Authors (including presenting author) :
Hui HH(1), Yeung L (1)
Affiliation :
(1)X-Ray department, Our Lady of Maryknoll Hospital, (2) Queen Elizabeth Hospital, (3)Kwong Wah Hospital, (4) Well-women clinic, (5)Private examination center
Introduction :
Full-field Digital Mammography (FFDM) systems are replacing the screen film system in Hong Kong for almost a decade already. Full-field Digital Mammography screening is common in developed country such as UK and USA. Recent Tomosynthesis technology development greatly improves breast cancer detection rate and reduces false positive recall rate of Breast screening women as well as unnecessary Biopsy. Hence quality assurance test of FFDM is important and had been routinely practice in various examination center/hospitals using different brands and Models according to manufacturing QA setting.
We think keeping the consistent image quality is very important as the new trend is patients can have their mammogram done in different hospitals among KCC cluster and sometimes they may have to perform breast biopsy while the mammogram is performed in another hospital or even private clinic, so knowing the comparative image accuracy between different hospitals is essential in good patient care.
The performance of different mammographic units varied according different vendors and sometime causing problems during radiologist trace lesions. In our literature scooping we found that studies to compare performance among different vendors are very limited, so we would like to perform a study to explore the performance of FFDM and 3D tomosynthesis mammography among different vendor. We had invited the major five mammographic unit vendors in Hong Kong to participate the study. They are listed as below: Siemens, Hologic, GE, Fuji and QST. Among the five vendors, GE did not have upfront model available in HK for the study and Siemens only have 2D model to participate. As we know that thick breast will have poorer image quality than average breast, thus we would like to look at how breast thickness affect image quality and detector performance and we also like to know if there is any difference among different vendors in phantom test simulating thick breast.
Objectives :
To compare the performance of 2D full-field digital mammograhy models and 3D tomosynthesis using ACR approved phantom.
To compare the performance of different models in different phantom thickness to simulate different breast thickness.
Methodology :
Use CIRS 086 phantom(ACR approved digital test phantom) to assess FFDM image quality, 3D tmosyntesis image quality, contrast noise ratio (CNR) and signal to noise ratio(SNR)of 2D and 3D models.
Image quality was assessed by scoring the phantom image by two observers and the representative from vendor.
Different thickness was assessed by adding different numbers of 1cm PMMA blocks.
Result & Outcome :
The average CNR ranged from 2.99 to 3.77 and SNR ranged from 52.14 to 62.51. The baseline CNR and SNR are quite consistence in ~5cm phantom thickness. The CNR and SNR drops linearly with the increased in phantom thickness. PlanMed (QST) showed the most significant drop in image scores with the increased in phantom thickness, while Siemens had the most dramatic increased in glandular dose in 7cm thickness and Siemens and Fuji had higher glandular dose than other vendors.
3 units of 3D tomosynthesis were compared, we found the glandular dose of 3D was higher than 2D in all the vendors. Image scores of PlanMed(QST) was slightly lower than the others, glandular dose of Hologic was slightly higher, but had a better image score when compared at same phantom thickness.
Co-location with:
