目的：对原发性胃淋巴瘤（primary gastric lymphoma, PGL）与进展期胃癌（advanced gastric cancer, AGC）的双源CT表现特点及病灶碘浓度进行比较,探讨双源CT鉴别诊断PGL与GC的临床应用价值。方法：回顾性收集我院经病理证实的50例PGL患者及50例AGC患者,对病灶的以下特征进行测量、比较和分析。特征包括①胃壁增厚的程度,②有无黏膜白线征,③病灶累及胃壁的范围,④病灶的强化程度,⑤病灶的碘浓度值。从中寻求适宜的鉴别诊断标准并予以评估。结果：PGL患者与AGC患者间的胃壁增厚程度（P=0.874）、病灶累及范围（P=0.718）差异均无统计学意义。与PGL患者相比,AGC患者的黏膜白线征阳性率更高（64%比24%, χ2=16.234, P<0.0001）,病灶强化更明显[(45.52±18.0) HU比(30.72±10.6) HU, P<0.001],病灶碘浓度值更高[（2.31±0.50) g/mL比(2.00±0.23) g/mL, P<0.001]。单独以黏膜白线征阳性、强化程度≥34.5 HU、碘浓度值≥2.25 g/mL诊断AGC的灵敏度分别为64%、76%和56%,特异度分别为76%、70%和88%。黏膜白线征与强化程度2项指标对于AGC的诊断灵敏度和特异度中等,考虑将二者联合应用,并联诊断AGC的灵敏度和特异度分别达90%和50%;串联诊断AGC的灵敏度和特异度分别达50%和96%。结论：应用双源CT获得的黏膜白线征、病灶强化程度和碘浓度值对于PGL与AGC的鉴别诊断具有一定价值。推荐以病灶碘浓度值≥2.25 g/mL为标准对AGC进行特异诊断;可将黏膜白线征阳性与强化程度≥34.5 HU并联诊断AGC,以提高诊断灵敏度。
Objective: To compare the CT findings and iodine concentration between primary gastric lymphoma (PGL) and advanced gastric cancer (AGC), and to evaluate the diagnostic efficacy of dual-source CT in differentiating PGL from AGC. Methods: A total of 50 PGL patients and 50 AGC patients were enrolled. Characteristics of the lesions on CT imaging were recorded, including gastric wall thickness, 'white line' sign of mucosa, sites involved, enhancement degree, and iodine concentration. Results: No significant difference in gastric wall thickness(P=0.874) or sites of stomach involved (P=0.718) were found between PGL and AGC groups. The AGC group had higher positive rate of 'white line' sign of mucosa (64% vs 24%, χ2=16.234, P<0.0001), higher enhancement degree [(45.52±18.0) HU vs (30.72±10.6) HU, P<0.001] and higher iodine concentration [(2.31±0.50) g/mL vs (2.00±0.23) g/mL, P<0.001] than those of PGL group. For diagnosis of AGC, the sensitivity of positive 'white line' sign of mucosa, enhancement ≥34.5 HU and iodine concentration ≥2.25 g/mL were 64%, 76% and 56%, respectively, and the specificity were 76%, 80% and 88%, respectively. Conclusions: The 'white line' sign of mucosa, the enhancement degree, the iodine concentration acquired by dual-source CT are capable of differentiating PGL from AGC. A criterion of iodine concentration ≥2.25 g/mL is recommended for diagnosing AGC. A combined criteria of positive 'white line' sign of mucosa and enhancement ≥34.5 HU in parallel is recommended for the sensitive diagnosis of AGC, with a sensitivity of 90%.
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