Gastrointestinal Abdominal Radiological Lecture Notes PDF

# Photo Album by wisam neriman ## Gastrointestinal abdominal radiol part I. The gastrointestina - **Imaging modalities** - Plain abdominal x-ray (AP, supine) - Contrast examinations - Barium swallow examination - Barium meal follow-through examination - Enteroclysis...

# Photo Album by wisam neriman ## Gastrointestinal abdominal radiol part I. The gastrointestina - **Imaging modalities** - Plain abdominal x-ray (AP, supine) - Contrast examinations - Barium swallow examination - Barium meal follow-through examination - Enteroclysis (small bowel enema) - Barium enema - US - CT and MR enterography and enteroclysis - Virtual colonoscopy ## Practice Guidelines: Dysphagia, 2014. - Dysphagia = difficulty or discomfort in swallowing. - A key decision is whether the dysphagia is oropharyngeal or esophageal. - Ask: location, types of foods/liquids, progressive/intermittent, duration of symptoms ### Oropharyngeal dysphagia = "high dysphagia" - Passage from the pharynx to the esophageous is impaired. - Patients have difficulty in initiating a swallow, and they usually identify the cervical area as the area presenting a problem. - Cough, repetitive swallowing, nasal regurgitation, choking is common. - Dysphagia appears about 1 second from swallowing, and patients spit rather than vomit. - Causes: infection, goiter, Zenker diverticulum, ostephytes, head/neck tumors, stroke, Parkinsons disease. ### Esophageal dysphagia = "low" dysphagia - Passage through the esophagus and the cardia is impaired. - Patients report chest pain, usually behind the sternum. - Pain is reported a little longer after swallowing took place. - Patients usually try to ease the pain by drinking water. - Forcefull swallowing is typical. - Most important cause to rule out is malignancy! - Causes: foreign bodies, irradiation, scleroderma, achalasia, stenosis due to reflux. ## Fig. 2 Evaluation and management of esophageal dysphagia - Dysphagia to solids or solids & liquids - Below sternal notch - Sometimes coughing after swallowing ### Esophageal dysphagia | Solids & liquids | Solids only | |:---|:---| | Motility problem | Acute | Intermittent | Progressive | | Progressive | Intermittent | Foreign body | Ring | Eosinophilic esophagitis | Acid | > 50 y/o weight loss | | Regurgitation | Acid | Chest pain | Esophageal spasm | GERD | Cancer | | Achalasia | Scleroderma | Barium swallow | Endoscopy | ## Esophageal dysphagia - Anatomy: upper 1/3 striated muscle. Lower 2/3 smooth muscle. ### Achalasia - The lower sphincter does not open properly. - Barium swallow study reveals a dilated esophagus with tapering distal end (bird's beak sign). ### Scleroderma - A systemic disease in which the lower 2/3 of the esophagus atrofies and thus dilates. - Due to fibrosis there is foreshortening and stricturing of the distal end. - The lower sphincter does not close properly, thus if the patient stands up, all the food „falls” ### Esophageal spasm - Retrosternal pain is independent of swallowing. - The intraluminal pressure is high. - The lower 2/3 of the esophagus assumes a corkscrew morphology. ## Gastritis - Hypertrophic gastritis: CT appearance. - (a) contrast enhanced CT shows a diffusely thick-walled stomach. - (b) endoscopy confirms CT findings. - This is not necessary a radiological diagnosis, but we may encounter it. - **Note:** bowel wall thickening is difficult to assess on ultrasound, especially gastric wall thickening. ## Functional ileus versus obstruction - General considerations: - 1. You want to order a(n) (upright, lateral decubitus, prone) plain abdominal film to look for: - Dilated loops of small or large bowel? - Focal or diffuse? - Air-fluid levels? - Air in the rectum? - 2. Then order a CT to look for: - Transition point. - 3. A small bowel series may be necessary to define the level of obstruction. - Abdominal X-ray demonstrating the typical haustration (white arrows) of the colon. - Abdominal X-ray demonstrating air-fluid levels and Kerkring folds of the small bowels. ## Peptic ulcers - **Benign ulcer:** barium swallow findings. Barium filling and double-contrast (barium + air) images show a large ulcer (arrow) which is a round collection of barium at the lesser curvature side of gastric antrum. - **Contrast-enhanced CT scan shows an active benign ulcer (arrow) with severe mural edema in the gastric body and antrum.** ## Complication of Gastric Ulcer - Perforation - **Chest x-ray:** free abdominal air appears as a radiolucent (dark) band below the diaphragm. - **Axial CT (venous phase) shows perforation on the anterior side of the stomach.** - **Tiny pockets of free abdominal air are also visible in the vicinity.** ## Gallstone ileus - Gallstone ileus in a 74-year-old male patient. - Axial and coronal CT images show a large laminated stone impacted in the terminal ileum. - More ventral side coronal image demonstrates cholecysto-duodenal fistula between the airfilled, thick-walled gallbladder and the second portion of the duodenum. ## Small bowel obstruction - Right femoral hernia - Right femoral hernia in a 77-year-old female patient with right lower quadrant pain. - On axial CT image, a short bowel loop filled with fluid is noted in the right inguinal area lateral to the pubic tubercle compressing the femoral vein, indicating right femoral hernia. - On the coronal image, the herniated bowel loop is incarcerated at the neck of the hernia sac. - Bowel loops proximal to the hernia are dilated with air and fluid, whereas the distal bowel loop is completely collapsed. ## Large bowel obstruction - **Mechanical**: - Volvulus (in elderly) - Diverticulitis (also common) - **Colorectal cancer (the most important!)** - **May be functional**: - Large bowel ileus (Ogilvie syndrome - acute pseudo-obstruction and dilatation of the large bowel without mechanical obstruction. - Causes: trauma, burn, surgical procedures, drugs, breathing impairement, electrolite imbalance, diabetes mellitus, uraemia) - **Oral barium is not administered because it could become impacted as water is absorbed from it.** - The cecum dilates the most even if the obstruction is as far as the sigmoid. - There are a few or no air-fluid levels as colon absorbs water. - There is usually no air in the rectum. - The small bowel is not dilated so long as the ilio-cecal valve is competent. ## Ileus and small bowel obstruction - **Mechanical obstruction:** - Adhesions (most common; 64-79%) - Herniation (15-25%) - Tumour (10-15%) - **Ileus (non-mechanical obstruction of bowel secondary to):** - Paralytic ileus (postsurgical, drugs, spinal cord lesions) - Inflammation (pancreatitis, cholecystitis, diverticulitis, ureteral stones) ### Functional lleus - Loss of normal peristaltic function due to irritation - Localized or generalized - Usually affects small bowel and has no transition point - Small bowel caliber is usually < 3 cm - Air can be seen in rectum because air continues to pass past site of aperistalsis ### Mechanical obstruction - Physical obstruction in the small or large bowel which may be partial or complete - Complete or partial - Transition point is the location at which bowel changes caliber from dilated to collapsed - Small bowel caliber proximal to obstruction is often > 3 cm - Complete obstruction results in no air within the rectum - **We need to differentiate the two quickly!** - **We need to know if ileus is associated with a life-threatening process (e.g.: peritonitis)!** - **If SBO is present, we must differentiate partial complete and closed loop causes** - Short, midly dilated small bowel segment (sentinel loop) ## Small bowel obstruction (closed-loop) - 85-year-old female patient with a history of gastric surgery. - When two points of the same loop of bowel are obstructed at a single location, we call it closed-loop obstruction. - These are mostly caused by adhesions. - The closed-loop remains dilated. - Vascular compromise (strangulation) is common. - (On the images a moderate amount of ascites is also present showing higher attenuation suggesting hemorrhagic ascites). ## Obstruction – colon cancer - X-ray: the dilated colon frames the dilated small bowel loops. - The descending colon contains little air which tells us that the problem lies somewhere here. - CT helps pinpoint the level of obstruction at the sigmoid (arrows). ## Colocolonic intussusception - A. The salient abnormality is within the right lower quadrant. - B. A predisposing condition responsible for an acute process is identified. - C. There is a small bowel obstruction. - D. Nonsurgical management is preferred. - E. The emergency department physician should immediately consent to droogу эститесь ## Appendicitis - Best Test(s): - CT of appendix with oral and IV contrast - Ancillary Tests: - Ultrasound of pelvis may be used instead of CT in children and/or women of reproductive age when CT is unavailable or contraindicated ### Diagnostic Algorithm | Suspected appendicitis | Spiral CT of appendix and laboratory evaluation | Equivocal results | | |:---|:---|:---|:---| | | | Diagnostic | Laparoscopy | | | Equivocal results | | | | | | | Ultrasound of abdomen/pelvis in children and women of reproductive age plus laboratory evaluation | | | | Diagnostic | | ## Best Test(s): - CBC with differential - Urinalysis ## Ancillary Tests: - Serum pregnancy test in women of reproductive age ## Right lower quadrant pain – appendicitis suspected ### Appropriateness Criteria | Variant 1: | Right lower quadrant pain, fever, leukocytosis. Suspected appendicitis. Initial imaging. | | | |:---|:---|:---|:---| | Procedure | Appropriateness Category | Relative Radiation Level | | | CT abdomen and pelvis with IV contrast | Usually Appropriate | 000 | | | CT abdomen and pelvis without IV contrast | May Be Appropriate | 000 | | | US abdomen | May Be Appropriate | 0 | | | MRI abdomen and pelvis without and with IV contrast | May Be Appropriate | 0 | | | US pelvis | May Be Appropriate | 0 | | | MRI abdomen and pelvis without IV contrast | May Be Appropriate | 0 | | | CT abdomen and pelvis without and with IV contrast | Usually Not Appropriate | 0000 | | | Radiography abdomen | Usually Not Appropriate | 000 | | | Fluoroscopy contrast enema | Usually Not Appropriate | 0000 | | | WBC scan abdomen and pelvis | Usually Not Appropriate | 0000 | | ## Right lower quadrant pain – appendicitis suspected ### Appropriateness Criteria, pregnant patient | Variant 3: | Pregnant woman. Right lower quadrant pain, fever, leukocytosis. Suspected appendicitis. Initial imaging. | | | |:---|:---|:---|:---| | Procedure | Appropriateness Category | Relative Radiation Level | | | US abdomen | Usually Appropriate | 0 | | | MRI abdomen and pelvis without IV contrast | Usually Appropriate | 0 | | | US pervis | May Be Appropriate | 0 | | | CT abdomen and pelvis with IV contrast | May Be Appropriate | 000 | | | CT abdomen and pelvis without IV contrast | May Be Appropriate | 000 | | | CT abdomen and pelvis without and with IV contrast | Usually Not Appropriate | 0000 | | | MRI abdomen and pelvis without and with IV contrast | Usually Not Appropriate | 0 | | | WBC scan abdomen and pelvis | Usually Not Appropriate | 0000 | | | Radiography abdomen | Usually Not Appropriate | 000 | | | Fluoroscopy contrast enema | Usually Not Appropriate | 000 | | ## Appendicitis ### CT and US appearance - Left image: the wall of the appendix is thick, it enhances vividly, and the surrounding fat has high density. - Right image: inflammation of the appendix is visible, but there is also extraluminal air = perforation. - **Ultrasonographic signs:** - Dilated (outer diameter > 6 mm), non compressable, thick walled appendix. - The surrounding fat shows increased echogenicity due to inflammation. - An indirect sign can be free abdominal fluid. - The appendix is difficult to visualize on US! ### Appendicitis MRI - Acute appendicitis: typical MRI signs; 28 year-old pregnant (16th week) female. - **A,B,C images are T2 weigthed.** - The arrowhead points to the appendicolith. - The white arrow points to the dilated appendix. - The black arrow points to oedemic fat. - **D is a fat suppressed image.** - All that show high signal intensity (bright) on this image is oedema around the inflammed appendix. ## Left lower quadrant paint- Diverticulitis is supected ### Appropriateness Criteria | Variant 1: | Left lower quadrant pain. Suspected diverticulitis. Initial imaging. | | | |:---|:---|:---|:---| | Procedure | Appropriateness Category | Relative Radiation Level | | | CT abdomen and pelvis with IV contrast | Usually Appropriate | 000 | | | CT abdomen and pelvis without IV contrast | May Be Appropriate | 000 | | | MRI abdomen and pelvis without and with IV contrast | May Be Appropriate | 0| | | MRI abdomen and pelvis without IV contrast | May Be Appropriate | 0 | | | US abdomen transabdominal | May Be Appropriate | 0 | | | CT abdomen and pelvis without and with IV contrast | Usually Not Appropriate | 0000 | | | Fluoroscopy contrast enema | Usually Not Appropriate | 000 | | | Radiography abdomen and pelvis | Usually Not Appropriate | 000 | | | US pelvis transvaginal | Usually Not Appropriate | 0 | | ## Diverticulosis and diverticulitis ### CT signs - At CT we see the tiny, air containing diverticuli hanging off of the bowel. - If there is inflammation, the bowel wall will thicken, and the density of the surrounding fat will increase. - Fat is normally black, if it is inflammed, it will get brighter. ## Diverticulosis - Radiology at a glance. Wiley-Blackwell 2010 ## Crohn's disease ### Crohn's Disease Evaluation and Treatment: Clinical Decision Tool. - Assoss inflammatory status | Perform clinical lab testing:| Select imaging modalities (if indicated)| Perform endoscopy | | |:---|:---|:---|:---| | Fever | | Identify symptoms without inflammatory markers | | | CBC | | | | | Abdominal pain | | | | | CRP | | | | | CMP | Perform CT-enterography OR magnetic resonance enterography | | | | Gl bleeding | | | | | Localized tenderness | | | Identify symptoms with inflammatory markers | | | Weight loss | | | | | Joint pain | | | | | Cutaneous signs | | | | | Fecal calprotectin | | | | | ESR | | | | - **Selection depends on local expertise and experience with imaging modalities. Magnetic resonance enterography is prefemed due to the reduction in ionizing radiation, particularly for younger patients.** - **If patient is less than 50 years of age, we suggest using magnetic resonance enterography** - **Consideration could be given as to whether** ### Table 3: Appropriateness of examination in Crohn's disease. | CE | US | CPD/CEUS | MDCT-E | MDCT-e | MR-E | MR-e | TLLS | |:---|:---|:---|:---|:---|:---|:---|:---| | First diagnosis | 8 | 7 | 7 | 9 | 8 | 9 | 8 | 7 | | Followup | 2 | 9 | 6 | 2 | 2 | 4 | 5 | 2 | | Relapse | 6 | 6 | 6 | 8 | 7 | 9 | 8 | 7 | | Complications | 7 | 6 | 6 | 9 | 8 | 9 | 8 | 6 | - 9: extremely appropriate; 7-8: usually appropriate; 4-6 doubt; 2-3: usually inappropriate; 1: extremely inappropriate [52]. - CE: conventional enteroclysis; US: ultrasonography; PD: power Doppler; CEUS: contrast-enhancement ultrasonography; MDCT-E: multidetector CT enteroclysis; MDCT-e: multidetector CT enterography; MR-E: magnetic resonance enteroclysis; MR-e: magnetic resonance enterography; TLLS: 99m Tc-HMPAO-labeled leukocyte scintigraphy; IV infusion: intravascular infusion; negativity of clinic and laboratory exams. ### Crohn's disease - **What is the most likely explanation for the abnormal small-bowel loop anterior to the bladder (B) on this contrast-enhanced CT examination of the lower abdomen?** - **A. Crohn disease** - B. Tuberculosis - C. Whipple disease - D. Ulcerated lymphoma - E. Small-bowel metastases - (CT: lead pipe morphology) - Same appearance on MR ### Crohn's disease- enteroenteral fistula - **(a) plain film enteroclysis of a 33-year-old patient. The arrows point to fistula between bowel loops.** - **(b) Coronal CT-n shows a similar configuration of a fistula. During this study the bowels were filled with fluid (neutral contrast).** ### Crohn's disease – MR signs - **Coomb-sign:** the vessels supplying the inflammed bowel dilate, and assume a coomb like appearance. - **Skip lesion in Crohn's disease.** - The yellow arrows point to contrast enhancing segments of bowel (layered appearance). - The green arrows point to normal bowel segments. ## Colorectal Cancer – screening ### Appropriateness Criteria #### Variant 1: - Colorectal cancer screening. Average-risk individual. Age greater than or equal to 50 years. - Initial screening, then follow-up every 5 years after initial negative screen. | Procedure | Appropriateness Category | Relative Radiation Level | |:---|:---|:---| | CT colonography | Usually Appropriate | 000 | | X-ray barium enema double-contrast | May Be Appropriate | 000 | | MR colonography | May Be Appropriate | 0 | | X-ray barium enema single-contrast | Usually Not Appropriate | 000 | #### Variant 2: - Colorectal cancer screening. Moderate-risk individual. First-degree family history of cancer or adenoma. - Initial screening, then follow-up every 5 years after initial negative screen. | Procedure | Appropriateness Category | Relative Radiation Level | |:---|:---|:---| | CT colonography | Usually Appropriate | 000 | |X-ray barium enema double-contrast | May Be Appropriate | 000 | | MR colonography | May Be Appropriate | 0 | | X-ray barium enema single-contrast | Usually Not Appropriate | 000 | ## CT colonography ### CT colonography - This study can be performed as a separate low dose scan, or as part of a routine abdominal CT. - In the latter the dose is much higher. CT colonography can be helpful when a stenosing cancer is found at colonoscopy due to which colonoscopy cannot be fully performed. ### Virtual colonoscopy - **Judy Yee, What colonoscopy seems too like? UGGF Medical Center, youtube.com** ### 3D - CT colonography 3D ### CT colonography - polyp - **CT Colonography Atlas For the Practicing Radiologist, Springer 2013.** ### CT colonography - colon cancer - **a. CT-lung window** - **b. CT- soft tissue window** - **c. 3D virtual colonoscopy** - **d. Endoscopic image** - **Of Colonography Atlas For the Practicing Radiologist, Springer 2013.**