Presentation on theme: "Radiography of the GI System"— Presentation transcript:
1 Radiography of the GI System Chapter 17Radiography of the GI System
2 Anatomy Of Digestive System Alimentary CanalMouthPharynxEsophagusStomachSmall / Large Intestine
3 Anatomy Of Digestive System Accessory glandsLiverGallbladderSalivary glandsPancreas
4 EsophagusLong muscular tube carries food and saliva from laryngopharynx to stomachApproximately 10 in. long in adultLies in midsagittal plane
5 Esophagus Originates around C-6 In thorax, it is anterior to spine, posterior to trachea and heartPasses through diaphragm through esophageal hiatus
6 Esophagus Inferior to diaphragm curves sharply left Increases in diameterJoins stomach at esophagogastric junctionAt level of xyphoid tip4 layers of the esophagusOutermost - fibrousMuscularSubmucosalInnermost - Mucosal
7 Stomach Dilated saclike portion of digestive tract Composed of same 4 layers as esophagusOutermost - fibrousMuscularSubmucosalInnermost - Mucosal
8 Stomach (cont’d) Divided into 4 parts CardiaFundusBodyPyloric portionEntrance to stomach is cardiac orificeControlled by cardiac sphincterExit is the pyloric orificeControlled by pyloric sphincter
9 Stomach (cont’d) Body Begins at cardiac notch Contains rugae Terminates at angular notchPyloric portionConsists of pyloric antrum and canal(antrum: cavity or chamber)
10 Body Habitus - Effect On Positioning HypersthenicHorizontal and superiorDependent portion above umbilicusAsthenicVertical and inferiorSthenicGenerally found between xyphoid process and iliac crest
11 Functions Of Stomach Breaks down food chemically Broken down material is called?chymeA storage area for further digestion
12 Small 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
13 Small Intestine Contains same four layers as stomach and esophagus Mucosa contains projections called villi to facilitate digestion and absorptionDivided into 3 parts:DuodenumJejunumIleum
14 Duodenum Contains 4 regions 8 - 10 inches in length Widest portion of small intestineFollows a C-shaped courseContains 4 regionsSuperior, descending, horizontal, ascending
15 Jejunum 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)
16 Valvulae conniventesMuscular bands encircling small bowel usually seen to traverse bowel wall at right angles to long axis of the bowel
17 Large 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?
18 Portions Of Large Intestine CecumAscendingJoins transverse colon at right colic flexureTransverseDescendingJoins transverse colon at left colic flexureSigmoidRectumAnal canal
19 Large IntestineThe muscular portion contains external bands of muscle known as taeniae coliThese bands create a series of pouches known as?haustra
23 Contrast Media Barium sulfate Water insoluble Iodinated contrast media Water solubleHorrible tasteDoes not adhere to wall of alimentary tractIndicated in case of perforation
24 Contrast Media Air Considered a negative contrast Generally administered by carbon dioxide crystal ingestionBarium and Air are often used as a double contrast agent
25 Preparing pt. for GI study Have contrast agents mixed and ready to goExplain exam to pt.Ensure pt. has followed preparation instructions!
26 Preparation cont’d Ensure that footboard is securely on table! Use short exposure timesUse high kVp to penetrate bariumTake exposures end of full expiration!
27 Radiography 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
28 AP 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!
29 RAO or LAO Positions Pt should be rotated 35 - 40 degrees Center about 2 inches lateral to MSPBottom of cassette below xyphoid
30 RAO or LAO Positions Pt must drink before and during exposure Use shielding!
31 Lateral Projection Place pt in lateral position Center midcoronal plane to cassetteBottom of cassette below xyphoid processPt must drink continuously before and during exposureUse shielding!
32 Structures 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
33 What is the Valsalva Maneuver? Useful in demonstrating esophageal varicesHave pt. first deeply inspireSwallow contrastBear downRecumbent position
34 Esophageal 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
35 Radiography 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
36 UGI 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
37 Single v. Double Contrast Single ContrastShows size, shape, and position of stomachExamines changing contour of stomach during peristalsisObserve filling and emptying of duodenal bulb
38 Double Contrast Mucosal lining is well visualized Small lesions are less easily obscured
41 UGI Study - PA Projection Prone PositionCenter at MSP if using 14 X 17CRPerpendicular to plane of film at level of L1-L2
42 UGI study - PA Projection Structures shown?Size, shape, and relative position of stomachEvaluation:All pertinent anatomyNo rotationExposure sufficient to penetrate bariumSurrounding structures visible
43 UGI Positioning - PA Oblique Projection RecumbentBody rotated degreesHypersthenic patients require more rotationCRPerpendicular to L1-L2Between vertebral column and elevated lateral border of the abdomen
44 UGI 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
45 UGI 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
46 Lateral Projection Position Lateral recumbent - right side CR Level of L1-L2Between midcoronal and anterior of abdomen
47 Lateral ProjectionStructuresPyloric canal and duodenal bulb in hypersthenic patientsEvaluationNo rotationAll pertinent anatomy
48 Small 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
49 Radiography 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)
50 Small 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
51 Small Intestine Follow Through 15 minutesImmediate
52 Small Intestine Follow Through 1 hour30 minutes
55 Preparation 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
56 Pt. 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
57 Single or double contrast Single demonstrates anatomy and tonus (contraction) of colon, along with most abnormalitiesFeces
58 Double ContrastDouble allows visualization of lumen along with any polyps or lesions
59 AP Projection - Barium Enema SupineMSP centered to cassetteCR at iliac crestEntire colon must be includedTwo cassettes are sometimes necessary
60 PA Projection - Barium Enema Pt. proneMSP centered to filmCR at iliac crestEntire colon must be visualizedBarium should be sufficiently penetrated with surrounding structures visible
61 PA Axial Projection - BE Pt. proneMSP centered to IRCR directed degrees caudal to ASISDemonstrates rectosigmoid area of colonArea must be centered to IR
63 AP Oblique Projection - BE Pt. SupineBody rotated degreesCR in. lateral to midline at iliac crest
64 AP Oblique Projection - BE LPO - Right colic flexure, ascending and sigmoid portions of colonRPO - Left colic flexure, descending colonMust demonstrate entire colonWhich oblique is this?
65 PA Oblique Projection (RAO)- Barium Enema Pt. proneLeft side elevated degreesCR at iliac crest, 1 -2 inches lateral to midline of body
66 PA Oblique Projection (RAO)- Barium Enema Best demonstrates hepatic flexureAscending and sigmoid portionEntire colon must be visualizedWhat projection is this similar to?
67 PA Oblique (LAO) - BE Pt. prone Right side elevated 35 - 45 degrees CR to iliac crest, inches lateral to midline
68 PA 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?
69 Lateral Projection - Barium Enema Lt. or Rt. lateral recumbent positionCenter midcoronal plane to filmCR enters midcoronal plane at level of ASIS
70 Lateral Projection - Barium Enema Best demonstrates rectum and distal sigmoid portions of colonRectosigmoid area should be centered, no rotation
71 Lateral Decubitus Positions - BE AP or PA projection
72 Left Lateral Decubitus Positions - BE Up side is air-filledMust include entire colonAir-filled portion must not be overpenetrated
73 Upright Position - Barium Enema Demonstrates air-filled flexures and transverse colon
74 Chassard Lapine’Demonstrates rectum, rectosigmoid juntion and sigmoid
75 What 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
76 Defecation(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.
77 Defecation 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.
78 Defecography 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)
79 Defecography A thickened barium contrast putty is injected into rectum then excreted by patient while radiologist watches and videotapes