[07.08] Imaging of the Gastrointestinal Tract V2 (1).pdf

Pattern recognition

What is the technique used in the interpretation of radiographs that relies on unique observation and description?

Imagination

What mental tool should students use to picture structures and understand their radiologic appearance?

Anatomy

What subject is a prerequisite for understanding radiology?

Transient

How are radiologic signs described when they only appear for a short duration during a disease's course?

Narrow the differential diagnosis

Characteristic radiologic signs allow a radiologist to do what when a single diagnosis is not possible?

Basic patterns

What are the fundamental imaging features called that do not represent normal anatomy, but pathology?

Record all of them

What is the duty of a radiologist regarding the changes in patterns along the course of a disease?

Compare present and previous films

How can a radiologist determine if a patient's condition has worsened or improved over time?

Shape

Circular, oblong, ovoid, and amorphous are examples of patterns described in terms of what?

Pneumonia

Which disease can be represented by different etiologies (viral, bacterial) but share the same pattern of abnormal opacity?

Mycoplasma pneumoniae

Dr. Hernandez mentioned Mycobacterium pneumoniae as a pattern example, but likely meant which organism?

Luminal dilatation/distention

In which pattern does the lumen widen and walls become curved?

Parallel and straight

Normally, how should the lines representing the intestinal walls appear?

Air or fluid

Luminal dilatation is caused by too much of what two substances?

Luminal narrowing

What is the opposite of luminal dilatation?

Diffuse wall thickening

What pattern refers to the even or distributed thickening of both intestinal walls?

Focal wall thickening

What pattern involves the thickening of only one part or segment of the wall?

Inward/Intraluminal protrusion

Which pattern involves a lesion that pouches inward into the lumen?

Outward/Extramural extension

In which pattern is the lumen diameter preserved while a bulge appears outside the lateral wall?

Serosa

A bulge on the outermost surface suggests pathology in which specific layer?

Wall erosion or disruption

Which pattern is characterized by smooth-bordered concavities along the wall and a larger lumen size?

Extracolonic/Extraintestinal spread

What is the pattern when the wall and diameter are preserved but a lesion is present outside?

White

What color represents the most dense structures, like bone, on a radiograph?

Black

What color represents air on a plain radiograph?

Gray

What color represents soft tissue on a radiograph?

Gas patterns

What is the first thing a radiologist should look at when reporting an abdominal radiograph?

Stomach

Which air-filled structure is located in the left upper hemi-abdomen?

Small bowels

Which intestinal structures are typically found in the middle of an abdominal radiograph?

Colon or large intestine

Which structure is found in the periphery of an abdominal radiograph?

Sigmoid and Rectum

Which two structures are located in the pelvic cavity area of a radiograph?

C-shaped

How is the duodenum described regarding its radiologic shape?

Jejunum

Which part of the small intestine is primarily located on the left of the patient?

Ileum

Which part of the small intestine is located in the Right Lower Quadrant (RLQ)?

Single bubble sign

Which sign refers to a plain abdominal radiograph of a newborn with a distended stomach?

Pylorus

A single bubble sign indicates an obstruction close to the distal part of the stomach, specifically what area?

Hypertrophic pyloric stenosis

Narrowing of the pyloric lumen caused by wall thickening in infants is called what?

Pyloric atresia

Name a congenital cause of the single bubble sign other than stenosis.

Proximal

In which direction relative to an obstruction do segments appear distended as a bubble?

Double bubble sign

Which sign is characterized by two gas-filled portions of the GI tract, usually the stomach and duodenum?

Duodenal atresia

What is the most common pathology identified with the double bubble sign?

Bilious vomiting

What clinical presentation in a newborn is highly suggestive of duodenal atresia?

Beyond the Ampulla of Vater

If a newborn's vomit is bilious, where is the obstruction likely located relative to the common bile duct?

Proximal to the Ampulla of Vater

If a newborn has non-bilious vomit, where is the obstruction located?

Fluid

In an ultrasound of a double bubble sign, what do the anechoic structures contain?

Anechoic

What is the term for structures that appear black on ultrasound because soundwaves pass through fluid?

Triple bubble sign

Which sign indicates an obstruction distal to the stomach and duodenum, possibly in the jejunum?

Jejunum

In a triple bubble sign, the third bubble represents which bowel segment?

Distal

As the number of "bubbles" increases, the site of obstruction is considered to be more what?

Football sign

Which sign is seen in cases of pneumoperitoneum where air is trapped within the peritoneum?

Pneumoperitoneum

What is the clinical term for air trapped within the abdominal cavity?

Median umbilical ligament and falciform ligament

Which two ligaments may represent the "sutures" in a football sign?

Perforated viscera

The football sign is caused by gas escaping from what?

Rigler sign

What is the sign where air outside the intestinal tract allows the visualization of the lateral walls?

Coffee bean sign

Which sign is characteristic of a sigmoid volvulus?

Sigmoid volvulus

What condition involves a greatly distended loop of the sigmoid colon extending from the pelvis to the abdomen?

T10

The apex of a sigmoid volvulus coffee bean loop often extends above which vertebral level?

Medial walls

In a coffee bean sign, the cleft of the bean is formed by the opposed what?

Chronic constipation and neurological conditions

What are two common causes of sigmoid volvulus mentioned in the source?

Air-fluid levels

What are the interfaces called that have a horizontal inferior part and a convex superior part?

Differential air-fluid leveling

What is the term for at least 2 air-fluid interfaces at different heights within the same loop of bowel?

Ileus

What term describes hypomotility of the intestinal tract without a physical obstruction?

Mechanical obstruction

In a series, 50% of radiographs with air-fluid levels represented what condition?

2 cm or greater

A difference in air-fluid levels in the same loop is suggestive of mechanical obstruction if the difference is what?

2.5 cm or greater

What height difference in air-fluid levels is suggestive of high-grade small bowel obstruction?

Bird’s beak or Rat tail sign

What sign represents the tapering of the inferior esophagus in achalasia?

Achalasia

What is the failure of organized peristalsis with impaired relaxation of the lower esophageal sphincter?

Barium

What contrast material is swallowed to produce a "Bird's Beak" sign on a radiograph?

Rat tail sign

In achalasia, if the bright esophagus is the body of a rat, the tapering end is called what?

Cupola or dome sign

Which sign shows narrowed, heterogeneous esophageal contrast resembling a church ceiling?

Focal wall erosion

What does the cupola or dome sign signify pathologically?

Cobblestone sign

What sign is characterized by longitudinal and circumferential fissures separating islands of mucosa?

Crohn’s disease

The cobblestone pattern is most commonly associated with which bowel disease?

Stomach

To determine if a contrast study is an upper GI series, what specific organ should you look for?

Barium enema

What is the typical term for a lower GI contrast study opacifying the rectum to the cecum?

Coin stack sign

What sign features stacked horizontal opacities representing wall disruption?

Small-bowel hematoma

Besides malabsorptive heteropathies, what else could a coin stack sign signify?

Valvulae conniventes

What anatomical structures are crowded together in a coin stack sign?

Plicae circulares

What is another name for the valvulae conniventes?

Collar sign

Which sign represents luminal constriction at sites of organ herniation?

Hiatal hernia

A collar sign encircling the thoracic cavity occupation by the stomach indicates what?

Inguinal or Scrotal hernia

A collar sign seen in the groin area indicates what type of herniation?

Diaphragmatic hernia

Gas-filled loops occupying the left hemithorax with a collar sign suggest what?

Coiled spring sign

What sign is seen when barium is trapped between an intussusception and the surrounding bowel?

Intussusception

What is the telescoping of two adjacent segments of the bowel called?

Target sign

What sign represents concentric layers of the bowel wall seen in submucosal edema or inflammation?

Mucosa

In a target sign, what does the inner layer represent?

Muscularis propria or Serosa

In a target sign, what does the outer layer represent?

Inflammatory

For target signs, should you consider a neoplastic or an inflammatory problem more likely?

Apple core sign

What focal stricture of the bowel has shouldered margins and resembles a partially eaten fruit?

Annular carcinoma of the colon

What is the most common cause of the apple core sign?

Donut sign

What is the imaging finding on ultrasound or CT caused by circumferential bowel wall thickening?

Pseudokidney sign

What is the other name for the donut sign in ultrasound because of its appearance?

Darker

On ultrasound, how does the periphery of a donut sign look compared to the center?

Colon cancer, IBD, and Intussusception

List three common causes of the donut sign/pseudokidney on ultrasound.

Caking sign

What sign involves the infiltration of omental fat by soft tissue opacity material?

Metastasis and Tuberculosis peritonitis

What are the two primary causes of omental caking?

Ascites

On ultrasound, what does the black area surrounding omental thickening represent?

Halo sign

Which CT sign presents with infiltration of fat between the muscularis and submucosa?

Inflammatory bowel disease

The Fat Halo Sign is nearly pathognomonic for which condition?

Chronicity

In the small bowel, the presence of a fat halo indicates what about the disease?