Diagnostic Imaging

Correct Answer: to get rid of non-cancerous tumours in the uterus

A computed tomography (CT) scanner uses X-rays, a type of ionizing radiation, to acquire images, making it a good tool for examining tissue composed of elements of a higher atomic number than the tissue surrounding them, such as bone and calcifications (calcium based tissues) within the body. MRI, on the other hand, uses non-ionizing radio frequency (RF) signals to acquire its images and is best suited for soft tissue. (Hence, statement 1 is correct.) MRI is also best suited for cases when a patient is to undergo the exam several times successively in the short term, because, unlike CT, it does not expose the patient to the hazards of ionizing radiation. (Hence, statement 2 is also correct.)

PET stands for Positron Emission Tomography, a nuclear medicine imaging technique that produces detailed three-dimensional images of functional processes in the body. It uses radioactive tracers (often FDG, a glucose analog) that emit positrons, which annihilate with electrons to produce gamma rays detected by the scanner. PET is crucial in oncology, neurology, and cardiology.

MRI stands for Magnetic Resonance Imaging, a diagnostic technique that uses strong magnetic fields and radio waves to create detailed images of internal body structures. It is particularly useful for imaging soft tissues like the brain, muscles, and organs. Options A, B, and C are plausible-sounding but incorrect combinations of medical and technical terms.

CAT scan stands for Computerized Axial Tomography (also called CT scan), which uses X-rays and computer processing to create detailed cross-sectional images of the body. The 'axial' refers to the scanning around the body's axis. Options A, B, and D are incorrect combinations of anatomical and technical terms.

Ultrasound technology uses high-frequency sound waves to create real-time images of the fetus inside the womb without using radiation. CAT Scans and X-rays use ionizing radiation which can harm the developing fetus, while LASER is not used for imaging purposes. Ultrasound is safe, effective, and widely used for prenatal monitoring throughout pregnancy.

CT (Computed Tomography) scanners use X-rays to create cross-sectional images of the body. Multiple X-ray measurements from different angles are processed by computer to generate detailed 3D images. Ultrasound uses sound waves, gamma rays are used in PET scans, and CT definitely uses X-rays, not 'none of these'.

Endogram is a radiograph taken with radiopaque liquid injected into canals.

Multidetector CT pulmonary angiography (CTPA) is the gold standard and best initial investigation for pulmonary thromboembolism. It provides direct visualization of thrombi within the pulmonary arteries with high sensitivity and specificity. D-dimer is sensitive but non-specific - useful for ruling out PE when negative but not diagnostic when positive. Colour Doppler ultrasound is used for detecting deep vein thrombosis in the legs (source of emboli), not the pulmonary embolism itself. Catheter pulmonary angiography is invasive and reserved for cases where CT is contraindicated or inconclusive.

Enneking staging system is the standard classification for benign and malignant bone and soft tissue tumours. It considers grade (G), site (T), and metastasis (M) - crucial for surgical planning. TNM staging is used for carcinomas and other systemic cancers, not primary bone tumours. Manchester and Edmonton are not recognised tumour staging systems.

Ultrasound comes from a machine that creates an image of the inside of your body. It shows what your baby looks like while still inside your womb (uterus). Ultrasound can tell you many things about your baby, such as:

• How well the baby’s heart works • How well other organs (such as the spine, brain and kidneys) are growing • The anticipated date of birth

RF (Rheumatoid Factor) is primarily used to diagnose rheumatoid arthritis, an autoimmune joint disease. Myeloma is diagnosed through different tests like electrophoresis. Myalgia refers to muscle pain and multiple sclerosis uses different diagnostic markers.

MRI technology uses the principles of nuclear magnetic resonance, where hydrogen nuclei in water molecules align with and are disturbed by magnetic fields. This creates signals that computers convert into detailed anatomical images. Electron spin resonance involves electron spins, not nuclei, and diamagnetism is a weak property unrelated to MRI.

Ultrasound has multiple applications: medical diagnosis (imaging organs, tissues), detecting congenital defects in the fetus (prenatal screening), and industrial non-destructive testing (finding cracks/flaws in metal). Since all three uses are valid, 'all of the above' is correct.