Mr. Jonathan R. Sykes Profile

Jonathan R. Sykes

at Christie NHS Foundation Trust

SPIE Involvement:

Author

Publications (1)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 30 May 2003 Paper

Automatic detection, with confidence, of implanted radiographic seeds at megavoltage energies using an amorphous Silicon imager

Jonathan Sykes, Philip Whitehurst, Christopher Moore

Proceedings Volume 5029, (2003) https://doi.org/10.1117/12.479678

KEYWORDS: Convolution, Radiotherapy, Gold, Amorphous silicon, Imaging systems, Signal to noise ratio, Detection and tracking algorithms, X-rays, Tissues, Image quality

Read Abstract +

The premise of image guided radiotherapy is the use of imaging to target the delivery of radiotherapy with high precision. Despite the high resolution of amorphous silicon flat panel imagers the detection of small implanted radiographic gold markers (length: 5mm, diameter: 0.8mm), visualised on portal images with low SNR and the inherent low contrast of mega-voltage photons, remains a significant, safety critical challenge. Convolution/correlation and sum of the squares of the difference (SSD) detection algorithms make use of marker templates to detect radiographic markers. However, direct convolution is not specific enough and SSD techniques fail in low SNR conditions. This report defines a robust SSD measure operating on a model template-to-clinical convolution image and a semi-empirical template self-convolution image, which is used to assign an objective measure of confidence to individual markers and unambiguously determine the separation of true and false detection distributions. The algorithm was tested on 9 clinical pelvic images produced by placing a template with 14 randomly arranged gold markers on patients during portal imaging. Using 95% confidence limits in a localised regional search for each of the 14 seeds, the number of correct detections averaged at 13, while the average number of false detections was less than 1.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

;

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years