Diagnostic Testing

1. Diagnostic Testing

2. Diagnostic Testing • A diagnostic test is any kind of medical test performed to aid in the diagnosis or detection of disease. • to diagnose diseases • to measure the progress or recovery from disease • to confirm that a person is free from disease • Types • Invasive • Minimally-invasive • Non-invasive

3. Diagnostic Testing • Other characteristics of tests include: • sensitivity • specificity • positive predictive value • negative predictive value • false positive • false negative

4. Test options • Consulting room tests • auscultation • height and girth • blood pressure • pulse • breath tests • reflex tests • eye examination • ophthalmoscopy • hearing test • digital rectal examination • vaginal exam

5. Requiring laboratory analysis Urine tests Stool tests Hair tests Saliva tests Blood tests Erythrocyte sedimentation rate (ESR) Complete blood count (CBC) Comprehensive metabolic panel (CMP) Arterial blood gas (ABG) DNA tests invasive examinations biopsies lumbar puncture Requiring microscopy Pap smears Testing options

6. Testing options • Requiring elaborate medical equipment • X-rays • barium enema • intravenous pyelogram (IVP test) • ultrasound scans • electrocardiogram (ECG or EKG) • electroencephalogram (EEG) • computer aided tomography (CAT) scans • positron emission tomography (PET) • magnetic resonance imaging (MRI) • endoscopy • colonoscopy • cystoscopy • sigmoidoscopy • colposcopy • blood test

7. X-Ray • “plain films” • Bone abnormalities – Fx, dislocation, joint spaces • Ectopic bone formation in soft tissue • Bone tumors

8. Arthrogram • X-ray after an injection of a dye • Shows the disruption of soft tissue or loose bodies in the joint • Uses a Fluoroscope

9. Fluoroscopy • Provides immediate projection of X-ray image on screen for viewing • Common for GI tract testing, cardiac catheterization, hip/shoulder injections • Portable x-ray in pros & D-I

10. Computed Tomography • Thin , fan shaped x-ray beam • Cross section view if tissue • Many angles • Visual image on a computer

11. Positron Emission Tomography (PET) • Nuclear medicine imaging technique which produces a three-dimensional image of functional processes in the body. • Detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer)

12. Bone Scan • IV – radioactive tracer • Bony lesions with inflammation will “take-up” more dye (Bone stress sites)

13. Magnetic Resonance Imaging • Electromagnets circle the body • Field up to 600,000x as strong as earth • Magnet aligns hydrogen atom in water molecules. When turned off, atoms continue to spin, emitting an energy that is detected by the computer. • Hydrogen atoms in different tissues spin at different rates

14. Ultrasonography • Used to view the location of, alignment of and measure the size of organs/tissue • Measures the reflection or transmission of high-frequency ultrasound waves • Computer calculates the distance from the sound-reflecting/absorbing surface and creates a two-dimensional image

15. Echocardiography • Uses ultrasound to produce image of cardiac structure/function • Can see the valves & dimensions of the 4 chamber

16. Electroencephalography • EEG • Records electrical potentials produced in the brain • Changes in brain wave patterns

17. Electromyography • Graphic recording of muscle contractions & the amt of electrical activity generated in a muscle • EMG • Surface or needle electrodes • Motor unit potentials can be observed on a oscilloscope screen or from a graphic recording (electromyogram)

18. Arteriography • Catheter is inserted into specific vessel • Contrast is injected & radiographs are taken • Blockage/Aneurysm

19. Electrocardiography • ECG/EKG • Electrical activity of the heart • Impulse formation, conduction, depolarization & repolarization of the atria & ventricles follows a normal pattern

20. Nerve Conduction Velocity • Conduction velocity of nerves • Apply stimulus to a peripheral nerve and measure the speed at which the muscle action occurs • Nerve compression/nerve fx

21. Synovial Fluid Analysis • Used to detect the reason for an joint effusion, increase ROM, by decreasing joint effusion • Not commonly used anymore • Looked for blood & infections

22. Serum Testing • CBC • Screen for numerous condtions • Anemia, diabetes, infection, monitor kidney function • RBC count, hemoglobin levels, hematocrit, WBC count, platelet count, cholesterol, etc

23. Urinalysis • UA • Specific gravity, pH, ketones, hemoglobin, protein, nitrates, WBC, drugs, hormones, electrolytes, glucose, RBC • Color, odor, volume

24. Urinalysis - Procedure • Specimen collection • Clear, clean container • Fresh urine……if longer than 1 hr, put in frig • Mid stream urine • Testing procedures • Briefly (< 1 sec) dip test strip into urine • Draw the edge of the strip along the rim to remove excess urine • Turn strip on its side and tab on a paper towel • After appropriate time (1 min), compare strip to side of container….if Leukocytes (+), reread @ 2 mins

25. Urinalysis – Testing for • Specific Gravity: Ability of kidneys to concentrate and dilute fluids; hydration levels • pH: Refers to how acidic or alkaline the urine is. Acidic urine is found in cases of diabetes & dehydration. Alkaline urine is a sign of a urinary tract infection or kidney disease • Glucose: Diabetes • Hemoglobin: Kidney disease or after intense exercise • Protein: Kidney disease • Nitrates: Infection • Ketones: Eating disorder, fasting • Leukocytes: Infection

26. Urinalysis - Normal • Specific Gravity: 1.016 – 1.022 • pH: 5-9…..morning urine • Glucosuria……none • Proteinuria……up to 30mg/dL • Hematuria…….up to 5Ery/uL is okay • Leukocytes…...none • Ketones……….none • Nitrates……….none

27. Urinalysis • Color: Normal – pale yellow • Dark –dehydrated • Red/brownish – blood, hemoglobin, myoglobin, bilirubin • Cloudy/milky – infection • Odor: • Foul/strong - infection