X-Ray Physics and Digital Imaging

Review key concepts related to x-ray physics and digital imaging through these flashcards.

What is the dual nature of x-ray energy?

X-rays exhibit properties of both waves and particles.

How are wavelength and frequency related in x-rays?

Wavelength and frequency are inversely related; higher energy x-rays have decreased wavelength and increased frequency.

What role does the filament play in x-ray production?

The filament is the source of electrons during x-ray production.

Why is tungsten used as a target in x-ray tubes?

Tungsten has a high atomic number (74) and a high melting point (3400°C), making it efficient for x-ray production.

What is the purpose of resistors in the x-ray circuit?

Resistors regulate the current passing through the circuit, primarily by impeding the flow of electrons.

What does rectification do in x-ray systems?

Rectification converts alternating current (AC) from the power utility to direct current (DC) used by x-ray tubes.

What happens during Bremsstrahlung interactions?

A projectile electron passes near a tungsten nucleus, losing energy and producing an x-ray photon.

How does kilovoltage (kVp) affect the quality of x-rays?

Higher kVp increases the speed of electrons and the quality or energy of the produced x-rays.

What is the effect of mAs on x-ray quantity?

The quantity of x-rays produced is directly proportional to the mA and the exposure time.

What principle does the line-focus principle describe?

It describes the relationship between the actual focal spot and the effective focal spot in x-ray production.

What is the anode heel effect?

The intensity of x-rays is greater on the cathode side of the tube and decreases towards the anode side.

How does the half-value layer (HVL) relate to x-ray beam intensity?

HVL is the amount of added filtration that reduces beam intensity to half of its original value.

What is the role of a digital image histogram in radiology?

It represents the range of digital pixel values relative to their prevalence, aiding in image processing.

What does the detective quantum efficiency (DQE) indicate in image receptors?

It measures the effectiveness of an imaging receptor in producing quality images with less x-ray exposure.

How does collimation affect patient dose during x-ray imaging?

Increased collimation reduces the field size and decreases patient dose.

What is the purpose of backup time in automatic exposure control (AEC) systems?

Backup time serves as a safety mechanism to limit exposure when AEC is improperly used.

What is the 15% rule in relation to kVp?

A 15% increase in kVp has the same effect on exposure to the IR as doubling the mAs.

How does grid ratio affect radiographic contrast?

An increased grid ratio improves scatter cleanup and increases radiographic contrast.

What does the air gap technique do?

It moves the image receptor away from the patient to reduce scatter radiation reaching the IR.

How does increasing SID affect x-ray beam intensity?

As SID increases, the x-ray beam intensity decreases due to spreading over a larger area.

What is the significance of the pixel bit depth in digital imaging?

Greater pixel bit depth allows for more precise digitization and a greater number of shades of gray.