Radiology and Diagnostic Testing Notes

Learning Objectives

  • Describe the use of contrast medium during diagnostic imaging.
  • Identify special preparations required for select X-ray procedures.
  • Explain the medical use of radiation therapy.
  • Describe the purpose of at least five different forms of diagnostic imaging.
  • Outline safety precautions for working in radiology.
  • Explain common positions used in radiology.

Mammography

  • Definition: Radiology examination of soft tissue of the breast to identify benign and malignant neoplasms (tumors).
  • Procedure:
    • Patient stands in front of X-ray equipment.
    • Technician positions patient for complete examination of breast tissue.
    • Procedure takes seconds per view, lasting <30 minutes.
    • Patients of childbearing age wear lead apron for protection.
  • Instructions for Patients:
    • Avoid using underarm deodorant, talcum powder, lotion, or perfume before examination.
  • Discomfort: Some patients may experience brief discomfort due to breast compression.
  • Guidelines by American Cancer Society: Women 40 and older should have yearly mammograms for early breast cancer detection. Many detected abnormalities may be benign.
  • Follow-up Actions: If a lump is detected, follow-up testing should occur immediately, including a biopsy for suspicious tissue.

Bone Densitometry (DXA)

  • Purpose: Measures bone density to detect osteopenia or osteoporosis using X-rays.
  • Patient Preparations:
    • Disrobe and change into gown, removing jewelry.
    • Calcium supplements and medications with calcium should be discontinued 24 hours prior.
  • After Procedure: Normal activities may resume immediately.

Kidneys, Ureters, and Bladder (KUB)

  • Definition: Abdominal flat plate using X-rays to assess urinary tract organs.
  • Purpose:
    • Detects kidney stones, diseases of the urinary tract, and foreign objects like IUDs.

Angiography

  • Definition: X-ray visualization of blood vessels after injecting radiopaque material.
  • Uses:
    • Myocardial infarction, stroke, renal artery stenosis, clots.
  • Procedure Considerations:
    • Contrast media enhances visibility; iodine allergy testing is necessary.
    • Post-procedure monitoring for bleeding or allergic reactions is essential.
  • Applications:
    • Cerebral, renal, and cardiac angiographies.
    • Cardiac catheterization can assess coronary artery status.

Arthrography

  • Definition: X-ray visualization of joint space to diagnose joint abnormalities.
  • Procedure: Involves injecting a local anesthetic and contrast medium or air into the joint; uses fluoroscope for evaluation.
  • Patient Considerations: Expect slight discomfort and rest afterwards for a day or two.

Ultrasound (Sonography)

  • Definition: Uses high-frequency sound waves to image internal structures.
  • Applications:
    • Fetal monitoring, detecting abnormalities like gallstones and tumors.
    • Not suitable for imaging bones or the lungs.
  • Procedure:
    • Non-invasive and painless; uses conduction material and ultrasonic transducer.
    • Patients should wear loose-fitting clothes; certain specific preparations might be needed.

Tomography (CT)

  • Definition: Produces cross-sectional views of the body to visualize dense areas.
  • Procedure:
    • Patient lies on a table moved into a scanner while an X-ray camera rotates around.
  • Advantages: More detailed images than standard X-rays, uses computed analysis for tissue density.
  • Preparation: In some cases, patients may need to avoid food/fluid before the exam.

Positron Emission Tomography (PET)

  • Definition: Uses radioactive substances to examine metabolic activity in the body.
  • Applications: Evaluates epilepsy, cancers, stroke, and Alzheimer’s disease.
  • Safety Note: Minimal radiation exposure due to short-lived radioactive elements.

Magnetic Resonance Imaging (MRI)

  • Definition: Visualizes internal tissues without ionizing radiation.
  • Considerations:
    • Patients may experience noise; if claustrophobic, open MRIs are available.
    • Strong magnetic fields restrict use in patients with certain medical devices.

Fluoroscopy

  • Definition: Real-time moving images of internal structures using a fluoroscope.
  • Applications: Includes GI series, intravenous pyelogram, orthopedic procedures.
  • Preparation: Patients receive specific instructions, particularly about dietary restrictions before the procedure.

Patient Preparation

  • General Guidelines:
    • Patients should wear gowns and remove metallic objects.
    • Health history should be considered before imaging to minimize radiation risk.

Special Preparations for X-ray Procedures

  • Specific X-ray procedures like angiograms, barium enemas, and CT often have detailed preparations regarding diet and cleansing processes.

Personnel & Patient Safety Precautions

  • Radiation Safety:
    • Use of barriers (lead aprons, shields) when working with X-ray equipment.
    • Regular monitoring of radiation exposure using film badges.
    • Implementing ALARA principle (As Low As Reasonably Achievable) for patient exposure. - Gonad shielding for reproductive-age patients.

Positioning Techniques in Radiology

  • Techniques include:
    • Anteroposterior (AP): Beam directed from front to back.
    • Posteroanterior (PA): Beam directed from back to front.
    • Oblique: Patient angled to expose hidden areas.
    • Lateral: Beam directed at one body side.
    • Axial: Beam angled along the body part's axis.

Scheduling Guidelines

  • Considerations include patient’s name, type of insurance, referring HCP's name, and contrast medium usage.
  • Sequence of procedures matters, especially with contrast media.

Case Study

  • Use critical thinking to determine alternative tests or preparations for a suspected diagnosis post-initial tests.