The process of detecting a pin mistakenly swallowed by a child is X-ray

Analyze the question: A child has swallowed a pin. Using X-rays to find (detect) the pin is a way of identifying what is wrong inside the body. We need the term for that use of X-rays.

Explain the concept: X-rays have several uses:

• Diagnosis: finding out what is wrong inside the body, such as broken bones, swallowed objects or lung problems. X-rays pass through soft tissue but are absorbed by dense materials like bone and metal, so these show up on the film.
• Therapy: using high-energy X-rays to destroy cancerous cells.
• Crystallography: using X-ray diffraction to study the arrangement of atoms in crystals.
• Mammography: a specific low-dose X-ray examination of the breast, used to detect breast tumours.

Solution:

1. Detecting a swallowed pin means locating a foreign object in the body. This is a medical imaging task, not treatment.
2. The pin is metal, so it absorbs X-rays strongly and appears clearly on the image.
3. This rules out therapy (no treatment is being given), crystallography (no crystal structure is being studied) and mammography (that applies only to the breast).
4. What remains is diagnosis, which is the use of X-rays to detect or identify a problem inside the body.

Answer: A. Diagnosis

Exam tip: Match the key word in the question to the use:

• Detect or locate a problem → Diagnosis
• Destroy or treat cancer → Therapy
• Study atomic structure → Crystallography
• Breast → Mammography