目的 基于影像组学方法,探讨多层螺旋CT（MSCT）四期增强扫描单一/不同期相及不同容积感兴趣区（VOI）的选择,在术前预测原发性肝细胞癌（HCC）微血管侵犯（MVI）中的价值。方法 回顾性收集88例经手术病理证实为HCC并行术前MSCT四期增强扫描的患者,其中包括47例MVI阳性患者和41例MVI阴性患者。在MSCT增强扫描的动脉早期、动脉晚期、门静脉期及延迟期图像中手动逐层勾画肿瘤ROI,获得瘤体容积感兴趣区VOI（Vt）,然后基于计算机自动膨胀算法将Vt外扩10 mm获得瘤体及瘤周VOI（Vt+Vp）。使用Pyradiomics软件分别从Vt和Vt+Vp中提取影像组学特征,随后采用15种特征选择方法和10种分类器构建150个预测模型,并通过十折交叉检验以验证模型的效能。使用准确度、敏感度、特异度、受试者工作特性曲线下面积（AUC）评估模型的效能,并比较性能最优的前三个预测模型。结果 MSCT四期增强扫描图像中预测HCC MVI状态的影像组学模型在门静脉期的表现优于其它期相及各期相的不同组合,其中最大的AUC值在Vt和Vt+Vp两种ROI中分别为0.768和0.782。此外,基于Vt+Vp的影像组学模型对MVI的预测效能优于基于Vt的影像组学模型,基于Vt+Vp性能最优的预测模型的AUC值、准确度、敏感度和特异度分别0.782、0.728、0.745和0.705。结论 采用影像组学方法术前无创性预测HCC MVI状态首选增强扫描的门静脉期,ROI首选瘤体联合瘤周10 mm区域。

Objective To investigate the value of single or different phases of contrast-enhanced multi-slice spiral CT（MSCT）in different volumetric regions of interest（ROI）to preoperatively predict the state of microvascular invasion in primary hepatocellular carcinoma（HCC）based on radiomics methods．Methods A total of 88 patients with HCC confirmed by surgical pathology who underwent preoperative MSCT quadruple-enhanced scan were retrospectively recruited,including 47 MVI-positive patients and 41 MVI-negative patients．The ROI was manually delineated slice-by-slice in the early arterial phase,late arterial phase,portal venous phase,and equilibrium phase of enhanced MSCT images to obtain the volume of tumor VOI（Vt）,and then Vt was expanded by 10 mm through the computer expansion algorithm automatically to obtain the volume of tumor and peritumor（Vt+Vp）．Pyradiomics software was used to extract radiomic features from Vt and Vt+Vp,followed by 150 discriminant models constructed with 150 feature selection methods and 10 classifiers,and then 10-fold cross-validation was used to evaluate the performance of these models．Using accuracy,sensitivity,specificity,area under the receiver operating characteristic curve（AUC）to assess model performance．The top three predictive models with the best performance were also compared．Results The radiomics model for predicting HCC MVI status in portal venous phase among quadruple-enhanced MSCT images outperformed other phases and different combinations of phases,achieving the highest AUC values of 0.768 and 0.782 in Vt and Vt+Vp respectively．In addition,the prediction performance of the radiomics model based on Vt+Vp was superior to models based on Vt．AUC value,accuracy,sensitivity,and specificity of the model with the best performance based on Vt+Vp were 0.782,0.728,0.745 and 0.705 respectively．Conclusions Radiomics models based on the portal venous phase of contrast-enhanced MSCT and tumor combined with the 10mm peritumoral area were more recommended to be employed to preoperative non-invasively predict the state of HCC MVI．

目的 探讨小于4 cm的胃神经鞘瘤（GS）的CT误诊与漏诊原因,从而加深影像科医师对GS的认识,提高其CT检出率及诊断准确率。方法 回顾性分析2019年3月—2022年10月经手术切除及病理证实的10例小于4 cm的GS患者的临床、CT及病理资料。在CT图像上评估肿瘤的位置、大小、形态、密度、强化特点及周围淋巴结等情况。结果 术前CT误诊7例,漏诊2例,仅1例正确诊断;10例病灶均起源于胃黏膜下;9例为圆形或类圆形;7例发生于胃体;平扫密度均低于肌肉组织,均呈渐进性强化。结论 小于4 cm的GS术前误诊率很高,且可发生漏诊。当CT检查提示胃体部黏膜下圆形或类圆形占位病变,平扫呈均匀稍低密度,增强呈渐进性强化时应考虑GS的可能,最终确诊需病理及免疫组化检查。

Objective To investigate the causes of CT misdiagnosis and missed diagnosis of gastric schwannomas（GS）smaller than 4 cm in size,and to improve radiologists’ awareness of GS and increase the detection rate and diagnostic accuracy．Methods Clinical,pathological and CT data of ten surgically and pathologically confirmed GS patients were retrospectively reviewed between March 2019 and October 2022．The location,size,shape,attenuation,enhancement features and surrounding lymph nodes of each tumor on CT were analyzed．Results Of the 10 patients,7 cases were misdiagnosed in preoperative CT examination,two cases were missed diagnosed and only one case was correctly diagnosed．All tumors originated from the submucosa in ten cases,and nine cases showed a round or oval shape．Seven lesions were located in the gastric body,and all tumors had homogeneous low attenuation compared to muscle on plain CT images．All cases displayed mild-moderate to obvious enhancement．Conclusions GS smaller than 4 cm have a high rate of misdiagnosis and missed diagnosis preoperatively．When CT examination indicates a submucosa tumor with a round-like shape in the gastric body and homogeneous mild hypoattenuation on plain CT,the possibility of GS should be raised．Pathological and immunohistochemical examinations are necessary to confirm the final diagnosis．