Gastrointestinal Tract.pptx

Gastrointestinal Tract Mrs. Amans Anatomy of the Bowel Wall 30-foot muscular tube Varies in diameter Originates at the lip and terminates at the anus The Esophagus has 4 layers The rest of the GI Tract has 5 layers  Anatomy of the Bowel Wall Sonographic structure of the...

Gastrointestinal Tract Mrs. Amans Anatomy of the Bowel Wall 30-foot muscular tube Varies in diameter Originates at the lip and terminates at the anus The Esophagus has 4 layers The rest of the GI Tract has 5 layers  Anatomy of the Bowel Wall Sonographic structure of the bowel is usually described with five layers: Three echogenic layers separated by two hypoechoic ones Using high-frequency transducers, the muscularis mucosa and the two layers of the muscularis propria can be resolved as well. Five layers of the bowel wall Anatomy of the Bowel Wall The five sonographic layers from interior to exterior are as follows: 1. Inner hyperechoic layer Represents the border between the digestive fluid and the mucosa 2. Hypoechoic layer— Mucosa, lamina propria, and lamina muscularis Usually thin 3. Hyperechoic layer— Submucosa 4. Hypoechoic layer— Muscular layer Its thickness depends upon the segment of the digestive tract 5. Outer hyperechoic layer—the serous layer Border to the peridigestive fat Anatomy of the Bowel Wall Anatomy of the Bowel Wall Mucosa Comprised of: Superficial mucosa Deep mucosa In the esophagus - composed of stratified squamous cells In the stomach and bowel - composed of simple and columnar cells Plasma membrane of the cells perform certain functions: microvilli enhance the absorptive area, goblet cells secrete mucus cells with cilia oscillate to aid in digestion. Anatomy of the Bowel Wall Superficial mucosal surface – Inner most surface Composed of epithelium Echogenic Anatomy of the Bowel Wall Mucosal surface Deep to the epithelium: Hypoechoic mucosal section: Lamina propria Muscularis mucosa Below the muscularis mucosa is the submucosa Anatomy of the Bowel Wall Submucosa Thickest layer Echogenic Deeper lies the muscularis propria Anatomy of the Bowel Wall Muscularis propria (aka muscularis externa) Echogenic Consists of: Inner circumferential layer Outer longitudinal layer of smooth muscle The final layer of the wall is the echogenic serosa, a thin epithelial layer on the periphery of the bowel. Anatomy of the Bowel Wall Serosa Final layer Thin epithelial layer Echogenic Anatomy of the Bowel Wall GI ultrasound should examine: The BWT Wall changes Vascular anomalies Motility Symmetry of thickness. BWT is the.4 The measurement should include the outer hyperechoic layer to the inner hyperechoic layer and be performed with mild compression. Transducer compression of the bowel wall will reduce thickness and can make it challenging to distinguish wall layers. Some wall thickening is nonspecific, which may make it difficult or impossible to diagnose disease processes, although the finding must be evaluated. Focal, irregular, and asymmetrical thickening of the bowel wall suggests malignancy.6  Anatomy of the Bowel Wall GI ultrasound should examine: BWT – measurement most consistently used Should include the outer hyperechoic layer to the inner hyperechoic layer Should be performed with mild compression Too much compression will reduce thickness and make the bowl walls hard to distinguish Some wall thickening is nonspecific, but the finding must be evaluated. Focal, irregular, and asymmetrical thickening of the bowel wall suggests malignancy  Anatomy of the Esophagus Esophagus Fibromuscular hollow tube within the thorax. Approximately 10 inches long Superior width - 1.4 cm Distal width - 2 cm Composed of four layers: Inner mucosa Submucosa Muscularis propria Outer adventitia It does not have a serosal layer.  Anatomy of the Esophagus Esophagus The mucosa layer - epithelium covering the entire lumen. The submucosa - thick layer that connects the mucosa to the muscular layer The muscular portion - made of longitudinal and circular muscle fibers. The outermost layer - adventitia composed of fibrous tissue Connects with the pharynx superiorly and with the stomach distally.  Anatomy of the Esophagus Sonographic Technique A sonoendoscope is often utilized Transabdominal sonography can depict most of the tubular structure Patient is supine Thyroid used as a window for the superior portion Heart used as an acoustic with the transducer adjacent to the left sternum for the midportion. Left liver lobe as an acoustic window for the inferior portion, esophagogastric junction, and stomach The The esophagogastric junction is within the superior abdomen (epigastric region) posterior to the left liver lobe and anterior to the aorta.  Anatomy of the Esophagus Sonographic Technique Esophagogastric Junction Place transducer inferior to the xiphoid and angle superiorly to locate the junction Giving an erect patient water to drink may ensure transabdominal views of the entire esophagus  Anatomy of the Esophagus Wall Dimensions Normal adult – 2 to 5 mm Esophageal wall thickness may differ depending on contraction and dilatation. Irregular measurements may be caused by a transient or acute condition. Focal causes are more likely to be long-lasting.  Anatomy of the Esophagus Wall Dimensions Acute abnormal wall thickness measurement can be due to: Spasm Esophagitis Hematoma Perforation Focal causes for wall thickness include: Tumor Hernia Varices Mucocele and are more likely to be long-lasting.  Anatomy of the Esophagus Wall Dimensions Acute abnormal wall thickness measurement can be due to: Spasm Esophagitis Hematoma Perforation Focal causes for wall thickness include: Tumor Hernia Varices Mucocele and are more likely to be long-lasting.  Anatomy of the Esophagus Disorders of the Esophagus Carcinoma Rare - 1% in the United States Most commonly - squamous cell carcinoma Mostly affects the upper and mid-esophagus Less commonly - adenocarcinoma Mostly affects the distal portion Each type affect men more than women Mostly over those 65 years of age or older  Anatomy of the Esophagus Disorders of the Esophagus Carcinoma The lesions begin as raised longitudinal plaque-like or polypoid areas Areas quickly enlarge circumferentially forming strictures Dysphagia develops Extension into the surrounding mediastinum is unimpeded due to lack of serosa in the esophagus 5 year survival rate is 20% Survival rates over 5 years are attributed to early detection.  Anatomy of the Esophagus Other Tumors of the Esophagus Rare malignant tumors of the esophagus: carcinosarcoma, mucoepidermoid carcinoma, adenoid cystic carcinom lymphoma glomangiomas Benign tumors of the esophagus: polyp, granular cell tumor adenoma papilloma (malignant potential) leiomyoma Sonographic tumor findings: wall deviations and disruptions wall thickening lesions with a polypoid, smooth-walled, vascular, or lobulated nature mass with isoechoic, cystic, partially cystic, or heterogeneous appearance  Anatomy of the Esophagus Sonographic tumor findings: Wall deviations and disruptions Wall thickening Lesions with a polypoid, smooth-walled, vascular, or lobulated nature Mass with isoechoic, cystic, partially cystic, or heterogeneous appearance  Anatomy of the Esophagus Disorders of the Esophagogastric Junction Includes: hiatal hernia esophageal varices anomalous motility tumors similar to those of the esophagus Esophagus and Esophagogastric Junction Esophagogastric junction. The esophagogastric junction is positioned posterior to the left liver lobe in this sagittal view (arrows). A target view of the stomach is seen adjacent to the left liver lobe (arrow). 26 Review What is the most common esophageal cancer in the United States? A. Adenocarcinoma B. Leiomyosarcoma C. GI stromal tumor D. Squamous cell carcinoma 27 Review For a patient diagnosed with esophageal carcinoma, what is attributed to a survival rate greater than 5 years? A. Detected with intraluminal scanning B. Incidental finding with esophageal varices C. Early detection D. Esophageal thickening noted on Valsalva maneuver 28  Anatomy of the Stomach Stomach Expanded part of the alimentary tract Lies in the left upper quadrant The fundus is medial to the spleen and anterior to the left kidney The body and antrum of the stomach lie posterior or inferior to the left lobe of the liver, anterior to the pancreas, and medial to the gallbladder and porta hepatis  Anatomy of the Stomach Stomach The antrum and body appear as a target-like structure inferior to the longitudinal left lobe Both hypo- and hyperechoic contents as well as air shadows can be seen Often, the gastroesophageal junction can also be visualized as a target-like structure just below the diaphragm and just to the left of the spine Gas, mucus, or fluid may fill the center of the stomach Rugal folds and posterior wall structure can be seen when stomach is filled Anatomy of the Stomach Sonographic Technique Within GI tract, stomach has most potential for a sonographic diagnosis. Layers of GI tract wall are thicker in stomach. Can be visualized transabdominally in normal patient Stomach exam can be done with a 3.5- or 5-MHz transducer. Gastric wall exam should be interrogated with a 5- or 7.5-MHz transducer. 31  Anatomy of the Stomach Sonographic Technique  Anatomy of the Stomach Sonographic Technique If uncertainty exists whether a cystic structure in the left upper quadrant represents the stomach, giving the patient a few sips of water through a straw produces a sparkling or swirling pattern in the stomach as the water flows. A recommendation to view the stomach also includes giving the patient 500 to 800 mL (approximately 20 to 30 oz) of plain water to allow filling of the cavity followed by sonographic exploration 10 to 15 minutes after the water ingestion. This allows air bubbles to diffuse from the water, which removes artifact that may be suspicious of disease. Usually, the stomach contains some air when the patient is supine. Anatomy of the Stomach Sonographic Technique Usually, stomach contains some air when patient is supine. Placing patient into right lateral decubitus position moves fluid into antrum and pyloric region of stomach. Provides better visualization and confirms identity of antrum and pyloric region. Placing patient into left lateral decubitus position often improves visualization of fundus. 34 Anatomy of the Stomach Recommended transducer position to acquire the best sonographic visualization of the stomach. 35 Anatomy of the Stomach Sonographic Technique If a solid-looking mass is suspected in the stomach or when detailed evaluation of gastric mucosa is required Examine patient first with minimal stomach contents and again after water ingestion. Position patient in upright, left lateral decubitus, supine, and right lateral decubitus positions to demonstrate most of the gastric mucosa. Some investigators recommend 1 mg of glucagon IV before patient drinks water to ensure fluid retention in stomach. Glucagon should produce 30 to 60 minutes of gastric distention. 36 Anatomy of the Stomach Sonographic Technique Stomach is expanded part of alimentary tract and normally lies in LUQ of abdomen. Fundus is medial to spleen and anterior to the left kidney. Body and antrum lie posterior or inferior to left liver lobe, anterior to pancreas, and medial to GB and porta hepatis. Antrum and body often appear as a target-like structure inferior to left liver lobe on longitudinal sonograms. Larger left liver lobe may allow visualization of esophagogastric junction as target-like structure below diaphragm and left of spine. 37 Anatomy of the Stomach Stomach Wall Measurements Undistended - 3 to 6 mm thick. When stomach is distended to a diameter of ≥8 cm, wall should measure 2 to 4 mm. Bowel wall thickening occurs with infiltration, inflammation, edema, or neoplastic invasion. Thickening >1 cm is generally considered due to malignancy. When fluid is present, rugal folds and posterior wall structure can often be visualized. 38 Stomach #11 Sonographic Technique If the stomach is not distended, its wall should measure approximately 3 to 6 mm thick. If the stomach is not distended, bowel wall should measure approximately 4 to 6 mm thick. When stomach is distended to a diameter of ≥8 cm, wall should measure 2 to 4 mm. Bowel wall thickening occurs with infiltration, inflammation, edema, or neoplastic invasion. Thickening >1 cm is generally considered due to malignancy. When fluid is present, rugal folds and posterior wall structure can often be visualized. 39 Stomach #12 Disorders of the Stomach Gastric Dilatation Many disorders can cause stomach to dilate. Acute dilation can occur after surgery, because of adhesions blocking the small bowel, tumor, ulcer disease, pyloric muscle hypertrophy, or after placement of a body cast. Unclear if dilation is caused by reflex paralysis of gastric motility or obstruction of duodenum by superior mesenteric artery impinging on it Tumor or ulcer disease may obstruct gastric outlet. Pyloric muscle hypertrophy is rare in adults, but when it does occur, it is usually associated with gastritis or ulcer disease. 40 Stomach #13 Disorders of the Stomach Gastric Dilatation Tumor or ulcer disease may obstruct gastric outlet. Pyloric muscle hypertrophy is rare in adults, but when it does occur, it is usually associated with gastritis or ulcer disease. Other factors contributing to stomach dilation are diabetes mellitus, scleroderma, or surgical vagotomy that may bring about gastric dilatation as a complication of neuropathy. Observing gastric peristalsis can differentiate atonic from obstructive dilatation. Distinction may be impossible in many cases because stomach wall rigidity is often seen in tumor infiltration and gastric ulcer disease, and uncoordinated peristaltic waves are seen in neuropathic conditions. Volvulus is another rare cause of gastric dilatation. 41 Stomach #14 Disorders of the Stomach Gastritis Inflammatory disorder of gastric mucosa Chronic gastritis is caused by several factors and may present as enlarged rugal folds with generalized thickening of mucosal layer of wall. Thickening may accompany Increased acid production as in Zollinger-Ellison syndrome or Decreased acid production as in Ménétrier disease 42 Stomach #15 Disorders of the Stomach Gastritis Chronic gastritis may also demonstrate hyperplastic and inflammatory polyps. A variation is atrophic gastritis—mucosa is thinned. Difficult to see sonographically, but it is considered a precursor of gastric carcinoma 43 Stomach #16 A B Figure 11-7 Gastritis. A: Longitudinal view of the distal stomach wall showing thickening (arrows). B: Transverse image of the same inflamed stomach wall demonstrating a thickened hypoechoic mucosal and submucosal layer (arrows). (Images courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 44 Stomach #17 Disorders of the Stomach Ulcer Disease Peptic ulcer disease (PUD) is a break, or ulceration, in protective mucosal lining of lower esophagus, stomach, or duodenum. Benign peptic gastric ulcers can occur anywhere in stomach but most often appear along antral portion of lesser curvature. Sonographically May be major wall thickening, usually caused by marked edema of submucosa, with milder thickening of gastric mucosa 45 Stomach #18 Disorders of the Stomach Ulcer Disease Complications of peptic ulcer disease, gastric or duodenal, include anterior or posterior perforation. Peptic duodenal ulcers are even more difficult to identify, but mucosal edema can sometimes suggest their presence. Endoscopic Ultrasound (EUS) May be required since it can detect defects, such as ulceration, in gastric wall required to diagnose superficial ulcerations of mucosal lining, as well as behind the base of defect 46 Stomach #19 A B Figure 11-8 Gastric ulcer. A, B: Longitudinal images demonstrate the gastric antrum in a patient with an air-filled benign gastric ulcer (arrow). (Images courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 47 Stomach #20 Disorders of the Stomach Ulcer Disease Complications of peptic ulcer disease—gastric or duodenal—include anterior or posterior perforation. Anterior perforation usually results in free intraperitoneal air and often subsequent peritonitis. Other describe appearance of free air in peritoneal region as increase echogenicity of a peritoneal stripe with multiple reflective artifact and a comet tail appearance. Important: Differentiate free air from bowel gas. 48 Stomach #21 Disorders of the Stomach Ulcer Disease Thickening of the bowel serosa may be observed due to peritoneal irritation and reactive edema. Generalized peritoneal infection or localized abscess may also result. Chief complications Posterior duodenal perforation is bleeding. Posterior stomach perforation may result in pancreatitis. 49 Stomach #22 Disorders of the Stomach Gastroduodenal Crohn Disease Crohn disease (CD) is an idiopathic inflammation that starts in the submucosa and spreads to all layers of the bowel wall. Disease is chronic and usually occurs in young adults. Mostly affects the terminal ileum and proximal colon Lesser extent affects mid and distal colon and small intestine. Rare in stomach and duodenum, approximately 2% to 8% of patient involvement 50 Stomach #23 Disorders of the Stomach Gastroduodenal Crohn Disease At time of diagnosis, entire wall is involved and sonographic appearance is a nonspecific hypoechoic target lesion if lumen is viewed transversely. Chronic inflammation is seen as hypervascularity in the wall. Advanced carcinoma, lymphoma, hematoma, and tuberculosis can appear similar. 51 Stomach #24 A B Figure 11-9 A and B Crohn disease. A, B: Longitudinal bowel demonstrating thickening of the layers because of inflammation related to Crohn disease. B: Vascular activity related to inflammation. 52 Stomach #25 C D Figure 11-9 C and D C, D: Transverse bowel with thickened mucosal layers caused by chronic inflammation. D: Vascular activity consistent with Crohn disease. (Images A–D: Courtesy of Joie Burns, Boise, ID.) 53 Stomach #26 Figure 11-9 E E: Abnormally thickened bowel because of Crohn disease. (Image E: Courtesy of Ted Whitten, Ultrasound Practitioner, Elliot Hospital, Manchester, NH.) 54 Stomach #27 Figure 11-10 Bowel with disease appearing similar to Crohn disease. A: Stomach cancer. B: Bowel lymphoma. C: Bowel abscess. D: Colitis. (Images courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 55 Stomach #28 Disorders of the Stomach Other Inflammatory Conditions Stomach infection can display marked thickening of stomach wall and swelling of the gastric rugae—a condition called phlegmonous gastritis. Most cases are caused by bacteria which include α-hemolytic streptococci Staphylococcus Escherichia coli Clostridium welchii Helicobacter pylori Proteus species 56 Stomach #29 Disorders of the Stomach Other Inflammatory Conditions Peritonitis occurs in 70% of cases. When gas-forming organisms such as E. coli or C. welchii are the cause, small gas bubbles may form in the gastric wall—this is a type of emphysematous gastritis. Swallowing a corrosive substance is a more common cause of emphysematous gastritis. 57 Stomach #30 Disorders of the Stomach Gastric Cancer Gastric or stomach cancer is an inclusive term for common cancers affecting the stomach. Incidence of gastric cancer has declined in the United States and represents approximately 1.5% of all new United States cancer cases annually. Stomach cancer is much more common in other parts of the world, particularly in less developed countries. Fifth most common neoplasm and the third most deadly worldwide 58 Stomach #31 Disorders of the Stomach Gastric Cancer Adenocarcinoma Adenocarcinoma is the most common type of cancer of the stomach. Accounts for 90 to 95 % of gastric cancers. Cancer type originates in the glandular tissue known as epithelial tissue. Expect sonographic appearance to demonstrate hypoechoic localized or diffuse thickening of the walls due to the invasion by the cancer or polypoid lesions. 59 Stomach #32 A B Figure 11-11 A: Adenocarcinoma of the lesser curvature of the stomach with irregular thickened wall (arrow). (Image courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) B: As illustrated, there are five stages of invasion with the progression of gastric carcinoma. 60 Stomach #33 Disorders of the Stomach Gastric Cancer Adenocarcinoma Gastric adenocarcinomas are primarily classified as cardia and noncardia based on their anatomic site and arise in the region adjoining the esophageal–gastric junction and thus share epidemiologic characteristics with esophageal adenocarcinoma. Noncardia cancer, also known as distal stomach cancer, is more common and arises in the lower portion of the stomach. Most gastric cancers spread primarily toward the serosa of the gastric wall. Some gastric tumors arise in the margin of a long-standing benign peptic ulcer. 61 Stomach #34 Disorders of the Stomach Gastric Cancer Adenocarcinoma Gastric Cancer Staging Staging procedures for cancers of the stomach can include radiologic imaging, laparoscopy, laboratory testing, EUS, CT, PET, MRI, and abdominal ultrasound. These procedures help diagnose and determine extent of the disease. Tumor, node, and metastasis (TNM) staging is the common way to determine the invasiveness of gastric cancer. 62 Stomach #35 Disorders of the Stomach Gastric Cancer Adenocarcinoma Gastric Cancer Staging The following is one example gastric cancer staging options Tumor (T) TX: unable to assess T0 or Stage 0: high grade, severely abnormal cells in the inner stomach lining, a defined lesion is not seen. T1 or Stage 1: tumor involvement of the lamina propria, muscularis, or submucosa (inner layers) T2 or Stage 2: tumor involvement of the muscularis propria (muscle layer) T3 or Stage 3: tumor advancement through layers of the muscle into the connective tissue (outer layer) T4 or Stage 4: tumor has progressed through the stomach layers into surrounding structures. 63 Stomach #36 Disorders of the Stomach Gastric Cancer Adenocarcinoma Gastric Cancer Staging The following is one example gastric cancer staging options Nodes (N) NX: lymph nodes cannot be assessed. N0: no cancer spread to the adjacent lymph nodes N1: cancer spread to 1 to 2 adjacent lymph nodes N2: cancer spread to 3 to 6 adjacent lymph nodes N3: cancer spread to 7 or more lymph nodes Metastasis (M) MX: metastasis cannot be assessed. M0: no cancer spread M1: cancer spread to other body regions 64 Stomach #37 Disorders of the Stomach Gastric Cancer Lymphoma Lymphoma is a cancer that usually begins in the lymph and node structures. Primary gastric lymphoma (PGL) is the most common extranodal non-Hodgkin lymphoma and represents a wide spectrum of disease, ranging from indolent low-grade marginal zone lymphoma or mucosa-associated lymphoid tissue lymphoma to aggressive diffuse large B-cell lymphoma. Incidence rate of this type of lymphoma is low, accounting for less than 5% of gastric malignancies. Cells of origin are lymphocytes located just above and below the muscularis mucosa usually at the antrum and body of the stomach. 65 Stomach #38 Disorders of the Stomach Gastric Cancer Lymphoma Endosonography characteristically reveals this involvement as well as a tendency for the tumor to spread laterally following the muscularis mucosa rather than vertically through the layers of the wall as in gastric carcinoma. Endoscopic appearances of PGL are ulcerated lesions, polypoidal lesions, thickened gastric folds and erosions. By transabdominal sonography, the thickened, hypoechoic gastric wall and the marked rugal thickening may be revealed. Sonographically, gastric carcinoma is sometimes more echogenic than lymphoma, and in infiltrative lesions all layers are more equally involved than in lymphoma. 66 Stomach #39 Figure 11-12 Gastric tumor invasion. Growth pattern of (A) lymphoma and (B) carcinoma of the stomach. 67 Stomach #40 Disorders of the Stomach Gastric Cancer Lymphoma Gastric Lymphoma Staging Lymphoma diagnostic procedures may include radiologic imaging, CT, PET, MRI, as well as abdominal ultrasound. Involvement of primary GI lymphoma often requires CT, MRI, PET, laboratory testing, bone marrow aspiration, and biopsy or EUS for staging. Procedures guide clinicians toward a diagnosis and aid in determination of the disease extent. 68 Stomach #41 Disorders of the Stomach Gastric Cancer Lymphoma Gastric Lymphoma Staging Staging agreement among many authorities regarding the grading of primary lymphoma Stage 1: Confined to GI tract Stage 2: Extending in the abdomen from primary GI site Stage 2E: Penetration of serosa to involve adjacent organs or tissues Stage 4: Disseminated extranodal involvement or concomitant supradiaphragmatic nodal involvement 69 Stomach #42 Disorders of the Stomach Gastric Cancer Gastrointestinal Stromal Tumor (GIST) GISTs belong to a category of gastrointestinal mesenchymal tumors that can have benign qualities or malignant potential. Start from the interstitial cells of Cajal and aid in digestive motility Even though this is a rare stomach tumor, it is the most common site for GISTs. Approximately 60% are gastric in location, and the second most prevalent site is the small bowel occurring at a rate of about 30%. The anorectum, colon, and esophageal can be affected by GIST formation, but these locations are much less common. 70 Stomach #43 Disorders of the Stomach Gastric Cancer Gastrointestinal Stromal Tumor (GIST) Smooth muscle tumor arises from the muscularis propria and is, therefore, primarily exophytic and usually with an appearance similar to the sonographically familiar uterine fibroid. GISTs mostly appear as a homogeneous hypoechoic mass, but can be difficult to differentiate sonographically or histologically from their benign counterpart, the leiomyoma, because they can also display with a heterogeneous appearance. A tumor smaller than 2 cm is usually not cancerous, although should be resected due to its potential to become malignant. 71 Stomach #44 Disorders of the Stomach Gastric Cancer Gastrointestinal Stromal Tumor (GIST) Researchers state that all GISTs will become malignant if left to evolve. Hemorrhage and cystic degeneration can occur with this type of tumor. GISTs are discovered with radiologic testing, similar to tests that diagnose gastric cancer and gastric lymphoma. A defined diagnosis for them requires biopsy and pathology testing. 72 Stomach #45 A B Figure 11-13 Gastrointestinal stromal cell tumors (GISTs) and a stomach leiomyoma comparison image. Note the similar heterogeneous texture and smooth contour. A: Malignant gastrointestinal stromal tumor of the fundal stomach (arrow). B: GIST of the dorsal antral wall of the stomach and anterior pancreas (arrow). (Images courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) C: Leiomyoma of the stomach antrum (arrow). C (Image courtesy of Susan R. Stephenson, Salt Lake City, UT.) 73 Stomach #46 Disorders of the Stomach Gastric Cancer Other Malignant Gastric Lesions Carcinoid Hemangioendothelioma Hemangiopericytoma Kaposi sarcoma Liposarcoma, myxosarcoma Fibrosarcoma Secondary tumors 74 Stomach #47 Disorders of the Stomach Gastric Cancer Other Malignant Gastric Lesions Sonographic findings Wall invasion, ulcerating lesion Wall thickening Polypoid lesion Hypoechoic lesion Vascular lesion Smooth walled intraluminal filling defect 75 Stomach #48 Disorders of the Stomach Benign Gastric Tumors Benign gastric tumors are rare. Most are asymptomatic. Hyperplastic polyps and gastric adenomas are polypoid masses arising from the gastric mucosa. Adenomas seem to have some malignant potential. Other types of tumors arise from the submucosal or muscle layer and spare the mucosa unless surface ulceration develops. Lipomas are generally echogenic. Smooth muscle tumors may show a typical swirled texture if they are large enough. 76 Quiz #5 When the stomach is not distended, what are the normal adult wall measurements? A. ≤ 2 mm thick B. 2 mm to 4 mm thick C. 4 mm to 6 mm thick D. ≥ 8 mm thick 77 Quiz #6 Which disease is an inflammatory disorder of the gastric mucosa? A. GI stromal tumors B. Lymphoma C. Gastritis D. Gastroduodenal Crohn Disease 78 Quiz #7 Posterior perforation of the stomach may result from which disease? A. Ectopic splenomegaly B. Pancreatitis C. Peritoneal irritation D. Bowel wall edema 79 Outline #4 I. Sonographic GI Examination Technique V. Small Bowel A. Patient Preparation A. Normal Anatomy B. Limitations B. Sonographic Technique C. Transducer Selection C. Disorders of the Small Bowel D. Patient Position VII. Vermiform Appendix II. Anatomy of the Bowel Wall A. Normal Anatomy of the Appendix A. Gut Interrogation B. Sonographic Technique III. Esophagus and Esophagogastric Junction C. Disorders of the Appendix A. Normal Anatomy of the Esophagus B. Sonographic Technique VIII. Colon and Rectum C. Disorders of the Esophagus A. Normal Anatomy of the Colon and Rectum D. Disorders of the Esophagogastric Junction B. Sonographic Technique IV. Stomach C. Disorders of the Colon A. Normal Anatomy of the Stomach IX. Sonographic Evaluation B. Sonographic Technique C. Disorders of the Stomach X. Special Diagnostic Techniques 80 Small Bowel Normal Anatomy Small bowel is a tubular structure approximately 20 feet in length and approximately 1 inch in diameter. Three sections The proximal Mid-level jejunum Distal ileum Sections of bowel begin at the pyloric sphincter and terminate at the ileocecal valve and have the same five bowel wall layers previously described. Inner mucosal layer is the absorptive surface. Mucosal folds Vavulae conniventes Kerckring folds/valves Plicae circulares Villi and microvilli that protrude from these folds increase surface area, allowing for increased absorption and secretion. 81 Small Bowel #1 Normal Anatomy If the small bowel is distended with fluid, the valvulae conniventes of the mucosa and other layers of the bowel wall are usually visible transabdominally. Duodenal bulb, the first portion of the duodenum, normally lies to the right of the gastric antrum, anterosuperior to the pancreatic head, and medial to the gallbladder. Shortest portion, beginning at the pylorus and ending at the medial side of the neck of the gallbladder. 82 Small Bowel #2 Normal Anatomy Second portion of the duodenum, the descending duodenum Bends inferiorly to the right of the pancreatic head Continues parallel with and to the right of the spine Bends to the left Extending inferior to the pancreas Passing between the superior mesenteric artery anteriorly and the aorta posteriorly, forming the third portion referenced as the transverse duodenum Fourth section, the ascending duodenum, extends superiorly and to the left, posterior to the stomach Jejunum begins at the duodenal – jejunal flexure, which frequently is referenced as the ligament of Treitz. 83 Small Bowel #3 Figure 11-14 The illustration presents an anterior view of the small bowel. The jejunum begins at the duodenal – jejunal flexure and the ileum ends at the cecum. There is no clear external line of demarcation between the jejunum and the ileum and the term jejuno-ileum is often used. LUQ, left upper quadrant; RLQ, right lower quadrant. (Reprinted with permission from Moore KL, Dalley AR, Agur AMR. Moore Clinically Oriented Anatomy. 7th ed. Wolters Kluwer; 2014.) 84 Small Bowel #4 Normal Anatomy Jejunum, the mid-section, the ileum, and the distal portion of the small bowel lie in the central portion of the abdomen, inferior to the liver and stomach and superior to the urinary bladder No marked delineation between the two sections of bowel Two sections are suspended by mesentery that allows mobility of the tubular bowel. Jejunum makes up 40% of this portion of bowel. Thicker wall and wider lumen than the ileum Ileum is the longest section and is positioned in the right inferior abdomen. 85 Small Bowel #5 Sonographic Technique Small bowel loops should be examined with a supine patient in a relaxed position. Methodical approach is necessary in order to thoroughly examine the entire bowel starting at the right inferior abdomen near the ileocecal valve. Situate the transducer in a transverse position and travel superiorly along the ascending colon until the superior bowel is reached, then move directly and slightly left scanning inferiorly to the distal bowel. Continue this “up and down” pattern until the entire small bowel is interrogated, using caution to overlap the movements. 86 Small Bowel #6 Figure 11-15 Illustration of recommended scanning technique for the jejunum and ileum. Place the transducer transversely in the right lower quadrant/pelvis and move superiorly to the region of the hepatic flexure of the colon. Slide the transducer left slightly and scan distally to the point of the inferior small bowel. Continue the “up-and-down” method, moving slightly left each pass until the entire bowel is viewed. 87 Small Bowel #7 Sonographic Technique Duodenum requires additional imaging in a C-shape pattern with the transducer kept in the transverse position to the bowel length. Start at the pylorus and continue through the terminal ascending duodenum. Small bowel is best visualized by examining both before and after ingestion of water. 88 Small Bowel #8 Sonographic Technique Drinking fluid may enhance visualization of the mucosa of the duodenum, jejunum, and ileum and demonstrate peristalsis. Best time to view the small bowel depends on the transit time of the fluid within the bowel. Valvulae conniventes, the folds in the inside bowel wall from which the microscopic villi protrude, can sometimes be demonstrated. If ileus or obstruction is present, ingesting fluid by mouth is not recommended. 89 Small Bowel #9 A B Figure 11-16 Duodenum. A: Arrows point to the duodenum currently empty of contents. B: Normal duodenum demonstrating filling. The hyperechoic “bright” central canal of the duodenum demonstrates water peristalsing through the superior part (arrow). (Images courtesy of Barbara Hall-Terracciano.) 90 Small Bowel #10 A B Figure 11-17 A and B Small bowel demonstrating wall conniventes. A: Longitudinal image of normal, nondistended small bowel (arrows). (Image courtesy of Barbara Hall-Terracciano.) B: Longitudinal image of edematous small bowel. Note the presence of fluid-filled “pockets” at the conniventes (arrow). (Image courtesy of Dr Taco Geertsma, UltrasoundCases.info.) 91 Small Bowel #11 C D Figure 11-17. C, D: Transverse images of normal, nondistended small bowel demonstrating valvulae conniventes (arrows). (Images courtesy of Barbara Hall-Terracciano.) 92 Small Bowel #12 Sonographic Technique MRI and CT enterography display detailed images of the small bowel, as well as stage cancerous processes. PET is utilized to diagnose, stage, and evaluate response to cancer treatments. 93 Small Bowel #13 Sonographic Technique Sonographic Small Bowel Wall Dimensions Normal luminal thickness for small bowel is 1 to 2 mm, although a thickness of 3 to 5 mm is considered normal in collapsed bowel if the wall is symmetrical. As with the entire GI tract, interrogate for wall thickness, wall symmetry, adjacent structures such as lymph nodes or masses, motility, changes to the wall, lumen, and vascular patterns. 94 Small Bowel #14 Figure 11-18 Small bowel. A: The longitudinal small bowel displays both the anterior and posterior wall in an ideal position for wall thickness measurement, see A arrows and calipers. B: A transverse view of small bowel (arrows) displays calipers measuring the normal wall thickness. (Images courtesy of Barbara Hall- Terracciano.) B 95 Small Bowel #15 Disorders of the Small Bowel Duodenum Duodenal Ulcer Peptic ulcer disease refers to the clinical presentation and disease state that occurs when there is a disruption in the mucosal surface at the level of the stomach or first part of the small intestine, the duodenum. Duodenal ulcers are part of a broader disease state categorized as peptic ulcer disease. Ulceration occurs from damage to the mucosal surface that extends beyond the superficial layer. Duodenal ulcers occur more frequently than other ulcers causing intermittent pain in the epigastric region usually 2 to 3 hours after ingesting a meal. According to multiple studies that have evaluated the prevalence of duodenal ulcers, they are estimated to occur in about 5 to 15% of the Western population. 96 Small Bowel #16 Disorders of the Small Bowel Duodenum Duodenal Ulcer Duodenal ulcers occur in the first portion of the duodenum 95% of the time and most of those are within 3 cm of the pylorus. Usually 6 mm outer diameter) Appears round when compression is applied Hyperechoic appendicolith with posterior acoustic shadowing Distinct appendiceal wall layers Implies non-necrotic (catarrhal or phlegmon) stage Loss of wall stratification with necrotic (gangrenous) stages Echogenic prominent pericecal and periappendiceal fat Periappendiceal hyperechoic structure: amorphous hyperechoic structure (usually >10 mm) seen surrounding a noncompressible appendix with a diameter above 6 mm 152 Vermiform Appendix #13 Disorders of the Appendix Appendicitis Findings Continued: Periappendiceal fluid collection Target appearance (axial section) Periappendiceal reactive nodal prominence/enlargement Wall thickening (3 mm or above) Mural hyperemia with color flow Doppler increases the specificity. Vascular flow may be lost with necrotic stages. Alteration of the mural spectral Doppler envelope May support diagnosis in equivocal cases A peak systolic velocity greater than 10 cm/s suggested as a cutoff A resistive index (RI) measured above 0.65 may be more specific. 153 Vermiform Appendix #14 Disorders of the Appendix Appendicolith (Fecolith) Appendicolith is a calcified deposit within the lumen of the appendix and may be caused by calcified fecal matter known as a fecolith. Fecoliths are stony pieces of feces obstructing the appendiceal lumen. Both the appendicolith and fecolith are usually smaller than 1 cm and can cause inflammation, abscess, and hyperemia. Obstructing structure displays posterior shadowing. 154 Vermiform Appendix #15 Disorders of the Appendix Mucocele Mucocele is distension of appendix by mucus. It is an uncommon lesion found in 0.25% of appendectomies. It is slightly more common in men than in women. RLQ pain resembling appendicitis is most common symptom. Patients may be asymptomatic. 155 Vermiform Appendix #16 Disorders of the Appendix Mucocele Mucoceles are classified into three groups Focal or diffuse hyperplasia Mucinous cystadenoma Mucinous cystadenocarcinoma Mucinous cystadenocarcinoma is considered to have malignant potential. A mucocele rupture can cause massive accumulation of gelatinous ascites. AKA: pseudomyxoma peritonei 156 Vermiform Appendix #17 Disorders of the Appendix Mucocele If mucocele is a mucinous cystadenocarcinoma variety, ascites is malignant. Patient has poorer prognosis. Association has been noted between mucoceles and the presence of one or more other colon tumors. Sonographically, mucocele appears as cystic or complex mass up to 7 cm in diameter, with through transmission, and located in RLQ. Lesion may be difficult to differentiate from ovarian cysts, mesenteric cysts, omental cysts, duplication cysts, renal cysts, or even abdominal abscess. 157 Vermiform Appendix #18 A B Figure 11-32 Appendix mucocele A: Longitudinal thickened appendix (arrow) without signs of an acute appendicitis that proved to be a mucus-filled appendix with chronic inflammation. B: Transverse image of the appendix demonstrating a thickened mucus-filled structure consistent with mucocele (arrow). (Images courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 158 Vermiform Appendix #19 Disorders of the Appendix Neuroendocrine Tumors Neuroendocrine tumors (NETs), previously known as carcinoid tumors, of the appendix are unusual, but are the most common primary tumor of the appendiceal tip from subepithelial neuroendocrine cells. Mostly asymptomatic and are typically located only because of findings involving appendicitis NETs arise from the subepithelial neuroendocrine cells lying on the lamina propria mucosae and the submucosal layer of the appendix wall. Local invasiveness is a good indicator of the degree of malignancy. Most appendiceal NETs are benign. 159 Vermiform Appendix #20 Disorders of the Appendix Neuroendocrine Tumors Sonographically Tumors appear as sharply marginated hypoechoic small masses without acoustic enhancement. Appendiceal carcinoids are NETs that classically arise at the appendiceal tip. More benign course than other GI carcinoids, rarely metastasizing, with a 5-year survival rate of greater than 90% 160 Vermiform Appendix #21 Disorders of the Appendix Other Disorders of the Appendix Sonographic detection of adenocarcinoma of appendix has been reported. Clinical presentation may be similar to that of acute appendicitis. Crohn disease of appendix can occur as an isolated condition or more commonly with Crohn disease of the colon or ileum. Sonographic appearance of these conditions is nonspecific. 161 Vermiform Appendix #22 Figure 11-33. Appendix adenocarcinoma. Appendiceal mucinous carcinoma demonstrating a large complex mass. (Images courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 162 Vermiform Appendix #23 Disorders of the Appendix Bacterial Ileocolitis and Mesenteric Adenitis When an abnormal appendix is not visualized sonographically, a search for other sonographic abnormalities in RLQ will sometimes visualize other GI findings. Enlarged lymph nodes adjacent to cecum may be observed. RLQ lymphadenopathy without associated appendicitis is termed mesenteric adenitis. Most common diagnosis at surgery if appendix is normal. Abnormal lymph nodes are rounder in outline than normal nodes. Must be >4 mm in AP diameter to be considered abnormal 163 Vermiform Appendix #24 Disorders of the Appendix Bacterial Ileocolitis and Mesenteric Adenitis In some cases, ileum, cecum, or both may show mild wall thickening as well as lymphadenopathy. Yersinia, Campylobacter, or Salmonella bacteria may be cultured from stool in some patients. Bacterial ileocolitis is usually a self-limited disease that does not require surgery. 164 Vermiform Appendix #25 Figure 11-34 Ileocolitis. Mesenteric lymph nodes. A: Thickened ileocecal valve (arrowhead) related to ileocolitis with reactive mesenteric lymph nodes (arrow). B: Hypervascularity of the ileocecal wall. (Images courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 165 Quiz #14 What anatomic landmark is located over the right side of the abdomen one-third of the distance from the anterior superior iliac spine to the umbilicus? A. McBurney point B. Murphy sign C. Ligament of Treitz D. Terminal jejunum 166 Quiz #15 What are the upper limit measurements for a normal appendix? A. 4 mm diameter and 1 mm thick B. 5 mm diameter and 1.5 mm thick C. 6 mm diameter and 2 mm thick D. 8 mm diameter and 2.5 mm thick 167 Quiz #16 Which of the following is an indicator of appendicitis? A. Pain and tenderness radiating to the left lower quadrant B. Noncompressible appendix greater than 6 mm in diameter C. Fluid collection between appendix and urinary bladder D. Thickened bowel wall demonstrated in ascending colon 168 Quiz #17 Although sonography is highly effective in the evaluation of acute appendicitis, why is CT currently considered superior? A. CT is superior at identifying location of appendix. B. Radiation doses continually decline with newer CT equipment. C. CT sensitivity and specificity is higher in adults. D. CT examination is less expensive. 169 Outline #6 I. Sonographic GI Examination Technique A. Patient Preparation V. Small Bowel B. Limitations A. Normal Anatomy C. Transducer Selection B. Sonographic Technique D. Patient Position C. Disorders of the Small Bowel II. Anatomy of the Bowel Wall VII. Vermiform Appendix A. Gut Interrogation A. Normal Anatomy of the Appendix III. Esophagus and Esophagogastric Junction B. Sonographic Technique A. Normal Anatomy of the Esophagus C. Disorders of the Appendix B. Sonographic Technique VIII. Colon and Rectum C. Disorders of the Esophagus A. Normal Anatomy of the Colon and Rectum D. Disorders of the Esophagogastric Junction B. Sonographic Technique IV. Stomach C. Disorders of the Colon A. Normal Anatomy of the Stomach IX. Sonographic Evaluation B. Sonographic Technique X. Special Diagnostic Techniques C. Disorders of the Stomach 170 Colon and Rectum Normal Anatomy of the Colon and Rectum Colon usually lies in the periphery of the abdomen, laterally on the right and left, and superiorly along the liver margin in the upper abdomen. Because the colon hosts gas-producing bacteria, often distended with gas than the rest of the bowel Its customary position, its larger diameter, and its characteristic haustral folds best seen at the ascending and transverse colon, which are up to 3 to 5 cm apart, can frequently help identify the colon. 171 Colon and Rectum #1 A B Figure 11-35 A and B Colon. A: Normal ascending colon (arrow). B: Normal transverse colon (arrows). 172 Colon and Rectum #2 C D Figure 11-35 C and D C: Normal colon demonstrating haustral marking (arrows). D: Normal cecum (arrow). (Images courtesy of Doña Ana Community College Diagnostic Medical Sonography program, Las Cruces, NM). 173 Colon and Rectum #3 Sonographic Technique Special scanning techniques are not available for evaluating the colon. Normal person usually has more air in colon than in small bowel. Colon’s larger diameter and prominent haustral indentations are often identifiable. Fluid-filled colon is unusual and generally indicates diarrhea or obstruction. Examiner may sometimes have difficulty differentiating a solid mass in colon from a small bowel lesion. Helpful to know where colon is located and to note greater amount of air in colon. 174 Colon and Rectum #4 Sonographic Technique Endoluminal rectal examination should be performed in both the axial and longitudinal directions, which allows better evaluation of Bowel wall layers involved Extent of invasion of any tumor that may be present Evidence of local lymphadenopathy 175 Colon and Rectum #5 Sonographic Technique Sonographic Colon, Rectum, and Anus Wall Dimensions Colon wall should measure 4 to 9 mm thick when not distended. 2 to 4 mm when the colon is distended to a diameter of 5 cm or more Rectum and anal wall thickness is similar to the wall dimensions of the colon. 176 Colon and Rectum #6 Figure 11-36. The illustration of the colon displays the anatomy and the recommended transducer position to acquire the best sonographic visualization of the colon. 177 Colon and Rectum #7 Disorders of the Colon Obstruction Normal colon usually partially filled with gas When colonic obstruction occurs, obstructed loop is likely to be gas filled. Colon obstruction easy to diagnose radiographically but difficult to diagnose sonographically Although a specific diagnosis is not always possible, dilated loop location may give clues. Cecal volvulus is manifested by dilation of right colon only. Sigmoid volvulus shows maximum dilatation in central abdomen. Diverticulitis with obstruction usually causes dilatation of left, perhaps entire colon, and obstructing rectal carcinoma appears similar. 178 Colon and Rectum #8 Disorders of the Colon Colon Crohn Disease (Form of Inflammatory Bowel Disease) Crohn disease of colon produces signs identical to Crohn disease of small bowel. Tends to be a transmural inflammation, potentially developing fistulae and pericolonic abscesses Multiple separate areas of colon may be involved. Right colon is a frequent site and associated ileal involvement is common. Typically colon bowel wall layers are not visible. Inflammatory activity, reflected by excess blood flow in bowel wall is shown with color Doppler. 179 Colon and Rectum #9 A B Figure 11-37 Crohn diseased colon. A: Thickening of the ascending colon wall in a longitudinal view. B: Thickening of the transverse ascending colon wall. (Images courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 180 Colon and Rectum #10 Disorders of the Colon Ulcerative Colitis (Form of Inflammatory Bowel Disease) Ulcerative colitis: chronic inflammatory disease Causes ulceration of colonic mucosa: most commonly in rectum and sigmoid colon Cause is unknown: a hypersensitivity or autoimmune mechanism is suspected. Condition begins in rectum and may extend proximally to entire colon. Unlike Crohn colitis, ulcerative colitis does not skip areas: spreads in continuous pattern. Patients at high risk of developing a virulent form of colon carcinoma Bowel wall appears thickened, usually hypoechoic, and sometimes bowel wall layers are visible sonographically. 181 Colon and Rectum #11 182 Colon and Rectum #12 A B Figure 11-38 Ulcerative colitis. A: Longitudinal colon with a thick hypervascular wall. This patient was diagnosed with pancolitis, a severe form of colitis that involves the entire colon (arrows). B: Hypervascularized thickened colon wall diagnosed with ulcerative colitis in a teenage female. C C: Thick-walled colon because of ulcerative disease. Notice the haustra may be prominent or absent. (Images courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 183 Colon and Rectum #13 Disorders of the Colon Diverticular Disease Diverticulosis: an acquired condition in which small hernias of mucosa (diverticula) form through muscular layer of colon Rectosigmoid colon is most often affected. Condition is associated with a low bulk diet. In Western countries, affects >50% of people older than 50 years Usually asymptomatic and is not sonographically detectable unless air or barium is present in diverticula 184 Colon and Rectum #14 Disorders of the Colon Diverticular Disease Diverticulitis results if one or more diverticula become filled with inspissated fecal material and then become inflamed. Often there is also inflammatory thickening of bowel wall and edema. Pericolic abscesses may form because of diverticular rupture or transmural spread of infection. Sonographically these abscesses appear as masses adjacent to colon. Abscesses may be hypoechoic or may contain gas. 185 Colon and Rectum #15 A B Figure 11-39 Diverticulitis. A: Arrow points to hypoechoic diverticulum of the sigmoid colon. B: Transverse image of the colon with diverticulum (arrow). C: An abscessed diverticulum is seen (arrow). (Images courtesy of Dr. Taco Geertsma, C UltrasoundCases.info.) 186 Colon and Rectum #16 Disorders of the Colon Colorectal Cancer Colorectal cancer was the third most common cancer, with 1.8 million new cases in 2018. Second leading cause of cancer death in men and women in the United States Lung and breast cancers were the most common cancers worldwide, each contributing 12.3% of the total number of new cases diagnosed in 2018. Majority of colon cancer develops in the rectum, followed by the sigmoid region and the rest of colon at the same rate. Transabdominal sonography demonstrates a large colon cancer as a nonspecific hypoechoic heterogeneous target lesion. 187 Colon and Rectum #17 A B Figure 11-40 Colon carcinoma. A: Ascending colon with a cancerous mass (arrows). B: Descending colon cancer. Note thickened hypoechoic irregular contoured walls (arrowheads). (Images A and B: Courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 188 Colon and Rectum #18 C F Figure 11-40 C and F C: Transverse mass seen at the arrows, diagnosed as moderate- to well-differentiated invasive adenocarcinoma of the sigmoid colon in a 36-year-old female. F: Surgical image of the cancerous lesion. (Incidentally, the sigmoid colon cancer diagnosis in this patient led to family member testing. One member was diagnosed with rectal cancer, another with colon cancer, and a third with precancerous polyps. The patient and three family members were treated using multiple methods to include chemotherapy and surgery.) 189 Colon and Rectum #19 D E Figure 11-40 D and E D, E: Air contrast barium enema displaying the same sigmoid colon lesion (arrows) seen in image C. (Images C-F: Courtesy of Cheryl Vance, San Antonio, TX.) 190 Colon and Rectum #20 Disorders of the Colon Colorectal Cancer With high-frequency endorectal probes, rectum can be imaged in transverse and longitudinal planes and can demonstrate layers of rectal wall. Endorectal ultrasound has been found to be excellent method to determine staging whether tumor extends beyond rectal wall. 191 Colon and Rectum #21 A B Figure 11-41 Rectal mass. A large carcinoma of the rectum (arrow) is demonstrated without (A) and with blood flow (B). (Images courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 192 Colon and Rectum #22 Disorders of the Colon Colorectal Cancer Staging of colorectal carcinoma can be defined by characteristics to include Depth of tumor penetration through rectal wall Lymph node involvement Distant metastatic disease 193 Colon and Rectum #23 Disorders of the Colon Colorectal Cancer Colorectal Cancer Staging (American Joint Committee on Cancer: Simplified) Tumor (T) TX: unable to assess T0: no evidence of primary tumor Stage 0: early stage with mucosal involvement only Stage 1: tumor involvement of the submucosa and possibly muscularis propria Stage 2: tumor advancement through outer layers of the colon and possibly attachment into adjacent tissue or organs No lymph node involvement or spread to distant sites Stage 3: tumor is same as stage 2. Lymph nodes are involved. No distant site association Stage 4: cancer may or may not have penetrated the bowel wall. It may or may not have spread to lymph nodes. Spread to a distant organ, distant lymph nodes, or the peritoneum 194 Colon and Rectum #24 Disorders of the Colon Lymphoma Lymphoma of colon appears similar to lymphoma of small bowel. A hypoechoic lesion—annular, eccentric, or diffusely involving the bowel wall—may be observed. 195 Colon and Rectum #25 Disorders of the Colon Other Disorders Inflammatory Disorders Other inflammatory colon conditions that may result in colon wall thickening include Ischemia Amebiasis Shigellosis Tuberculosis Pseudomembranous colitis Radiation colitis Endometriosis Pancreatitis In ischemic colitis, little or no flow is detectable with power Doppler imaging. 196 Colon and Rectum #26 Figure 11-42 Ischemic bowel. Affected bowel wall shows thickening and increased echogenicity. (Image courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 197 Colon and Rectum #27 Disorders of the Colon Other Disorders Irritable Bowel Syndrome Irritable bowel syndrome (IBS) is a chronic painful condition causing recurrent diarrhea with a mucus discharge and alternating constipation. Affected individuals suffer from nausea, noncardiac chest pain, sporadic heartburn, and abdominal bloating. Lack of characteristic imaging features and no diagnostic biomarkers make IBS difficult to recognize. 198 Colon and Rectum #28 A B Figure 11-43 Irritable bowel. A: Longitudinal widened colon with narrowing (arrows), indicative of irritable bowel. B: Longitudinal widened colon with heterogeneous contents, similar to (A). C: Transverse widened colon displaying effects of irritable bowel. C (Images courtesy of Barbara Hall-Terracciano.) 199 Colon and Rectum #29 Disorders of the Colon Other Disorders Cystic Fibrosis Cystic fibrosis affects the bowel, mostly the terminal ileum or proximal large intestine by obstructing, which can result in rupture and sepsis. In an infant, this is called meconiumileus; in an adult, it is known as distal intestinal obstructive syndrome. Decreased peristalsis results in the normally thick meconium in an infant or a combination of meconium and fecal matter in an adult, lacking the ability to maneuver through the bowel. Ultrasound imaging demonstrates thickened wall, dilatation, wall hypervascularization, intussusception, thick intraluminal contents, and lymph node enlargement. 200 Colon and Rectum #30 Disorders of the Colon Benign Tumor The same lesions seen elsewhere in bowel can also involve colon and include Leiomyomas Lipomas Fibromas Hemangiomas 201 Colon and Rectum #31 Figure 11-44 Benign colon polyp. Colon polyp on a stalk (arrows). (Image courtesy of Dr. Taco Geertsma, UltrasoundCases.info.) 202 Quiz #18 In Western countries, what is the third leading cause of death from cancer? A. Breast carcinoma B. Colon carcinoma C. Lung carcinoma D. Stomach carcinoma 203 Quiz #19 Which stage of colorectal cancer can be defined when the cancer has spread to nearby lymph nodes? A. Stage I B. Stage II C. Stage III D. Stage IV 204 Outline #7 I. Sonographic GI Examination Technique A. Patient Preparation V. Small Bowel B. Limitations A. Normal Anatomy C. Transducer Selection B. Sonographic Technique D. Patient Position C. Disorders of the Small Bowel II. Anatomy of the Bowel Wall VII. Vermiform Appendix A. Gut Interrogation A. Normal Anatomy of the Appendix III. Esophagus and Esophagogastric Junction B. Sonographic Technique A. Normal Anatomy of the Esophagus C. Disorders of the Appendix B. Sonographic Technique VIII. Colon and Rectum C. Disorders of the Esophagus A. Normal Anatomy of the Colon and Rectum D. Disorders of the Esophagogastric Junction B. Sonographic Technique IV. Stomach C. Disorders of the Colon A. Normal Anatomy of the Stomach IX. Sonographic Evaluation B. Sonographic Technique X. Special Diagnostic Techniques C. Disorders of the Stomach 205 Sonographic Evaluation Sonography is not likely to replace barium studies of GI tract as a principal method of visualizing GI anatomy and function nor likely to replace CT in the overall staging of GI malignancies. Sonography exams in evaluation of abdominal disorders are growing. Transabdominal and endoscopic sonography has unique ability to visualize layers of bowel wall, which is often useful in the diagnosis or staging of GI lesions. Additionally, sonographic endoscopy to direct biopsy and needle aspiration of GI lesions is developing as a valuable diagnostic tool. 206 Sonographic Evaluation #1 207 Sonographic Evaluation #2 208 Sonographic Evaluation #3 209 Quiz #20 What is the unique role of either transabdominal or endoscopic sonography in the imaging evaluation of the gastrointestinal tract? A. Excellent follow-up to PET imaging B. Increased sensitivity than CT imaging space C. Higher specificity than CT or barium studies D. Visualization of the layers bowel wall 210  Outline #8 I. Sonographic GI Examination Technique A. Patient Preparation V. Small Bowel B. Limitations A. Normal Anatomy C. Transducer Selection B. Sonographic Technique D. Patient Position C. Disorders of the Small Bowel II. Anatomy of the Bowel Wall VII. Vermiform Appendix A. Gut Interrogation A. Normal Anatomy of the Appendix III. Esophagus and Esophagogastric Junction B. Sonographic Technique A. Normal Anatomy of the Esophagus C. Disorders of the Appendix B. Sonographic Technique VIII. Colon and Rectum C. Disorders of the Esophagus A. Normal Anatomy of the Colon and Rectum D. Disorders of the Esophagogastric Junction B. Sonographic Technique IV. Stomach C. Disorders of the Colon A. Normal Anatomy of the Stomach IX. Sonographic Evaluation B. Sonographic Technique X. Special Diagnostic Techniques C. Disorders of the Stomach 211 Special Diagnostic Techniques Contrast agents have been and are currently being studied for use and for sonographic visualization of the GI tract more prominently in European countries compared with the United States. Contrast-enhanced endoluminal sonography is used to differentiate malignant from benign masses, assess depth of cancer invasion of the GI tract walls, examine fistulas, and determine vascular flow to differentiate fibrous from inflammatory strictures and study inflammatory bowel disease, among others. Contrast agents were used initially as Doppler signal enhancers, including in contrast-enhanced EUS examinations. 212 Special Diagnostic Techniques #1 Both color Doppler and power Doppler imaging can be used, especially for regions with very low flow volumes, where the unenhanced signal is very weak or the signal- to-noise ratio is very poor. Highly vascularized bowel wall and lesions can be determined with Doppler imaging based on the signal intensity. This contributes to determining inflamed and uninflamed regions of bowel, as well as assisting with the determination of benign versus malignant lesions. 213 Special Diagnostic Techniques #2 Elastography is used to indicate and define bowel wall lesions. Ability to discern bowel-related fibrosis from inflammation using elastography also aids in the diagnosis of inflammatory bowel disease. 214