BACKGROUND To analyse if performing unenhanced CT of the liver aids in the evaluation of metastatic lesions, response assessment or alter the size of the lesions, compared with portal phase alone, in patients with hepatic metastases from breast carcinoma. PATIENTS AND METHODS One-hundred and fifty-three CT scans of 36 women were included. Scans consisted of unenhanced, arterial and portal delayed phases of the liver. Two readers sorted which phase was best for visualization of metastases, evaluated the number of lesions detected in each phase, selected the best phase for assessment of response in two consecutive scans, and measured one target lesion in all the phases. Χ2 was used to compare differences among phases and paired t test for measurement differences. RESULTS Unenhanced, arterial and portal phases were considered better phases by readers 1/2 in 68/67%, 27/28% and 69/70%, and some lesions were missed in 2%, 11% and 7%, respectively. Sensitivity was significantly better for unenhanced and portal phases compared to arterial phase. Comparison between consecutive scans was considered better in unenhanced (80/79%), followed by portal (70/69%) and arterial phases (31/31%). Maximum diameter of target lesions was 15% greater in unenhanced phase (p < 0.001). CONCLUSIONS Portal and unenhanced phases of the liver allow better detection and delineation of metastatic hepatic lesions from breast carcinoma. In most cases, unenhanced CT is the best phase to assess response and provides the largest diameter. Therefore, we recommend the use of unenhanced CT in the evaluation of patients with breast carcinoma and suspected or known hepatic metastatic disease.

中文翻译：

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肝脏未增强期在转移性乳腺癌扫描方案中的作用：对敏感性、反应评估和大小测量的影响。

背景 与单纯门静脉期相比，在乳腺癌肝转移患者中，分析肝脏平扫 CT 是否有助于评估转移性病灶、评估疗效或改变病灶大小。患者和方法 包括 36 名女性的 153 次 CT 扫描。扫描包括肝脏的未增强期、动脉期和门脉延迟期。两位读者对哪个阶段最适合转移瘤的可视化进行分类，评估在每个阶段检测到的病灶数量，在两次连续扫描中选择最佳阶段来评估反应，并在所有阶段测量一个目标病灶。Χ2 用于比较相位之间的差异，并使用配对 t 检验测量差异。结果未增强，68/67%、27/28% 和 69/70% 的读者 1/2 认为动脉期和门脉期较好，部分病灶漏诊率分别为 2%、11% 和 7%。与动脉期相比，未增强期和门静脉期的敏感性明显更好。连续扫描之间的比较在未增强 (80/79%) 中被认为更好，其次是门静脉期 (70/69%) 和动脉期 (31/31%)。在未增强期，目标病灶的最大直径增加了 15%（p < 0.001）。结论 肝脏的门脉期和非增强期可以更好地检测和描绘来自乳腺癌的转移性肝病灶。在大多数情况下，平扫 CT 是评估反应的最佳阶段并提供最大的直径。所以，