乳腺X线摄影中乳腺肿块、密度与辐射剂量的相关性研究

目的：通过对临床可触及肿块的乳腺肿瘤患者健侧及患侧乳腺的平均腺体剂量（average gland dose,AGD）进行分析,分析乳腺肿块、密度与辐射剂量之间的相关性。方法：收集2019年1—12月于复旦大学附属肿瘤医院就诊的临床可触及乳腺肿块的患者204例,对患者行双侧乳腺头尾（craniocaudal,CC）位及内外斜（mediolateral oblique,MLO）位标准摄影检查,统计乳腺密度、压迫厚度、不同年龄段的辐射剂量,探讨乳腺X线摄影中乳腺肿块、密度与辐射剂量之间是否存在相关性。结果：在204例患者中,右侧乳腺有肿块的患者101例,左侧乳腺有肿块的患者103例。根据腺体类型进行分类,脂肪型（a型）5例,散在纤维腺体型（b型）52例,不均匀致密型（c型）132例,极度致密型（d型）15例;根据年龄进行分类,40岁以下的患者30例,41～50岁的患者65例,51～60岁的患者52例,61～70岁的患者40例,71岁以上的患者17例。比较乳腺肿块患者的健侧及患侧乳腺的AGD时,患侧乳腺的AGD较健侧乳腺的AGD高30.66%,差异有统计学意义（P<0.05）。不同乳腺腺...     

数字乳腺断层融合X线成像中平均腺体剂量与乳腺密度、压迫厚度的关系

【摘要】目的：探讨数字乳腺断层融合X线成像（DBT）中平均腺体剂量（AGD）与乳腺密度、压迫厚度的关系。方法：搜集在DBT Combo模式［即DBT和全视野数字化乳腺摄影(FFDM)分别在同一乳腺、在同一压迫厚度下进行摄影］下行双侧乳腺摄影的女性患者271例。分析共542幅DBT和542幅FFDM的单侧乳腺头尾位图像。结果：①压迫厚度与AGDDBT呈正向较强相关（r=0.920,P＜0.001）,乳腺密度与AGDDBT呈正向较弱相关（r=0.263,P＜0.001）。压迫厚度和乳腺密度分别是AGDDBT的独立影响因素（B压迫厚度=0.046,B乳腺密度=0.084,P<0.001）。压迫厚度对AGDDBT的影响较乳腺密度大（压迫厚度、乳腺密度的标准化系数分别为0.940、0.143）。②压迫厚度与△AGD（AGDDBT减去AGDFFDM）呈负向较弱相关（r=-0.287,P＜0.001）,乳腺密度与△AGD呈负向中等相关（r=-0.616,P＜0.001）;乳腺密度和压迫厚度分别是△AGD的独立影响因素（B压迫厚度=-0.012,B乳腺密度=-0.219,P<0.001）;乳腺密度对△AGD的影响较压迫厚度大（压迫厚度、乳腺密度的标准化系数分别为-0.580、-0.366）。③在乳腺密度＞75%且压迫厚度为56~75mm和76~95mm时,AGDDBT均值低于AGDFFDM,差异有统计学意义（P＜0.05）。在乳腺密度为25%～50%且压迫厚度为76~95mm时,AGDDBT均值与AGDFFDM相仿（P＞0.05）。在乳腺密度为51%～75%且压迫厚度为56~75mm时,AGDDBT均值与AGDFFDM相仿（P＞0.05）。在其他乳腺密度和压迫厚度分层中（压迫厚度均≤95mm）,AGDDBT均值高于AGDFFDM,差异有统计学意义（P＜0.05）。结论:AGDDBT与乳腺密度、压迫厚度呈正相关,压迫厚度对AGDDBT的影响更大。△AGD与乳腺密度、压迫厚度呈负相关;乳腺密度对△AGD的影响更大。在乳腺密度＞75%且压迫厚度为56~95mm时,AGDDBT均值低于AGDFFDM;在其他乳腺密度及压迫厚度分层（压迫厚度均≤95mm）中,AGDDBT均值高于或等于AGDFFDM。     

全野数字乳腺X线摄影降低辐射剂量的初步研究

＿目的：探讨全野数字乳腺X线摄影的曝光条件,找出影响图像质量和平均腺体剂量（AGD）的因素,为乳腺摄影提供参考。方法：采用GE全野数字乳腺X线机对fluke NA 18-220乳腺模体进行摄影,首先采用AOP 模式下的标准模式曝光,压力设定为12daN,厚度为42 mm,结果形成28 kV,45 mAs,Mo／Rh 曝光条件,以此为参照基准,设定两组实验：以管电流为单变量,设值为8～90 mAs（间隔为机器旋钮可调节的数值）;以管电压为单变量,设值为22～36 kV（间隔为1）,曝光并记录AGD值。上述过程重复3次取平均值。2位影像学医师和1位技师分别独立进行软阅读,参照美国放射学会评分标准,对模体中钙化点、尼龙纤维、肿块灶的显示进行评分。结果：与自动曝光模式相比,手动曝光模式管电压下降3 kV,管电流下降20 mAs,影像质量符合诊断标准,辐射剂量有效下降。管电压的变化对 AGD 的影响比管电流要大。结论：以自动条件作为参照标准,在保障图像诊断质量前提下,管电压和管电流可分别有效降低,以减少辐射。     

两种摄影模式下的乳腺X射线摄影的剂量比较

目的 对比分析数字乳腺X射线断层融合成像和全数字化乳腺X射线摄影两种模式下乳腺X射线摄影剂量比较,以及平均腺体剂量与乳腺密度、压迫厚度的关系。方法 回顾性收集2020年10月至2022年5月在昆明医科大学第一附属医院行数字乳腺X射线断层融合成像（DBT）的乳腺疾病患者以及同时期在本院行全数字化乳腺X射线摄影（FFDM）的体检人群的乳腺X射线摄影资料,记录压迫厚度、压迫力度及平均腺体剂量（AGD）,由两名从事乳腺影像诊断的高年资医师依照2013年ACR BI-RADS MAMMOGRAPHY对乳腺腺体密度进行分型,分为a （腺体组织<25%）、b （腺体组织约25%~50%）、c （腺体组织约50%~75%）、d （腺体组织>75%）4型,分析在FFDM、DBT模式下,不同腺体密度、不同压迫厚度与AGD的关系。结果 无论是FFDM还是DBT模式,随着乳腺腺体密度增加AGD逐渐增加,AGD_a型b_型c_型d_型,差异有统计学意义（F=861.63、617.83、330.33、451.45、290.47,P<0.001）。行FFDM的c、d型乳腺,压迫厚度为31~40 mm时AGD较低。在相同压迫厚度下,a、b、c、d型乳腺AGD_DBT均高于AGD_FFDM,差异有统计学意义（a型：t=-17.88、-42.19、-29.90、-28.14、-24.95,P<0.001;b型：t=-49.18、-35.94、-27.25、-28.37、-24.10,P<0.001;c型：t=-11.78、-32.90、-23.13、-20.51、-18.24,P<0.001;d型：t=-7.94、-26.24、-17.24、-15.44、-13.81,P<0.001）,乳腺厚度为61~70 mm的d型乳腺AGD两者差异最大,为1.07 mGy （95%CI：0.92~1.22）。AGD与乳腺密度、压迫厚度正相关,且FFDM的相关性强于DBT。结论 乳腺X射线摄影AGD与乳腺密度、压迫厚度正相关,与FFDM相比,DBT会增加AGD,但AGD增幅在安全范围内,临床工作中行DBT检查对乳腺疾病患者有益。     

乳腺X射线摄影中受检者辐射剂量评估研究进展

乳腺X射线摄影在乳腺癌的筛查和诊疗中发挥了重要作用, 但X射线的使用在提高乳腺癌检出率的同时也会增加乳腺癌的发病风险, 这种风险随着辐射剂量的增加而变大。乳房腺体组织是辐射敏感组织, 国际社会非常关注乳腺X射线摄影检查中受检者平均腺体剂量的评估。传统的二维乳腺X射线摄影和数字乳腺体层合成摄影中受检者剂量学研究已较为成熟, 较新的乳腺锥形束CT扫描中受检者剂量的评估方法尚在研究阶段。本文对不同类型乳腺X射线摄影检查设备中受检者辐射剂量的评估方法及辐射剂量相关影响因素的研究现状进行综述和探讨。     

乳腺密度评估:使用全自动软件一对一比较数字乳腺X线摄影和数字乳腺体层摄影

正摘要目的使用全自动化软件比较数字乳腺X线摄影和数字乳腺体层摄影(DBT)的乳腺密度。方法该研究获得机构批准并得到全部参与者的知情同意,每位参与者均进行DBT和全视野乳腺X线摄影(FFDM)。通过软件计算两种检查的乳腺密度百分比。结果50例连续病人(平均51岁,35~83岁)接     

数字乳腺摄影系统的质量控制检测与评价

目的 对3套数字乳腺摄影系统进行质量控制检测与评价。方法 应用欧洲乳腺癌普查和诊断质量控制导则中推荐的方法,结合国内乳腺摄影评价标准,对3套数字乳腺摄影系统进行X线发生器性能质量控制检测与评价;分别应用直接数字化X线摄影技术(DR)、相位对比乳腺摄影(PCM)和计算机X线摄影技术(CR)系统在4个厚度下(30、40、50及60mm)对乳腺专用对比度细节检测模体(CDMAM3.4)进行AEC曝光成像,计算与评价每一厚度下的平均腺体剂量(AGD)和影像质量因子(IQF)。结果 DR和CR的X线机性能检测符合现有标准;等效PMMA厚度分别为30、40、50、60mm时,DR系统的AGD分别为1.20、1.42、1.75、2.20mGy;PCM系统AGD分别是0.82、1.19、1.33、1.70mGy;CR系统AGD为0.59、0.88、1.47、2.19mGy。在相应的模体厚度下,DR系统的IQF值为21.36、21.57、27.25和30.58;PCM和CR系统的IQF值分别为28.02、29.10、35.90、41.24和39.78、39.30、43.85、48.08。结论 GBZ186-2007标准不适用于PCM系统X线机性能部分性能的评价。本研究的3套系统自动曝光下平均腺体剂量均符合欧洲标准。在国内检测规范欠缺的情况下,可参考国际标准或指南对数字乳腺系统进行常规监测。     

点压数字摄影与数字乳腺体层摄影的一对一对比

目的评价数字乳腺体层摄影(DBT)是否至少等同于点压数字摄影(DSCV)。方法在获得研究机构的批准和书面同意后,对女性进行筛查时同时进行DBT和DSCV检查。由2名不同资质的放射科医生(阅片者1和阅片者2)对DBT和DSCV诊断的准确度进行评价。结果连续召回52例不伴     

The effect of different exposure parameters on radiation dose in digital mammography and digital breast tomosynthesis: A phantom study

IntroductionThere are concerns regarding the increase in radiation dose among women undergoing both digital mammography (DM) and digital breast tomosynthesis (DBT). The aim of this study was to evaluate the effect of different exposure parameters on entrance skin dose (ESD) and average glandular dose (AGD) for DM and DBT using a phantom.MethodsThe ESD and AGD of 30 DM and DBT (cranio-caudal projection) examinations using a tissue equivalent phantom where acquired using a GE Senographe Essential DM unit. Commercial phantoms were used to simulate three different breast thicknesses and compositions. Tube potential, tube load, and target/filter combinations were also varied with ESD and AGD recorded directly from the DM unit. Comparisons were made using the non-parametric Kruskal Wallis, Mann–Whitney, and Wilcoxon signed rank tests.ResultsThe individual ESD values for 4 cm, 5 cm, and 6 cm thick phantoms for DM and DBT at Rh/Rh target/filter combination and 30–32 kV/56 mAs levels were 5.06 and 4.18 mGy; 5.82 and 5.08 mGy; and 7.26 and 11.4 mGy, respectively; while AGDs were 1.57 and 1.30 mGy, 1.33 and 1.39 mGy; and 1.29 and 3.60 mGy, respectively. The Kruskal–Wallis test showed a statistically significant difference in AGD for DM (P = .029) but not for DBT (P = 0.368). The Mann–Whitney and Wilcoxon signed rank tests showed no statistically significant difference for ESD or AGD between both DM and DBT techniques (P = .827 and .513). The percentage differences in ESD for phantom thicknesses of 4 cm, 5 cm, and 6 cm between DBT and DM ranged between −21% and 36%; while for AGD between −21% and 64.2%.ConclusionsThe ESD and AGD for single view projection in DM and DBT showed differences at 4 and 6 cm breast thicknesses and compositions but not at 5 cm thickness with 30–32 kV and a Rh/Rh target/filter combination.Implications for practiceA fibro-fatty breast results in less radiation dose variations in terms of ESD and AGD between DM and DBT techniques.     

Dose comparison between screen/film and full-field digital mammography

The study purpose was the comparison between doses delivered by a full-field digital mammography system and a screen/film mammography unit, both using the same type of X-ray tube. Exposure parameters and breast thickness were collected for 300 screen/film (GE Senographe DMR) and 296 digital mammograms (GE Senographe 2000D). The entrance surface air kerma (ESAK) was calculated from anode/filter combination, kV_p and mAs values and breast thickness, by simulating spectra through a program based on a catalogue of experimental X-ray spectra. The average glandular dose (AGD) was also computed. Results showed an overall reduction of average glandular dose by 27% of digital over screen/film mammography. The dose saving was about 15% for thin and thick breasts, while it was between 30% and 40% for intermediate thicknesses. Full-field digital mammography dose reduction is allowed by wider dynamic range and higher efficiency of digital detector, which can be exposed at higher energy spectra than screen/film mammography, and by the separation between acquisition and displaying processes.     

Simultaneous measurement of patient dose and distribution of indoor scattered radiation during digital breast tomosynthesis

Introduction

Breast cancer incidence increases from the age of 30 years. As this age range coincides with that in which women usually pursue pregnancy, undergoing medical examinations for conditions such as breast cancer is a concern, especially when pregnancy is uncertain during the first eight weeks. Moreover, in this age range, breast often exhibits a high density, thus compromising diagnosis. For such density, digital breast tomosynthesis (DBT) provides a more accurate diagnosis than 2D mammography given its higher sensitivity and specificity. However, radiation exposure increases during DBT, and it should be determined.

Breast cancer detection: Comparison of digital mammography and digital breast tomosynthesis across non-dense and dense breasts

IntroductionBreast density is associated with an increase in breast cancer risk and limits early detection of the disease. This study assesses the diagnostic performance of mammogram readers in digital mammography (DM) and digital breast tomosynthesis (DBT).MethodsEleven breast readers with 1–39 years of experience reading mammograms and 0–4 years of experience reading DBT participated in the study. All readers independently interpreted 60 DM cases (40 normal/20 abnormal) and 35 DBT cases (20 normal/15 abnormal). Sensitivity, specificity, ROC AUC, and diagnostic confidence were calculated and compared between DM and DBT.ResultsDBT significantly improved diagnostic confidence in both dense breasts (p = 0.03) and non-dense breasts (p = 0.003) but not in other diagnostic performance metrics. Specificity was higher in DM for readers with >7 years' experience (p = 0.03) in reading mammography, non-radiologists (p = 0.04), readers who had completed a 3–6 months training fellowship in breast imaging (p = 0.04), and those with ≤2 years’ experience in reading DBT (p = 0.02), particularly in non-dense breasts.ConclusionDiagnostic confidence was higher in DBT when compared to DM. In contrast, other performance metrics appeared to be similar or better with DM and may be influenced by the lack of experience of the reader cohort in reading DBT.Implications for practiceThe benefits of DBT may not be entirely accrued until radiologists attain expertise in DBT interpretation. Specificity of DBT varied according to reader characteristics, and these characteristics may be useful for optimising pairing strategies in independent double reading of DBT as practiced in Australia to reduce false positive diagnostic errors.     

髋关节数字化断层融合摄影的低剂量研究

目的 探讨髋关节数字化断层融合(DTS)摄影中最佳剂量比的设定,以最大程度地减少患者接受的辐射剂量.方法 90例行髋关节数字化断层融合摄影的患者,以随机数字表法,分别以6、7、8倍的剂量比组进行DTS检查,使用单因素方差分析比较不同剂量比设定下所得的图像质量和辐射剂量.结果 3组的表面吸收剂量(ESD)、剂量面积乘积(DAP)、图像质量评分分别为[(3.76±1.89)mGy、(18.41±11.71)dGy ·cm²、3.03±0.24]、[(5.24±2.76)mGy、(26.99±13.34)dGy ·cm²)、3.60±0.11]、[(6.39±1.75)mGy、(36.96±22.49)dGy ·cm²、3.64±0.09],各组间差异有统计学意义(F=10.94、9.45、139.26, P<0.05),通过3组间两两比较,ESD值和DAP值均是6倍剂量比组<7倍剂量比组<8倍剂量比组.6倍剂量比组的图像质量评分低于其他两组,7倍剂量比组和8倍剂量比组的图像质量评分差异无统计学意义.结论 剂量比是决定DTS检查辐射剂量的重要参数,髋关节DTS检查的剂量比设置为7时,可实现低曝光剂量和高图像质量的平衡,以最大限度地保护患者免受不必要的辐射损害.     

Assessment of the uterine dose in digital mammography and digital breast tomosynthesis

IntroductionDigital Mammography (DM-2D) and more recently Digital Breast Tomosynthesis (DBT), are two of the most effective imaging modalities for breast cancer detection, often used in screening programmes. It may happen that exams using these two imaging modalities are inadvertently performed to pregnant women. The objective of this study is to assess the dose in the uterus due to DM-2D and DBT exams, according to two main irradiation scenarios: in the 1st scenario the exposure parameters were pre-selected directly by the imaging system, while in the 2nd scenario, the maximum exposure parameters were chosen.MethodsThe mammography equipment used was a Siemens Mammomat Inspiration. A physical anthropomorphic phantom, PMMA plates (simulating a breast thickness of 6 cm) and thermoluminescent dosimeters (TLDs) were used to measure entrance air kerma values on the phantom's breast and abdomen in order to successively estimate the mean glandular dose (MGD) and the dose in the uterus. For the two irradiation scenarios chosen, two-breast imaging modalities were selected: 1) DBT in Cranio-Caudal (CC) view (with 28 kV and 160 mAs as exposure parameters), 2) DBT and DM in Medio Lateral-Oblique (MLO) and CC views (with 34 kV and 250 mAs as exposure parameters).ResultsIn the 1st scenario, the TLD measurements did not detect significant dose values in the abdomen whereas the MGD estimated using the D.R. Dance model was in close agreement with data available in the literature. In the 2nd scenario, there was no significant difference in MGD estimation between the different views, whereas the air kerma values in the abdomen (in DBT mode, CC and MLO) were 0.049 mGy and 0.004 mGy respectively. In CC DM-2D mode the abdomen air kerma value was 0.026 mGy, with no significant detected value in MLO view.ConclusionsFor the dose in the uterus, the obtained values seem to indicate that DM-2D and DBT examinations inadvertently performed during pregnancy do not pose a significant radiological risk, even considering the case of overexposure in both breasts.Implications for practiceThe accurate knowledge of the doses in DM-2D and DBT will contribute to raise the awareness among medical practitioners involved in breast imaging empowering them to provide accurate information about dose levels in the uterus, improving their radiation risk communication skills and consequently helping to reduce the anxiety of pregnant women undergoing this type of examinations.     

Patient dose in full-field digital mammography: an Italian survey

The aim of this study was to compare performance and patient dose of full-field digital mammography units for clinical use. Measurements of linearity and automatic exposure control stability were performed on four units installed in as many Italian sites. The tube output was also obtained by the same ionization chamber, permitting to evaluate ratios mGy/mAs for each available spectrum. The entrance air-kerma was calculated over a sample of 800 cranio-caudal mammograms and the average glandular dose obtained, assuming two mean glandular compositions of 50 and 30%, respectively. Digital systems showed very good linearity and comparable responses. The stability of the automatic exposure control was better than 5% for all systems. Regarding doses, the two mammography units that work mainly in contrast mode deliver, respectively, 17 and 28% more dose compared with those working in standard mode. For the latter mode, the mean average glandular dose was in the range 1.25–1.37 mGy and 1.37–1.49 mGy for the 50 and 30% glandular composition, respectively. Results of this study were compared with those of other surveys, showing that full-field digital mammography allows a significant clinical dose reduction compared with screen/film mammography.