Segmentation of nasopharyngeal carcinoma (NPC) lesions in MR images.
Int J Radiat Oncol Biol Phys
; 61(2): 608-20, 2005 Feb 01.
Article
in En
| MEDLINE
| ID: mdl-15667983
ABSTRACT
PURPOSE:
An accurate and reproducible method to delineate tumor margins from uninvolved tissues is of vital importance in guiding radiation therapy (RT). In nasopharyngeal carcinoma (NPC), tumor margin may be difficult to identify in magnetic resonance (MR) images, making the task of optimizing RT treatment more difficult. Our aim in this study is to develop a semiautomatic image segmentation method for NPC that requires minimal human intervention and is capable of delineating tumor margins with good accuracy and reproducibility. METHODS AND MATERIALS The segmentation algorithm includes 5 stages masking, Bayesian probability calculation, smoothing, thresholding and seed growing, and finally dilation and overlaying of results with different thresholds. The algorithm is based on information obtained from the contrast enhancement ratio of T1-weighted images and signal intensity of T2-weighted images. The algorithm is initiated by the selection of a valid anatomical seed point within the tumor by the user. The algorithm was evaluated on MR images from 7 NPC patients and was compared against the radiologist's reference outline.RESULTS:
The algorithm was successfully implemented on all 7 subjects. With a threshold of 1, the average percent match is 78.5 +/- 3.86 (standard deviation) %, and the correspondence ratio is 66.5 +/- 7%.DISCUSSION:
The segmentation algorithm presented here may be useful for diagnosing NPC and may guide RT treatment planning. Further improvement will be desirable to improve the accuracy and versatility of the method.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Algorithms
/
Image Processing, Computer-Assisted
/
Magnetic Resonance Imaging
/
Nasopharyngeal Neoplasms
Type of study:
Prognostic_studies
/
Qualitative_research
Limits:
Female
/
Humans
/
Male
Language:
En
Journal:
Int J Radiat Oncol Biol Phys
Year:
2005
Document type:
Article
Affiliation country:
China