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孤立性肺结节(solitary pulmonary nodule, SPN)是指肺内孤立的、单发的、直径小于或等于3 cm、长径与短径之比≤1.5的实质性病灶, 周围无与病灶关联的肺不张、炎症、局部淋巴结肿大[1-2]。SPN的诊断一直是胸部影像学诊断的难点和热点, PET-CT能从功能代谢和解剖形态两方面来判断病变性质, 对于肺结节的诊断与鉴别诊断具有很高的灵敏度、特异度和准确率, 但仍有一定的假阴性和假阳性, 而常规PET-CT加高分辨率CT(high resolution CT, HRCT)能降低假阴性率, 提高肺结节的检出率和诊断正确率[3], 本研究探讨18F-FDG PETCT双时相显像结合HRCT对SPN的鉴别诊断价值, 报告如下。
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173例SPN患者经病理或随访证实恶性病变41例, 良性病变132例。其中, 18F-FDG PET-CT双时相显像和18F-FDG PET-CT双时相+HRCT对SPN良恶性的鉴别诊断结果见表 1。结果显示: 18F-FDG PET-CT双时相+HRCT对SPN诊断的灵敏度、特异度、准确率、阳性预测值及阴性预测值均显著高于18F-FDG PET-CT双时相显像(χ2=8.2, P < 0.05;χ2=19.7, P < 0.01;χ2=20.1, P < 0.01;χ2=20.8, P < 0.001;χ2=10.8, P < 0.01)。因HRCT能详细显示组织解剖和病理改变细节, 故对SPN定性诊断具有一定的价值(图 1)。
方法 灵敏度 特异度 准确率 阳性预测值 阴性预测值 PET-CT 91.3 42.6 77.4 51.8 60.6 PET-CT+HRCT 97.7 93.5 96.8 97.9 93.7 表 1 18F-FDGPET-CT双时相显像与同机高分辨率CT对孤立性肺结节鉴别诊断的价值
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良恶性SPN的18F-FDG PET-CT双时相显像SUV结果见表 2。由表 2数据分析显示, 良性结节SUV早期与SUV延迟比较, t=2.92, P < 0.05;恶性结节SUV早期与SUV延迟比较, t=3.14, P < 0.01。恶性病变组的SUV变化率(即: RI)[(42.50±3.87)%]显著高于良性病变组[(26.90±7.23)%](t=6.03, P < 0.01)。采取延迟显像可以更好地区别良恶性, 尤其是延迟显像大大提高了SUV在2.5附近的结节的诊断准确率。
良性结节 恶性结节 SUV早期 2.84±0.41 6.26±0.72 SUV延迟 2.73±0.36 6.88±0.72 滞留指数 42.50±3.87 26.90±7.23 表 2 18F-FDG PET-CT双时相显像SUV对孤立性肺结节良恶性的鉴别诊断价值
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HRCT显示SPN病灶的最大径为3 cm, 最小径为0.4 cm, 平均(2.2±0.5)cm。HRCT对SPN病灶本身及其周围诸多阳性征象的检出率较同机得到的CT图像高(表 3), 进一步从解剖形态上增加了PET-CT对SPN的诊断信息, 尤其是区分良、恶性结节。
CT征象 PET-CT同机CT 同机高分辨率CT 分叶 66(38.2) 86(49.7) 毛刺 62(35.9) 77(44.5) 胸膜牵拉 24(13.8) 32(18.5) 血管集束 15(8.7) 20(11.6) 磨玻璃样 3(1.7) 23(13.3) 空泡征 3(1.7) 5(2.9) 表 3 18F-FDGPET-CT中的CT及高分辨率CT对孤立性肺结节内部及周围征象检出率
[病灶数(%)]
18F-FDGPET-CT双时相显像结合高分辨率CT诊断孤立性肺结节的价值
Dual phase time scan combine high resolution CT to diagnose solitary pulmonary nodule by 18F-FDGPET-CT
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摘要:
目的 探讨18F-FDG PET-CT双时相显像结合高分辨率CT(HRCT)对孤立性肺结节(SPN)的鉴别诊断价值。 方法 经CT证实符合SPN的病例173例,应用PET-CT技术对SPN病例进行双时相显像及同机HRCT,早期显像于注射18F-FDG后50~60 min,并行HRCT,延迟显像于注射后2~2.5 h进行。测定病灶两次显像的SUV,并计算两次显像SUV的变化率,根据病灶HRCT的形态学特征, 进行综合诊断判断良恶性, 所得结果与随访结果作对照比较。 结果 173例SPN患者经病理或随访证实恶性病变41例、良性病变132例。恶性病变组早期显像的SUV为6.26±0.72,延迟显像的SUV为6.88±0.74,滞留指数为(42.50±3.87)%;良性病变组早期显像的SUV为2.84±0.41,延迟显像的SUV为2.73±0.36,滞留指数为(26.90±7.23)%。 结论 18F-FDG PET-CT双时相显像结合HRCT鉴别诊断SPN的方法简便、准确率高,具有广泛的临床实用价值。 -
关键词:
- 硬币病变, 肺 /
- 氟脱氧葡萄糖F18 /
- 正电子发射断层显像术 /
- 体层摄影术, X线计算机
Abstract:Objective To evaluate the role of dual phase scan combine high resolution computerized tomography(HRCT)by 18F-FDG PET-CT imaging in the diagnosis of solitary pulmonary nodule(SPN). Methods 173 patients with SPN demonstrated by CT, All these patients underwent dual time point combine HRCT 18F-FDG PET/CT imaging.The imaging protocol included the early imaging combine HRCT of PETCT at 50-60 min and delayed imaging of PET at 2-2.5 h post injection 18F-FDG.The standardized uptake value(SUV)was calculated for both time points.All results were expressed as the percentage change in SUV. According to characteristic in focal morphology by HRCT found, general inspection and diagnosis were benign or malignant, It was compared the result and following up result. Results Histopathology demonstrated or following up result 41 patients with malignant lesions and 132 patients with benign lesions.The SUV of malignant lesions was SUV 6.26±0.72 in early imaging, ,and 6.88±0.74 in delayed imaging.The retention index of malignant lesions was(42.50±3.87)%.The SUV of benign lesions was 2.84±0.41 in early imaging, and 2.73±0.36 in delayed imaging.The retention index of benign lesions was(26.90±7.23)%. Conslusions 18F-FDG PET-CT dual time point imaging combine HRCT is a simple practical method and accurate ratio high for the diagnosis of SPN.The method will be widely clinically practised. -
表 1 18F-FDGPET-CT双时相显像与同机高分辨率CT对孤立性肺结节鉴别诊断的价值
(%) 方法 灵敏度 特异度 准确率 阳性预测值 阴性预测值 PET-CT 91.3 42.6 77.4 51.8 60.6 PET-CT+HRCT 97.7 93.5 96.8 97.9 93.7 表 2 18F-FDG PET-CT双时相显像SUV对孤立性肺结节良恶性的鉴别诊断价值
良性结节 恶性结节 SUV早期 2.84±0.41 6.26±0.72 SUV延迟 2.73±0.36 6.88±0.72 滞留指数 42.50±3.87 26.90±7.23 表 3 18F-FDGPET-CT中的CT及高分辨率CT对孤立性肺结节内部及周围征象检出率
[病灶数(%)] CT征象 PET-CT同机CT 同机高分辨率CT 分叶 66(38.2) 86(49.7) 毛刺 62(35.9) 77(44.5) 胸膜牵拉 24(13.8) 32(18.5) 血管集束 15(8.7) 20(11.6) 磨玻璃样 3(1.7) 23(13.3) 空泡征 3(1.7) 5(2.9) -
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