ENHANCED BOLD RESPONSE IN BREAST TUMORS INDUCED BY BREATH HOLDING

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 目前的肿瘤成像方案，特别适用于乳腺癌候选病例，要求使用药物造影剂。这些药物需要静脉注射，给患者带来额外的不适，同时还需要有资格的人员开始静脉注射。理想的替代方案是允许完全非侵入性的程序，只需利用肿瘤的固有生理学。肿瘤的一个决定性特征是其对氧气的高亲和力，导致局部血流特征的改变。 BOLD成像是功能磁共振研究中最常用的成像，它测量刺激任务导致的给定区域的血流动力学变化。由于血液中氧气水平的变化，简单的屏气会导致缺氧，在功能磁共振研究中显示出更大胆的反应。这项研究展示了周期性缺氧引起的乳腺的大胆反应，以及它在区分肿瘤和其他乳腺组织方面的前景。 扫描方案使用3D螺旋成像序列和光谱-空间脉冲来抑制脂肪。两名健康志愿者(均为24岁)和一名乳腺肿瘤患者(36岁)参与了这项研究。健康志愿者在1.5T Signa GE扫描仪上进行扫描，而患者则在1.5T Twin GE扫描仪上进行扫描。每位受试者屏气15次，S间歇15次，S 15次，有规律地呼吸，共7个周期。 BOLD结果的数据分析采用了禤浩焯、李等人建立的时间进程相关方法。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平行。正如预期的那样，在低氧条件下，致癌区域的反应早于健康区域，结果表明，恶性组织与健康组织之间的时间延迟为7.5S。这项研究展示了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.