Department of Imaging Physics, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA.
J Appl Clin Med Phys. 2010 Feb 4;11(1):3073. doi: 10.1120/jacmp.v11i1.3073.
Average CT (ACT) and PET have a similar temporal resolution and it has been shown to improve registration of the CT and PET data for PET/CT imaging of the thorax. The purpose of this study was to quantify the effect of ACT attenuation correction on PET for gross tumor volume (GTV) delineation with standardized uptake value (SUV) for liver and esophageal lesions. Our study included 48 colorectal cancer patients with metastasis in the liver and 52 esophageal cancer patients. These patients underwent a routine PET/CT scan followed by a cine CT scan of the thoracic region for ACT. Differences between the two PET data sets (PET HCT and PET ACT ) corrected with the helical CT (HCT) and ACT were quantified by analyzing image alignment, maximum SUV (SUV max ), and GTV. The 67% of the colorectal and 73% of the esophageal studies demonstrated misregistration between the PET HCT and HCT data. ACT was effective in removing misregistration artifacts in 65% of the misregisted colorectal and in 76% of the misregisted esophageal cancer patients. Misregistration between the CT and PET data affected GTVs due to the change in SUV max with ACT. A change of SUV max greater than 20% between PET HCT and PET ACT was found in 15% of the colorectal and 17% of the esophageal cases. Our results demonstrated a more pronounced effect of misregistration for the smaller lesions (< 5 cm 3 ) near the diaphragm (< 5 cm). ACT was effective in improving registration between the CT and PET data in PET/CT for the colorectal and esophageal cancer patients.
平均 CT（ACT）和 PET 具有相似的时间分辨率，已被证明可改善 CT 和 PET 数据的配准，从而提高胸部 PET/CT 成像的准确性。本研究的目的是量化 ACT 衰减校正对肝脏和食管病变的标准摄取值（SUV）勾画的 GTV 有何影响。本研究纳入了 48 例结直肠癌肝转移患者和 52 例食管癌患者。这些患者进行了常规的 PET/CT 扫描，然后对胸部进行电影 CT 扫描以获取 ACT。通过分析图像配准、最大 SUV（SUV max）和 GTV，量化了两种 PET 数据集（PET HCT 和 PET ACT）与螺旋 CT（HCT）和 ACT 校正的差异。67%的结直肠和 73%的食管研究显示，PET HCT 和 HCT 数据之间存在配准错误。ACT 可有效去除 65%配准错误的结直肠和 76%配准错误的食管癌患者的配准伪影。由于 ACT 引起的 SUV max 变化，CT 和 PET 数据之间的配准错误会影响 GTV。在 15%的结直肠和 17%的食管病例中，PET HCT 和 PET ACT 之间的 SUV max 变化大于 20%。我们的结果表明，膈肌附近（<5cm）较小的病变（<5cm 3）的配准错误影响更明显。ACT 可有效改善 PET/CT 中结直肠癌和食管癌患者 CT 和 PET 数据之间的配准。
