Radiographic Upper Extremity Positioning

Summary

This video script covers essential techniques for radiographic imaging of the upper limbs, focusing on elbow and humerus X-rays. Key topics include proper positioning for AP, lateral, and oblique elbow views, along with tips for optimal exposure and use of grids in different body types. The script emphasizes accuracy in capturing detailed images, ensuring the elbow and humerus are correctly aligned for diagnostic clarity. Special attention is given to pediatric cases, where tape may be needed to secure the limb. The guide is structured to accommodate both standard and trauma cases, providing a comprehensive overview for radiography professionals.

Takeaways

• 😀 Proper positioning is crucial for clear x-ray images, including aligning the elbow, forearm, and humerus correctly.
• 😀 For an AP (anterior-posterior) elbow x-ray, ensure the elbow is extended and the humerus is at the same plane as the forearm.
• 😀 A second x-ray may be needed if the elbow is bent; this provides a different angle for more complete imaging.
• 😀 The O-Blake elbow method involves external rotation of 45 degrees, helping to separate the radius and ulna for clearer visualization.
• 😀 Internal rotation, with the palm down, will cause the radius and ulna to cross, making it harder to view the radial tuberosity.
• 😀 For a lateral elbow x-ray, the center ray should be placed in the middle of the elbow, and the forearm, humerus, and wrist should be in the same plane at a 90-degree angle.
• 😀 When performing an AP humerus x-ray, ensure the patient’s palm is up, and the shoulder is rotated outward to avoid superimposing the shoulder joint.
• 😀 In trauma situations, take x-rays on the tabletop rather than standing, and adjust radiographic technique based on whether a grid is used.
• 😀 For lateral humerus x-rays, there are several variations depending on patient positioning, such as facing the receptor, back against the receptor, or lying on the table.
• 😀 For pediatric patients, tape can be used to prevent curled fingers, ensuring a more accurate x-ray from the fingertips to the forearm.
• 😀 When performing x-rays on small children or infants, be sure to bisect the middle of the cassette for proper alignment of the arm and shoulder joints.

Q & A

What is the proper technique for taking an AP (anteroposterior) X-ray of the elbow?

The correct technique for taking an AP X-ray of the elbow involves ensuring that the elbow is fully extended and the central ray is perpendicular to the humerus. It is crucial to take two X-rays: one where the central ray is perpendicular to the humerus and another where the central ray is perpendicular to the forearm.

Why is it recommended to take two X-rays of the elbow in some cases?

Two X-rays are recommended to ensure clear visibility of the elbow's anatomy. One X-ray should show the humerus, while the second one should focus on the forearm, ensuring no distortion or overlapping of structures in the image.

What is an O'Blake elbow X-ray, and when is it typically used?

The O'Blake elbow X-ray is a type of external rotation X-ray, performed with a 45-degree external rotation of the elbow. It is often requested by radiologists as it provides a clear view of the radial tuberosity by separating the radius and ulna. This technique is used for better visualization of these structures in certain diagnostic situations.

What is the difference between external and internal rotation X-rays of the elbow?

In an external rotation X-ray (O'Blake elbow), the radius and ulna are separated, which allows a better view of the radial tuberosity. In contrast, an internal rotation X-ray (with the palm down) causes the radius and ulna to cross over, making the radial tuberosity less visible.

What is the proper positioning for a lateral elbow X-ray?

For a lateral elbow X-ray, the elbow should be bent to a 90-degree angle, with the central ray directed at the middle of the elbow. The humerus, forearm, and wrist must be aligned in the same plane. If the patient is standing, ensure that the chamber is at the appropriate distance, but if trauma is suspected, the X-ray may need to be performed on a tabletop.

When should a grid be used for an X-ray of the humerus, and why?

A grid should be used for an X-ray of the humerus if the chamber has a built-in grid, especially when taking X-rays in an upright position. The grid helps reduce scatter radiation and improves image quality. However, if the part being X-rayed is thicker than a knee, a grid may not be necessary. The radiographic technique should adjust based on whether a grid is used.

How should the positioning be for an AP humerus X-ray?

For an AP humerus X-ray, the patient should be positioned with their palm facing up. The central ray should be directed to the mid-humerus, and the X-ray should capture both the shoulder joint and the elbow joint. The best positioning for this is usually with the patient standing, but for trauma cases, it may need to be performed on a tabletop.

What are the different ways to position a patient for a lateral humerus X-ray?

There are several ways to position a patient for a lateral humerus X-ray: 1) with the patient facing the image receptor and the elbow lateral; 2) with the patient's back against the image receptor, palm down; 3) with the patient lying on the table with their palm down; or 4) transversely, with the X-ray passing across the body to capture either the upper or lower part of the humerus.

How can tape be used when performing X-rays on small children?

When X-raying small children, tape can be used to help keep their fingers in the proper position, preventing them from curling. Tape should be placed from the fingertips down, and the X-ray should cover the full 17-inch length from the fingertips to the mid-humerus or lower part of the arm, depending on the area being imaged.

What should be the radiographic technique when using a grid for an upright humerus X-ray?

When using a grid for an upright humerus X-ray, the radiographic technique should be adjusted to higher settings, typically 70 kVp. This is because the grid reduces scatter radiation, requiring a higher exposure to achieve optimal image quality.