Radiographic Image Quality and Faults

Interpretation, Image Quality, and Faults

• The presentation covers radiographic image interpretation, focusing on quality, positioning, and exposure adequacy.
• It also discusses potential imaging faults, how to avoid them, and strategies for identification.
• Finally, the presentation compares and contrasts digital and film radiography regarding image faults.

Learning Objectives

• Students will learn how to describe a radiographic image in terms of quality, positioning, and appropriate exposure relevant to the area of interest.
• Assess potential imaging faults and methods to prevent, identify, and address them.
• Compare the advantages and disadvantages of digital and film radiography in relation to faults.

Simplified Radiographic Report

• A sample format for a radiographic report is provided.
• The report includes sections for description (patient name, history, area imaged, and projections), radiographic diagnosis (image description, variations from normal, summary of findings), differential diagnosis (prioritising list, most significant, and incidental findings), and recommendations (further recommendations, imaging, surgery, diagnostics, ongoing management).

How to Remember Comments

• Use the mnemonic "Pink Camels Collect Extra Large Apples" to remember the key aspects to consider: Positioning, Centering, Collimation, Exposure, Labelling, and Artefacts.

Area Imaged/Positioning

• The area of interest dictates the necessary projections.
• Minimizing non-pathological variations is crucial, achieved by adhering to standard views, positioning, and exposure settings.

Radiographic Projections

• Radiographic projections are named based on the direction the primary beam penetrates the body part.
• Lateral radiographs are named according to the side the animal is positioned on.

Patient Positioning

• Principles of radiographic positioning prioritize minimizing geometric distortion and magnification.
• Use orthogonal views; positioning the animal correctly.
• Essential procedures for radiographic positioning include proper centering.

Geometric Distortion

• The beam diverges as it exits the X-ray generator, leading to distortion.

Magnification

• Magnification is a result of the ratio between object-focus distance and object-film distance.

Orthogonal Views

• Orthogonal views are essential for assessing abnormalities in three dimensions.

Centering

• Center the image to the anatomical area of interest using bony landmarks.
• Accurate centering allows for close collimation.
• Collimator light aligns to accurate centering.

Collimation

• Accurate collimation reduces scatter radiation, dose, and enhances image contrast and quality.

Exposure

• Exposure errors (too dark/too white) need to be identified and addressed, by altering exposure settings.
• The quality of the exposure impacts the appearance of the image; too dark or too light result from inappropriate exposure.
• Film and digital exposures use different techniques to avoid problems.
• For Film/Screen, adjusting techniques includes "over-exposure" (over-developed), and "under exposure" (under developed).
• Digital systems use techniques like "quantum mottle" (under exposure).

Labelling

• Radiographs must have clear labeling (name, date, L/R marker).
• Markers must be visible and not obscured by the body part.
• Dental radiographs commonly use dots for side identification.
• Animal name and examination date are essential identifiers.
• These labels can be added electronically to digital images

Viewing a Radiograph

• Lateral views should have the rostral part of the animal positioned to the viewer's left.
• Ventrodorsal/Dorsoventral views should have the rostral part of the animal positioned left of the viewer.
• Lateromedial/Mediolateral extremities should have the proximal limb in an upright position.
• Cranial/dorsal limbs are observed positioned to the left of the viewer when viewing the image.
• Lateral aspects of extremities should face the left side of the viewer.

Image Orientation

• Correct image orientation is crucial for accurate interpretation.
• Ensure correct anatomical orientation when viewing images.

Quality - Artefacts

• Analyze and identify common artefacts in both film/screen and digital radiography.
• Radiographic artefacts include errors in labelling (name, date, and laterality marker).
• Faults may include poor positioning, collimation errors, motion blur, and artefacts (fogging).
• Consider patient-related artefacts (e.g., wet coats, mud, syringes).

Fogging and Scatter Radiation

• Scatter causes random blackening, reducing image quality and requiring mitigation.
• Appropriate collimation and using grids reduces scatter.
• Use grids to prevent scatter; place them between the cassette and the patient.

Film/Screen Faults

• Film/screen faults arise from various issues, including inappropriate storage (fogging), and under/over-exposure.
• Exposure issues may lead to an under-developed or over-developed film.

Digital Faults

• Digital faults can be linked to post-exposure issues (partial erasure, fading, white specks) or workstation faults (incorrect algorithm/cropping, or artefact).

Description of the Image

• Image description focuses on characterizing the image for further analysis and interpretation.

Röentgen Signs

• A table outlines various röentgen signs (size, shape, number, position, opacity, and margins), their corresponding changes, and possible causes.

Opacity

• Opacity refers to how much X-rays are absorbed by the tissue.
• Radiolucent (low absorption, appears dark) and radiopaque (high absorption, appears light) are the two types.
• Tissues with varying densities absorb X-rays differently, creating distinct images on radiographs.
• A chart depicts the various levels of opacity, from air to metal.

Border Effacement

• Border effacements are a result of two tissues being in close contact, making margins indistinguishable.
• Right middle lobar pneumonia, pleural effusion, and peritoneal effusion are potential causes.

Finishing the Report

• Summarize the findings, consider differentials (DAMNITV).
• Avoid biases in analysis and ensure thoroughness of examination.
• Further diagnostic tests may be advisable.

Let's Have a Go

• This section provides examples to practice.
• This section has examples for practical application and practice exercises.

This quiz focuses on the interpretation of radiographic images, emphasizing the quality, positioning, and sufficiency of exposure. It also covers common imaging faults, their prevention, and strategies for identification, as well as a comparison between digital and film radiography. Students will enhance their skills in creating simplified radiographic reports.