甲型H1N1流感与严重急性呼吸综合征和人禽流感的异同

目的：评价^18F-脱氧葡萄糖（FDG）双探头符合线路断层显像（DHTC）结合血清肿瘤标志物分析对肺部肿块良恶性鉴别的应用价值，并对两种方法进行比较。方法：160例胸部X线或CT怀疑肺癌的患行FDG DHTC检查及三项肿瘤标志物－－癌胚抗原（CEA）、CYFRA21－1及神经特异性烯醇化酶（NSE）测定，两种检查间隔时间不超过2周。对肺部病变的FDG浓聚程度及特征进行分析，以局部斑块状明显浓聚灶且靶／非靶比值（T／N比）≥1．3为阳性（肺癌）；反之，肺部病变无明显放射性浓聚，或浓聚呈云片状、散在性模糊的影像且T／N比＜1．3为阴性（良性病变）。三项肿瘤标志物中有1项或1项以上超过正常值上限即为阳性（肺癌）。上述检查完成后1个月内得到病理等最终诊断结果。结果：127例患最终确诊为肺癌，另外33例为肺部良性病变。FDG DHTC对肺癌诊断的灵敏度、特异性和准确性分别为94．5％、84．8％和92．5％。血清肿瘤标志物测定对肺癌诊断的灵敏度、特异性和准确性分别为67．7％、84．8％和71．3％。卡方检验显示FDG DHTC对肺癌诊断的灵敏度和准确性均明显优于血清肿瘤标志物测定，但两的特异性一致。在7例FDG DHTC检查假阴性的肺癌患中，有4例血清肿瘤标志物测定为阳性，提示后对肺癌的诊断仍有一定的参考价值。结论：FDG DHTC检查对肺癌的诊断是一种灵敏可靠的方法。虽然血清肿瘤标志物测定对肺癌诊断的灵敏度和准确性均远低于FDG DHTC检查，但二综合分析仍有助于提高肺癌诊断的阳性率。

Similarities and differences among H1N1 influenza, severe acute respiratory syndrome and human avian influenza

OBJECTIVE: To evaluate the performance of FDG dual-head tomography with coincidence (DHTC) imaging and serum tumor marker assays in identifying lung carcinoma in 160 patients with abnormal findings on chest radiography. METHODS: A prospective evaluation of FDG imaging with DHTC and the measurement of 3 serum tumor markers for lung cancer (carcinoembryonic antigen, CYFRA21-1 and neuron specific enolase) were performed in two weeks in 160 consecutive patients with known or suspected lung malignancy. All images were analyzed visually, and the count ratio of tumor to normal tissue (T/N ratio) was calculated. It was considered positive if the FDG uptake was increased relative to that in the adjacent lung tissue, and the uptake was focal and the T/N ratio > or = 1.3. The serum tumor marker test was considered positive for malignancy if the serum level of at least 1 marker was elevated. RESULTS: 127 patients were proven to have lung cancer by pathology, and 33 patients had benign lung disease. The sensitivity, specificity and accuracy of FDG DHTC in assessing lung cancer were 94.5%, 84.8% and 92.5%, respectively, and those of the serum tumor markers were 67.7%, 84.8% and 71.3%, respectively. FDG DHTC showed significantly higher sensitivity (P < 0.001) and accuracy (P < 0.001) than serum tumor markers. Four patients with lung cancer had negative findings on FDG DHTC but had positive serum markers. CONCLUSION: FDG DHTC imaging is a powerful tool for evaluating patients with lung lesions suggestive of malignancy. Although the determination of serum tumor marker levels is less accurate than FDG DHTC, the combination of a positive FDG result and positive tumor markers may be helpful in improving the diagnosis of lung cancer.