University of Torino, Torino, Italy; INFN - National Institute for Nuclear Physics, Torino, Italy; CPqCTR - Research Center in Radiation Sciences and Technologies, UESC - State University of Santa Cruz, Ilhéus, Brazil.
CPqCTR - Research Center in Radiation Sciences and Technologies, UESC - State University of Santa Cruz, Ilhéus, Brazil.
Phys Med. 2022 Sep;101:112-119. doi: 10.1016/j.ejmp.2022.08.009. Epub 2022 Aug 18.
This investigation aims to study the optimization in digital mammography, considering a diverse percentage of breast glandularity using the contrast-detail metric.
The Figure of Merit (FOM), defined as the ratio of the square of the Inverted Image Quality Figure (IQF) by the Mean Glandular Dose (MGD), was used. A Monte Carlo simulation study was carried out to calculate the Normalized Glandular Dose (DN). A contrast detail analysis employing the test object Contrast-Detail Mammography Phantom (CDMAM, type 3.4) was performed in the Hologic digital mammography system-model Selenia located in the Research Center in Radiation Sciences and Technologies (CPqCTR) facilities (Brazil). It employed the CIRS phantom with 20 %, 30 %, 50 % of glandularity, and 6.0 cm in thickness.
It was obtained new acquisition parameters for all glandularities that achieved a decrease in the MGD up to ∼ 50 %, maintaining the same image quality. The study was validated using the CIRS, TORMAM, and ACR phantoms through the contrast-to-noise ratio (CNR), the signal-to-noise ratio (SNR), and the MGD values obtained with the optimized parameters and the four AEC modes, which are the optimization proposed by the manufacturer.
In this work, a new procedure was proposed that estimated the IQF value using the equivalence criterion between the CIRS phantom and the CDMAM test object with their respective PMMA plates. Based on the optimization carried out in this investigation, the AEC parameters, considering diverse glandularities, could be improved. This achievement permits the implementation of new protocols that optimize the ratio between the image's quality and the breast dose with 6.0 cm in thickness and 20 %, 30 %, and 50 % glandularity using contrast-detail metric.
本研究旨在利用对比细节度量标准，针对不同百分比的乳腺组织，对数字乳腺成像进行优化。
使用品质因数（FOM），其定义为倒易质量图（IQF）的平方与平均乳腺剂量（MGD）的比值。进行了蒙特卡罗模拟研究以计算归一化乳腺剂量（DN）。在 Hologic 数字乳腺成像系统-Selenia 中，使用对比度细节分析测试对象对比度细节乳腺摄影体模（CDMAM，类型 3.4），该系统位于辐射科学和技术研究中心（CPqCTR）设施（巴西）。它使用 CIRS 体模，具有 20%、30%、50%的乳腺组织和 6.0 厘米的厚度。
为所有乳腺组织获得了新的采集参数，这些参数可将 MGD 降低至约 50%，同时保持相同的图像质量。通过对比噪声比（CNR）、信噪比（SNR）以及使用优化参数和四个 AEC 模式（制造商提出的优化模式）获得的 CIRS、TORMAM 和 ACR 体模的 MGD 值，对该研究进行了验证。
在这项工作中，提出了一种新的程序，该程序使用 CIRS 体模和 CDMAM 测试对象与其各自的 PMMA 板之间的等效标准来估计 IQF 值。基于本研究进行的优化，考虑到不同的乳腺组织，可以改进 AEC 参数。这一成果可以实施新的协议，以对比度细节度量为基础，优化厚度为 6.0 厘米、乳腺组织为 20%、30%和 50%的图像质量与乳房剂量之间的比率。
