Question

radiographic pathology for technologists

Chapter 5: ABDOMINAL & GASTROINTESTINAL SYSTEM Answer the following questions with a short answer (2-3 sentences). • Please submit only the answer portion of this exercise to the instructor. • Make sure to number your answers. 1. Describe the differences, both clinical and radiographic, between a mechanical bowel obstruction and paralytic ileus. 2. Explain the connection between colonic polyps and the development of colorectal cancer. 3. Describe the role of CT in the staging of various Gl cancers. 4. Explain the physiologic alteration that causes esophageal varices, and describe the radiographic appearance of this disorder. 5. Compare and contrast the various gastric tubes in terms of their uses and radiographic appearance.

Answer 1

1.Mechanical Obstruction

- Bowel is physically blocked by problems outside the intestine, in the bowel wall, or in the intestinal lumen

- Examples: adhesions, Crohn's disease, and tumors

#. Paralytic ileus - obstruction of the intestine due to paralysis of the intestinal muscles.

lleus Pseudo-obstruction Crampy abdominal pain, constipation, obstipation, nausea, vomiting, anorexia Mechanic Obstruction (Simple) Crampy abdominal pain, constipation, obstipation, nausea, vomiting, anorexia Sympt Mild abdominal oms pain, bloating, nausea, vomiting, obstipation, constipation, Borborygmi, tympanic, peristaltic waves, hypoactive or hyperactive bowel sounds, distension, localized tenderness Borborygmi, peristaltic waves, high-pitched bowel sounds, rushes, distension, localized tenderness Physic Silent abdomen, al distension, Exami tympanic nation Findin gs Plain Large and small Radio bowel dilatation, graph diaphragm elevated Isolated large bowel dilatation, diaphragm elevated Bow-shaped loops in ladder pattern, paucity of colonic gas distal to lesion, diaphragm mildly elevated, air-fluid levels

2. Colonic polyps and the development of colorectal cancer :-

Colon Polyps

Raised Protrusion of Colonic Mucosa

Benign type:

-Hyperplastic (most common)

Neoplastic Types:

-Adenomatous Polyp

----Tubular Adenoma (2nd most com)

----Tubulovillous Adenoma

----Villous Adenoma (more worrisome=>villous is the villain)

Hyperplastic:

Polyp is benign and will not progress to carcinoma

Hyperplastic Polyp

hyperplasia of glands

-Serrated "sawtooth" appearance

-Look like Starfish

Left Colon usu Rectosigmoid

Benign-->no malignant potential

Tubular Andenoma (TA)

is a low grade dysplasia that could progress to carcinoma

-Usu Pedunculated (stalked)

-"Blue on Top" of glands (nuclei collects on top

-High N:C nucleus to Cytoplasm ratio

-Can exist with Villi, called Tubulovillious: worst prognosis

Adenomatous Polyp

Neoplastic proliferation of glands

-Benign BUT has ability to become cancer Premalignant

-May become cancer via adenoma-carcinoma sequence or Serrated Pthwy

Adenoma-Carcinoma Sequence (Pathway)

Most common pathway

APC mutation w/subsequent KRAS/p53 mutations

Often Left Sided/DistaL Carcinomas

1. APC gene mutation creates risk for development of Polyp (must lose both copies of APC)

2. KRAS mutation occurs that allows for development of polyp

3. p53 mutations and increased COX expression cause Polyps to develop into carcinoma

ASPIRIN protects against this sequence as it prevents COX expression

--this pathway is implicated in FAP

TA is the precursor polyp

Leads to FAP

3.

Grade CT finding om Absence of ascites, normal peritoneal fat and no peritoneal thickening/enhancement/implan Absence of ascites but increased density of peritoneal fat and/or peritoneal thickening and enhancement Absence of ascites but presence of peritoneal nodule Presence of ascites and/or increased density o peritoneal fat and/or peritoneal thickening and enhancement Presence of ascites and peritoneal nodule/mas

4. Physiological alterations that causes esophageal varices are :-

- cirrhosis

- heart failure

- blood clots

- sarcoidosis

- Wilson's disease

- hemochromatosis

- schistosomiasis

Radiological appearance of esophageal varices is serpentine like filling defects of esophagus