Department of Radiology, Group Health, Tacoma Medical Center, Tacoma, WA 98405, USA.
AJR Am J Roentgenol. 2012 Sep;199(3):703-8. doi: 10.2214/AJR.11.7836.
The purpose of this study was to compare the differences in kinetic assessments of lesions at breast MRI performed with higher and lower temporal resolution.
All consecutively evaluated BI-RADS category 4, 5, and 6 lesions imaged with breast MRI and pathologically confirmed from October 2005 to August 2009 were identified. Patients underwent MRI with one of two dynamic contrast-enhanced protocols: one with 90-second (October 2005-June 2006) and another with 180-second (July 2006-August 2009) temporal resolution. Studies were processed with a computer-aided evaluation system with initial and delayed contrast-enhanced time points with the k-space centered 90 and 450 seconds after contrast injection. Initial-phase peak enhancement, delayed-phase predominant curve type, and worst curve type were recorded and compared for benign and malignant lesions across protocols.
The analysis set comprised 993 lesions: 145 imaged with the 90-second acquisition (17 benign, 28 ductal carcinoma in situ [DCIS], 100 invasive cancer) and 848 imaged with the 180-second acquisition (212 benign, 145 DCIS, 491 invasive cancer). Peak enhancement was significantly higher for both benign lesions (p = 0.01) and invasive cancers (p = 0.0008) with the 180-second protocol. Peak enhancement of DCIS was similar in the two protocols (p = 0.88). Delayed-phase kinetics were similar for the two protocols for both benign and malignant lesions when defined by predominant or worst curve type.
Although it has lower temporal resolution, a 180-second acquisition may be preferable because it allows higher spatial resolution and captures higher initial-phase peak enhancement without loss of delayed-phase kinetic information.
本研究旨在比较采用更高和更低时间分辨率进行乳腺 MRI 病变的动力学评估的差异。
所有在 2005 年 10 月至 2009 年 8 月间进行的乳腺 MRI 检查并经病理证实的 BI-RADS 分类 4、5 和 6 类病变均被识别。患者接受了两种动态对比增强方案之一的 MRI 检查：一种方案的时间分辨率为 90 秒（2005 年 10 月至 2006 年 6 月），另一种方案的时间分辨率为 180 秒（2006 年 7 月至 2009 年 8 月）。研究采用计算机辅助评估系统进行处理，具有初始和延迟对比增强时间点，在对比剂注射后 90 和 450 秒时 k 空间居中。记录和比较了两个方案中良性和恶性病变的初始相峰值增强、延迟相优势曲线类型和最差曲线类型。
分析集包括 993 个病变：145 个采用 90 秒采集（17 个良性、28 个导管原位癌[DCIS]、100 个浸润性癌），848 个采用 180 秒采集（212 个良性、145 个 DCIS、491 个浸润性癌）。180 秒方案的良性病变（p=0.01）和浸润性癌（p=0.0008）的峰值增强均显著升高。两种方案的 DCIS 峰值增强相似（p=0.88）。两种方案对良性和恶性病变的延迟相动力学均以优势或最差曲线类型定义时相似。
虽然 180 秒采集的时间分辨率较低，但由于其允许更高的空间分辨率和捕获更高的初始相峰值增强而不丢失延迟相动力学信息，因此可能更可取。
