April 2026 ~ King's of Radiology

Radiology

Radiology is a branch of medicine that uses imaging technology to diagnose and treat disease. Radiology may be divided into two different areas, diagnostic radiology and interventional radiology.
X-Ray

X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of your body. The images show the parts of your body in different shades of black and white. This is because different tissues absorb different amounts of radiation.
USG (Ultrasonogram)

An ultrasound is an imaging test that uses sound waves to make pictures of organs, tissues, and other structures inside your body. It allows your health care provider to see into your body without surgery. Ultrasound is also called ultrasonography or sonography.
CT Scan

The term “computed tomography,” or CT, refers to a computerized x-ray imaging procedure in which a narrow beam of x-rays is aimed at a patient and quickly rotated around the body, producing signals that are processed by the machine’s computer to generate cross-sectional images, or “slices.” These slices are called tomographic images and can give a clinician more detailed information than conventional x-rays. Once a number of successive slices are collected by the machine’s computer, they can be digitally “stacked” together to form a three-dimensional (3D) image of the patient that allows for easier identification of basic structures as well as possible tumors or abnormalities.
MRI

Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body.

X-ray Basics for Radiographers: Principles, Technique & Practical Guide

RadiographerApril 18, 2026Exposure Factors, Image Quality, Radiation Safety, Radiographer Education, Radiography Basics, X-Ray No comments

X-ray Basics for Radiographers: Principles, Technique & Practical Guide

X-ray imaging is the most commonly performed diagnostic investigation in radiology. For a radiographer, understanding both the basic principles and practical factors affecting image quality is essential to produce accurate and diagnostic images while minimizing radiation exposure.

Basic Principle of X-ray

Figure: X-ray attenuation showing density differences

X-rays are a form of electromagnetic radiation
They penetrate the body and are differentially absorbed
Bone → White
Soft tissue → Grey
Air → Black

Components of an X-ray System

Figure: Components of X-ray system

X-ray Tube: Produces X-rays
Control Panel: Adjusts exposure settings
Detector: Captures image
Grid: Reduces scatter radiation

Exposure Factors

Figure: Effect of kVp and mAs on image quality

kVp: Controls penetration (High kVp → low contrast)
mAs: Controls image density
Time: Affects motion blur

Image Quality Factors

Figure: Contrast, sharpness and distortion

Contrast: Black vs white difference
Density: Image brightness
Sharpness: Detail clarity
Distortion: Shape accuracy

Radiation Safety (ALARA)

Figure: Radiation safety practices

Use collimation
Maintain distance
Apply shielding
Avoid repeat exposures

Common Mistakes in X-ray

Figure: Examples of positioning and exposure errors

Improper positioning
Rotation
Motion blur
Over/under exposure
Artifacts

Practical Tips for Radiographers

✔ Confirm patient identity
✔ Ensure correct positioning
✔ Use proper exposure factors
✔ Check for artifacts
✔ Instruct patient clearly

Quick Checklist

✔ Correct patient
✔ Correct view
✔ Proper positioning
✔ Correct exposure
✔ No artifacts

Clinical Relevance

A technically good X-ray is essential for accurate diagnosis. Poor technique may lead to misinterpretation and repeat imaging.

Summary

X-ray depends on tissue density and exposure factors
kVp and mAs are critical
Proper positioning is essential
Avoid common errors
Follow radiation safety principles