Radiology is the “vision” of modern medicine. It is the field where physics, anatomy, and clinical pathology collide to allow us to see through the skin and diagnose what ails the human body. However, for a student, this unit can be intimidating. You aren’t just learning how to “take a picture”; you are learning the complex physics of radiation, the chemistry of contrast media, and the patterns of disease that manifest as subtle shadows on a screen.
Below is the exam paper download link
Past Paper On Radiology And Diagnostic Medical Imaging For Revision
Above is the exam paper download link
The most effective way to transition from a student who “knows the theory” to a practitioner who can “interpret the film” is through repeated practice. Past papers are your best friend here. They show you exactly which anatomical landmarks examiners love to point out and which safety protocols are non-negotiable.
Below, we have compiled some of the most frequent Q&As found in Radiology and Diagnostic Imaging revision materials to help you focus your study.
How Do X-rays Produce an Image on a Radiograph?
This is a fundamental physics question. X-rays are a form of high-energy electromagnetic radiation. When they pass through the body, they are “attenuated” (absorbed or scattered) differently depending on the density of the tissue:
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Bone: Very dense; absorbs most X-rays and appears white (radiopaque).
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Soft Tissue/Fluid: Moderately dense; appears in various shades of grey.
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Air/Lungs: Least dense; allows most X-rays to pass through and appears black (radiolucent).
What Is the Difference Between “Sensitivity” and “Specificity” in Diagnostic Imaging?
In your revision papers, you will often encounter these statistical terms.
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Sensitivity: The ability of an imaging modality to correctly identify those with the disease (the “True Positive” rate).
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Specificity: The ability of the test to correctly identify those without the disease (the “True Negative” rate). For example, an MRI is highly sensitive for detecting early soft tissue tumors, but it might have lower specificity because it can pick up non-cancerous “incidental” findings.
When Is a CT Scan Preferred Over an MRI?
This is a favorite comparison question for examiners.
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CT (Computed Tomography): Uses X-rays. It is much faster and is the gold standard for looking at bone fractures, acute head trauma (to check for bleeding), and lung pathologies.
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MRI (Magnetic Resonance Imaging): Uses magnetic fields and radio waves (no radiation). It is superior for soft tissues, such as the brain, spinal cord, ligaments, and tendons.
Why Is “ALARA” the Most Important Principle in Radiology?
Radiation safety is a major part of the curriculum. ALARA stands for “As Low As Reasonably Achievable.” It means that medical professionals must use the lowest dose of radiation possible to get a clear diagnostic image. This involves three key factors:
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Time: Minimize the time spent near a radiation source.
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Distance: Increase the distance from the source (Inverse Square Law).
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Shielding: Using lead aprons or walls to block scattered radiation.
What Is the Role of Contrast Media in Medical Imaging?
Sometimes, tissues have similar densities and don’t show up clearly on their own. Contrast media (like Barium or Iodine) are “high-atomic-number” substances that temporarily increase the density of certain areas. For instance, drinking a Barium meal allows a radiologist to see the lining of the esophagus and stomach in vivid detail on a fluoroscopy screen.

Conclusion
Diagnostic imaging is a fast-evolving field, with new AI-assisted tools and 3D reconstruction techniques arriving every year. However, the core principles of physics and anatomy remain the same. Mastering these through past paper practice is the only way to ensure you are ready for the pressure of a final exam.

