能谱CT对于胃间质瘤及胃神经鞘瘤诊断及鉴别诊断的价值评估

Clinical value of CT spectral imaging in differential diagnosis of gastric interstitialoma and gastric neurilemmoma

目的探讨能谱CT对于胃间质瘤及胃神经鞘瘤诊断及鉴别诊断的价值。方法回顾性分析22例胃间质瘤及10例胃神经鞘瘤患者的临床、能谱CT表现、能谱数据及病理资料,所有患者均行动脉期及门静脉期能谱CT扫描模式,获得140 k Vp混合能量图像及最佳Ke V单能量图像。结果最佳Ke V单能量图像与混合能量图像相比CNR明显增高（P=0.000）。最佳Ke V单能量图像对于病变定位的准确性（94%）高于混合能量图像的准确性（88%）;最佳Ke V单能量图像中能更真实地反映病变的CT值,最佳Ke V单能量图像动脉期胃间质瘤病灶内有血管显示的共有9例,占41%,均为高危险度间质瘤,胃神经鞘瘤病灶内未见血管显示;而门静脉期病变内未见明确血管显示,动脉期对高危险度间质瘤诊断的意义较大;胃神经鞘瘤及胃间质瘤均呈延时强化,胃神经鞘瘤动脉期CT值（97±20）Hu至（23±16）Hu,静脉期CT值（145±32）Hu至（30±11）Hu;胃间质瘤动脉期CT值（160±53）Hu至（39±10）Hu,静脉期CT值（191±62）Hu至（44±10）Hu。动脉期及静脉期胃神经鞘瘤与胃间质瘤40~140 Ke V各单能量图像CT比较差异均有统计学意义（P〈0.05）。结论最佳ke V单能量图像比混合能量图像能获得更好的病变与肌肉间的对比噪声比（CNR）;能谱曲线能直观地显示胃间质瘤及胃神经鞘瘤的延时强化特征,且动脉期及静脉期40~140 Ke V单能量CT值比较胃间质瘤CT值高于胃神经鞘瘤。

Objective To investigate the clinical value of CT spectal imaging in differential diagnosis of gastric interstitialoma and gastric neurilemmoma. Methods We reviewed the clinical presentation, CT spectral imaging and pathological findings in patients with gastric interstitialoma（n=22） and gastric neurilemmoma（n=10）. All patients had undergone arterial-phase and portal-phase CT spectral imaging to generate the polychromatic（140 k Vp） and optimal monochromatic images（140 ke V）. Results The optimal Kev images had remarkably higher contrast-to-noise ratio（CNR） than the polychromatic images（P=0.000）. The accuracy rate of lesion localization with the optimal ke V images（94%） was higher than that with polychromatic images（88%）. Optimal Ke V images also may account for the actual CT values of the lesions. Optimal Kev images visualized blood vessels in 9 cases（41%） of gastric interstitialoma（which were confirmed to be of high risk） and in none case of gastric neurilemmoma during artery phase, but failed to show any blood vessels during portal phase in all cases, suggesting the diagnostic value during artery phase for high-risk gastric interstitialoma. The two types of lesions showed prolonged enhancement in optimal monochromatic images. The CT values of gastric neurilemmoma [（97±20）Hu to（23±16）Hu for 40~140 ke V] were lower than those of gastric interstitialoma [（160±53）Hu to（39±10）Hu for 40~140 ke V]（all P 〈0.05）. The CT values of gastric neurilemmoma were（97±20）Hu to（23±16）Hu in artery phase, and（145±32）Hu to（30±11）Hu in the portal phase; these figures for gastric interstitialoma were（160±53）Hu to（39±10）Hu and（191±62）Hu to（44±10）Hu. The resuls showed significant difference between in 40~140 ke V images（all P 〈0.05）. Conclusion Optimal Kev images may have better CNR,. Both gastric interstitialoma and neurilemmoma show features of prolonged enhancement on optimal Kev images. The CT values of gastric interstitialoma during arterial phase and 40~140 Kev portal phase are greater than those of gastric neurilemmoma.