Medical Terminology Flashcards: Diagnostic Tests, Lab Values, Imaging, Procedures

CBC stands for complete blood count, the most commonly ordered blood test. It measures red blood cell count and hemoglobin indicating oxygen-carrying capacity, hematocrit indicating the percentage of blood volume occupied by red cells, white blood cell count indicating immune function and infection, white blood cell differential breaking down the types of white cells, and platelet count indicating clotting ability. Abnormal results help diagnose anemia, infection, inflammation, bleeding disorders, and blood cancers.

MRI stands for magnetic resonance imaging. It uses a powerful magnetic field and radiofrequency pulses to create detailed cross-sectional images of internal body structures without using ionizing radiation. Hydrogen atoms in body tissues align with the magnetic field, and when radiofrequency pulses are applied, the atoms emit signals that a computer converts into images. MRI excels at imaging soft tissues including the brain, spinal cord, joints, muscles, and abdominal organs. Contraindications include certain metallic implants, pacemakers, and cochlear implants.

CT stands for computed tomography, a diagnostic imaging method that uses X-rays taken from multiple angles and computer processing to create cross-sectional images of the body. CT is preferred over MRI for acute trauma evaluation because it is faster, for detecting bone fractures with high detail, for chest and abdominal emergencies, for detecting acute bleeding, and for patients who cannot undergo MRI due to metallic implants or claustrophobia. CT with contrast dye enhances visualization of blood vessels and organs.

An electrocardiogram, abbreviated ECG or EKG, is a recording of the electrical activity of the heart over time. The term breaks into electro meaning electrical, cardio meaning heart, and gram meaning a record. Electrodes placed on the skin detect electrical impulses generated by the heart as it contracts and relaxes. An ECG detects arrhythmias, myocardial infarction, chamber enlargement, electrolyte imbalances, and effects of cardiac medications.

Ultrasound, also called sonography, uses high-frequency sound waves to create real-time images of internal body structures. The term combines ultra meaning beyond and sound, referring to frequencies above human hearing. A transducer emits sound waves that bounce off tissues and return as echoes, which a computer converts into images. Ultrasound is used for pregnancy monitoring, abdominal imaging of the liver, gallbladder, and kidneys, cardiac assessment called echocardiography, vascular evaluation of blood flow, and guiding needle biopsies.

Venipuncture means puncturing a vein with a needle, from veni meaning vein and puncture meaning to pierce. It is performed to draw blood for laboratory testing or to insert an intravenous line. Phlebotomy means cutting into or opening a vein, from phlebo meaning vein and tomy meaning incision. In modern usage, phlebotomy and venipuncture are often used interchangeably to mean blood drawing. A phlebotomist is a healthcare professional trained to draw blood. Therapeutic phlebotomy refers to removing blood to treat conditions like hemochromatosis or polycythemia vera.

Urinalysis is a general screening test that examines the physical, chemical, and microscopic properties of urine. It includes visual appearance like color and clarity, dipstick testing for pH, protein, glucose, blood, leukocyte esterase, and nitrites, and microscopic examination for cells, casts, crystals, and bacteria. A urine culture is a specific microbiological test that identifies the exact organism causing a urinary tract infection and determines which antibiotics will be effective against it.