利用计算机辅助分析在动态乳腺磁共振成像中导管原位癌（DCIS）的动力学特征

Vag Tibor, Baltzer Pascal A T, Dietzel Matthias, Benndorf Matthias, Gajda Mieczyslaw, Camara Oumar, Kaiser Werner A

Institute of Diagnostic and Interventional Radiology, Friedrich Schiller University Jena, Jena, Germany.

Acta Radiol. 2010 Nov;51(9):955-61. doi: 10.3109/02841851.2010.508171.

BACKGROUND

Enhancement characteristics of breast lesions are regarded as a major criterion for their differential diagnosis in dynamic breast MRI (bMRI). However, ductal carcinoma in situ (DCIS) exhibits a highly heterogeneous enhancement pattern when kinetic analysis is performed conventionally by manual placement of region of interest (ROI) and therefore its diagnosis remains challenging.

PURPOSE

To compare enhancement characteristics of DCIS lesions on dynamic bMRI using manual ROI placement with computer-aided analysis and to evaluate whether the latter might increase the detection rate of kinetic features suspicious for malignancy.

MATERIAL AND METHODS

The enhancement patterns of 47 histopathologically verified pure DCIS lesions were evaluated on bMRI images using manual ROI placement as well as a commercially available computer analysis software. The latter is able to automatically assess enhancement characteristics of a whole lesion pixelwise. Kinetic features evaluated included classification of lesion enhancement pattern into washout, plateau or persistent curve type. A washout and plateau enhancement pattern are regarded as suggestive for malignancy.

RESULTS

Morphological classification revealed focus-like enhancement in 2 lesions, mass enhancement in 11, and non-mass enhancement in 34. Manual placement of ROI demonstrated a suspicious enhancement pattern in 51.1% of the DCIS lesions, which could not be significantly increased using computer-aided analysis. Of the mass and non-mass-enhancing DCIS lesions, 90.9% and 38.3%, respectively, demonstrated suspicious kinetic curves. After application of the automated analysis software, the detection rate of suspicious enhancement patterns was unchanged in mass DCIS lesions and increased to 52.9% in non-mass DCIS lesions (P=0.33). However, the increase in the detection of washout curves alone was significant (P=0.02). In all, 40% of G1, 41.1% of G2, and 60% of G3 lesions demonstrated a suspicious curve type with manual evaluation. Computer analysis increased the detection of suspicious enhancement patterns in a non-significant manner to 50%, 58.8%, and 70%, respectively.

CONCLUSION

The detection of suspicious enhancement curves could not be significantly increased in DCIS lesions when using computer-aided analysis despite a significantly higher detection rate of washout curves alone.

背景

乳腺病变的强化特征被视为动态乳腺磁共振成像（bMRI）中鉴别诊断的主要标准。然而，当通过手动放置感兴趣区域（ROI）进行传统的动力学分析时，原位导管癌（DCIS）表现出高度异质性的强化模式，因此其诊断仍然具有挑战性。

目的

比较在动态bMRI上使用手动ROI放置与计算机辅助分析时DCIS病变的强化特征，并评估后者是否可能提高对可疑恶性动力学特征的检出率。

材料与方法

使用手动ROI放置以及市售的计算机分析软件，在bMRI图像上评估47例经组织病理学证实的纯DCIS病变的强化模式。后者能够逐像素自动评估整个病变的强化特征。评估的动力学特征包括将病变强化模式分类为廓清型、平台型或持续型曲线类型。廓清型和平台型强化模式被视为提示恶性。

结果

形态学分类显示2例为局灶样强化，11例为肿块样强化，34例为非肿块样强化。手动放置ROI显示51.1%的DCIS病变有可疑强化模式，使用计算机辅助分析时这一比例无显著增加。在肿块样和非肿块样强化的DCIS病变中，分别有90.9%和38.3%表现出可疑的动力学曲线。应用自动分析软件后，肿块样DCIS病变中可疑强化模式的检出率不变，非肿块样DCIS病变中增加至52.9%（P=0.33）。然而，仅廓清曲线的检出增加具有显著性（P=0.02）。总体而言，在手动评估时，40%的G1级、41.1%的G2级和60%的G3级病变表现出可疑曲线类型。计算机分析将可疑强化模式的检出率分别非显著性提高至50%、58.8%和70%。