demonstrates air-filled flexures and transverse colon
74Chassard Lapine’Demonstrates rectum, rectosigmoid juntion and sigmoid
75What is a Defecography? (evacuation proctography) Radiographic exam of defecation process under fluoroscopyUsed to evaluate disorders of lower bowel not evident by tests such as colonoscopy or sigmoidoscopy
76Defecation(Having a bowel movement) is a complex action requiring coordination with relaxation and contraction of a large number of musclesControlled by nervous system, but is also under voluntary control.
77Defecation cont’d Process is initiated by arrival of stool into rectum This sensation leads to chain of events which ends in evacuation of stool from anusDefecation is voluntarily controlled in healthy, normally functioning people.
78Defecography is used to Evaluate: Chronic ConstipationRectal prolapse (walls of rectum protrude through anus and become visible outside body)Rectocele (outpouching of rectum)Fecal incontinenceAnismus (inappropriate spasm of anal sphincter)
79Defecography A thickened barium contrast putty is injected into rectum then excreted by patient while radiologist watches and videotapes