ENHANCED BOLD RESPONSE IN BREAST TUMORS INDUCED BY BREATH HOLDING

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 目前的肿瘤成像方案，特别是应用于乳腺癌候选人，要求使用药物造影剂。 这些药剂需要静脉注射，导致患者额外的不适，同时还需要合格的人员开始IV。一种通过简单地利用肿瘤的先天生理机能来实现完全非侵入性手术的替代方案是理想的。 肿瘤的一个定义属性是它们对氧的高亲和力，导致局部改变的灌注特性。 BOLD成像，最常用于功能磁共振成像研究，测量由刺激任务引起的给定区域的血流动力学变化。 在fMRI研究中，简单的屏气会引起缺氧，由于血流中氧气水平的变化，BOLD反应会增加。 这项研究证明了周期性缺氧导致的乳腺BOLD反应，以及它在区分肿瘤和其他乳腺组织方面的前景。 扫描协议使用3D螺旋堆叠成像序列，并使用频谱空间脉冲进行脂肪抑制。两名健康志愿者（均为24岁）和一名乳腺肿瘤患者（36岁）参加了这项研究。 健康志愿者在1.5T Signa GE扫描仪上扫描，而患者在1.5T Twin GE扫描仪上扫描。 每个参与者屏住呼吸15秒，然后进行15秒的常规呼吸，共7个周期。 BOLD结果的数据分析采用Adrian Lee等人建立的时间过程相关方法。 该方法将屏气周期与正弦函数相关联。 Gd增强图像中的恶性区域与缺氧刺激的早期反应BOLD图像中观察到的区域相同。 正如预期的那样，在缺氧条件下，致癌区域比健康区域更早做出反应，结果表明恶性组织与健康组织之间的时间延迟为7.5秒。 这项研究证明了BOLD图像如何在没有造影剂的情况下识别肿瘤区域，并有可能提供额外的诊断信息。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Current protocols for tumor imaging, specifically applied with breast cancer candidates, call for the use of pharmaceutical contrast agents. These agents require intravenous injection causing additional discomfort to the patient while also requiring qualified personnel to start the IV. An alternative that allows for a totally non-invasive procedure, by simply exploiting the innate physiology of tumors, is ideal. A defining property of tumors is their high affinity for oxygen, causing regionally altered perfusion characteristics. BOLD imaging, most commonly used in fMRI studies, measures the hemodynamic variation in a given region resulting from a stimulating task. Simple breath holding, which induces hypoxia, shows an increased BOLD response in fMRI studies due to variation of the oxygen levels in the bloodstream. This study demonstrates the BOLD response in the breast resulting from periodic hypoxia, and its promise in differentiating tumors from other breast tissue. The scan protocol used a 3D ¿stack of spirals¿ imaging sequence with a spectral-spatial pulse for fat suppression. Two healthy volunteers (both age 24) and one breast tumor patient (age 36) participated in the study. The healthy volunteers were scanned on a 1.5T Signa GE scanner, while the patient was scanned on a 1.5T Twin GE scanner. Each participant held their breath for 15 s intervals followed by 15 s of regular breathing, for 7 cycles. Data analysis of BOLD results applied a time course correlation method established by Adrian Lee et al. The method correlates the breath holding cycle to sinusoidal functions. Malignant regions present in Gd enhanced images paralleled regions observed in early response BOLD images stimulated by hypoxia. As expected, carcinogenic regions responded earlier than healthy regions under hypoxic conditions, with results indicating a 7.5 s time delay between the malignant verses healthy tissue. This study demonstrates how BOLD images can identify tumor regions without contrast agents, with the potential of providing additional diagnostic information.