What is the recommended positioning for a Kidney, Ureter, Bladder (KUB) X-ray in infants?

Recommended Positioning for KUB X-ray in Infants

For optimal KUB (Kidney, Ureter, Bladder) X-ray imaging in infants, the recommended position is supine with proper immobilization to minimize movement artifacts and ensure diagnostic quality images.

Proper Positioning Technique

Patient Preparation

• Change the diaper immediately before the examination to avoid leakage and prevent scatter-related artifacts 1
• Ensure the diaper is adequately fastened and clean before proceeding with imaging 1

Positioning Steps

1. Place the infant in a supine position (on their back) on the examination table
2. Position arms along the body, secured with appropriate immobilization devices 1
3. Ensure symmetry of the studied areas for correct image interpretation 1
4. Center the X-ray beam to include the entire urinary tract from the upper poles of the kidneys to the bladder

Immobilization Techniques

• Use comfortable immobilization devices such as:
  • Vacuum mattresses (highly effective for comfortable immobilization) 1
  • Cushions or sandbags
  • Safety straps
  • Immobilization splints and pads

Important Considerations

Radiation Safety

• Use collimation to reduce the irradiated area, including only necessary landmarks 1
• Limit beam "on" time as it is directly proportional to radiation dose 1
• Consider removing the anti-scatter grid in infants <20 kg to reduce patient dose with limited loss of image quality 1

Field of View Guidelines

• The cranial extent of the KUB should be at the T10 vertebral level to adequately capture the upper poles of both kidneys while minimizing radiation exposure 2
• The caudal extent should include the entire bladder and urethra

Parental Involvement

• The presence of a parent in the examination room is essential to reduce anxiety and improve cooperation 1
• Parents can assist with immobilization when necessary, but should be properly protected from radiation

Special Situations

For Very Young or Uncooperative Infants

• Consider feeding immediately before imaging to induce natural sleep 1
• Comfortably wrap the infant with a blanket on the camera bed 1
• Dim the lights to help induce sleep 1
• Use a pacifier for reassurance 1

For Mobile Infants

• More robust immobilization techniques may be required
• If the first image shows motion artifacts, consider repeating after the infant falls asleep for improved image quality 1

Common Pitfalls to Avoid

• Inadequate immobilization leading to motion artifacts and repeated exposures
• Improper positioning causing asymmetry and difficult interpretation
• Excessive cranial extension of the imaging field beyond T10, which increases radiation exposure without diagnostic benefit 2
• Failure to change diapers before the examination, which can create artifacts and complicate image interpretation 1

By following these positioning guidelines, healthcare providers can obtain high-quality KUB X-ray images in infants while minimizing radiation exposure and ensuring patient comfort and safety.