Focused Collimator for Dual Modality Breast Imaging

描述（由申请人提供）： 乳房X光检查目前是乳房筛查的黄金标准。然而，阳性预测值（乳腺X线摄影确定为阳性的病例中真正阳性的比例）仅为20 - 25%。因此，绝大多数的乳腺活检是阴性的。活检对许多人来说是一种非常不愉快的经历，特别是当它是假阳性时。弗吉尼亚大学夏洛茨维尔分校（UVa）的研究人员开发了一种新的诊断乳腺扫描仪，通过将数字X射线乳腺摄影和scintimmography相结合，使用专用的小视场伽马相机，在一个共同的机架上。静脉注射~（99）Tc ~（99）M_2O_3作乳腺显像，可优先集中于恶性肿瘤部位。双模态扫描仪的早期临床评价显示了更准确诊断的有希望的结果，特别是对小肿块。目前的双模态扫描仪使用乳房X线摄影系统，其上已连接有平行孔准直器和伽马照相机。因此，伽马相机中的每个像素观察垂直于伽马检测器表面的射线路径，而X射线检测器中的每个像素观察聚焦在点源处的射线路径。这种几何差异会产生配准误差，特别是对于厚乳房和位于乳房顶部附近的肿块，限制了双重成像诊断方法的全部益处。第一阶段小企业创新计划（SBIR）提案的具体目标是：（a）为目前在UVa的系统生产小型聚焦准直器，（B）开发一种微制造方法，使用灵敏、成本效益高的光刻胶作为电铸模具来制造聚焦准直器，以及（c）评估在UVa系统上使用聚焦准直器的配准情况。第II阶段SBIR的具体目标是：（a）根据第I阶段的实验数据设计改进的双模态乳腺成像系统，（B）制造适用于新系统的全尺寸乳腺摄影准直器，以及（c）测试包含全尺寸准直器的双模态乳腺成像系统。

DESCRIPTION (provided by applicant): Mammography is currently the gold standard for breast screening. However, the positive predictive value (fraction of cases identified as positive by mammography that truly are positive) is only 20 - 25%. Thus the vast majority of breast biopsies performed are negative. Biopsy is a very unpleasant experience for many, especially when it is a false positive. Researchers at the University of Virginia at Charlottesville (UVa) have developed a new diagnostic breast scanner by combining digital x-ray mammography and scintimammography, using a dedicated small field-of-view gamma camera, on a common gantry. In scintimammography, technetium-99m sestamibi is injected intravenously and concentrates preferentially at the site of malignant tumor. Early clinical evaluation of the dual modality scanner has shown promising results for more accurate diagnosis especially for small masses. The current dual modality scanner utilizes a mammography system, to which has been attached a parallel hole collimator and a gamma camera. Thus, each pixel in the gamma camera views a ray path perpendicular to the gamma detector surface, while each pixel in the x-ray detector views a ray path focused at the point source. This geometric discrepancy produces co-registration errors, especially for thick breasts and for masses lying near the top of the breast limiting the full benefit of the dual imaging diagnostic approach. The specific aims for this Phase I Small Business Innovation Program (SBIR) proposal are to (a) produce small focused collimators for the system currently at UVa, (b) to develop a microfabrication method using a sensitive, cost effective photoresist as the electroforming mold to fabricate the focused collimator, and (c) to evaluate co-registration using focused collimators on the UVa system. The specific aims for the Phase II SBIR are (a) to design an improved dual modality breast imaging system based on the experimental data of Phase I, (b) to fabricate a full-size mammography collimator appropriate for the new system, and (c) to test the dual modality breast imaging system incorporating the full-size collimator.