Radiography Of The GI System

1. Radiography Of The GI System Kyle Thornton DMI 63

3. Esophagus Long muscular tube that carries food and saliva from laryngopharynx to stomach Approximately 10 in. long in adult Lies in the midsagittal plane Originates around C-6 In the thorax, it is anterior to the spine, posterior to trachea and heart Passes through diaphragm through esophageal hiatus

4. Esophagus Inferior to diaphragm curves sharply left Increases in diameter Joins stomach at esophagogastric junction Cardiac antrum At level of xyphoid tip 4 layers of the esophagus Outermost - fibrous Muscular Submucosal Innermost - Mucosal

5. Stomach Dilated saclike portion of digestive tract Composed of same 4 layers as esophagus Divided into 4 parts Cardia Fundus Body Pyloric portion

6. Stomach Cardia Immediately surrounding esophageal opening Fundus Superior portion Fills dome of left hemidiaphragm Generally contains gas Body Begins at cardiac notch Contains rugae Terminates at angular notch Pyloric portion Consists of pyloric antrum and canal

7. Stomach Anterior and posterior surface Right border marked by lesser curvature Left border marked by greater curvature Begins at esophogogastric junction, terminates at pylorus 4-5 times longer than lesser curvature Entrance to stomach is the cardiac orifice Controlled by cardiac sphincter Exit is the pyloric orifice Controlled by pyloric sphincter

8. Body Habitus And Its Effect On Positioning Hypersthenic Horizontal and superior Dependent portion above umbilicus Asthenic Vertical and inferior Sthenic Generally found between xyphoid process and iliac crest

9. Functions Of The Stomach Storage area for further digestion Food is chemically broken down This broken down material is called chyme

10. Small Intestine Extends from pyloric sphincter to ileocecal valve Joins large intestine at right angle Digestion and absorption of food occur in small intestine Approximately 22 feet in length in adult Contains same four layers as stomach and esophagus The mucosa contains projections called villi to facilitate digestion and absorption Divided into three parts: Duodenum Jejunum Ileum

11. Duodenum 8 - 10 inches in length Widest portion of small intestine Follows a C-shaped course Contains 4 regions Superior, descending, horizontal, ascending The first region is known as the duodenal bulb The fourth portion joins the jejunum and is supported by the ligament of Trietz The head of the pancreas is contained in the duodenal loop - second portion

12. Jejunum And Ileum Jejunum Upper remaining two-fifths of small bowel Ileum Terminates at ileocecal valve Both are gathered into freely movable loops (gyri) Attached to posterior abdominal wall by mesentary Generally found in central and lower part of abd. cavity within arch of large intestine

13. Large Intestine Begins at right iliac region Joins ileum of small intestine Forms an arch around the small intestine Four main parts Cecum Colon Rectum Anal canal

14. Large Intestine About 5 feet in length in adult Greater in diameter than small intestine Contains same four layers as esophagus, small intestine, and stomach The muscular portion contains external bands of muscle known as taeniae coli These bands create a series of pouches known as haustra The large intestine functions to reabsorb fluids and eliminate waste products

15. Portions Of The Large Intestine Cecum Ascending Joins transverse colon at right colic flexure Transverse Descending Joins transverse colon at left colic flexure Sigmoid Rectum Anal canal

16. Variations In Body Habitus Hypersthenic The colon generally lies in the periphery of the abdomen May require more films to adequately display the anatomy Asthenic Intestines are bunched together Lie low in the abdomen

17. Contrast Media Barium sulfate Water insoluble Iodinated contrast media Water soluble Horrible taste Does not adhere to wall of alimentary tract Indicated in case of perforation Air Considered a negative contrast Generally administered by carbon dioxide crystal ingestion Barium and Air are often used as a double contrast agent

18. Imaging Notes/Preparation Have contrast agents mixed and ready Explain examination to patient Ensure that patient has followed preparation instructions Ensure that footboard is securely on table Use short exposure times Use high kVp to penetrate barium Take exposures at the end of full expiration

19. Radiography Of The Esophagus Can use double or single contrast The barium should flow to sufficiently coat the esophagus Examinations can be done in the upright or recumbent position The exam will usually be started with fluoroscopy

20. AP or PA Projection Place patient supine or prone Center the midsagittal plane to the film Bottom of film should be placed just below tip of xyphoid Patient should commence drinking contrast before exposure and continue drinking during exposure Use shielding for every exposure

21. RAO or LAO Positions Patient should be rotated 35 - 40 degrees Center about two inches lateral to MSP Bottom of film below xyphoid Patient must drink before and during the exposure Use shielding

22. Lateral Projection Place patient in lateral position Center the midcoronal plane to the film Bottom of film below xyphoid process Patient must drink continuously before and during exposure Use shielding

23. Structures Shown/Film Evaluation Entire barium filled esophagus from lower neck to stomach Barium should be sufficiently penetrated Surrounding structures should be visible, not overpenetrated No rotation on AP, PA, or lateral projections Esophagus should be displayed between heart and spine on oblique projections

24. Valsalva Maneuver Useful in demonstrating esophageal varices Have patient first deeply inspire Swallow contrast Bear down This should be done in the recumbent position

25. Radiography Of The Stomach Referred to as the Upper GI Series Generally consists of fluoroscopy and serial radiographs Single or double contrast is used Patient should follow a low residue diet for 2 days prior to the examination Patient must be NPO after midnight AP scout generally obtained prior to exam

26. Single v. Double Contrast Single Contrast Shows size, shape, and position of the stomach Examines changing contour of stomach during peristalsis Observe filling and emptying of duodenal bulb Double Contrast Mucosal lining is well visualized Small lesions are less easily obscured

27. UGI Positioning - PA Projection Position Prone Center between MSP and Mid-Axillary line if using small film Center at MSP if using 14 X 17 CR Perpendicular to plane of film at level of L1-L2 Structures Size, shape, and relative position of stomach Pyloric canal and duodenal loop in hypo or asthenic patients Evaluation All pertinent anatomy No rotation Exposure sufficient to penetrate barium Surrounding structures visible

28. UGI Positioning - PA Oblique Projection Position Recumbent Body rotated 40 - 70 degrees Hypersthenic patients require more rotation CR Perpendicular to L1-L2 Between vertebral column and elevated lateral border of the abdomen Structures Entire duodenal loop Best image of pyloric canal and duodenal bulb Evaluation All pertinent anatomy No superimposition of pylorus and duodenal bulb Duodenal bulb and loop in profile

29. UGI Positioning - AP Oblique Projection Position Supine Right side elevated 30 - 60 degrees Average about 45 degrees CR Between vertebral column and left lateral border at L1-L2 Structures Fundic portion of stomach filled with barium Evaluation All pertinent anatomy No superimposition of pylorus and duodenal bulb Barium filled fundus

30. Lateral Projection Position Lateral recumbent - right side CR Level of L1-L2 Between midcoronal and anterior of abdomen Structures Anterior/posterior portions of stomach Pyloric canal and duodenal bulb in hypersthenic patients Evaluation No rotation All pertinent anatomy

31. UGI Positioning - AP Projection Position Supine CR MSP at L1-L2 Between MSP and left side if using small film At MSP if using 14 X 17 Structures Barium filled fundic portion Hiatal hernias, if present

32. Wolf Method - Hiatal Hernia Patient rotated 40-45 degrees Patient lies on compression sponge CR angled about 20 degrees caudal Patient must drink during exposure Very useful in diagnosing hiatal hernia

33. Radiography Of Small Intestine Contrast administration Orally Retrograde Reflux filling via barium enema Direct injection of contrast through NG tube Enteroclysis

34. Small Intestine Preparation Low residue diet for 2 days prior when possible NPO after midnight before the exam Examination Procedure Scout film obtained Patient drinks barium Films obtained in prone or supine position Films begin at 15 minutes after barium Barium usually reaches ileocecal valve in about 2 -3 hours

35. Small Bowel - AP/PA Projection Patient supine or prone CR centered to level of L2 for early films Iliac crest for later films Continue taking radiographs until barium reaches terminal ileum Fluoroscopic spot films may be taken of terminal ileum

36. Radiography Of The Colon Single or double contrast Single demonstrates the anatomy and tonus of the colon, along with most abnormalities Double allows visualization of the intestinal lumen along with any polyps or lesions

37. Preparation Of The Colon Patient must take a laxative on the day prior to the examination Patient may have a clear liquid on the day prior to the exam NPO after midnight Cleansing enemas may also be indicated

38. Patient Preparation Explain the examination fully to the patient Use care when inserting the enema tip Retention-type balloon tips should only be inflated under fluoroscopic control Barium should only be administered under fluoroscopic control

39. PA Projection - Barium Enema Pt. prone MSP centered to film CR at iliac crest Entire colon must be visualized The barium should be sufficiently penetrated with surrounding structures visible

40. PA Axial Projection - BE Pt. prone MSP centered to film CR directed 30 - 40 degrees caudal to ASIS Demonstrates rectosigmoid area of colon This area must be centered to film

41. PA Oblique Projection (RAO)- Barium Enema Pt. prone Left side elevated 35 - 45 degrees CR at iliac crest, 1 -2 inches lateral to midline of body Best demonstrates right colic flexure Ascending and sigmoid portion Entire colon must be visualized

42. PA Oblique (LAO) - BE Pt. prone Right side elevated 35 - 45 degrees CR to iliac crest, 1 - 2 inches lateral to midline Best demonstrates left colic flexure Descending portion of colon Entire colon must be visualized

43. Lateral Projection - Barium Enema Lt. or Rt. lateral recumbent position Center midcoronal plane to film CR enters midcoronal plane at level of ASIS Best demonstrates rectum and distal sigmoid portions of colon There should be no rotation Rectosigmoid area should be centered

44. AP Projection - Barium Enema Supine position MSP centered to cassette CR at iliac crest Demonstrates entire colon Entire colon must be included Two cassettes are sometimes necessary

45. AP Axial Projection - BE Pt. supine MSP centered to film CR to 2 in. above iliac crest 30 - 40 degrees cephalic Demonstrates rectosigmoid area of colon Rectosigmoid area should be free of superimposition Rectosigmoid area centered to film

46. AP Oblique Projection - BE Pt. supine Body rotated 35 - 45 degrees CR 1 - 2 in. lateral to midline at iliac crest LPO - Right colic flexure, ascending and sigmoid portions of colon RPO - Left colic flexure, descending colon Must demonstrate entire colon

47. Lateral Decubitus Positions - BE Lateral recumbent position Horizontal CR to MSP at level of iliac crest Demonstrates AP or PA projection Dependent side is barium filled Up side is air-filled Must include entire colon Air-filled portion must not be overpenetrated

48. Upright Positions - Barium Enema Cassette must be lowered to compensate for the drop of the bowel in this position Demonstrates air-filled flexures and transverse colon