October 2026 - Anatomical Imaging Study Guide

Core ideas to know

Learn the relationships, not a string of isolated definitions. These are the facts that let you reason through unfamiliar wording.

• Radiography uses ionising x-rays and shows dense structures such as bone strongly because they absorb more radiation.
• Computed tomography (CT) combines many x-ray measurements into cross-sectional images and therefore also uses ionising radiation.
• Magnetic resonance imaging (MRI) uses a magnetic field and radiofrequency energy, giving strong soft-tissue contrast without x-rays.
• Ultrasound forms real-time images from reflected high-frequency sound and is useful for motion and fluid-filled structures.
• A cross-sectional image may be sagittal, frontal or transverse, and its labels should be read before assuming orientation.

A reliable way to answer

Use the same short process every time so the wording of the question does not decide your method for you.

1. Identify the modality from its stated energy source: x-ray, magnet and radio waves, or sound.
2. Identify the plane and locate obvious landmarks before naming a smaller structure.
3. Compare tissue density or signal within that modality rather than across unrelated image types.
4. Choose the modality whose strengths match the structure or process described in the stem.

Distinctions that earn marks

Terms to know

Modality

A particular imaging method and its physical mechanism.

Contrast

The visible difference that lets adjacent tissues be distinguished.

Cross-section

An image representing a slice through the body.

Key points

• Radiographs and CT use ionising x-rays; MRI and ultrasound do not.
• CT is cross-sectional, while an ordinary radiograph is a projection.
• Always establish plane and orientation before interpreting a labelled image.