MLS Diagnostic Procedures & Reporting 1 — Questions and Answers

Question 1: Which diagnostic test is commonly used to detect bacterial infections in the bloodstream?

Complete Blood Count (CBC)
Blood Culture (Correct answer)
Serum Electrolyte Panel
Lipid Profile

Correct answer: Blood Culture

A blood culture is the gold standard diagnostic test for detecting bacterial or fungal infections in the bloodstream, a condition known as bacteremia or septicemia. Blood samples are collected and incubated in a nutrient-rich medium to allow any present microorganisms to grow. Positive cultures can then be identified, and their susceptibility to antibiotics can be determined, guiding appropriate treatment.

Question 2: What is the primary purpose of performing a Polymerase Chain Reaction (PCR) test?

To identify blood clotting disorders
To amplify DNA for detection of pathogens (Correct answer)
To measure blood glucose levels
To assess kidney function

Correct answer: To amplify DNA for detection of pathogens

Polymerase Chain Reaction (PCR) is a powerful molecular biology technique used to amplify specific segments of DNA exponentially. This amplification allows for the detection of even minute amounts of genetic material from pathogens like viruses or bacteria, making it invaluable for diagnosing infectious diseases, identifying genetic disorders, and forensic analysis. PCR creates millions of copies of a target DNA sequence, enabling its detection and study.

Question 3: Which of the following tests is used to diagnose tuberculosis (TB)?

Rapid Strep Test
Mantoux Tuberculin Skin Test (TST) (Correct answer)
D-dimer Test
Hematocrit Test

Correct answer: Mantoux Tuberculin Skin Test (TST)

The Mantoux Tuberculin Skin Test (TST), also known as a PPD test, is a common diagnostic tool used to screen for latent tuberculosis infection. It involves injecting a small amount of tuberculin purified protein derivative (PPD) into the forearm. A localized immune reaction (induration) observed after 48-72 hours indicates exposure to Mycobacterium tuberculosis, though further tests are needed to confirm active disease.

Question 4: Which diagnostic imaging technique is commonly used to visualize soft tissue structures such as the liver, kidneys, and heart?

X-ray
Ultrasound (Correct answer)
MRI
CT Scan

Correct answer: Ultrasound

Ultrasound imaging uses high-frequency sound waves to create real-time images of internal body structures. It is particularly effective for visualizing soft tissues and organs like the liver, kidneys, and heart because sound waves reflect differently off various tissue densities. Unlike X-rays, it does not use ionizing radiation and can show movement, blood flow, and organ function dynamically, making it a versatile and safe diagnostic tool.

Question 5: Which laboratory test is commonly used to assess thyroid function?

C-reactive Protein (CRP)
Thyroid-Stimulating Hormone (TSH) (Correct answer)
Blood Urea Nitrogen (BUN)
Erythrocyte Sedimentation Rate (ESR)

Correct answer: Thyroid-Stimulating Hormone (TSH)

Thyroid-Stimulating Hormone (TSH) is the primary screening test for assessing thyroid function because it reflects how well the pituitary gland is stimulating the thyroid gland. Elevated TSH levels typically indicate an underactive thyroid (hypothyroidism), while low TSH levels suggest an overactive thyroid (hyperthyroidism). This test provides a sensitive and early indicator of thyroid dysfunction, guiding further diagnostic steps.

Question 6: What is the primary reason for using a standardized format when reporting laboratory test results?

To reduce the time required for reporting
To ensure consistency and accuracy (Correct answer)
To allow patients to interpret results on their own
To increase the number of tests ordered

Correct answer: To ensure consistency and accuracy

Using a standardized format for reporting laboratory test results is crucial to ensure consistency and accuracy across different healthcare settings and providers. This standardization minimizes misinterpretation, reduces the likelihood of errors, and allows for clear, unambiguous communication of vital patient information. Ultimately, it enhances patient safety and supports effective clinical decision-making.

MLS Diagnostic Procedures & Reporting 1

Which diagnostic test is commonly used to detect bacterial infections in the bloodstream?