Chapter 12: Trauma Radiography

Detailed Chapter Overview

Trauma radiography represents a specialized and highly critical area of diagnostic imaging, demanding a unique combination of technical skill, adaptability, and clinical judgment under high-pressure situations. This chapter provides a definitive guide to the principles and practices essential for performing radiography on injured patients. The core philosophy of trauma imaging is adaptation—modifying standard procedures to obtain diagnostic images without further injuring the patient. A central theme is the unwavering adherence to fundamental principles: obtaining two projections 90 degrees to each other, ensuring the entire structure of interest is included, and prioritizing the safety of the patient and healthcare team above all else. The chapter meticulously details the use of horizontal beam (cross-table) radiography, a cornerstone technique for obtaining lateral projections on immobile patients, particularly for the cervical spine, hip, and other major joints. It provides a comprehensive survey of positioning strategies for various trauma scenarios, emphasizing how to manipulate the central ray and image receptor instead of the patient. Specific, life-saving trauma series are explored in depth, including the initial horizontal beam lateral for clearing the cervical spine and the axirolateral inferosuperior (Danelius-Miller) projection for hip fractures. The chapter also addresses the radiographer's role within the larger trauma team, stressing the importance of clear communication, efficiency, and maintaining a calm, professional demeanor in a chaotic environment. For every adaptation and specialized projection, rigorous evaluation criteria are established, training the radiographer to think critically and creatively to overcome any obstacle and produce images that are vital for immediate patient care.

In-Depth Study Guide

Core Principles of Trauma Radiography

Trauma radiography is governed by a set of foundational principles that must not be compromised, even in the most challenging circumstances. These principles ensure that diagnostic information is obtained safely and effectively.

1. Two Projections at 90-Degree Angles

This is the most fundamental rule in radiography, and it is especially critical in trauma to fully evaluate the nature and extent of an injury.

• Purpose: A single projection is insufficient to determine the alignment of fracture fragments, the direction of dislocation, or the location of foreign bodies. A second view, taken at a right angle to the first, provides the necessary three-dimensional information.
• Adaptation: In trauma, the patient often cannot be rotated into standard positions (e.g., a lateral). The radiographer must adapt by moving the x-ray tube and image receptor around the patient. This is typically achieved with a **horizontal beam lateral projection**, where the tube is horizontal and the IR is placed vertically against the patient.

2. Include Entire Structure of Interest

The radiographic field must be large enough to include the entire bone or joint in question.

• Long Bones (e.g., femur, humerus): For any long bone, both the joint proximal and the joint distal to the injury must be included on the image series. This is to rule out associated dislocations or secondary fractures. If the entire bone cannot fit on a single IR, two separate images must be taken, with overlap.
• Joints: For any injured joint, at least one inch of the proximal and distal long bones must be included.

3. Maintain Safety of Patient and Personnel

• Patient Safety First: The most important rule is **do no further harm**. Never move a patient with a suspected spinal, head, or pelvic injury unless cleared by a physician. All movements should be slow, deliberate, and coordinated with the trauma team. Do not remove splints, collars, or traction devices without permission.
• Radiation Protection: The chaotic nature of a trauma situation does not negate the principles of ALARA. The radiographer must:
  • Collimate tightly to the area of interest.
  • Shield the patient's gonads and any radiosensitive areas outside the region of interest.
  • Provide lead aprons to all essential personnel who must remain in the room.
  • Announce "X-RAY!" loudly and clearly before making an exposure to allow non-essential personnel to step away.

Specific Trauma Projections and Adaptations

Cervical Spine Trauma

Dorsal Decubitus (Horizontal Beam) Lateral Projection:

• Purpose: This is the **first and most critical image** taken on any patient with a suspected cervical spine injury. It must be performed and cleared by a physician before the patient is moved or the cervical collar is removed.
• Positioning: The patient remains supine on the backboard or cart. The IR is placed vertically against the patient's shoulder, and the CR is directed horizontally, centered to the mid-coronal plane at the level of C4.
• Evaluation Criteria: All seven cervical vertebrae, as well as the C7-T1 interspace, must be clearly visualized. If the shoulders obscure C7-T1, a **"Swimmer's" Lateral (Twining Method)** must be performed to visualize this critical area.

Shoulder and Humerus Trauma

• AP Neutral Rotation: The initial AP view is taken "as is," without any attempt to rotate the injured arm.
• Scapular Y Lateral: A crucial view for assessing dislocations. The patient is rotated into an anterior oblique position until the scapula is in a true lateral profile. The humeral head should be superimposed over the junction of the "Y" (formed by the acromion, coracoid, and scapular body).
• Transthoracic Lateral (Lawrence Method): Used for the proximal humerus when the patient cannot abduct their arm. The CR is directed horizontally through the patient's thorax from the uninjured side. A breathing technique is employed to blur the overlying ribs.

Pelvis and Hip Trauma

• AP Pelvis: The initial projection is a single AP view of the entire pelvis. The legs are imaged "as is," without any attempt at internal rotation, to prevent displacement of fracture fragments.
• Axiolateral Inferosuperior (Danelius-Miller Method): This is the essential **trauma cross-table lateral** projection for the hip.
  • Purpose: To obtain a lateral view of the femoral head, neck, and acetabulum without moving the patient's injured leg.
  • Positioning: The patient remains supine. The IR is placed vertically in the crease above the iliac crest of the affected side, angled so it is parallel to the femoral neck. The CR is directed horizontally and perpendicular to the IR, entering the medial aspect of the upper thigh. The uninjured leg must be flexed and elevated out of the way of the beam.
  • Evaluation Criteria: The entire femoral head and neck, acetabulum, and any orthopedic hardware must be clearly demonstrated. The lesser trochanter should be seen in profile posteriorly.

Lower Limb Trauma

• Knee: A horizontal beam lateral is performed with the patient supine. The CR is directed horizontally, and the IR is placed vertically against the medial or lateral aspect of the knee.
• Tibia/Fibula: Requires two projections 90 degrees apart. Often, this means an AP view followed by a horizontal beam lateral, with the IR placed vertically behind the leg.
• Ankle/Foot: Can often be positioned for standard AP, oblique, and lateral views with minimal movement, but adaptations may be necessary. For a lateral ankle/foot, a cross-table projection is standard if the patient cannot roll onto their side.