Introduction to Pathophysiology Diagnostic Studies and Tests Flashcards

used to visualize lesions or structures directly by inserting a tube into the body through an opening or through the body wall

may facilitate a diagnosis or be used to obtain a specimen for further examination and diagnosis or perform simple surgery

e.g. remove cartilage debris from a knee joint

X-Ray film

CT scan

ultrasound

MRI

PET

ionizing radiation provides an image on film of bones and soft tissues that varies in density with absorption of the x-rays striking the tissues

used as a preliminary screen for problems such as fractures or pneumonia

may be used to illustrate digestive tract abnormalities in more detail

low-dose x-ray films are used to detect lesions in breast tissue

two x-ray beams are used simultaneously to measure the thickness of bone

a cross-section of tissues is provided by scanning machine taking x-ray films in a series of shots from all directions; these measure differences in tissue density

high-frequency sound waves that bounce off body structures are used to obtain images by ultrasonography

assesses the blood flow in arteries and veins by measuring sound waves reflected from moving red blood cells

measures the efficiency of heart valves and heart function

use a magnetic field surrounding the body and the hydrogen content of the body. radio waves provide the energy source

nuclear machine tests involve tracking the distribution of radioactive tracer substance in the body

involves radioisotops used with a scanner and computer to provide a cross-sectional functional image of a tissue such as the brain

ECG, EKG

Stress tests

EEG

by attaching electrodes to the chest and limbs of a patient, the conduction system of the heart can be assessed

the rate, rhythm, and characteristics of the contractions can be recorded by the machine

exercise electrocardiography

electrocardiographic measurements and blood pressure are monitored during a period of controlled exercise on a treadmill or stationary bicycle to determine the cardiac response to increased workload

electroencephalogram

the electrical activity of the neurons in the brain is determined by electrodes attached to the scalp; the activity is then recorded as waves by the machine

both pulmonary volumes and capacities

can be measured using a spirometer, a machine into which the patient breathes through a mouthpiece

hematology testing

blood chemistry tests

blood is checked for its components and its blood clotting capability

depending on the particular test, blood may be procured from a vein or a small puncture on the fingertip

is used to check the count and characteristics of all formed elements or cells as well as hemoglobin and hematocrit

indicates the amount of hemoglobin in the blood for oxygen transport, independent of the number of red blood cells

measures the amount of glucose bound to hemoglobin

reflects the blood glucose levels over a period of time

it is used to monitor control of diabetes mellitus over the past 90 to 120 days

indicates the percentage of erythrocytes in a specific volume of blood

the number of white blood cells is not significant in measuring the cell volume

hematocrit can indicate fluid imbalance or anemia

often referred to as a "differential count" determines whether there has may provide a clue to the cause of a problem

may be used to confirm abnormalities related to the production of blood cells such as megaloblastic anemia or leukemia

may be performed if bacteremia or unknown infection is present

evaluate various clotting times and serum levels of the clotting factors

these tests may be used to determine deficits of individual factors or monitor anticoagulant treatment

is used to detect the presence of abnormal hemoglobin

level indicates the level of iron storage

automated electronic systems are now in widespread use

make use of computerized multiple analyzers that can run a number of tests rapidly

arterial blood gases for acid-base balance

serum hormone

lipid levels

serum electrolytes

glucose

serum enzymes and isoenzymes

serum levels of bilirubin

urea or ammonia

major changes are occurring in the area of immunodiagnostic testing as improved methods are developed to assess serum antigen and antibody levels

chromosome analysis, including techniques used in cytogenetics and molecular biology, is used to examine the chromosomes and/or DNA to determine chromosome or genetic abnormalities in affected individuals or carriers to determine paternity or in forensic science

serum drug levels are checked in patients in whom there is a narrow therapeutic range of a drug and risk of toxicity or who have severe renal or liver disease or potenital drug interactions

routine urinalysis is used to check the physical and chemical characteristics of a freshly collected urine specimen physical examination of the specimen includes its appearance of specific gravity

collected by means of a lumbar puncture

the pressure is measured, and the fluid is examined for appearance, protein and glucose levels, and the presence of cells or microorganisms

a fecal specimen is checked for its physical characteristics such as color and consistency

presence of occult blood is determined by the guaiac test

stool cultures are used to check for parasites as well as other microbial content

any body fluids or exudates from lesions may be examined for the presence of microorganisms. which then may be identified