Yi Chin A, Lee Kyung Soo, Kim Byung-Tae, Choi Joon Young, Kwon O Jung, Kim Hojoong, Shim Young Mog, Chung Myung Jin
Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
J Nucl Med. 2006 Mar;47(3):443-50.
Recent advances in the technology of helical multidetector CT allow precise evaluations of nodule hemodynamics. In addition, the efficacy of tissue characterization has improved, and now sensitivity and specificity of >90% are achieved. Moreover, the efficacy of PET for the tissue characterization of solitary pulmonary nodules (SPNs) has also become of importance. The purpose of this study was to compare the diagnostic accuracy of helical dynamic (HD) CT (HDCT) and integrated PET/CT for pulmonary nodule characterization.
One hundred nineteen patients with an SPN underwent both HDCT (unenhanced scans, followed by series of images at 30, 60, 90, 120 s and at 5 and 15 min after intravenous injection of contrast medium) and integrated PET/CT. On HDCT, a nodule was regarded as malignant with a net enhancement of > or =25 Hounsfield units (HU) and a washout of 5-31 HU. On integrated PET/CT, nodules were considered malignant with a > or =3.5 maximum standardized uptake value and an 18F-FDG uptake greater than that of mediastinal structures. The sensitivity, specificity, and accuracy of the 2 modalities for malignancy were compared using the McNemar test.
There were 79 malignant and 40 benign nodules. The sensitivity, specificity, and accuracy for malignancy on HDCT were 81% (64/79 nodules), 93% (37/40), and 85% (101/119), respectively, whereas those on integrated PET/CT were 96% (76/79), 88% (35/40), and 93% (111/119), respectively (P = 0.008, 0.727, and 0.011, respectively). All malignant nodules were interpreted correctly on either HDCT or PET/CT.
Integrated PET/CT is more sensitive and accurate than HDCT for the malignant nodule characterization; therefore, PET/CT may be performed as the first-line evaluation tool for SPN characterization. Because HDCT has high specificity and acceptable sensitivity and accuracy, it may be a reasonable alternative for nodule characterization when PET/CT is unavailable.
螺旋多排探测器CT技术的最新进展使得对结节血流动力学的精确评估成为可能。此外，组织特征分析的效能有所提高，目前灵敏度和特异度均达到了90%以上。而且，PET对孤立性肺结节（SPN）的组织特征分析效能也变得至关重要。本研究的目的是比较螺旋动态（HD）CT（HDCT）和PET/CT一体化成像对肺结节特征分析的诊断准确性。
119例SPN患者同时接受了HDCT（平扫，随后在静脉注射造影剂后30、60、90、120秒以及5和15分钟时进行系列图像采集）和PET/CT一体化成像检查。在HDCT上，净增强值≥25亨氏单位（HU）且洗脱值为5 - 31 HU的结节被视为恶性。在PET/CT一体化成像上，最大标准化摄取值≥3.5且18F - FDG摄取高于纵隔结构的结节被视为恶性。使用McNemar检验比较两种检查方式对恶性病变的灵敏度、特异度和准确性。
共有79个恶性结节和40个良性结节。HDCT对恶性病变的灵敏度、特异度和准确性分别为81%（64/79个结节）、93%（37/40）和85%（101/119），而PET/CT一体化成像的分别为96%（76/79）、88%（35/40）和93%（111/119）（P分别为0.008、0.727和0.011）。所有恶性结节在HDCT或PET/CT上均被正确判读。
PET/CT一体化成像在恶性结节特征分析方面比HDCT更敏感、准确；因此，PET/CT可作为SPN特征分析的一线评估工具。由于HDCT具有高特异度以及可接受的灵敏度和准确性，当无法进行PET/CT检查时，它可能是结节特征分析的合理替代方法。
