Diagnostic Imaging

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.)

Isospora belli is a species of internal parasites. It is responsible for the condition isosporiasis. Autofluorescence aids detection.

Glycosuria is the medical term for the presence of glucose (sugar) in the urine, which can indicate diabetes mellitus or other metabolic conditions. The term derives from 'glyco' (sugar) and 'uria' (urine). Gonadotropism relates to hormonal effects, asphyxia is lack of oxygen, and albuminuria refers to albumin protein in urine.

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.

Acridine orange is a nucleic acid selective fluorescent cationic dye useful for cell cycle determination. It is cell-permeable, and interacts with DNA and RNA by intercalation or electrostatic attractions respectively.

The confirmatory test used to diagnose AIDS is Western Blot test.

Aniline Blue WS is a mixture of methyl blue and water blue. It may also be either one of them. Aniline blue or its constituents are used to stain collagen, as the fibre stain in Masson's trichrome.

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.

It is one of the most common yeast species to be found on the body surface and is often isolated as an incidental finding from skin and urine.

Western blot is used to detect specific proteins, including antibodies against HIV. ELISA (A) is the initial screening test, but Western blot (C) is the confirmatory test that detects antibodies to specific HIV proteins by their molecular weight. FISH (B) is for DNA/RNA localization, Northern blot (D) detects RNA, and Southern blot (E) detects DNA.

FISH (Fluorescence In Situ Hybridization) is the standard screening test for aneuploidy syndromes like Down syndrome, Turner syndrome, etc. It uses fluorescent probes to detect chromosomal abnormalities.

GeneXpert testing system distinguishes fairly well between NTMs and mycobacterium tuberculosis. NTMs (non-tuberculous mycobacteria) are emerging microbes that cause a spectrum of diseases including TB-like lung disease, localised infections of the lymphatic system, skin, soft tissue or bone and systemic disease.