What are the advantages of digital image?
- image reconstruction
- image reformatting
- wide dynamic range
- image processing
- fast storage and retrieval
- fast and high quality image distribution
- controlled viewing
- image analysis
What affects digital image quality?
- Resolution (high matrix, small pixel size = good resolution)
- Noise
- Detective quantum efficiency (DQE) -> how well a system converts incoming data to output viewing device (perfect = 1, realistic = 0.3-0.7)
What is PACS?
- picture archiving and communications system
- is electeonic method of storing and accessing medical imaging examinations
What are advantages of PACS?
- remote access
- long term archiving
- immediate access to image
- improved image interpretation
- cost
What are the disadvantages of PACS?
- image quality dependent on monitor quality
- initial cost
- transition period
What is RIS?
- radiology information system
- data for radiology department to store patient data and images
What does RIS include?
- patient registration and scheduling
- list and tracking capabilities
- request and document scanning
- reporting
- image storage
What is HIS?
- historical information system
- stores inpatient data working with RIS and PACS
What does HIS include?
- patient tracking
- images and reports
- hospital administration (health care funds)
- referring doctor
What is DICOM?
- Digital imaging and communciation in medicine
- standard computer language so all types and brands of equipment are the same
What needs to be checked before sending an image to PACS?
- patient name, ID and DOB
- date and departmental details
- sidemarkers and orientation
- image is of diagnostic quality
What is data integrity?
- refers to accuracy and consistency of patient images and reports
- physical and logical
What is physical integrity?
- end of life (x-ray, PACS)
- power outages
- natural disaster
- system design faults
What is logical integrity?
- images and reports belonging to the correct painters
- package contains enough images and report information
How can data integrity be comprimised?
- human error
- transfer errors
- bugs/viruses
- comprised hardware
- physical compromise to device
What is ALARA?
- as low as reasonably achievable
What are the three levels of dose?
- Absorbed dose = energy deposited in a Kg of substance by RT
- Equivalent dose = absorbed dose weighted for harmful effects of different radiation
- Effective dose = equivalent dose weighted for harm of different tissues
What are the dose limits?
- occupational: 20mSv per year no more then 50 in one year
- public: 1 mSv per year
What is protection of the patient?
- correct patient and site
- limit number of exposures (avoid repeats)
- corrext SID and exposure selection
- adequate filter
- use lead shielding
What is the protection for the operator?
- stay behind protective barrier
- minimise time and exposure
- maximise distance from x-ray source
- wear protective clothes and TLD
- do not hold patient
