Which of the following techniques is used to detect cancers of the internal organs?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → All of these.
Cancer is detected by biopsy and histopathological study of the suspected tissue, and by blood and bone marrow tests in leukaemias. A tumour deep inside the body cannot be seen directly, so imaging techniques are used to find cancers of the internal organs. The book names three such techniques, so all of them are correct.
Option (1) Radiography (use of X-rays). — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Radiography takes pictures of the inside of the body using X-rays.
Option (2) CT (computed tomography). — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Computed tomography uses X-rays to make a three-dimensional image of the internal organs.
Option (3) MRI (magnetic resonance imaging). — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Magnetic resonance imaging uses strong magnetic fields and non-ionising radiations to detect changes in living tissue.
NCERT Extract:
Cancer – “… Techniques like radiography (use of X-rays), CT (computed tomography) and MRI (magnetic resonance imaging) are very useful to detect cancers of the internal organs. Computed tomography uses X-rays to generate a three-dimensional image of the internals of an object. MRI uses strong magnetic fields and non-ionising radiations to accurately detect pathological and physiological changes in the living tissue.”