肺错构瘤的正电子发射计算机体层摄影-CT表现

Positron emission tomography CT features of pulmonary hamartomas

目的分析肺错构瘤的脱氧氟代葡萄糖（18F-FDG）PET—CT表现特点。方法回顾性分析12例经手术证实的肺错构瘤的PET—CT表现。其中8例行双时相显像。患者均行胸部屏气MSCT扫描。采用Pearson和Spearman进行相关性分析。2种诊断方法的准确性比较采用McNemar x2检验。结果12例肺错构瘤均表现为边界清楚的周围型肺结节，7例有分叶，5例为圆形或类圆形。5例内部既无脂肪成分又无钙化，4例内部只有小灶状脂肪成分、无钙化，3例内部只有钙化、无脂肪成分。病变的均径为（1．4±1．0）cm，11例≤2．0cm，仅1例〉2．0cm。最大标准摄取值（SUVmax）＊＊、SUVmax延识、SUVmax变化值（ASUVmax）和储留指数（RI）分别为（0．80±0．67）、（0．63±0．33）、（-0．08±0．24）和（-7．91±22．39）％。常规显像没有摄取、轻度摄取增高和明显摄取增高分别为8、3和1例，其中SUVmaxI〉2．5的有1例。8例行双时相显像的患者：延迟显像摄取升高1例、不变5例、下降2例。SUVmax常‰与均径呈正相关（r=0．913，P〈0．01），与内部是否有脂肪成分和（或）钙化无相关性（P〉0．05）。18F—FDGPET—CT与MSCT诊断为良性病变的肺错构瘤分别为11和8例（P〉0．05）。1例有分叶和胸膜牵拉的病变，MSCT误诊为肺癌，PET—CT可疑恶性；3例有分叶、内部无脂肪成分和钙化的病变，MSCT可疑恶性，PET—CT均诊断良性。结论肺错构瘤在18F—FDGPET．CT上多没有或仅有轻度摄取增高，延迟显像摄取多不变或下降。对于有分叶、内部无脂肪成分和钙化的肺错构瘤，18F—FDGPET—CT比MSCT能更好地判断病变的良恶性。

Objective To analyze 18 F-FDG PET-CT features of pulmonary hamartomas. Methods The 18F-FDG PET-CT findings in 12 patients with pulmonary harmatomas proved histopathologically were analyzed retrospectively. Eight patients underwent a dual-time-point PET-CT examination. Each patient underwent a breath-hold MSCT scan. The correlations between the lesions＇ FDG uptakes and other factors were analyzed with Pearson and Spearman correlation analysis. The diagnostic accuracies of two modalities were compared using McNemar X2 test. Results All 12 pulmonary hamartomas presented as well-defined peripheral lung nodules, with lobular （ n = 7 ） or round shape （ n = 5 ）. Fat or calcification was found in 7 nodules. Four lesions contained fat only, and three lesions contained calcification only. The mean diameter was （1.4±1.0）cm,and most of lesions were 〈2.0 cm （n =ll）.The SUVmax on routine scan, the SUVmax on delayed scan, ASUVmax and retention index （ RI ） of pulmonary hamartomas were （ 0. 80 ± 0. 67 ） , （0. 63 ± 0. 33 ） , （ - 0. 08 ± 0. 24 ） and （ - 7.91 ± 22. 39 ） % , respectively. Only one lesion showed intense uptake （SUVmax〉2. 5）,the other 11 lesions showed mild to moderate uptake （SUVmax 〈 2. 5 ）. The uptake of lesions on delayed scan were increased in 1 nodule, no change in 5 nodules and decreased in 2 nodules. There was a positive correlation between the SUVmax and the diameter of pulmonary hamartomas （P 〈 0. O1 ）, while the tumor components （fat and^or calcification ） were not correlated with the SUVmax （ P 〉 0. 05）. The correct diagnosis of 18 F-FDG PET-CT and MSCT were in 11 and 8 patients （ P 〉 0. 05 ）. Three cases with lobulated shape suspicious of malignancy by MSCT were considered benignity by PET-CT.Conclusion The pulmonary hamartoma usually shows no significant uptake on 18F-FDG PET-CT. The uptake on delayed scan is not changed or decreased. 18 F-FDG PET-CT has a higher diagnostic accuracy than MSCT for hamartomas with lobular shape and no detectable fat or calcification on CT.