moving from analog to digital 2.0

Moving From Moving From Analog to DigitalAnalog to Digital

Not if, but when!Not if, but when!

The X-Ray Academy of Texas

Learning ObjectivesLearning Objectives

• Define the key terms used in digital Define the key terms used in digital imagingimaging

• List the equipment needed to List the equipment needed to perform digital imagingperform digital imaging

• Explain the computed radiography Explain the computed radiography (CR) digital system(CR) digital system

• Explain the digital radiography (DR) Explain the digital radiography (DR) systemsystem

Learning ObjectivesLearning Objectives

• Compare CR and DR digital systemsCompare CR and DR digital systems• Recognize the importance of using Recognize the importance of using

exposure technique charts with exposure technique charts with digital imagingdigital imaging

• Describe the processing and post-Describe the processing and post-processing of a digital imageprocessing of a digital image

• Explain what a picture archival and Explain what a picture archival and communications system (PACS) is communications system (PACS) is and how it is usedand how it is used

19-Dec-0919-Dec-09 44Stacy L. Palmer R.T. (R) Stacy L. Palmer R.T. (R)

Imaging StagesImaging Stages

1.1. Image Image AcquisitionAcquisition

2.2. Image ProcessingImage Processing

3.3. Image DisplayImage Display

4.4. Image StorageImage Storage


Analog Analog An analog system uses an intensifying An analog system uses an intensifying screen to create a latent image on x-ray screen to create a latent image on x-ray film. The film is then processed, creating film. The film is then processed, creating a manifest image that can be interpreted a manifest image that can be interpreted by a physician. It is later stored in the file by a physician. It is later stored in the file

room.room.


Problems with Film:• 10% of films are not available when we want

them!• 15% of films are “hard” to locate or find!

• Search for films will approach 20 to 90 minutes per case

• 25% of films are “misplaced” or not retrievable (misfiled).

• 10% of films are lost (referrals, residents, etc.)

• Recent study – physicians spend two weeks/year (100 hours/year) trying to locate or find the films they need. • Cost in physician time is estimated from

$60 to $80 per study.


Consider This About Typical Radiology

& Diagnostic Imaging Departments:• 82% are

profitable.• 56% are the No. 1.

source of revenue.• 44% are also

measured as #1 Cost Center.

• 69% could be more profitable.

• 75% can increase productivity/efficiency

• 68% now mandated to reduce costs by more than 12% within 15 months.

Source: Radiology Management, Volume 23 No 1


Cost of Film Over 7 Years:Cost of Film Over 7 Years: {$15.82 Per Film Per Exam {$15.82 Per Film Per Exam

Per Year}Per Year}100,000 exams/year @ 100,000 exams/year @

$1,600,000$1,600,000

1997 1996 19950

1

2

3

4

5

6

7

1997 1996 1995

Film

Supplies

Staff

Overhead

Dollars

(Purchase, sort, utilization, storage, handling, staffing, disposing)

It Is Estimated That A Single Sheet Cost $50 Over Its Life

Source: Mayo Clinic Film Expense Study, 1997


Digital ImagingDigital Imaging

Digital Imaging is any Digital Imaging is any modality that creates an modality that creates an

image that can be viewed image that can be viewed or stored on a computer.or stored on a computer.


Digital ModalitiesDigital Modalities

• CT (1970’s)CT (1970’s)• FluoroscopyFluoroscopy• MRI MRI • Nuclear MedicineNuclear Medicine• MammographyMammography• UltrasoundUltrasound• X-RayX-Ray


DR / Direct DR / Direct RadiographyRadiographyIn a system of direct radiography, also called

direct capture radiography, the image receptor is composed of an array of

electronic sensors that respond to the radiation exiting the patient. These sensors send that information in digital format to a

computer.

Digital RadiographyDigital Radiography• Referred to as “cassette-less” Referred to as “cassette-less”

because the detector is incorporated because the detector is incorporated into the x-ray table or upright wall into the x-ray table or upright wall unitunit• Equipment may be indirect or direct Equipment may be indirect or direct

conversionconversion• Images are ready for viewing within Images are ready for viewing within

secondsseconds


DR / Charge Coupled DR / Charge Coupled DeviceDevice

High Radiation / High Noise Zone

Low Radiation / Low Noise Zone

CCDLensReflector

Scintillator

X-ray tube

DR / Charge Coupled DR / Charge Coupled DeviceDevice


CR / Computed CR / Computed Radiography Radiography

Computed RadiographyComputed Radiography

• Image obtained Image obtained using cassettes using cassettes containing containing photostimulable photostimulable phosphor platesphosphor plates

• CR systems CR systems equipment equipment includes reader includes reader for image for image processingprocessing


CR / Computed CR / Computed RadiographyRadiography

Note: The phosphor plates used in Note: The phosphor plates used in computed radiography are not as computed radiography are not as sensitive to light as x-ray, but are sensitive to light as x-ray, but are extremely sensitive to scatter extremely sensitive to scatter radiation.radiation.

Digital Imaging System Digital Imaging System Technical Technical

ConsiderationsConsiderations• KilovoltageKilovoltage

• May be slightly higher than that used for May be slightly higher than that used for conventional radiographyconventional radiography

• CenteringCentering• Body part of interest must be placed in or Body part of interest must be placed in or

near the center of the detectornear the center of the detector• Multiple exposures on one cassetteMultiple exposures on one cassette

• Although not recommended, if IR is divided Although not recommended, if IR is divided for two separate exposures, the portion not for two separate exposures, the portion not being exposed must be covered with a lead being exposed must be covered with a lead shieldshield


ConsiderationsConsiderations• Over- and underexposureOver- and underexposure

• Degree of image density is not an accurate Degree of image density is not an accurate indicator of over- or underexposureindicator of over- or underexposure

• Density may be indicated by a unique Density may be indicated by a unique number that correlates to the amount of number that correlates to the amount of exposureexposure

• CollimationCollimation• Limit the field of radiation to the anatomy Limit the field of radiation to the anatomy

of interestof interest• Inadequate collimation can result in Inadequate collimation can result in

inappropriate contrastinappropriate contrast


ConsiderationsConsiderations• Open cassettesOpen cassettes

• An exposed IR begins to lose the An exposed IR begins to lose the image within 15 seconds of opening image within 15 seconds of opening the IRthe IR

• GridsGrids• Digital systems are more sensitive to Digital systems are more sensitive to

scatter radiationscatter radiation• Use grids as appropriateUse grids as appropriate

Body Part Algorithms


DigitizingDigitizingX-Ray Digitizer – A scanner used to X-Ray Digitizer – A scanner used to

convert existing analog images convert existing analog images into a DICOM format.into a DICOM format.


Image MatrixImage Matrix


•Pixel

•Voxel

•Dynamic Range

Image MatrixImage Matrix


Histogram/Brightness Histogram/Brightness LevelLevel


Soft Tissue

Lung


Window Level and Window Level and WidthWidth


Window Level and Window Level and Density Density


Window Width and Window Width and ContrastContrast

Exposure Technique Exposure Technique ChartsCharts

• Ability to manipulate the computer Ability to manipulate the computer image contrast and density does image contrast and density does not eliminate the need for not eliminate the need for technique chartstechnique charts

• Use technique charts to select mA, Use technique charts to select mA, kVp, and time to avoid kVp, and time to avoid unnecessary patient exposureunnecessary patient exposure

“Dose Creep”


Dose Response CurveDose Response Curve


NoiseNoise


Viewing the ImageViewing the Image• The computer-The computer-

processed image can processed image can be viewed on a be viewed on a computer monitor or computer monitor or printed on film or printed on film or paper. paper.

• For an image on a For an image on a screen to have the screen to have the quality approaching quality approaching that of a film image, a that of a film image, a special monitor must be special monitor must be used with a resolution used with a resolution of 1024 x 1024 pixels. of 1024 x 1024 pixels.

Image Processing and Image Processing and Post-processingPost-processing

• Both allow image manipulation ofBoth allow image manipulation of• DensityDensity• Structures demonstratedStructures demonstrated

• Subtraction permits viewing of bone only Subtraction permits viewing of bone only or tissues onlyor tissues only

• Contrast enhancement adjusts contrast Contrast enhancement adjusts contrast from very high to very lowfrom very high to very low


Post Processing Post Processing TechniquesTechniques

•Subtraction

•Contrast Enhancement

•Edge Enhancement

•Black and White Reversal


Digital Subtraction


Edge EnhancementEdge Enhancement


Contrast EnhancementContrast Enhancement


Black and White Black and White ReversalReversal


QA SoftwareQA Software

• Repeat AnalysisRepeat Analysis• Dose Consistency ReportingDose Consistency Reporting


Advanced AnnotationsAdvanced Annotations• Positioning MarkersPositioning Markers• Add predetermined text or free textAdd predetermined text or free text• Zoom and roam imageZoom and roam image• Invert imageInvert image• Apply shuttersApply shutters• Show/hide histogramShow/hide histogram• Advanced measurement options Advanced measurement options

(Orthopedic Application)(Orthopedic Application)• Stitching for full leg/full spineStitching for full leg/full spine


DICOMDICOM

DDigital igital IImaging and maging and CoCommunications in mmunications in MMedicineedicine

DICOM is the format that nearly all medical images are displayed in . It is

similar to JPEG or GIF formats for images in computer languages.


PACSPACS

Picture Archival and Picture Archival and Communications SystemCommunications System

Picture Archival and Picture Archival and Communication Communication Systems (PACS)Systems (PACS)

• PACS used to manage images PACS used to manage images • PACS network consists ofPACS network consists of

• ComputersComputers• ServersServers• ArchivesArchives


What are the advantages What are the advantages of PACSof PACS

• Faster delivery of medical images to the Faster delivery of medical images to the clinicians that evaluate and report on them. clinicians that evaluate and report on them. Resulting in faster availability of results. Resulting in faster availability of results.

• No lost or misplaced images, which means No lost or misplaced images, which means fewer patients being postponed or fewer patients being postponed or cancelled for consultations or surgery while cancelled for consultations or surgery while waiting for new images.waiting for new images.

• Flexible viewing with the ability to Flexible viewing with the ability to manipulate images on screen, which means manipulate images on screen, which means patients can be diagnosed more effectively.patients can be diagnosed more effectively.


What are the advantages What are the advantages of PACSof PACS

• Instant access to previous images Instant access to previous images and patient records.and patient records.

• Better collaboration, as PACS can be Better collaboration, as PACS can be viewed from multiple terminals and viewed from multiple terminals and locations by a range of clinicians, locations by a range of clinicians, allowing discussion over diagnoses .allowing discussion over diagnoses .

• Fewer unnecessary re-investigations, Fewer unnecessary re-investigations, which will in turn reduce the amount which will in turn reduce the amount of radiation to which patients are of radiation to which patients are exposed.exposed.

• No space needed for film storage.No space needed for film storage.


HIS/RISHIS/RIS

• HIS – Hospital Information SystemHIS – Hospital Information System• Patient demographic information Patient demographic information

entered by the entered by the FacilityFacility at check in. at check in. (Electronic Medical Record)(Electronic Medical Record)

• RIS – Radiology Information SystemRIS – Radiology Information System• Study information entered by the Study information entered by the

Radiology DepartmentRadiology Department when the when the study is ordered.study is ordered.


Fully Integrated Fully Integrated SystemSystem

With Agfa's IMPAX RIS solution you can With Agfa's IMPAX RIS solution you can electronically manage your radiology electronically manage your radiology operations, end-to-end, from patient operations, end-to-end, from patient

registration through worklist registration through worklist generation and medical reporting to generation and medical reporting to

transcription and business transcription and business intelligence. Optional modules offer intelligence. Optional modules offer

scheduling and management scheduling and management reporting capabilities, to provide a reporting capabilities, to provide a

true end-to-end solution. true end-to-end solution.

SummarySummary

• With CR and DR the image is With CR and DR the image is produced, processed, viewed, and produced, processed, viewed, and stored on a computerstored on a computer

• CR uses an IR and requires a reader CR uses an IR and requires a reader to process the imageto process the image

• DR is a cassette-less process that DR is a cassette-less process that produces an image within secondsproduces an image within seconds

• Use technique charts to select Use technique charts to select exposure factorsexposure factors

SummarySummary

• The appearance of digital images can be The appearance of digital images can be manipulated during and after processingmanipulated during and after processing

• PACS is a network used to manage the PACS is a network used to manage the images obtained through DRimages obtained through DR

• DR technical considerations include DR technical considerations include kilovoltage, part centering, number of kilovoltage, part centering, number of exposures per IR, over- and exposures per IR, over- and underexposure, cassette integrity, and underexposure, cassette integrity, and collimationcollimation

Clicker QuestionClicker Question

Opening a cassette containing an Opening a cassette containing an exposed imaging plate may result exposed imaging plate may result in: in:

a) an image with excessive a) an image with excessive densitydensity

b) an image with insufficient b) an image with insufficient densitydensity

c) erasure of the imagec) erasure of the image

Clicker QuestionClicker Question

Data acquisition in which x-ray Data acquisition in which x-ray energy is converted to light and energy is converted to light and then to an electric signal describes then to an electric signal describes the DR process of: the DR process of:

a) direct conversiona) direct conversion

b) indirect conversionb) indirect conversion


Thank-YouThank-You

moving from analog to digital 2.0

Health & Medicine