Radiology：断层融合技术可提高乳房X光成像**度

　　一项发表在《放射学》杂志1月刊上的研究显示，将断层融合技术(对乳房进行三围成像)与数字乳房X线摄影结合起来可提高放射肿瘤诊断精确度，同时还能大大降低非癌症病例的回诊次数。

　　来自美国麻省总医院的Elizabeth A. Rafferty博士和同事们进行了一项多中心试验，共涉及1192名女性，这些女性均接受了双乳房内外斜位和头尾位的数字X光成像和断层融合成像。放射肿瘤学家然后对同时接受这两种成像的女性和只接受乳房X线成像的女性进行了诊断精确度和回诊率方面的比较。

　　研究人员发现，同时接受断层融合成像和数字乳房X光成像可大大提高诊断效果，使研究中的全部27名放射肿瘤学家更准确地做出相应的诊断。此外，将二者结合起来还能显著降低患者的回诊率。最后，这种联合方式对某些激进型癌症的敏感性也得到了明显提升，提升幅度在15到22个百分点之间，而对于原为癌症来说，这种联合疗法对其的敏感性也有3个百分点的提升。

　　研究人员表示：“总的来说，将断层融合成像与数字乳房X光成像联合起来不仅能大大提高诊断的精准度，而且还能显著降低假阳性病例回诊率，这样就能避免女性进行不必要的额外检测，同时降低她们的焦虑、不便以及相关花费。”

Assessing Radiologist Performance Using Combined Digital Mammography and Breast Tomosynthesis Compared with Digital Mammography Alone: Results of a Multicenter, Multireader Trial

Purpose

To compare radiologists’ diagnostic accuracy and recall rates for breast tomosynthesis combined with digital mammography versus digital mammography alone. 

Materials and Methods

Institutional review board approval was obtained at each accruing institution. Participating women gave written informed consent. Mediolateral oblique and craniocaudal digital mammographic and tomosynthesis images of both breasts were obtained from 1192 subjects. Two enriched reader studies were performed to compare digital mammography with tomosynthesis against digital mammography alone. Study 1 comprised 312 cases (48 cancer cases) with images read by 12 radiologists; study 2, 312 cases (51 cancer cases) with 15 radiologists. Study 1 readers recorded only that an abnormality requiring recall was present; study 2 readers had additional training and recorded both lesion type and location. Diagnostic accuracy was compared with receiver operating characteristic analysis. Recall rates of noncancer cases, sensitivity, specificity, and positive and negative predictive values determined by analyzing Breast Imaging Reporting and Data System scores were compared for the two methods. 

Results

Diagnostic accuracy for combined tomosynthesis and digital mammography was superior to that of digital mammography alone. Average difference in area under the curve in study 1 was 7.2% (95% confidence interval [CI]: 3.7%, 10.8%; P < .001) and in study 2 was 6.8% (95% CI: 4.1%, 9.5%; P < .001). All 27 radiologists increased diagnostic accuracy with addition of tomosynthesis. Recall rates for noncancer cases for all readers significantly decreased with addition of tomosynthesis (range, 6%–67%; P < .001 for 25 readers, P < .03 for all readers). Increased sensitivity was largest for invasive cancers: 15% and 22% in studies 1 and 2 versus 3% for in situ cancers in both studies. 

Conclusion

Addition of tomosynthesis to digital mammography offers the dual benefit of significantly increased diagnostic accuracy and significantly reduced recall rates for noncancer cases.