Which imaging modality uses a series of X-ray photographs from different angles to create a cross-sectional image?

Which imaging modality uses a series of X-ray photographs from different angles to create a cross-sectional image?

• A. MRI
• B. Ultrasound
• C. CT scan
• D. PET scan

Answer: (C)

The concept being tested is how cross-sectional images are produced by combining multiple X-ray views. Computed tomography achieves this by rotating an X-ray source and detectors around the patient, capturing many projections from different angles. A computer then reconstructs these data into thin slices—cross-sectional images—so you can see a specific “slice” through the body and examine internal structures in detail from multiple perspectives. Other imaging methods don’t create cross-sectional X-ray slices in the same way. Magnetic resonance imaging uses strong magnetic fields and radio waves to generate images and does not rely on X-ray projections. Ultrasound uses sound waves to create real-time images and avoids ionizing radiation. PET scans map metabolic activity using radioactive tracers, providing functional information rather than the anatomical cross-sections produced by CT.

The concept being tested is how cross-sectional images are produced by combining multiple X-ray views. Computed tomography achieves this by rotating an X-ray source and detectors around the patient, capturing many projections from different angles. A computer then reconstructs these data into thin slices—cross-sectional images—so you can see a specific “slice” through the body and examine internal structures in detail from multiple perspectives.

Other imaging methods don’t create cross-sectional X-ray slices in the same way. Magnetic resonance imaging uses strong magnetic fields and radio waves to generate images and does not rely on X-ray projections. Ultrasound uses sound waves to create real-time images and avoids ionizing radiation. PET scans map metabolic activity using radioactive tracers, providing functional information rather than the anatomical cross-sections produced by CT.