Computerized classification of benign and malignant masses on digitized mammograms: a study of robustness

RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate the robustness of a computerized method developed for the classification of benign and malignant masses with respect to variations in both case mix and film digitization. MATERIALS AND METHODS: The classification method included automated segmentation of mass regions, automated feature-extraction, and automated lesion characterization. The method was evaluated independently with a 110-case database consisting of 50 malignant and 60 benign cases. Mammograms were digitized twice with two different digitizers (Konica and Lumisys). Performance of the method in differentiating benign from malignant masses was evaluated with receiver operating characteristic (ROC) analysis. Effects of variations in both case mix and film digitization on performance of the method also were assessed. RESULTS: Categorization of lesions as malignant or benign with an artificial neural network (or a hybrid) classifier achieved an area under the ROC curve, Az, value of 0.90 (0.94 for the hybrid) on the previous training database in a round-robin evaluation and Az values of 0.82 (0.81) and 0.81 (0.82) on the independent database for the Konica and Lumisys formats, respectively. These differences, however, were not statistically significant (P > .10). CONCLUSION: The computerized method for the classification of lesions on mammograms was robust with respect to variations in case mix and film digitization.     

乳腺癌钙化168例X线分析

目的　通过对乳腺癌钙化的分析 ,评估钼靶软线摄影对乳腺癌钙化的诊断意义。方法　对 16 8例女性患者采用上海产MO 30型乳腺摄影机进行乳腺照相 ,并对照手术病理结果 ,分析乳腺癌钙化的X线特征 ,病理类别关系及临床指导意义。结果　乳腺癌钙化的出现率是 32 % ,其中恶性钙化占 96 % (16 1/ 16 8) ,乳腺癌钙化而无肿物的占 2 8% (4 7/ 16 8) ,乳腺癌钙化以导管内癌及浸润性导管癌为首位 ,占 73 % (12 2 / 16 8)。结论　乳腺钼靶软线摄影在诊断乳腺癌钙化方面是其它影像学检查所不能替代的 ,在诊断与鉴别诊断中有重要价值。     

乳腺良恶性肿块的钼靶X线征象分析

目的提高对乳腺疾病的钼靶X线征象认识。材料和方法良性病变60例(69个病灶),恶性病变51例(55个病灶),年龄13～72岁。患者均行乳腺钼靶X线摄影并经手术病理证实。结果良性病灶多为圆形、卵圆形,边缘规则,等密度、低密度或混合密度,80％的病灶可见完全或不完全的晕环。恶性病灶多为分叶形或不规则形,80%为高密度,20%为等密度,没有低密度和混合密度病灶。病灶边缘模糊,61％伴有钙化,39％患侧血管增粗扭曲紊乱。结论钼靶乳腺摄影是乳腺影象学检查的首选方法,95%以上的病变可望术前作出正确诊断。     

Preoperative MR-guided wire localization for suspicious breast lesions: Comparison of manual and automated software calculated targeting

Objectives

Preoperative magnetic resonance (MR) guided wire localization is a frequently used tool to target MR-only visible breast lesions. Different techniques are available. Targeting can be performed using automated software or a manual approach. Aim of this study therefore was to compare manually and automated software assisted wire localization of suspicious breast lesions regarding to image time and accurate positioning.

Methods

60 females with suspicious breast lesions underwent MR-guided wire localization. In 30 patients a manual target calculation and in another 30 patients a software calculated approach was used. Time measurements for MR imaging as well as calculation of the target coordinates were performed. Furthermore size measurements of (i) lesions, (ii) distance to wire anchor as well as, (iii) distance to skin were performed. A Mann-Whitney-test was used for statistical evaluation.

Results

Total imaging time was shorter for the automated software calculated approach but failed to show a statistical significant difference (p = 0.13). Time for localization of the lesions was significantly shorter for the software based method (p < 0.001). Lesion sizes, distances to wire anchor and skin showed no statistically significant differences.

Conclusions

Preoperative MR-guided wire localization of suspicious lesions that are accessible horizontally, a manually or automated software generated target calculation can be used. As MR guided wire localization of breast lesions needs its time in total, a minimal time consuming approach and therefore an automated software calculated targeting (if available) should be preferred.     

钼靶摄片诊断乳腺导管内癌价值的初步探讨

目的探讨乳腺钼靶摄片对乳腺导管内癌（ductal carcinoma in Situ,DCIS）的诊断价值。方法按照病人主诉分组,回顾性分析20例患者、21个经病理证实为DCIS病灶的钼靶影像特征,与病理结果对照研究。结栗以触诊乳腺肿物为主诉的9例患者10个病灶中,表现为结节并微小钙化者6例,乳头血性溢液者1例,片状增高密度影2例,另1例患者影像表现阴性,上述后3例病灶行细针穿刺细胞学检查确诊;以腺体增厚为主诉的5例患者中,钼靶表现为腺体结构紊乱,密度不均,其中2例伴微小钙化及乳头溢液,单纯性微小钙化3例;以单纯性乳头溢液为主诉者2例,均伴微小钙化,导管造影示导管局部显影中断或间断显影;以乳腺癌术后复查发现另一侧乳腺单纯性微小钙化灶者2例;1位患者因乳腺脂肪瘤而漏诊。结论钼靶影像学能为DCIS的诊断提供重要依据,尤其对临床检查阴性的患者,乳腺钼靶摄片辅以导管造影及细针穿刺细胞学检查是诊断早期乳腺癌不可或缺的手段。     

Breast cancer screening for older women with intellectual disability living in community group homes

Breast cancer is one of the commonest cancers to affect women. Present health service guidelines call for screening and mammography for all women aged between 50 and 65 years in an effort to increase early detection and improve survival rates. Nulliparity is one of the associated risk factors for breast cancer. Women with intellectual disability (ID) are increasing in longevity and are frequently nulliparous, and therefore, they are at increased risk of developing breast cancer. The aim of the present study was to review the uptake and knowledge of women with ID living in the community of breast screening programmes. A postal survey of women aged ≥ 50 years with ID living in community group homes was used to gather data. Only one-third of the women carried out regular breast examination and a similar proportion had received invitations to mammography. General practitioners and practice nurses were currently playing very minor roles in breast screening these women. Primary health care professionals may be missing opportunistic health promotion opportunities and the support services for women with ID living in the community could be provided with better training and resources to improve breast cancer screening in this vulnerable group.     

How significant is detection of ductal carcinoma in situ in a breast screening programme?

PURPOSE: To compare the histological grades of screen detected and non-screen detected ductal carcinoma in situ (DCIS) and to identify any differences that might support the contention that DCIS found by breast screening represents an over-diagnosis. The aim was also to establish whether any particular mammographic features of DCIS can be used to predict tumour grade reliably. MATERIALS AND METHODS: Biopsy proven cases of DCIS (n=153) were reviewed with respect to grade and subdivided into high, intermediate and low grades using the Van Nuys classification. A more aggressive subset of DCIS (microinvasive and interval cancers) were similarly analysed. Mammograms were reviewed with regard to abnormal features and distribution, and the appearances correlated with grade. RESULTS: Fifty-four percent (53/98) of screen detected and 62% (34/52) of non-screen detected DCIS were high grade. The rest were equally intermediate and low grade, with no statistical difference between the two groups. Eighty-four percent of the aggressive subset of tumours were high grade. Micro-calcification was present in 90% and in 10% there were soft tissue changes alone. Seventy-six percent of linear branching calcification was associated with high grade DCIS. Only 13% of high grade DCIS demonstrated punctate micro-calcification; however, 38% of cases of punctate micro-calfication were associated with high grade tumours and there was a great deal of overlap between the groups. CONCLUSION: Most cases of DCIS in both screen and non-screen detected groups were high grade. Only one in five was low grade. Analysis of the aggressive subgroup underlines the significance of high grade DCIS. Mammographic patterns are not always reliable in the prediction of tumour grade. The detection of DCIS in screening programmes is important and should not be regarded as over-diagnosis.     

A New Estrogen Receptor Antagonist – An Overview of Available Data

A population-based study was performed to compare the characteristics of clinically detected breast cancers and cancers detected by the Dutch screening program. To determine whether differences are most likely to be explained by earlier diagnosis or by the detection of biologically different cancers in the screening program, comparisons were stratified according to tumor size. Data were obtained from the population-based Eindhoven Cancer Registry. During the period 1996–1999, 568 screen-detected and 630 clinically detected invasive breast cancers were available for analysis. Compared with patients with clinically detected breast cancer, women with screen-detected breast cancer had smaller tumors (P < 0.0001), were more likely to have negative lymph nodes (P < 0.0001), tumors with a positive estrogen (P = 0.007) or progesterone (P = 0.019) receptor status and a lower mitotic activity index (P = 0.009). In the group with cancers 1.0 cm the screen-detected were more likely to have negative estrogen receptors (P = 0.027). The group with screen-detected tumors 1.1–2.0 cm across were more likely to have positive estrogen and progesterone receptors (P = 0.005 and P = 0.044, respectively) and tended to have a lower mitotic activity index (P = 0.078). No significant differences were found between screen-detected and clinically detected breast cancers of 2.1–3.0 cm across. After adjustments for tumor size, most of the differences between clinically detected and screen-detected breast cancers disappeared, suggesting that screen-detected breast cancers represent tumors in an earlier phase of their development, not a biologically different class.