Vomweg T W, Teifke A, Schreiber W G, Schmidt M, Thelen M
Klinik und Poliklinik für Radiologie, Klinikum der Universität Mainz, Germany.
Rofo. 2002 Nov;174(11):1445-9. doi: 10.1055/s-2002-35350.
Presentation of a new protocol for simultaneous acquisition of both low and high resolution T 1 -weighted images of breast lesions for dynamic contrast-enhanced MR mammography. Demonstration of possible diagnostic improvement with representative measurements in patients with suspected breast cancer by adding morphologic parameters from high resolution sequences to the analysis of the signal-time curve.
Dynamic MR imaging was performed with a 1.5 T system (Magnetom SONATA, Siemens Medical Systems, Germany) and the manufacturer's double-breast coil. Coronal T 1 -weighted 3D FLASH sequences (spatial resolution 1.25 x 1.25 mm 2; slice thickness 1.7 mm) were acquired once before and five times after administration of contrast medium (Gd-DTPA, 0.15 mmol/kg) injection. In addition, a high resolution T 1 -weighted 3D-FLASH sequence (spatial resolution, 0.63 x 0.63 mm 2) was obtained before administration of contrast medium and after the third post-contrast low-resolution sequence. Except for the acquisition matrix, all imaging parameters were identical for both 3D pulse sequences. To assure comparison of the measured signal intensities for both T 1 -weighted sequences, calibrating phantom measurements were performed using a dilution series of Gd-DTPA.
Phantom measurements demonstrated similar signal intensities and enhancement pattern for both sequences. A combined protocol consisting of both pulse sequences can be employed and does not interfere with the signal-time curve analysis. By measuring one high resolution sequence 3:18 minutes after administration of contrast medium, morphologic features can be evaluated without interference from barely enhancing surrounding tissue. The overall study time is not increased. The improved spatial resolution slightly increases the severity of motion artifacts.
The new protocol is a clever way to improve the measurement of morphologic features without relevant loss of dynamic information. It is superior to converting the entire investigation to high resolution sequences and does not add any costs by not extending or duplicating the investigation. How much the new protocol can improve the specificity or sensitivity of MR-mammography is currently investigated on a larger patient group.
介绍一种用于动态对比增强乳腺磁共振成像时同时采集乳腺病变低分辨率和高分辨率T1加权图像的新方案。通过将高分辨率序列的形态学参数添加到信号-时间曲线分析中，对疑似乳腺癌患者进行代表性测量，以证明可能的诊断改善。
使用1.5T系统（德国西门子医疗系统公司的Magnetom SONATA）和制造商的双侧乳腺线圈进行动态磁共振成像。在注射造影剂（钆喷酸葡胺，0.15 mmol/kg）前采集一次冠状面T1加权3D FLASH序列（空间分辨率1.25×1.25 mm²；层厚1.7 mm），注射后采集五次。此外，在注射造影剂前和第三次注射造影剂后的低分辨率序列后，获取高分辨率T1加权3D-FLASH序列（空间分辨率0.63×0.63 mm²）。除采集矩阵外，两个3D脉冲序列的所有成像参数均相同。为确保两个T1加权序列测量信号强度的可比性，使用钆喷酸葡胺稀释系列进行校准体模测量。
体模测量显示两个序列的信号强度和增强模式相似。可以采用由两个脉冲序列组成的联合方案，且不干扰信号-时间曲线分析。在注射造影剂3分18秒后测量一个高分辨率序列，可在不受周围组织轻微增强干扰的情况下评估形态学特征。总体研究时间未增加。提高的空间分辨率会使运动伪影的严重程度略有增加。
新方案是一种在不损失动态信息的情况下改善形态学特征测量的巧妙方法。它优于将整个检查转换为高分辨率序列，且不通过延长或重复检查增加任何成本。目前正在更大的患者群体中研究新方案能在多大程度上提高乳腺磁共振成像的特异性或敏感性。
