Viewing Medical Images on a Viewing Medical Images on a PDAPDA

NSF REU “Computer Applications to Medicine”University of Virginia, Summer 2006

Andrew Jurik, Vanderbilt University

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Contents• Motivation• Goals• Current State of the Art

• System Diagram• Requirements• Demonstration

• Evaluation• Conclusion• Future Work• Acknowledgements

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Motivation

• PDAs are very portable

• Quick access to images

• Increase convenience for radiologists

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Goals

• Create a working system that implements secure image transmission from a server to PDA, allowing radiologists review those images

• To learn– C#– Web Services– Databases– Security– Image Manipulation

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Current State of the Art - Standards

• HIPAA – Health Insurance Portability and Accountability Act– Sufficient security measures, rules about who can view

medical information

• PACS – Picture Archiving and Communications System– Acquires, transmits, stores, retrieves, and displays digital

images

• DICOM – Digital Imaging and COmmunication in Medicine– File format developed to define connectivity and

communication protocols of medical imaging devices

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Current State of the Art - Imaging

• CT scans are 512 x 512 pixels with 256 gray levels (24-bit color)

• MR images are 256 x 256 pixels with 256 gray levels (24-bit color)

• A Pocket PC has240 x 320-pixel screens,16-bit color (65536 colordepth, no more than 64gray levels)

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Current State of the Art[1]

• Viewing on PDAs ~8 minutes on average• Head scans

– PDAs: ~5 mins– PACS workstation: ~2.3 mins

• Chest scans– PDAs: ~10 mins– PACS workstation: ~5 minutes

• Interpretations were generally consistent on both machines with a few exceptions in which the PACS was able to pick up more

[1] Merlina Trevino, “Radiologists examine images in the palms of their hands”, http://www.diagnosticimaging.com/pacsweb/newsupdate/showArticle.jhtml?articleID=59300898

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Basic System Diagram

Web Services

Web Server & Database

PDA

(client-side application)

Caveat: This program should be used for preliminary viewing of medical images only. The PDA hardware is not at a point yet to permit a comprehensive diagnosis.

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Requirements• Usability

– Simple, easy-to-understand GUI

• Security / Auditing– Password authentication– Log access attempts– Secure transmissions (an efficient solution to saving

securely could not be attained within the time frame)

• Annotation– Allow radiologist to annotate image in various ways

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Demonstration

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Evaluation

• The program is fully functional– Freehand annotation, panning, resizing,

contrast/brightness control, invert colors, image text data, save annotation text, save image in three file formats

• Limitations that prevent HIPAA compliance and practical commercialization at this point:

– Not DICOM-compliant– Using mySQL server to store images, not PACS

server– Save operation is not encrypted, encryption for

everything else uses only server authentication (client authentication would make access more secure)

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Conclusions

• Although this program will not be used by radiologists anytime soon, the fundamental idea behind the use of a PDA to view medical images is solid.

• Future work and development of both hardware and software will allow diagnostic compatibility at some point in the (probably near) future

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Future Work

• Overcoming aforementioned limitations

• Add biometric authentication

• E-mail support to send to referring physician or other radiologist

• Allow user to record voice and save along with image

• Implement video support for moving images

Viewing Medical Images on a Viewing Medical Images on a PDAPDA

NSF REU “Computer Applications to Medicine”University of Virginia, Summer 2006

Andrew Jurik, Vanderbilt University