薄层CT对早期肺腺癌的浸润性征象分析

目的 探讨早期肺腺癌的浸润性CT征象，为临床选择合理的治疗方案提供依据。 方法 回顾性分析2015年1月至2020年10月惠州市中心人民医院收治的经手术后组织病理学检查结果证实的101例肺腺癌患者男性42例、女性59例，年龄28~75（56.5±9.4）岁]的薄层CT影像学资料，包括结节内部特征（实性成分、血管征、支气管征、空泡征）、边缘特征（光整、分叶征、毛刺征、胸膜凹陷征）、结节长径、CT值、相对CT值、结节体积、CT值/体积的比值等。根据病理亚型将患者分为浸润前组（25例）和浸润组（76例），并对2组数据进行对照分析。 计量资料的比较采用Mann-Whitney U检验和独立样本t检验，计数资料的比较采用χ2检验或Fisher确切概率法，并绘制受试者工作特征（ROC）曲线，计算最佳临界值和曲线下面积（AUC）。 结果 浸润前组25例患者中有纯磨玻璃结节20例（80.0%）、混合磨玻璃结节5例（20.0%）。浸润组76例患者中有纯磨玻璃结节13例（17.1%）、混合磨玻璃结节26例（34.2%）、实性结节37例（48.7%）。浸润组患者结节内部出现实性成分、支气管征、血管征、空泡征的概率均高于浸润前组，且差异均有统计学意义82.9%（63/76）对20.0%（5/25）、26.3%（20/76）对4.0%（1/25）、43.4%（33/76）对16.0%（4/25）、32.9%（25/76）对8.0%（2/25），χ2=4.14~33.82，均P<0.05]。浸润前组患者结节边缘光整的概率高于浸润组，且差异有统计学意义68.0%（17/25）对10.5%（8/76），χ2=33.36，P<0.001]，浸润组患者结节边缘出现分叶征、毛刺征、胸膜凹陷征的概率均高于浸润前组，且差异均有统计学意义73.7%（56/76）对32.0%（8/25）、71.1%（54/76）对0、47.4%（36/76）对0，χ2=14.08、Fisher确切概率法，均P<0.001]。浸润前组与浸润组患者的结节长径7.50（6.50, 8.25） mm对13.00（11.00, 16.00） mm]、CT值?537.00（?612.00, ?418.00） HU对?61.00（?318.25, 21.50） HU]、相对CT值?289.00（?412.00, ?210.50） HU对?758.50（?839.00, ?534.25） HU]、结节体积 0.18（0.14, 0.26） cm3对 0.86（0.44, 2.16） cm3]、CT值/体积的比值?2685.00（?3564.00, ?1972.00）对?48.19(?422.14，12.80）]的差异均有统计学意义（Z=?6.51~?5.43，均P<0.001）。浸润前病变与浸润性病变的最佳临界值:当结节长径≥8.75 mm时，灵敏度为87.5%、特异度为84.0%；当结节体积≥0.31 cm3时，灵敏度为82.9%、特异度为88.0%；当CT值为?464 HU时，灵敏度为89.5%、特异度为72.0%；当CT值/体积的比值为?1681.7时，灵敏度为93.4%、特异度为88.0%。结节长径、CT值、结节体积、CT值/体积的比值的AUC分别为0.902（95%CI:0.843~0.962）、0.889（95%CI:0.824~0.955）、0.863（95%CI:0.784~0.942）、0.936（95%CI:0.886~0.985）。 结论 早期肺腺癌的浸润性CT征象与其结节体积、长径、密度、内部特征、边缘特征有关，需多平面仔细观察相关征象，综合分析，一旦发现其具有浸润倾向，应及早手术。

Analysis of invasive signs of early lung adenocarcinoma by thin-slice CT

Objective To investigate the invasive signs of early lung adenocarcinoma by thin-slice CT and to provide the basis for selecting rational clinical treatment. Methods Thin-slice CT findings of 101 patients (42 males and 59 females, aged 28–75 (56.5±9.4) years) with lung adenocarcinoma confirmed by surgical histopathology examination in Huizhou Central People's Hospital from January 2015 to October 2020 were retrospectively analyzed. The imaging characteristics of nodules including internal characteristics (solid component, vascular sign, bronchial sign, and vacuole sign), marginal characteristics (smooth edges, lobulation sign, spiculated sign, and pleural indentation sign), long diameter, CT value, relative CT value, volume, and CT value/volume ratio. According to pathological subtypes, 25 patients were classified into the pre-invasion group, and 76 were classified into the invasive group. Two groups were compared, and Mann-Whitney U test and independent sample t test were used to compare the measurement data. χ2 test and Fisher's exact probability method were used for counting data comparison. Receiver operating characteristic curves were drawn and the optimal critical value and the area under the curve (AUC) were calculated. Results The pre-invasion group (25 cases) had 20 cases (80.0%) of pure ground-glass nodules and 5 cases (20.0%) of mixed ground-glass nodules. The invasion group (76 cases) had 13 cases (17.1%) of pure ground-glass nodules, 26 cases (34.2%) of mixed ground-glass nodules, and 37 cases (48.7%) of solid nodules. The probability of the internal characteristics of nodules including solid components, vascular signs, bronchial signs, and vacuole signs in the invasion group were significantly higher than that in the pre-invasion group (82.9% (63/76) vs. 20.0% (5/25), 26.3% (20/76) vs. 4.0% (1/25), 43.4% (33/76) vs. 16.0% (4/25), 32.9% (25/76) vs. 8.0% (2/25); χ2=4.14–33.82; all P<0.05). The probability of smooth edges in the pre-invasion group was significantly higher than that in the invasion group (68.0% (17/25) vs. 10.5% (8/76), χ2=33.36, P<0.001). The probability of lobulation signs, spiculated signs, and pleural indentation signs in the invasion group were significantly higher than that in the pre-invasion group (73.7% (56/76) vs. 32.0% (8/25), 71.1% (54/76) vs. 0, 47.4% (36/76) vs. 0; χ2=14.08, Fisher's exact probability method; all P<0.001). Statistically significant differences existed in long diameter (7.50 (6.50, 8.25) mm vs. 13.00 (11.00, 16.00) mm), CT value (?537.00 (?612.00, ?418.00) HU vs. ?61.00 (?318.25, 21.50) HU), relative CT value (?289.00 (?412.00, ?210.50) HU vs. ?758.50 (?839.00, ?534.25) HU), volume (0.18 (0.14, 0.26) cm3 vs. 0.86 (0.44, 2.16) cm3), CT value/volume ratio (?2685.00 (?3564.00, ?1972.00) vs. ?48.19 (?422.14, 12.80)) between pre-invasion group and invasion group (Z=?6.51 to ?5.43; all P<0.001). Optimal cutoff values existed between the pre-invasive and invasive lesions. When the long diameter of nodules was ≥8.75 mm, the sensitivity and specificity were 87.5% and 84.0%, respectively. When the nodule volume was ≥0.31 cm3, the sensitivity and specificity were 82.9% and 88.0%, respectively. When the CT value was ?464 HU, the sensitivity and specificity were 89.5% and 72.0%, respectively. When the CT value/volume ratio was ?1681.7, the sensitivity and specificity were 93.4% and 88.0%, respectively. The AUC of long diameter, CT value, volume, and CT value/volume ratio of nodules were 0.902 (95%CI: 0.843–0.962), 0.889 (95%CI: 0.824–0.955), 0.863 (95%CI: 0.784–0.942), and 0.936 (95%CI: 0.886–0.985), respectively. Conclusions CT findings of the invasion signs of early lung adenocarcinoma are related to the volume, length, density, internal characteristics, and marginal characteristics of the nodules. The relevant signs need to be carefully observed in multiple planes and for a comprehensive analysis. Once found that it has a tendency to infiltrate, it should be operated as soon as possible.