Pathology Recognition and Image Critique Across All Regions

Pathology Recognition and Image Critique Across All Regions

The ability to evaluate a radiographic image critically is one of the most important skills you will use every day in clinical practice. A technically perfect image that is misidentified or misread can lead to patient harm. A repeat exposure adds unnecessary radiation dose. This lesson ties together positioning knowledge, anatomy, and pathology recognition into a single, unified skill set.

The Four-Step Image Critique Model

Use this model in the same order every time, for every image.

Step 1 – Patient Identification and Marker Verification. Confirm that the patient's name, date of birth, date of service, and facility name are visible on the image. Confirm that a right (R) or left (L) anatomical marker is present and is within the collimated field — not overlying critical anatomy. A missing or incorrect marker is a patient-safety error. If you cannot verify the marker, the image must be repeated and the discrepancy documented before the image is released.

Step 2 – Collimation and Positioning. The collimated field should include all required anatomy with no more than approximately one centimeter of space beyond the region of interest on each side. Poor collimation increases patient dose and reduces contrast. Check that the part was correctly centered, that the correct projection was used (PA vs. AP, oblique angle, etc.), and that there is no rotation or motion blur that obscures diagnostic information.

Step 3 – Density and Contrast. Brightness (receptor exposure) and contrast must allow visualization of both bone and soft tissue as required for the study. Digital systems provide wide latitude, but over- or underexposure still degrades image quality and can mask pathology. Insufficient contrast can hide a subtle fracture line or a soft-tissue mass.

Step 4 – Anatomy Demonstrated. Confirm that all required structures are shown. A chest PA must include both costophrenic angles, both apices, and the entire width of the thorax. A lateral lumbar spine must show all five vertebral bodies and the lumbosacral junction. Missing anatomy means a repeat is warranted.

Common Radiographic Signs of Pathology

You are not diagnosing — that is the physician's role. However, you must recognize findings that affect how you position, whether a repeat is needed, and whether you should alert a supervising radiologist or physician immediately.

Fractures. A fracture appears as a lucent (dark) line through bone cortex or as cortical disruption. Impacted fractures may show increased density at the fracture site. Stress fractures may be invisible acutely and show up as a sclerotic line or periosteal reaction on follow-up. When pathologic fracture is suspected, handle the patient with extra care and confirm with the ordering provider before moving the extremity.

Lobar Pneumonia. Consolidation replaces air in the alveoli with fluid and cells, making the lung appear opaque (white). A classic sign is the air bronchogram: visible dark bronchi surrounded by white consolidated lung. The cardiac border or diaphragm may be obscured (silhouette sign) depending on which lobe is affected. Positioning note: an upright PA chest is preferred because gravity-dependent changes are most visible, and the diaphragm is depressed by standing.

Pleural Effusion. Fluid in the pleural space appears as a homogeneous opacity that blunts the costophrenic angle on an upright PA chest. Large effusions layer along the lateral chest wall. A lateral decubitus projection (affected side down) demonstrates even small free-flowing effusions and distinguishes free fluid from loculated collections.

Degenerative Joint Changes / Degenerative Disc Disease. Osteoarthritis presents as joint space narrowing, subchondral sclerosis (increased whiteness at joint surfaces), and osteophyte formation (bone spurs). In the spine, disc space narrowing and end-plate sclerosis are hallmarks of degenerative disc disease. These findings are best seen on weight-bearing views when applicable.

Renal Calculi on KUB. Kidney stones (calculi) are typically calcified and appear as small, rounded, or irregular opaque densities overlying the expected course of the ureters or within the renal shadows. A KUB (kidneys, ureters, bladder) radiograph must include the entire urinary tract from the upper poles of the kidneys to the base of the bladder.

Sinus Opacification. Air-filled paranasal sinuses appear black (lucent). When a sinus is opacified by infection or fluid, it appears white (opaque) or shows an air-fluid level. Waters' projection (parietoacanthial) is the primary view for the maxillary sinuses. An upright or seated position is required to demonstrate air-fluid levels.

Foreign Bodies. Metallic foreign bodies appear bright white and are easy to identify. Soft-tissue foreign bodies (glass, plastic, wood) may be difficult or invisible on radiographs. Always note any unexpected opacities and inform the supervising clinician.

Safety Priorities in Image Critique

• Never release an image without confirming patient identification and the correct anatomical marker. This is a non-negotiable step in every clinical setting.
• Recognize immediately any finding that suggests an unstable condition — a tension pneumothorax, a markedly displaced fracture, or a severely widened mediastinum — and alert the supervising radiologist or physician without delay.
• Do not repeat an image without appropriate authorization and a clear clinical reason. Each repeat is additional radiation dose to the patient.
• Stay within your scope of practice: identify findings that affect your technical work; do not interpret or diagnose.

Applying Critique Skills to Your Credentials

Both the ARRT Limited Scope examination and the ARRT Radiography (RT-R) examination test image evaluation and anatomy. Your State Radiologic License requires that images you produce meet diagnostic standards. Employers expect technologists who can catch their own positioning errors before releasing poor images. Strong critique skills protect patients, protect your license, and reflect professional competence.