Image storage

8 Image storage

The ability to store patient information in a format that means that it is secure, can be readily accessed by authorised users only and the information does not degrade over time

Storage criteria

Security	Unauthorised viewing of data should not be possible and therefore: Passwords • Need to be changed on a regular basis • Linked to each individual user • Use of automated password generators (APG) Hand held device (unique to each person authorised to use the system) Person requests a password APG server sends a password User inputs the password The password is changed every time the user goes onto the system Firewalls • Automatically identify information coming from external sources Either allow information in, e.g., from a GP surgery Or exclude information, e.g. from external viruses • Part of the internal network • Should be updated at regular intervals Antivirus software • Software packages to protect against Viruses Worms Cookies • Viruses, etc. gain access via internet connections including e-mail • Software should be updated at regular intervals • Regular checks should be run on stand-alone computers with internet access Individual monitor security • Antivirus software should be run at regular intervals • Internal security settings should be set at high: Firewall – on Block cookies Block pop-ups Allow automatic updates for firewalls and antivirus software • Cookies should be deleted at regular intervals Removal of external disk drives • Consider blocking or removing external disk drives • Prevents the introduction of viruses from external computers via CDs and DVDs
Access	Limited to the requirements of each user, e.g. • Managers limited to management information • Clinicians limited to patient details; all information contained in patient records • Receptionists limited to patient’s contact details, clinic lists • Individual passwords used and changed at regular intervals • Automatic record of: Who accessed a file The date and time is was accessed Who added to the file Who deleted part of a file.
	Note If part of the file is deleted it should remain on the record but show it has been deleted, e.g. with a line through the record
	• It is important that staff: Log off as well as log on to the computer Do not give anyone their password Do not write down their password
Speed of Access	• It is important that patient information can be found quickly and easily • Optical disks allow quick and easy access • But have problems due to the size of radiographic images • Images will be stored on the World Wide Web • On a dedicated site • With a dedicated search engine to recall the information
Stability	• Stored images should not degrade over time • Storage media needs to have a long life and equipment needs to be available to read the image at a later date
Stability	Note New computers cannot read floppy disks, so any information stored on these is no longer accessible • Storing images on the World Wide Web may solve these problems
Backup	• Backup is important in case of breakdown or virus attack • Information should be backed up automatically • A separate copy of all data should ideally be stored away from the main site. If this is not possible, a dedicated room should be used • It should not be stored on the same intranet system
Storage Capacity	• A capacity of 0.6 Gbytes, would be capable of storing all details, reports, film locations, appointments, X-ray room details, registrations, etc. for about 1 million patients • That represents the storage of all patient data (in an average hospital) for about 10 years
Storage Capacity	But • 2.5 Gbytes is only capable of storing about 170, 35 × 43 cm chest films • Data compression may be able to reduce storage requirements by as much as 50% • Again storage on the World Wide Web will solve these problems