Manual or auto-mode: Does this affect radiation dose in digital mammography without compromising image quality?

IntroductionIn current practice, auto-filter exposure mode is used for most screening mammography examinations. However, with better understanding of the side effects of radiation, it is important to examine exposure parameters and practises to minimise radiation dose to patients. The purpose of this phantom study is to investigate the impact that different exposure modes (manual, auto-time and auto-filter) have on radiation dose, while maintaining images of diagnostic quality.MethodsThis study was conducted in three stages. In the first stage, 125 images were taken using a Gammex 156 phantom with polymethyl methacrylate blocks to reflect varying thicknesses (4.5, 5.0, 5.5, 6.0 and 6.5 cm). In the second stage, three mammographers independently assessed image quality and assigned scores based on the number of distinct fibers, masses and speck groups visible. Images with acceptable quality were further investigated in the third stage by comparing their average glandular dose (AGD) using the Kruskal–Wallis H test and Dunn's post-hoc pairwise analysis.ResultsSignificant differences in AGD were shown between the auto-filter mode and manual mode techniques for 6.0 cm, and between auto-time mode and manual mode techniques for 6.5 cm (p < 0.05).ConclusionFor 4.5, 5.0 and 5.5 cm phantoms, as AGD was not significantly different among the different modes, the auto-filter may remain the most practical option. However, significant reductions in AGD were obtained for the 6.0 and 6.5 cm phantoms when manual mode techniques were used.Implications for practiceManual mode techniques can potentially provide dose-saving opportunity in 6.0 and 6.5 cm breast thickness though future work on human breast should be done to confirm this. Results from this study will support future research based on patient data.     

Do Decreased Breast Microcalcifications After Neoadjuvant Chemotherapy Predict Pathologic Complete Response?

BackgroundClinical response evaluation by image examination after neoadjuvant chemotherapy for breast cancer is important for determining drug response and progression. Mammography is less correlated with pathologic response assessment than magnetic resonance imaging or ultrasonography. The present study clarified characteristics of breast cancer patients with decreased microcalcifications after neoadjuvant chemotherapy to increase the accuracy of mammographic assessment.Patients and MethodsConsecutive patients who received neoadjuvant chemotherapy for breast cancer at our hospital from January 2013 to June 2017 were retrospectively reviewed. Characteristics of cases of microcalcifications before neoadjuvant chemotherapy and those showing a reduction after were examined. Stromal tumor-infiltrating lymphocytes were evaluated in the biopsy. Pathologic complete response was also explored in patients exhibiting a decrease in microcalcifications by neoadjuvant chemotherapy.ResultsSeventy breast cancer cases were included; 37 had no malignant microcalcifications before neoadjuvant chemotherapy and 33 did. Breast cancer with microcalcifications was significantly more positive for human epidermal growth factor receptor 2 than those without microcalcifications (48% vs. 22%, P = .018). Only 6 of 33 patients with microcalcifications before neoadjuvant chemotherapy showed a decrease after treatment. These patients tended to have high stromal tumor-infiltrating lymphocytes (50% vs. 17%), segmental microcalcifications (66% vs. 33%), and pleomorphic/linear microcalcifications (83% vs. 37%).ConclusionThese results suggest that neoadjuvant chemotherapy is able to decrease malignant calcifications, particularly segmental and pleomorphic/linear microcalcifications. By clarifying the mechanisms of formation and disappearance of microcalcifications, a consensus can be reached on whether microcalcifications apparent by mammography are useful for evaluating response to neoadjuvant chemotherapy.     

数字乳腺断层摄影技术中大、小角度曝光的辐射剂量比较

背景与目的：数字乳腺断层摄影技术（digital breast tomosynthesis，DBT）是近几年推出的一项用于乳腺X线摄影检查的技术，可较好地显示乳腺病灶，对乳腺病变的检出和诊断具有重要意义。目前人们多集中于大或小角度曝光的辐射剂量研究，而有关大、小角度曝光辐射剂量有何差异的研究报道较少。对DBT中采用大、小角度曝光的辐射剂量进行分析和比较，以了解DBT检查时运用不同曝光角度在辐射剂量方面的差异。方法：2016年7月—2016年9月，收集临床可触及乳腺肿块在复旦大学附属肿瘤医院进行乳腺X线摄影检查的患者共209例，100例入组DBT-HR模式行常规全数字化乳腺X线摄影（full field digital mammography，FFDM）和DBT的大角度摄影、109例入组DBT-ST模式行常规FFDM和DBT的小角度摄影。分别比较两种曝光角度的辐射剂量差异，并对不同乳腺腺体类型、不同年龄阶段和不同摄影体位的辐射剂量差异进行比较。结果：DBT检查时采用HR模式的平均腺体剂量（average gland dose，AGD）均值2.76 mGy较ST模式的AGD均值1.37 mGy高出50.36%，差异有统计学意义（P<0.05）。DBT检查下对不同乳腺腺体类型比较时，HR模式的AGD值差异无统计学意义（P>0.05）；ST模式的AGD值差异有统计学意义（P<0.05）；对两种模式进行组间比较时，HR模式 b、c、d三种腺体类型的AGD值分别增加了50.16%、51.20%和45.19%，并可见c型腺体的AGD增幅最大，d型腺体的AGD增幅最少，差异有统计学意义（P<0.05）。对不同年龄阶段患者比较时，两种模式的AGD值差异均有统计学意义（P<0.05）；对两种模式的AGD值进行组间比较时，HR模式5组年龄段的AGD值分别增加了52.17%、50.53%、45.56%、51.54%和49.04%，并可见≤40岁年龄段患者的AGD值增幅最大，51~60岁年龄段患者的AGD值增幅最少，差异有统计学意义（P<0.05）。对头尾（cranio-caudal，CC）位和内外侧斜（medial-lateral oblique，MLO）位不同压迫厚度的断层辐射剂量比较时，两种模式的AGD差异值均有统计学意义（P<0.05）；对两种模式的AGD值进行组间比较时，HR模式5组不同压迫厚度的AGD值在CC位分别增加了37.07%、47.94%、53.09%、50.06%和49.79%；在MLO位分别增加了35.15%、46.24%、53.26%、49.14%和48.04%；且2种体位均显示压迫厚度40~49 mm组的AGD值增幅最大，压迫厚度≤29 mm组的AGD值增幅最少，差异有统计学意义（P<0.05）。结论：DBT检查时采用大或小角度曝光的辐射剂量是有差异的，且不同乳腺腺体类型、不同年龄阶段患者、不同摄影体位的辐射剂量均有差异，但仍在规定的辐射剂量值范围内，所以DBT检查是一项安全、可靠的技术，临床可根据实际需要开展应用。     

Resuming Breast Imaging Services in the Aftermath of the COVID-19 Pandemic: Safety and Beyond

As the Coronavirus disease 2019 (COVID-19) epidemic begins to stabilize, different medical imaging facilities not directly involved in the COVID-19 epidemic face the dilemma of how to return to regular operation. We hereby discuss various fields of concern in resuming breast imaging services. We examine the concerns for resuming functions of breast imaging services in 2 broad categories, including safety aspects of operating a breast clinic and addressing potential modifications needed in managing common clinical scenarios in the COVID-19 aftermath. Using a stepwise approach in harmony with the relative states of the epidemic, health care system capacity, and the current state of performing breast surgeries (and in compliance with the recommended surgical guidelines) can ensure avoiding pointless procedures and ensure a smooth transition to a fully operational breast imaging facility.     

Standardised or individualised X-ray tube angle for mediolateral oblique projection in digital mammography?

IntroductionWe aimed to investigate whether there were any differences in positioning criteria related to the presentation of the pectoralis major muscle (pectoral muscle) for women of different heights using a standardized 60° X-ray tube angle for mammograms in mediolateral oblique (MLO) projection.MethodsData from MLO mammograms of right breasts of 45,193 women screened in BreastScreen Norway 2016–2019 were used. The positioning criteria were related to the pectoral muscle length (measure A and measure B), width and shape and considered adequate or inadequate depending on the degree of fulfilling the criteria. Data associated with the pectoral muscle were extracted from Volpara, an automated software for breast density assessment. Information on height was obtained from a self-reported questionnaire received by the women together with the invitation to attend the screening program. Women were divided into three groups based on the height percentiles (P) in the Norwegian growth curves: < 25th percentile (<P25th: ≤163 cm), 25th-75th percentile (P25–P75th: 164–170 cm), and >75th percentile (>P75th: >170 cm). Logistic regression was used to analyse the odds of adequate pectoral muscle length A and B, and shape, adjusting each model for screening technique and equipment model. Results were presented with odds ratios (OR) and 95% confidence intervals (CI).ResultsMean age of the screened women was 61.5 (SD = 4.8) years. The adequate measure for the pectoral muscle length A was obtained for 25.9% (11,724/45,193), length B for 76.3% (34,489/45,193), width for 75.0% (33,894/45,193) and shape for 97.6% (44,118/45,193) of the mammograms. Adjusted odds of an adequate pectoral muscle length A were lower for women of <P25th (OR = 0.90, 95% CI: 0.86–0.95) compared to women of P25-75th. Odds of an adequate pectoral muscle length B were lower for women of <P25th (OR = 0.88, 95% CI 0.84–0.93) and higher for women of >P75th (OR = 1.08, 95% CI 1.02–1.14) compared to women of P25-75. Odds of an adequate pectoral muscle shape were higher for women of <P25th (OR = 1.14, 95%CI 1.08–1.19) and lower for women of >P75th (OR = 0.92, 95% CI 0.87–0.97) compared to women of P25-75th.ConclusionThe 60° X-ray tube angle might suit most of the female population offered mammographic screening in Norway, but women of a relatively low height (163 cm or lower) might benefit from an X-ray tube angle less than 60-degrees.Implications for practiceUsing 60° X-ray tube angle for the MLO mammograms in BreastScreen Norway fit the majority of the participating women. More research is needed to change the protocol associated with the tube angle for women shorter than 163 cm.     

Validación del instrumento Informed Choice para medir la decisión informada de mamografía en mujeres chilenas usuarias de atención primaria

ObjetivoAdaptar y validar el instrumento Informed Choice (IC) para la decisión de mamografía al contexto chileno.DiseñoEstudio transversal, analítico, de adaptación y validación psicométrica.EmplazamientoCentro de atención primaria del sector sur oriente de Santiago de Chile.Métodos1) traducir y contra-traducir IC; 2) realizar un grupo focal para la relevancia cultural/lingüística; 3) examinar la validez del contenido; 4) pilotar el instrumento; 5) aplicar para validación. Para la consistencia interna se usó el alfa de Cronbach, prueba de esfericidad de Bartlett y la medida de Kaiser-Meyer-Olkin para determinar correlaciones entre las variables y análisis factorial.ResultadosSe construyeron 3 versiones del IC, modificándose según la opinión de usuarios y expertos. La validación se llevó a cabo en una muestra de 70 mujeres. La edad media fue de 54,4 años, el 47,1% de educación secundaria completa y el 92,9% al menos se había realizado alguna vez una mamografía. Se realizó análisis factorial del IC y se eliminó uno de sus ítems. El alfa de Cronbach final fue 0,79.ConclusiónEl uso de instrumentos de medición requiere de su validación previa ya que la versión original puede variar de acuerdo al contexto cultural donde será aplicado y las necesidades locales particulares. El proceso de validación del IC permite contar con un instrumento confiable para medir la decisión de las mujeres que deben realizarse la mamografía en la dimensión conocimiento, actitud e intención hacia el examen.Palabras clave: Toma de decisiones en salud, Cáncer de mama, Mamografía     

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.     

原发性乳腺淋巴瘤的影像学表现与病理学特征

目的分析原发性乳腺淋巴瘤的超声、钼靶X线、CT的影像学表现及组织病理学特征。方法回顾性分析40例(47个病灶)原发性乳腺淋巴瘤的临床资料、超声、钼靶X线、CT表现及病理特征。结果 40例中超声检出47个肿块,33个(33/47,70.21%)呈椭圆形或圆形,40个(40/47,85.11%)边界清晰,35个(35/47,74.47%)表现为低回声,31个(31/47,65.96%)后方回声增强,26个(26/47,55.32%)有较丰富血流信号。对21例行钼靶X线检查,于18例中发现21个病灶,11个(11/21,52.38%)边界清楚,14个(14/21,66.67%)形态规则,18个(18/21,85.71%)呈高密度。对7例行CT检查,共检出8个病灶,6个(6/8,75.00%)病灶为等增强或略高增强的规则肿块;所有病灶均无钙化、毛刺征。结论原发性乳腺淋巴瘤影像学表现有一定特点,但仍缺乏特异性,确诊仍要依靠组织病理学及免疫组化。     

乳腺照相辅以导丝定位活检对诊断乳腺原位癌的意义

目的 探讨乳腺X线钼靶照相辅以细针穿刺导丝定位活检技术对提高原位癌诊断率的意义。方法 收集1997—2000年病理确诊的乳腺癌679例；以及近半年来手术或活检病理证实的乳腺癌74例，术前51例行乳腺钼靶照相，其中4例行定位活检。比较两个时期乳腺原位癌的发现率。结果 1997—2000年679例乳癌患者原位癌18例，占乳癌2．7％。近半年来74例乳癌患者中，原位癌4例，发现率为5．4％。比1997—2000年明显增高。结论 乳腺钼靶X线照相及穿刺定位活检技术可以提高原位癌的诊断率。