Biopsy

Biopsy, the examination of a sample of tissue removed from a living patient (in contrast to necropsy, the examination of tissue after death), is a valuable aid in establishing a precise diagnosis using specific hospital lab equipment. Samples of muscle, liver, kidney, lung, and other tissues may be removed safely and simply by passing a needle through the skin and into the target organ or tissue, sometimes using ultrasound, CT scanning, or fluoroscopy to help guide the needle. Tumors and cysts in organs such as the breast, ovary, testis, or thyroid can be sampled in the same way. Once obtained, the tissue sample may be examined under a microscope and subjected to a variety of biochemical tests, thereby yielding a diag¬nosis that is accurate.

Endoscopic investigation

Early endoscopes as, hospital lab equipments, were simply rigid or partially rigid tubes, sometimes with complex lens systems and interior lighting, and were of limited use. In the late 1950s, the introduction of fiberoptics enabled endoscopes to be completely flexible, thereby greatly increasing this hospital lab equipment’s versatility. Today, many specialized endoscopes are available, enabling physicians to view directly virtually any structure in the body, including the digestive tract, nasal sinuses, lungs, bladder, abdominal cavity, and joints. In addition, many endo¬scopes can be fitted with attachments that enable samples of tissue to be taken for biopsy or surgical procedures to be carried out.
Magnetic Resonance Imaging (MRI)

Unlike X-ray radiography, CT scanning, and radionuclide imaging, MRI (magnetic resonance imaging), as hospital lab equipment, does not employ potentially harmful ioniz¬ing radiation. Instead, it exploits the natural behavior of the protons (nuclei) of hydrogen atoms when they are subjected to a very strong magnetic field and radio waves. As a result of this stimulation, the protons emit radio signals, which are detected and computer processed to generate an image. The most abundant sources of protons in the body are the hydrogen atoms in water molecules; an MRI scan therefore reflects differences in the water content of tissues.

Superficially, MRI scans look like CT scans. How¬ever, CT scans usually show little differentiation in soft tissues; MRI scans show more of the detailed structure because of differences in water content within these tissues. For example, white and gray matter in the brain is relatively poorly differentiated in some hospital lab equipments like CT scans, while they are distinct and well defined in MRI scans.

Positron Emission Tomography (PET) scanning

PET (positron emission tomography) scanning is a development of radionuclide scanning and resembles at in many ways. Both techniques use a radioactive substance introduced into the body to produce an image that reflects the level of activity of tissues. How¬ever, radionuclide scanning usually produces an image analogous to a conventional X-ray picture; PET manning gives a cross-sectional image that is analogous to a CT scan.

In PET scanning, a substance that takes part in metabolic biochemical processes is labeled with a radioisotope to make it radioactive; it is then injected into the bloodstream. The most metabolically active areas of tissue take up the substance. In the tissue, the substance emits positrons. The positrons, in turn, release photons, which are then detected by an array of sensors around the patient. The sensors are linked to a computer, which calculates the origins of the photons to construct an image of the distribution of the substance within the tissues.

PET scanning is currently being utilized for investigating brain tumors, locating the origin of epileptic activity, and studying the brain function in various mental illnesses. It is anticipated that PET scanning will be used for other organs.