CDS | Interpreting Abdominal X-Ray Radiographs for Medical Students

Abdominal X-Rays

• An erect abdominal x-ray is advantageous over a supine film because it allows for better demonstration of free gas under the diaphragm.

Abbreviations and Definitions

• AXR stands for Abdominal X-Ray.

Radiation Dose

• An abdominal radiograph (AXR) has a radiation dose equivalent to 0.05-0.5 mSv.

Series on Interpreting Plain Abdominal Radiographs

• The subsequent parts of the series will cover the approach to interpreting plain abdominal radiographs, including normal and abnormal findings.

Decubitus Film

• A decubitus film is taken with the patient in the lateral decubitus position for abdominal radiographs.

Radiation Dose Equivalent of Different X-Rays

• A KUB (Kidneys, Ureters, Bladder) x-ray has a radiation dose equivalent to 50 posteroanterior chest x-rays.

Appearance of Metallic Objects

• A metallic object appears as a dense, white, or extremely opaque structure in a plain radiograph.

Distinguishing Normal Small Bowel from Normal Colon

• Normal small bowel is distinguished from normal colon by its feathery appearance and central location, while the colon is peripheral and has a haustral pattern.

'Mottled' Appearance

• A 'mottled' appearance in a plain radiograph indicates bowel ischemia or infarction.

Gas in the Portal Vein

• Finding gas in the portal vein on a plain radiograph is significant because it indicates bowel necrosis or infarction.

Appreciating Normality in Plain Radiographs

• The best approach to appreciate normality in plain radiographs is to examine the film systematically, assessing the lung bases, diaphragm, liver, spleen, kidneys, stomach, small bowel, and colon.

Gastric Pseudotumor

• A 'gastric pseudotumor' on a supine film represents a normal stomach bubble.

Differentiating Normal Small Bowel from Normal Colon

• Normal small bowel is differentiated from normal colon by its central location, feathery appearance, and lack of haustral pattern.

Assessing Technical Details

• The main purpose of assessing the technical details of an abdominal radiograph is to ensure the film is adequate for interpretation.

Viewing an Abdominal Radiograph

• When viewing an abdominal radiograph, one should note the patient's position, kilovoltage, and exposure.

Absence of Bowel Dilatation or Extraluminal Air

• The absence of bowel dilatation or extraluminal air on an abdominal radiograph indicates a low risk of bowel obstruction or perforation.

Densities in Chest Radiographs

• Differences in densities are important for clarity of outlines on chest radiographs.

Normal Finding in the Left Upper Quadrant

• A normal finding within the left upper quadrant on an abdominal radiograph is the stomach bubble.

Iatrogenic Structures

• Examples of iatrogenic structures that may be identified in an abdominal x-ray include surgical clips, intrauterine devices, and pacemakers.

Loss of Properitoneal Fat Planes

• The loss of properitoneal fat planes surrounding the major abdominal organs may indicate inflammatory or malignant processes.

Identifying Vertebrae

• The L3 or L4 vertebral body serves as a useful reference point for identifying vertebrae in an abdominal x-ray.

Iatrogenic Objects

• Examples of iatrogenic objects that may be identified in an abdominal x-ray include bullets, per rectum objects, and surgical staples.

Renal Outline

• The usual length of the renal outline in an abdominal x-ray is 10-12 cm.

Location of Kidneys

• The kidneys are usually located in the upper retroperitoneum in an abdominal x-ray.

Pelvic Structures

• If full within the pelvis, the bladder can be observed more clearly on an abdominal x-ray.

Artifacts

• Artifacts that may be seen on an abdominal x-ray include pyjama buttons, coins in pockets, or body piercings.

Learn the basics of interpreting plain abdominal radiographs with this quiz. Designed for medical students starting out as doctors, this quiz will cover the common radiological interpretations and help you understand the normal radiographs.