Paspulati Raj Mohan, Gupta Amit
Division of Abdominal Imaging, Department of Radiology, University Hospitals Case Western Reserve University, 11100 Euclid Avenue, Cleveland, OH 44106, USA.
Department of Radiology, University Hospitals Case Western Reserve University, 11100 Euclid Avenue, Cleveland, OH 44106, USA.
PET Clin. 2016 Oct;11(4):403-23. doi: 10.1016/j.cpet.2016.05.004. Epub 2016 Jul 21.
PET/computed tomography (PET/CT) is an established hybrid imaging technique for staging and follow-up of gastrointestinal (GI) tract malignancies, especially for colorectal carcinoma. Dedicated hybrid PET/MR imaging scanners are currently available for clinical use. Although they will not replace regular use of PET/CT, they may have utility in selected cases of GI tract malignancies. The superior soft tissue contrast resolution and depiction of anatomy and the functional information obtained from diffusion-weighted imaging (DWI) provided by MR imaging in PET/MR imaging are advantages over CT of PET/CT for T staging and follow-up of rectal carcinoma and for better characterization of liver lesions. Functional information from DWI and use of liver-specific MR imaging contrast agents are an added advantage in follow-up of liver metastases after systemic and locoregional treatment. New radiotracers will improve the utility of PET/MR imaging in staging and follow-up of tumors, which may not be [18F]-2-fluoro-2-deoxy-d-glucose avid, such as hepatocellular carcinoma and neuroendocrine tumors. PET/MR imaging also has application in selected cases of cholangiocarcinoma, gallbladder cancer, and pancreatic carcinoma for initial staging and follow-up assessment.
正电子发射断层扫描/计算机断层扫描（PET/CT）是一种成熟的混合成像技术，用于胃肠道恶性肿瘤的分期和随访，尤其是结直肠癌。专用的混合PET/MR成像扫描仪目前已可供临床使用。尽管它们不会取代PET/CT的常规使用，但在胃肠道恶性肿瘤的某些特定病例中可能具有实用价值。PET/MR成像中MR成像提供的软组织对比分辨率更高，能更好地显示解剖结构以及从扩散加权成像（DWI）获得的功能信息，这相对于PET/CT中的CT而言，在直肠癌的T分期和随访以及肝病变的更好特征化方面具有优势。DWI的功能信息以及肝脏特异性MR成像造影剂的使用，在全身和局部区域治疗后肝转移的随访中是一个额外的优势。新型放射性示踪剂将提高PET/MR成像在肿瘤分期和随访中的实用性，这些肿瘤可能对[18F]-2-氟-2-脱氧-D-葡萄糖不摄取，如肝细胞癌和神经内分泌肿瘤。PET/MR成像在胆管癌、胆囊癌和胰腺癌的某些特定病例中也可用于初始分期和随访评估。
