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Poster ‐ 10: QA of Ultrasound Images for Prostate Brachytherapy
Author(s) -
Szpala Stanislaw,
Kohli Kirpal S.
Publication year - 2016
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4961784
Subject(s) - imaging phantom , image quality , ultrasound , brachytherapy , prostate , prostate brachytherapy , medicine , nuclear medicine , quality assurance , signal to noise ratio (imaging) , computer science , medical physics , artificial intelligence , radiology , image (mathematics) , cancer , telecommunications , radiation therapy , external quality assessment , pathology
Purpose: The current QA protocol of ultrasound systems used in prostate brachytherapy (TG128) addresses geometrical verifications, but the scope of evaluation of image quality is limited. We recognized importance of the latter in routine practice, and designed a protocol for QA of the images. Methods: Images of an ultrasound prostate phantom (CIRS053) were collected with BK Flex Focus 400. The images were saved as bmp after adjusting the gain to 50% for consistent results. Mean pixel values and signal to noise ratio were inspected in the representative sections of the phantom, including the mock prostate and the unechoic medium. Constancy of these numbers over a one year period was looked at. Results: The typical intensity in the mock prostate region in the transverse images ranged between 95 and 118 (out of 256), and the signal to noise was about 10. The intensity in the urethra region was about 170±40, and the unechoic medium was 2±2. The mean and the signal to noise ratio remained almost unchanged after a year, while the signal in the unechoic medium increased to about 7±4. Similar values were obtained in the sagittal images. Conclusions: The image analysis discussed above allows quick evaluation of constancy of the image quality. This may be also useful in troubleshooting image‐quality problems during routine exams, which might not be due to deterioration of the US system, but other reasons, e.g. variations in tissue properties or air being trapped between the probe and the anatomy.