Principles of Radiography 1
110 Questions
4 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following are patient/subject factors that affect radiographic technique? (Select all that apply)

  • Image Quality Factors
  • Tissue Mass Density (correct)
  • Effective Atomic Number (correct)
  • Patient Thickness (correct)

What is subject contrast?

The degree of differential absorption resulting from the differing absorption characteristics of the tissues in the body.

What body type is described as having a large frame and being overweight?

Hypersthenic

Define attenuation in the context of radiography.

<p>The reduction in the total number of x-ray photons remaining in the beam after passing through a given thickness of material.</p> Signup and view all the answers

Which of the following conditions are considered additive pathologies? (Select all that apply)

<p>Hydrocephalus (B), Congestive Heart Failure (C)</p> Signup and view all the answers

What type of pathology requires decreasing the mAs during radiographic procedures?

<p>Destructive pathology</p> Signup and view all the answers

The basic photometric unit is the ______.

<p>lumen</p> Signup and view all the answers

True or False: A patient history is irrelevant in determining radiographic technique adjustment.

<p>False (B)</p> Signup and view all the answers

What happens to the luminous intensity when viewed from the side?

<p>It decreases. (B)</p> Signup and view all the answers

What is the relationship between bore obstruction and radiographic technique?

<p>Bowel obstruction requires a decrease in technique.</p> Signup and view all the answers

What has led to reconfigured ergonomic digital workstations for Radiographers and Radiologists?

<p>The viewing requirements of flat panel digital display devices.</p> Signup and view all the answers

Ambient light levels should be increased for the best viewing of digital display devices.

<p>False (B)</p> Signup and view all the answers

What is the purpose of calibrating digital equipment?

<p>To recognize dead pixels and 'auto-fill' the areas.</p> Signup and view all the answers

Flatfielding is performed during ______ to offset the irregular variation of the anode-heel effect.

<p>pre-processing</p> Signup and view all the answers

What technique is used to correct defective pixels in digital IRs?

<p>Signal Interpolation (A)</p> Signup and view all the answers

What is image lag?

<p>Image that is not completely visible and is corrected by applying offset voltage.</p> Signup and view all the answers

Which of the following is NOT a post-processing action?

<p>Direct Exposure (C)</p> Signup and view all the answers

Image inversion results in a black appearance of soft tissue and a white appearance of bone.

<p>False (B)</p> Signup and view all the answers

How many shades of gray does a 16-bit dynamic range DR system have?

<p>65,536</p> Signup and view all the answers

Image subtraction is commonly used in ______.

<p>Digital Subtraction Angiography (DSA)</p> Signup and view all the answers

What does pixel shift allow for in image processing?

<p>Correction of patient motion in a series of images.</p> Signup and view all the answers

Which adjustment impacts the visibility of detail in an image?

<p>Window Width (B)</p> Signup and view all the answers

What is the effect of increasing window level in image processing?

<p>Increase density (brightness) (D)</p> Signup and view all the answers

What is the primary effect of destructive pathologies on x-ray beam attenuation?

<p>Decreased attenuation of the x-ray beam (C)</p> Signup and view all the answers

When managing a patient with increased destructive pathology, how should the mAs be adjusted?

<p>Decreased by 25-50% (D)</p> Signup and view all the answers

Which of the following conditions is classified under additive pathologies?

<p>Aortic Aneurysm (C)</p> Signup and view all the answers

What is the relationship between destructive pathology and IR exposure?

<p>Directly proportional (C)</p> Signup and view all the answers

Which statement is true regarding effective techniques for imaging patients with chronic destructive pathologies?

<p>Use standard kVp with reduced mAs (A)</p> Signup and view all the answers

What is the primary factor influencing spatial resolution in digital radiography?

<p>The size of the pixels involved (A)</p> Signup and view all the answers

Which condition would most likely require an increase in radiographic technique due to fluid presence?

<p>Ascites (A)</p> Signup and view all the answers

In the context of imaging pathologies, which of the following describes a condition that does not significantly alter radiographic density?

<p>Fractures without gross swelling (C)</p> Signup and view all the answers

What anatomical feature is most effectively visualized with long-scale contrast adjustments?

<p>Lung processes (C)</p> Signup and view all the answers

Which of the following statements about radiographic quality is true?

<p>Multiple factors influence the fidelity of the anatomical imaging. (D)</p> Signup and view all the answers

Which of the following pathologies is considered a destructive pathology affecting bone density?

<p>Hyperparathyroidism (A)</p> Signup and view all the answers

What is the minimum percentage of bone loss required before changes can be detected on a radiograph?

<p>50% (D)</p> Signup and view all the answers

Which of the following best defines the term 'image quality' in radiography?

<p>The clarity of the anatomical structure being imaged (A)</p> Signup and view all the answers

What defines the portion of the pixel face available for transmitting light on an LCD monitor?

<p>Aperture Ratio (C)</p> Signup and view all the answers

What is the primary disadvantage of an LCD monitor when viewing images at an angle?

<p>Loss of image contrast (B)</p> Signup and view all the answers

What is contrast resolution primarily used for in radiography?

<p>To differentiate between anatomical structures of similar subject contrast (A)</p> Signup and view all the answers

Which mechanism continues to emit light after the initial stimulation of a phosphor?

<p>Phosphorescence (B)</p> Signup and view all the answers

How is distortion minimized in radiographic imaging?

<p>By keeping the patient's body part parallel to the image receptor (C)</p> Signup and view all the answers

Among the following, which light emission process occurs alongside the flow of electrons in materials?

<p>Electroluminescence (D)</p> Signup and view all the answers

What term describes the degree of sharpness of structural lines on a radiograph?

<p>Recorded Detail (B)</p> Signup and view all the answers

What is a significant advantage of LED monitors over fluorescent backlit monitors?

<p>Lower energy consumption (A)</p> Signup and view all the answers

What condition is considered optimal for the viewing of images on LCD monitors?

<p>Dim ambient light (B)</p> Signup and view all the answers

What is the primary concern when interpreting medical images in terms of visibility of detail?

<p>Optimization of contrast and optical density (C)</p> Signup and view all the answers

What is the effect of foreshortening in radiographic imaging?

<p>Objects appear shorter than their actual length (C)</p> Signup and view all the answers

How does the brightness requirement for a white image with black text compare to one with white text on a black background in LED displays?

<p>It requires more power (B)</p> Signup and view all the answers

What is the role of photometry in digital imaging?

<p>To measure the response of the human eye to visible light (A)</p> Signup and view all the answers

What is the main benefit of reducing ambient light levels for LCD monitors?

<p>Improves image contrast (A)</p> Signup and view all the answers

What is the term for the misrepresentation of true size or shape in imaging?

<p>Image Distortion (C)</p> Signup and view all the answers

What distinguishes photopic vision from scotopic vision in the context of radiographic interpretation?

<p>Photopic vision uses cone cells in bright light while scotopic vision uses rod cells in dim light (D)</p> Signup and view all the answers

Which of the following correctly describes image inversion in digital imaging?

<p>It allows for improved visibility of pathology by reversing color contrasts. (A)</p> Signup and view all the answers

When would pixel shift be primarily used in digital imaging?

<p>To correct for misalignment in the patient's position during imaging. (C)</p> Signup and view all the answers

What is the primary purpose of region of interest (ROI) in digital imaging?

<p>To select specific areas for detailed analysis and rescaling. (B)</p> Signup and view all the answers

What is the primary function of pre-processing in digital imaging?

<p>To ensure images are artifact-free before display (B)</p> Signup and view all the answers

What is the role of edge enhancement in post-processing of images?

<p>To clarify and highlight regions with fractures and small high-contrast tissues. (D)</p> Signup and view all the answers

In what scenario would image subtraction be most beneficial?

<p>In Digital Subtraction Angiography (DSA) to highlight blood vessels. (D)</p> Signup and view all the answers

Which process involves repairing dead pixels by assigning digital values from surrounding pixels?

<p>Signal Interpolation (A)</p> Signup and view all the answers

What type of image correction is applied to address the irregular variation caused by the anode-heel effect?

<p>Flatfielding (B)</p> Signup and view all the answers

How frequently are gain images generated in the calibration of digital equipment?

<p>Every few months (C)</p> Signup and view all the answers

Which issue is corrected by applying offset voltage before acquiring the next image?

<p>Image Lag (B)</p> Signup and view all the answers

What technique is used to address line noise in digital imaging?

<p>Offset Correction from Dark Reference Zone (B)</p> Signup and view all the answers

What is the role of automatic calibration images like offset images?

<p>To make IR response more uniform (D)</p> Signup and view all the answers

Which of the following best describes the action of interoperability between adjacent pixels?

<p>Signal Interpolation (D)</p> Signup and view all the answers

What adjustment should be made to kVp when dealing with additive pathology?

<p>Increase kVp by 5-15% (B)</p> Signup and view all the answers

How does additive pathology affect IR exposure?

<p>It reduces IR exposure. (A)</p> Signup and view all the answers

What is the relationship between additive pathology and technical factors in radiography?

<p>Additive pathology requires adjusted technical factors for effective imaging. (C)</p> Signup and view all the answers

What does an increase of 15% in kVp achieve in terms of exposure to the IR?

<p>It doubles the exposure to the IR. (A)</p> Signup and view all the answers

What is an indicator of the presence of additive pathology in a patient?

<p>An increase in external anatomical deviations. (D)</p> Signup and view all the answers

What impact does patient thickness have on x-ray attenuation?

<p>Thicker body sections absorb more x-rays than thinner sections. (A)</p> Signup and view all the answers

Which body type would most likely require special considerations due to its physical characteristics?

<p>Hypersthenic: It is large and overweight. (D)</p> Signup and view all the answers

How does subject contrast influence radiographic quality?

<p>Higher subject contrast improves radiographic detail. (A)</p> Signup and view all the answers

In what way does effective atomic number affect radiographic contrast?

<p>Higher effective atomic numbers increase the differential absorption. (C)</p> Signup and view all the answers

What is a consequence of inadequate adjustment of exposure techniques based on patient characteristics?

<p>Image quality may suffer, leading to diagnostic challenges. (B)</p> Signup and view all the answers

Which factor is directly proportional to the number of x-rays leaving a body section?

<p>Patient density. (D)</p> Signup and view all the answers

What does the term 'attenuation' specifically refer to in medical imaging?

<p>The interaction of x-rays with matter leading to absorption or scattering. (C)</p> Signup and view all the answers

Which aspect of patient characteristics requires consideration in radiographic technique but does not relate to geometric factors?

<p>Effective atomic number. (B)</p> Signup and view all the answers

Which condition requires an adjustment to the radiographic technique due to the presence of liquid in the abdomen?

<p>Ascites (A)</p> Signup and view all the answers

What is a common outcome for imaging a skeletal structure affected by osteoporosis?

<p>50% bone loss before visibility (D)</p> Signup and view all the answers

Which of the following statements correctly describes the factors that influence image quality?

<p>Spatial resolution is limited by pixel size in digital radiography (A)</p> Signup and view all the answers

In radiographic imaging, which condition is classified as an additive pathology?

<p>Multiple Myeloma (C)</p> Signup and view all the answers

Which tissue has the highest effective atomic number?

<p>Bone (C)</p> Signup and view all the answers

What defines a high-quality radiograph?

<p>Ability to visualize anatomic structures accurately (C)</p> Signup and view all the answers

Which condition signifies the need to decrease the radiographic technique due to higher air levels in the GI tract?

<p>Aerophagia (C)</p> Signup and view all the answers

How does emphysema typically affect tissue composition in radiographic imaging?

<p>Decreased mass density of lung tissue (A)</p> Signup and view all the answers

Which contrast material has the lowest effective atomic number?

<p>Air (D)</p> Signup and view all the answers

How does chronic destructive pathology primarily affect x-ray beam attenuation?

<p>Decreases the overall density (D)</p> Signup and view all the answers

Observing physical indications of pathology during patient assessment helps in which key area of radiography?

<p>Preventing unnecessary repeat radiographs (D)</p> Signup and view all the answers

In terms of spatial resolution, what is a critical factor in digital imaging?

<p>Pixel size (A)</p> Signup and view all the answers

What does visibility of detail in radiographic imaging primarily depend on?

<p>Contrast resolution and optical density (C)</p> Signup and view all the answers

Which of the following pathologies is associated with a decrease in tissue thickness?

<p>Emphysema (A)</p> Signup and view all the answers

How can foreshortening affect the representation of anatomical structures in imaging?

<p>It causes structures to appear shorter than their actual length. (A)</p> Signup and view all the answers

What type of tissues absorb x-rays and appear white on a radiograph?

<p>Radiopaque tissue (D)</p> Signup and view all the answers

Which of the following best describes the effect of dense pathologies on radiographic images?

<p>Decreased visibility of structures (A)</p> Signup and view all the answers

What defines the term 'distortion' in radiographic imagery?

<p>An error in representing true size or shape of an object. (C)</p> Signup and view all the answers

Which practice helps to reduce distortion in radiographic imaging?

<p>Positioning the image receptor parallel to the central ray (B)</p> Signup and view all the answers

What is a potential impact of reviewing patient history before imaging?

<p>Provides clues about potential pathology (A)</p> Signup and view all the answers

What element differentiates photopic vision from scotopic vision?

<p>The roles of cones and rods under different lighting conditions. (D)</p> Signup and view all the answers

What is meant by the term 'contrast resolution' in radiography?

<p>The ability to distinguish between tissues with similar densities. (A)</p> Signup and view all the answers

Which process quantifies light perception in human vision, established by the CIE?

<p>Quantification of illumination through footcandles (D)</p> Signup and view all the answers

What is the primary purpose of calibration in the digital imaging system?

<p>To identify and auto-fill dead pixels (D)</p> Signup and view all the answers

What is a significant challenge in imaging that can lead to shape distortion?

<p>Misalignment of the central ray with the body part (C)</p> Signup and view all the answers

Which technique is employed to repair dead pixels in digital images before processing?

<p>Interpolation (C)</p> Signup and view all the answers

How often are gain images generated in the calibration process?

<p>Every few months (C)</p> Signup and view all the answers

What is the primary function of flatfielding in digital image pre-processing?

<p>To offset irregular variations (D)</p> Signup and view all the answers

What does signal interpolation primarily correct for in digital imaging?

<p>Defective pixels (C)</p> Signup and view all the answers

What does the term 'image lag' refer to in the context of digital imaging?

<p>Incomplete visibility of an electronic latent image (B)</p> Signup and view all the answers

Which of the following best illustrates a pre-processing step in digital imaging?

<p>Repairing dead pixel areas before processing (A)</p> Signup and view all the answers

What type of correction is applied to address line noise in digital imaging?

<p>Dark reference zone correction (A)</p> Signup and view all the answers

Flashcards

Ergonomics

Designing workstations to improve workplace efficiency and reduce strain on the user.

Ambient Light

The general lighting level in an environment. Reducing it improves digital display viewing.

Software Artifacts

Imperfections in digital images, like dead pixels. Systems correct these.

Calibration

Adjusting digital equipment to ensure accurate image representation.

Signup and view all the flashcards

Dead Pixels

Pixels that don't function properly, appearing as dark spots on an image.

Signup and view all the flashcards

Flatfielding

Pre-processing technique to correct uneven brightness in images.

Signup and view all the flashcards

Signal Interpolation

Fixing flawed pixels by using data from surrounding, good pixels.

Signup and view all the flashcards

Image Lag

Incomplete image visibility due to digital image receptor technology.

Signup and view all the flashcards

Line Noise

Artifacts in an image caused by voltage variations. Fixed by voltage correction.

Signup and view all the flashcards

Pre-processing

Manipulating images before display to remove and correct artefacts.

Signup and view all the flashcards

Post-processing

Manipulating images after acquisition for improved viewer experience.

Signup and view all the flashcards

Image Annotation

Adding text or labels to a digital image.

Signup and view all the flashcards

Dynamic Range

The range of brightness levels visible from an image. High dynamic range contains a wide array of subtle light tones.

Signup and view all the flashcards

Window/Leveling

Adjusting image display properties to improve visualization.

Signup and view all the flashcards

Magnification

Enlarging a specific region of an image to improve detail.

Signup and view all the flashcards

Subject Contrast

The difference in how tissues absorb X-rays, creating contrast on an image.

Signup and view all the flashcards

Patient Thickness

Thicker body parts absorb more X-rays than thinner ones.

Signup and view all the flashcards

Tissue Mass Density

Different patients may have same thickness but different density.

Signup and view all the flashcards

Effective Atomic Number

A measure of how a substance absorbs X-rays.Different tissues have different atomic numbers.

Signup and view all the flashcards

Attenuation

Reduction of X-rays as they pass through matter.

Signup and view all the flashcards

Pathology

Any deviation from normal tissue, potentially affecting X-ray technique.

Signup and view all the flashcards

Additive Pathology

Pathology increasing tissue thickness/density, requiring more X-ray exposure.

Signup and view all the flashcards

Destructive Pathology

Pathology decreasing tissue thickness/density, requiring less X-ray exposure.

Signup and view all the flashcards

Spatial Resolution

Ability to see fine details on an image.

Signup and view all the flashcards

Contrast Resolution

Ability to distinguish structures of similar tissue types.

Signup and view all the flashcards

Distortion

Misrepresentation of size or shape on an image.

Signup and view all the flashcards

Image Luminance

Brightness of image source, often a monitor.

Signup and view all the flashcards

Inverse Square Law

Luminance intensity decreases rapidly with distance.

Signup and view all the flashcards

Photometry

Study of how the eye perceives visible light.

Signup and view all the flashcards

Illuminance

Intensity of light falling on a surface.

Signup and view all the flashcards

Luminance

Brightness of a light source or surface.

Signup and view all the flashcards

Additive Pathology

A type of pathology where tissue thickness or density increases, requiring more X-ray exposure.

Signup and view all the flashcards

Destructive Pathology

A type of pathology where tissue thickness or density decreases, requiring less X-ray exposure.

Signup and view all the flashcards

Chest Pathology

Describes various medical conditions affecting the chest region, impacting X-ray images.

Signup and view all the flashcards

Decreased mAs

Reducing the milliampere-second (mAs) value in X-ray imaging.

Signup and view all the flashcards

IR Exposure

The amount of radiation reaching the image receptor in X-ray imaging.

Signup and view all the flashcards

Destructive Pathology

A pathology that decreases tissue thickness or density, requiring less X-ray exposure.

Signup and view all the flashcards

Active Osteomyelitis

A form of bone infection requiring adjustments to radiographic technique.

Signup and view all the flashcards

Bowel Obstruction

A condition where the bowel is blocked, potentially requiring adjustments to radiographic technique focusing on the taut air.

Signup and view all the flashcards

Skeletal Pathology

A change in bone structure or density, which may require adjustment to radiographic imaging techniques, only visible after a significant reduction in bone mass.

Signup and view all the flashcards

Spatial Resolution

The ability to image small objects with high contrast, influenced by pixel size in digital radiography.

Signup and view all the flashcards

Subject Contrast

The difference in X-ray absorption between different tissues on an image.

Signup and view all the flashcards

Radiographic Image Quality

Describes how accurately an anatomical structure is depicted on an X-ray.

Signup and view all the flashcards

Image Distortion

Misrepresenting the size or shape of structures in an X-ray due to imperfections.

Signup and view all the flashcards

Contrast Resolution

The ability to distinguish between similar tissues on an image.

Signup and view all the flashcards

Image Detail/Recorded Detail

Sharpness of structural lines on an image.

Signup and view all the flashcards

Resolution

The ability to see separate objects as distinct.

Signup and view all the flashcards

Distortion

Misrepresentation of an object's size or shape on an image.

Signup and view all the flashcards

Size Distortion

Magnification or reduction of an object's apparent size on an image.

Signup and view all the flashcards

Photometry

The science of how the human eye responds to visible light.

Signup and view all the flashcards

Photometric Quantities

Quantifiable measures related to the perception of visible light by the human eye.

Signup and view all the flashcards

Response of the Eye

The difference between dim-light and bright-light vision.

Signup and view all the flashcards

Image Luminance

The brightness of an image, usually from a monitor. It depends on the light source and monitor type.

Signup and view all the flashcards

Aperture Ratio

The part of a pixel on an LCD monitor that lets light through.

Signup and view all the flashcards

LED Monitor

A monitor that uses light-emitting diodes to display images.

Signup and view all the flashcards

Backlight

The light source behind an LCD monitor that illuminates the image.

Signup and view all the flashcards

Ambient Light

The general light level in a room.

Signup and view all the flashcards

Viewing Angle

The angle from which an LCD monitor's image is viewed without significant contrast loss.

Signup and view all the flashcards

LCD Monitor

A video display that uses liquid crystals to show images.

Signup and view all the flashcards

Light Emission

The process of a material emitting light as a response to an outside stimulus.

Signup and view all the flashcards

Image Flip

Reorienting a digital image by vertically or horizontally flipping it.

Signup and view all the flashcards

Image Inversion

A post-processing technique that makes bone appear black and soft tissue white on an image.

Signup and view all the flashcards

Image Subtraction

A method that removes parts of a series of images to highlight specific areas.

Signup and view all the flashcards

Pixel Shift

A technique used to correct patient motion in a series of images.

Signup and view all the flashcards

Region of Interest (ROI)

Allows focusing on a specific image area to calculate mean pixel value; useful for image rescaling.

Signup and view all the flashcards

Software Artifacts

Imperfections in digital images, such as dead pixels or faulty pixel rows/columns.

Signup and view all the flashcards

Calibration

Adjusting digital equipment to ensure accurate image representation, recognizing dead pixels, and making the IR response uniform.

Signup and view all the flashcards

Pre-processing

Manipulating images before display to remove defects and correct artifacts, like dead pixels.

Signup and view all the flashcards

Flatfielding

A pre-processing step to correct uneven brightness variations, often caused by anode-heel effect.

Signup and view all the flashcards

Signal Interpolation

Fixing defective pixels by using data from surrounding, good pixels.

Signup and view all the flashcards

Image Lag

An incomplete image that is not completely visible, requiring applying offset voltage.

Signup and view all the flashcards

Dead Pixels

Pixels that don't function properly, showing as dark spots on the image.

Signup and view all the flashcards

Offset and Gain images

Automatic calibration images that make the IR response more uniform.

Signup and view all the flashcards

Subject Contrast

Difference in X-ray absorption between different tissues, creating contrast on an image.

Signup and view all the flashcards

Patient Thickness

Thicker body parts absorb more X-rays than thinner ones, affecting image quality.

Signup and view all the flashcards

Attenuation

Reduction in X-rays as they pass through matter.

Signup and view all the flashcards

Patient/Subject Factors

Characteristics of the patient that affect image quality, such as body type and composition.

Signup and view all the flashcards

Technique Considerations

Factors to adjust X-ray technique to improve image quality based on patient characteristics.

Signup and view all the flashcards

Radiographic Contrast

Result of IR gradient multiplied by subject contrast; overall contrast in the image.

Signup and view all the flashcards

Subject Contrast

Difference in X-ray absorption between various tissues influencing image contrast.

Signup and view all the flashcards

Body Types

Classifications of body types (hypersthenic, sthenic, hyposthenic, asthenic) affecting X-ray technique.

Signup and view all the flashcards

Additive Pathology

A type of pathology where tissue thickness or density increases, requiring more X-ray exposure.

Signup and view all the flashcards

Radiolucent

Describes a material that allows X-rays to pass through easily, appearing dark on an X-ray image.

Signup and view all the flashcards

Pathology (in X-ray)

Any deviation from normal tissue that might affect X-ray image quality or technique.

Signup and view all the flashcards

Increased kVp for Additive Pathology

Increasing the kVp (kilovoltage peak) is a method to increase penetration for thicker, denser body parts.

Signup and view all the flashcards

IR exposure and Additive Pathology

Increased tissue density reduces the amount of radiation reaching the Image Receptor (IR).

Signup and view all the flashcards

Tissue Mass Density

Different patients may have equal body part thicknesses, but different mass densities affect X-ray absorption.

Signup and view all the flashcards

Effective Atomic Number

A measure of how a substance absorbs X-rays, varying greatly between tissues.

Signup and view all the flashcards

Subject Contrast

The difference in X-ray absorption between tissues, creating contrast on images.

Signup and view all the flashcards

Pathology

Any deviation from normal tissue composition; may alter X-ray technique.

Signup and view all the flashcards

Additive Pathology

Pathology increasing tissue thickness/density, needing more X-ray exposure.

Signup and view all the flashcards

Destructive Pathology

Pathology decreasing tissue thickness/density, needing less X-ray exposure.

Signup and view all the flashcards

Patient History

Information about a patient's medical history, crucial to determine X-ray technique.

Signup and view all the flashcards

Patient Physical Indications

Observing visible clues or outward signs of an underlying illness, shaping the X-ray technique.

Signup and view all the flashcards

Destructive Pathology

Pathology decreasing tissue thickness/density, requiring less X-ray exposure.

Signup and view all the flashcards

Active Osteomyelitis

A form of bone infection requiring adjustments to radiographic technique.

Signup and view all the flashcards

Bowel Obstruction

A condition where the bowel is blocked, potentially requiring adjustments to radiographic technique focusing on the taut air.

Signup and view all the flashcards

Skeletal Pathology

A change in bone structure or density, requiring adjustment to radiographic imaging techniques, only visible after a significant reduction in bone mass.

Signup and view all the flashcards

Spatial Resolution

The ability to image small objects with high subject contrast influenced by the pixel size in digital imaging.

Signup and view all the flashcards

Subject Contrast

The difference in X-ray absorption between tissues, creating contrast on the image.

Signup and view all the flashcards

Radiographic Image Quality

Describes how accurately an anatomical structure is depicted on an X-ray.

Signup and view all the flashcards

Image Distortion

Misrepresenting the size or shape of structures in an X-ray due to imperfections.

Signup and view all the flashcards

Software Artifacts

Imperfections in digital images, like dead pixels or faulty pixel rows/columns.

Signup and view all the flashcards

Calibration

Adjusting digital equipment to ensure accurate image representation, recognizing dead pixels, and making the IR response uniform.

Signup and view all the flashcards

Pre-processing

Manipulating images before display to remove defects and correct artifacts, like dead pixels.

Signup and view all the flashcards

Flatfielding

A pre-processing step to correct uneven brightness variations, often caused by the anode-heel effect.

Signup and view all the flashcards

Signal Interpolation

Fixing defective pixels by using data from surrounding, good pixels.

Signup and view all the flashcards

Image Lag

An incomplete image that is not completely visible, requiring applying offset voltage.

Signup and view all the flashcards

Dead Pixels

Pixels that don't function properly, appearing as dark spots on the image.

Signup and view all the flashcards

Offset and Gain images

Automatic calibration images that make the IR response more uniform.

Signup and view all the flashcards

Contrast Resolution

The ability to distinguish between and image similar tissues in an X-ray or similar image.

Signup and view all the flashcards

Image Detail/Recorded Detail

The sharpness of structural lines on a radiograph. Describes the visibility of the structure on the image.

Signup and view all the flashcards

Resolution

The ability to see separate objects as distinct and different.

Signup and view all the flashcards

Distortion

A misrepresentation of an object's true size or shape on a radiographic image.

Signup and view all the flashcards

Size Distortion

Magnification or reduction of an object's apparent size on an image.

Signup and view all the flashcards

Photometry

The science of how the human eye responds to visible light.

Signup and view all the flashcards

Photometric Quantities

Quantifiable measures related to the perception of visible light by the human eye.

Signup and view all the flashcards

Response of the Eye

The difference between how the eye sees bright light (photopic) and dim light (scotopic).

Signup and view all the flashcards

Study Notes

Principles of Radiography 1: Patient-Image Optimization & Viewing the Medical Image

  • Julie Kloft, MSRS, RT(R), Clinical Coordinator & Professor of Radiography
  • The presentation covers patient/subject factors, image-quality factors, and exposure technique factors relevant to optimizing radiographic images.

Patient/Subject Factors

  • Subject Contrast: The degree of differential absorption resulting from tissue differences in the body.
  • Patient Thickness: Denser objects absorb more radiation.
  • Tissue Mass Density: Different patients with equal thickness can have varying mass densities.
  • Effective Atomic Number: This varies greatly among tissues, significantly impacting subject contrast. Materials/substances and their effective atomic number are listed.
  • Object Shape: Technique adjustments compensate for patient size, shape, and composition. Positioning is related to geometric factors.

Image-Quality Factors

  • Spatial Resolution: Ability to image small objects with high contrast (e.g., bone and soft tissue).
  • Contrast Resolution: Ability to distinguish structures with similar subject contrast (e.g., liver and spleen).
  • Distortion: Misrepresentation of true object size or shape on the radiograph. Foreshortening (shorter than actual length) and elongation (longer than actual length) are types of shape distortion. Magnification can distort size. Distortion reduced by proper positioning (body part parallel to IR and Central Ray perpendicular to both).
  • IR Response: The display device's response to the incoming light depends on photometry (the science of human eye response to light).

Pathology

  • Pathology can affect tissue thickness/composition, altering effective atomic number (or density). This changes x-ray attenuation.
    • Additive conditions increase attenuation, and require increased kVp. Examples include Effusion, Hydrocephalus, and more.
    • Destructive conditions decrease attenuation, and require a decrease of mAs. Examples include Osteoporosis, Emphysema, and other conditions.
  • Collecting patient history and observing physical characteristics is important to avoid repeat radiographs.

Viewing the Medical Image

  • The science of photometry is important when using digital imaging and viewing technologies (Digital Imaging devices).
  • Photometric quantities: Lumen, luminous flux, candlepower, etc.
  • Understanding eye response (photopic and scotopic vision) is important for effective image viewing and analysis.

Image Display

  • Luminance: The measurement of source brightness in candela per sq meter or nit. Luminance intensity measures the luminous flux emitted into the entire viewing area.
  • Cosine Law explains how intensity of light is reduced from the side on LCDs. LCD monitors should be examined straight-on so intensity and contrast are maximized.
  • Inverse Square Law – Luminance intensity decreases as the square of the distance from the light source increases.

Digital Imaging Considerations

  • Artifacts such as dead pixels are addressed by pre-processing methods. Calibration is used to identify and correct these issues.
  • Pre-processing methods correct for image lag, line noise and other issues in digital images.
  • Flatfielding corrects for anode-heel effect.
  • Signal interpolation corrects defective pixels by averaging the response of surrounding pixels.

Post-Processing

  • Window/Leveling allows visualization of a broader range of gray scales.
  • Image Annotation adds labels, patient info, and other data to the image.
  • Image Inversion changes the appearance of the image (white and black areas swap to improve visibility).
  • Magnification is performed by using the larger matrix size to improve spatial resolution of small anatomical portions of the image.
  • Image Flip reorients the image.
  • Pixel Shift adjusts for patient movement.
  • Additional post-processing features include edge enhancement, highlighting, and zooming for detailed analysis.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Patient Image Optimization & Viewing the Medical Image PDF

Description

This quiz delves into the critical aspects of patient-image optimization in radiography. Covering patient factors such as tissue density and subject contrast, as well as image-quality factors like spatial resolution, this assessment is essential for those in the medical imaging field.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser