Improve the diagnostic accuracy of CBCT for oral lesions

摘要 口腔癌占美国所有癌症的2.5%。它的五年存活率是世界上 主要癌症类型的发病率。早期诊断和治疗是改善口腔颌面部恶性肿瘤预后的关键 癌症患者。对比增强计算机断层扫描（CT）和磁共振成像（MRI）是 目前最广泛接受的口腔癌诊断和分期的成像模式。然而，在这方面， 由于它们的高成本、高患者辐射暴露（CT）和大占地面积，CT和MRI不是 牙科诊所使用的标准成像模式。此外，CT图像中的口腔病变经常 被假牙造成的金属伪影所掩盖，降低了灵敏度并增加了误诊。 已知CT对于检测口腔癌具有高特异性但低灵敏度。 锥形束CT（CBCT）减少了对患者的辐射暴露，降低了购买和操作成本， 以及占地面积，与CT相比。它在牙科中得到了广泛的应用。然而，CBCT在 口腔癌成像和分期目前是有限的，尽管其广泛可用。这主要是因为它的穷人。 软组织对比度分辨率，这使得肿瘤块难以可视化， 经常被忽视。CBCT在口腔癌骨浸润术前评估中的作用， 仅在少数研究中进行了评估，结果不一致。强金属制品的存在也 降低了CBCT图像的质量，如在CT的情况下。 我们提出了一种多光谱容积CT（mSCT）技术，以1）增加软组织对比度 2）减少图像金属伪影; 3）改善对比CT中的肿瘤轮廓 显像这些将通过以下方式实现：1）用独特的碳纳米管（CNT）改造传统的CBCT X射线源阵列由我们的团队发明;和2）结合双能CT（DECT）和虚拟单能 以低成本提供映像（VMI）功能。该器械保留了CBCT的所有临床功能和实用性， 其可取的属性。该技术不仅有可能实现口腔病变的精确成像， 使用广泛使用的CBCT经过改装，降低了成本和患者辐射暴露， 目前的临床实践，而且还通过筛查或/和 机会性成像 具体目标是：1）优化mSCT以实现高软组织对比分辨率; 2）减少金属 伪影，并通过合并基于光谱滤波器的双能量和虚拟 3）构建mSCT扫描仪原型并表征其系统性能; 和4）显示增加的软组织对比度、减少的金属伪影和改善的口腔病变描绘 与CBCT相比，

ABSTRACT Oral cancer accounts for 2.5% of all cancers in the United States. It has one of the lowest five-year survival rates among the major cancer types. Early diagnosis and treatment are critical to improve the prognosis of oral cancer patients. Contrast enhanced computed tomography (CT) and magnetic resonance imaging (MRI) are currently the most widely accepted imaging modalities for diagnosis and staging of oral cancer. However, because of their high cost, high patient radiation exposure (CT), and large footprint, CT and MRI are not the standard imaging modalities used in dental clinics. In addition, oral lesions in the CT images are frequently obscured by metal artifacts caused by dental prostheses, reducing the sensitivity and increasing false diagnosis. CT is known to have a high specificity but low sensitivity for detection of oral cancers. Cone beam CT (CBCT) reduces the radiation exposure to the patient, the cost to purchase and to operate, as well as the footprint, compared to CT. It has found wide applications in dentistry. However, CBCT’s role in oral cancer imaging and staging is currently limited, despite its wide availability. This is primarily due to its poor soft tissue contrast resolution, which makes it difficult to visualize the tumor mass, and neoplastic processes are frequently overlooked. The role of CBCT in preoperative assessment of bone invasion from oral cancer has been evaluated in only a few studies with inconsistent results. The presence of strong metal artifacts also degrades the quality of the CBCT images, as in the case of CT. We propose a multisource spectral volumetric CT (mSCT) technology to 1) increase the soft tissue contrast of dental CBCT; 2) reduce the image metal artifacts; and 3) improve the tumor delineation in contrasted CT imaging. These will be achieved by 1) retrofitting the conventional CBCT with a unique carbon nanotube (CNT) x-ray source array invented by our team; and 2) incorporating dual energy CT (DECT) and virtual monoenergetic image (VMI) capabilities at low cost. The device maintains all the clinical functionality and utility of CBCT and its desirable attributes. The technology has the potential to not only enable precision imaging of oral lesions using the widely available CBCT after modification, reducing the cost and patient radiation exposure compared to the current clinical practice, but also improve earlier detection of oral cancer through either screening or/and opportunistic imaging. The Specific Aims are: 1) Optimizing mSCT to achieve high soft tissue contrast resolution; 2) Reducing metal artifacts and improving tumor delineation by incorporating spectral filter based dual-energy and virtual monoenergetic imaging; 3) Constructing a prototype mSCT scanner and characterizing its system performance; and 4) Demonstrating increased soft tissue contrast, reduced metal artifact and improved oral lesion delineation in mSCT compared to CBCT.