X-Ray Basics and Technology

X-Ray

• X-ray is a form of electromagnetic radiation.
• Discovered in 1895 by Wilhelm Roentgen.
• Roentgen received the Nobel Prize in Physics in 1901.

X-Ray Machine

• Converts regular electricity into high voltage current.
• Contains an X-ray tube, which converts high voltage current into X-rays.
• X-rays pass through a diaphragm that controls the size of the beam.
• X-ray filters remove weak X-ray waves.

X-Ray Image Formation

• X-rays pass through the body and are attenuated by different tissues.
• Dense tissues like bone absorb more X-rays, appearing white on the image.
• Air, like in the lungs, absorbs less X-rays, appearing black on the image.
• Soft tissues like muscles appear various shades of gray depending on density.

X-Ray Table

• Used to position patients during examinations.
• Can be stationary or movable.

Grid

• A metal plate used to filter X-rays and prevent scatter radiation.
• Prevents secondary X-rays from reaching the film.
• Generally used for thicker body parts with more scatter radiation.
• Not used for thin parts like hands and feet.

Bucky Stand

• A metal stand for upright examinations, often used for chest X-rays.
• Contains a built-in grid.

Pregnant Females

• Review indications for X-ray examination with the referring doctor.
• Protect the abdomen with a lead apron.
• 10-day rule: married females should only be exposed during the first 10 days of their menstrual cycle.

Radiologic Staff Safety

• Avoid direct exposure to X-rays.
• Stand behind lead partitions during exposure.
• Use film badges to monitor radiation exposure.
• Use ALARA (As Low As Reasonably Achievable) principle.
• X-ray rooms should be isolated by lead sheets or special materials.

Radiographic Examination Procedures

• Patient position: On the table or standing beside the Bucky stand.
• Examination techniques:
  • Exposure factors: include kilovoltage (kVp), Milliampere Seconds (mAs),
  • Focal Film Distance (FFD): Distance between X-ray tube and film (usually 100 cm, 150-180 cm for chest).
  • Object Film Distance (OFD): Distance between part examined and film (increase in OFD leads to magnification).
  • Central Ray (CR): Center of X-ray beam, positioned in the center of the part being examined.
• Image Receptor:
  • Film screen Cassette: X-ray film placed in a cassette and processed with chemicals.
  • Digital Image: X-rays fall on a phosphorous plate, read by a machine and transferred to a computer.

Film Sizes

• 14 x 17, 14 x 14, 12 x 15, 10 x 12, 8 x 10 (inches)
• 30 x 40, 24 x 30, 18 x 24 (centimeters)

Respiration for Radiographic Exams

• Patients stop breathing during exposure to minimize image blurring.
• Deep inspiration for chest X-rays, deep expiration for abdomen, and no breath holding for extremities.

Anatomical Terminology

• Midclavicular line: Passes through the center of the clavicle.
• Midaxillary line: Passes through the center of the axilla.
• Anterior/posterior axillary line: Passes through the anterior/posterior axillary folds.
• Epigastric line: One inch below the xiphoid process of the sternum.

Hand Terminology

• Palmer surface: Front or anterior surface of the hand.
• Dorsal surface: Back or posterior surface of the hand.
• Pronation: Palm facing down.
• Supination: Palm facing up.

Foot Terminology

• Planter surface: Sole of the foot.
• Dorsal surface: Top surface of the foot.

Radiographic Positioning

• Basic positions: Basic views required for a specific area, ideally two perpendicular views.
• Additional, optional, or special views: Additional views to clarify diagnosis or answer specific questions.
• Part being examined should be close to the film.
• Part should be positioned parallel to the film.

Common Positioning Terms

• Posteroanterior (PA): X-rays pass from back to front.
• Anteroposterior (AP): X-rays pass from front to back.
• Lateral Decubitus: Patient lying on their side.
• Axial: Along the long axis of the part.
• Tangential: X-rays pass tangentially to the part.

Relation Terms

• Proximal: Close to the body.
• Distal: Far from the body.
• Medial: Towards the midline of the body.
• Lateral: Away from the midline of the body.

Cephalic/Caudal Angle

• Cephalic angulation: X-ray beam angled towards the head.
• Caudal angulation: X-ray beam angled towards the feet.

Film Identification

• Mark right (R) or left (L) side of the patient.
• Include patient name, date of study, hospital number, and part examined.

Movement Terms

• Flexion: Bending a joint.
• Extension: Straightening a joint.
• Abduction: Moving a limb away from the body.
• Adduction: Moving a limb towards the body.

Gonadal Protection

• Protect the gonads (testes and ovaries) from X-ray exposure using a lead shield.
• Important to protect reproductive organs.

Explore the fundamental concepts of X-rays, from their discovery by Wilhelm Roentgen to the technology behind X-ray machines. Learn how X-ray images are formed and the role of different components like filters, grids, and tables in the imaging process.