advanced image acquisition- unit 1- chapter 25- the imaging process

What are the five phases of the imaging process?

Image acquisition, image processing, image archiving, image display, and image analysis.

What is the first phase of the imaging process?

Image acquisition.

What is the second phase of the imaging process?

Image processing.

What is the third phase of the imaging process?

image archiving

What is the fourth phase of the imaging process?

image display

What is the fifth phase of the imaging process?

image analysis

Is the image acquisition process the same for every imaging modality?

No. The image acquisition process is unique to each imaging modality.

What types of digital image acquisition have been used in x-ray?

Photostimulable Phosphor Imaging Plates (PSP IPs), flat panels, Charged Coupled Devices (CCDs), and Complementary Metal Oxide Semiconductor (CMOS) sensors.

What are the two types of flat-panel image acquisition?

Direct conversion and indirect conversion.

What does PSP IP stand for?

Photostimulable Phosphor Imaging Plate.

What does CCD stand for?

charged coupled device

What does CMOS stand for?

Complementary Metal Oxide Semiconductor.

What are other examples of image acquisition techniques in radiology?

Computed Tomography, Sonography, Magnetic Resonance, etc.

How is image processing achieved in digital imaging?

Through software manipulation of the image.

Is raw image receptor data appropriate to use for diagnosis?

no

When is raw image receptor data initially processed?

Immediately after the exposure is taken.

Can an image be processed further after its initial processing?

Yes. It can be manually processed further after it is displayed on the workstation monitor.

How can digital images be stored?

Through a variety of storage options.

Where are digital images typically stored?

Locally on the acquisition system computer and on the facility's PACS.

What is commonly done within PACS to prevent the loss of images?

Backups and off-site backups of images are commonly used.

What is necessary to view images in digital imaging?

a monitor

What monitor characteristics can affect how digital images are displayed?

Resolution, brightness, and contrast.

What traditional image-quality factors are evaluated during image analysis?

Image receptor exposure, contrast, spatial resolution, and distortion.

When does the radiographer control the factors that affect image receptor exposure, contrast, spatial resolution, and distortion?

Before the x-ray beam is detected by the image receptor (IR).

What variables must technologists understand and work with?

Technical factor selection, subject density, contrast, pathology and patient conditions, equipment functionality, and image processing.

Is medical diagnosis within the radiographer's scope of practice?

No. Medical diagnosis is not permitted.

What type of diagnosis is required of the radiographer?

technical diagnosis

What is the radiographer considered the professional expert in?

Creating the image, assessing image quality, and understanding the technology behind image creation.

What are the two major categories shown under image analysis?

Visibility of detail and geometric properties.

What two factors are included under visibility of detail?

Image receptor exposure and contrast.

What technical factors are related to image receptor exposure in image analysis?

mAs and kVp.

What other factors are related to image receptor exposure?

Focal spot, anode heel effect, distance, filtration, beam restriction, anatomical part, grid construction, and image receptor.

What factors related to the patient or anatomy can influence image receptor exposure?

Tissue type, tissue thickness, contrast media, and pathology.

What factors are associated with grid construction?

Grid ratio and grid frequency.

What types of image receptors are included in image analysis?

Digital systems and film-screen systems.

What two major factors make up the geometric properties of an image?

spatial resolution and distortion

What factors affect spatial resolution?

Geometry, image receptor, and motion.

What factors are included under geometry when evaluating spatial resolution?

focal spot and distance

What distance factors are important when evaluating spatial resolution?

OID and SID

What type of image receptor is specifically associated with spatial resolution in the diagram?

Film-screen systems.

What three types of motion can affect spatial resolution?

Voluntary motion, involuntary motion, and equipment motion.

Are digital systems also related to motion and spatial resolution?

Yes. Digital systems are included in the motion/spatial-resolution section of the image-analysis diagram.

What are the two types of distortion?

Size distortion and shape distortion.

What two main factors affect shape distortion?

Alignment and angulation.

What three components must be considered when evaluating alignment?

The central ray, the part, and the image receptor.

What aspects of angulation are considered when evaluating shape distortion?

direction and degree

What image-quality factor is affected by focal spot and distance?

spatial resolution

What image-quality factor is affected by voluntary, involuntary, and equipment motion?

spatial resolution

What image-quality factor is affected by OID and SID?

Distortion, specifically size distortion.

What image-quality factor is affected by improper alignment?

shape distortion

What image-quality factor is affected by angulation?

shape distortion

What three things must be properly aligned to control shape distortion?

The central ray, the anatomical part, and the image receptor.

What two characteristics describe angulation?

Direction and degree.

What factors related to the x-ray beam and technique must be understood when analyzing image receptor exposure?

mAs, kVp, focal spot, anode heel effect, distance, filtration, and beam restriction.

What anatomical factors must be considered when analyzing an image?

The anatomical part, tissue type, tissue thickness, contrast media, and pathology.

What grid characteristics must be understood during image analysis?

Grid ratio and grid frequency.

Why must a radiographer understand the relationships among all of the image-analysis factors?

Because image quality depends on the relationships among image receptor exposure, contrast, spatial resolution, distortion, technical factors, patient/anatomical factors, equipment, and imaging-system characteristics.