Comparison between solid pseudopapillary neoplasms of the pancreas and pancreatic ductal adenocarcinoma with cystic changes using computed tomography

BACKGROUND Solid pseudopapillary neoplasms of the pancreas(SPN)share similar imaging findings with pancreatic ductal adenocarcinoma with cystic changes(PDAC with cystic changes),which may result in unnecessary surgery.AIM To investigate the value of computed tomography(CT)in differentiation of SPN from PDAC with cystic changes.METHODS This study retrospectively analyzed the clinical and imaging findings of 32 patients diagnosed with SPN and 14 patients diagnosed with PDAC exhibiting cystic changes,confirmed through pathological diagnosis.Quantitative and qualitative analysis was performed,including assessment of age,sex,tumor size,shape,margin,density,enhancement pattern,CT values of tumors,CT contrast enhancement ratios,“floating cloud sign,”calcification,main pancreatic duct dilatation,pancreatic atrophy,and peripancreatic invasion or distal metastasis.Multivariate logistic regression analysis was used to identify relevant features to differentiate between SPN and PDAC with cystic changes,and receiver operating characteristic curves were obtained to evaluate the diagnostic performance of each variable and their combination.RESULTS When compared to PDAC with cystic changes,SPN had a lower age(32 years vs 64 years,P<0.05)and a slightly larger size(5.41 cm vs 3.90 cm,P<0.05).SPN had a higher frequency of“floating cloud sign”and peripancreatic invasion or distal metastasis than PDAC with cystic changes(both P<0.05).No significant difference was found with respect to sex,tumor location,shape,margin,density,main pancreatic duct dilatation,calcification,pancreatic atrophy,enhancement pattern,CT values of tumors,or CT contrast enhancement ratios between the two groups(all P>0.05).The area under the receiver operating characteristic curve of the combination was 0.833(95%confidence interval:0.708-0.957)with 78.6%sensitivity,81.3%specificity,and 80.4%accuracy in differentiation of SPN from PDAC with cystic changes.CONCLUSION A larger tumor size,“floating cloud sign,”and peripancreatic invasion or distal metastasis are useful CT imaging features that are more common in SPN and may help discriminate SPN from PDAC with cystic changes.

Multiphase computed tomography radiomics of pancreatic intraductal papillary mucinous neoplasms to predict malignancy

BACKGROUND Intraductal papillary mucinous neoplasms(IPMNs)are non-invasive pancreatic precursor lesions that can potentially develop into invasive pancreatic ductal adenocarcinoma.Currently,the International Consensus Guidelines(ICG)for IPMNs provides the basis for evaluating suspected IPMNs on computed tomography(CT)imaging.Despite using the ICG,it remains challenging to accurately predict whether IPMNs harbor high grade or invasive disease which would warrant surgical resection.A supplementary quantitative radiological tool,radiomics,may improve diagnostic accuracy of radiological evaluation of IPMNs.We hypothesized that using CT whole lesion radiomics features in conjunction with the ICG could improve the diagnostic accuracy of predicting IPMN histology.AIM To evaluate whole lesion CT radiomic analysis of IPMNs for predicting malignant histology compared to International Consensus Guidelines.METHODS Fifty-one subjects who had pancreatic surgical resection at our institution with histology demonstrating IPMN and available preoperative CT imaging were included in this retrospective cohort.Whole lesion semi-automated segmentation was performed on each preoperative CT using Healthmyne software(Healthmyne,Madison,WI).Thirty-nine relevant radiomic features were extracted from each lesion on each available contrast phase.Univariate analysis of the 39 radiomics features was performed for each contrast phase and values were compared between malignant and benign IPMN groups using logistic regression.Conventional quantitative and qualitative CT measurements were also compared between groups,viaχ2(categorical)and Mann Whitney U(continuous)variables.RESULTS Twenty-nine subjects(15 males,age 71±9 years)with high grade or invasive tumor histology comprised the"malignant"cohort,while 22 subjects(11 males,age 70±7 years)with low grade tumor histology were included in the"benign"cohort.Radiomic analysis showed 18/39 precontrast,19/39 arterial phase,and 21/39 venous phase features differentiated malignant from benign IPMNs(P<0.05).Multivariate analysis including only ICG criteria yielded two significant variables:thickened and enhancing cyst wall and enhancing mural nodule<5 mm with an AUC(95%CI)of 0.817(0.709-0.926).Multivariable post contrast radiomics achieved an AUC(95%CI)of 0.87(0.767-0.974)for a model including arterial phase radiomics features and 0.834(0.716-0.953)for a model including venous phase radiomics features.Combined multivariable model including conventional variables and arterial phase radiomics features achieved an AUC(95%CI)of 0.93(0.85-1.0)with a 5-fold cross validation AUC of 0.90.CONCLUSION Multi-phase CT radiomics evaluation could play a role in improving predictive capability in diagnosing malignancy in IPMNs.Future larger studies may help determine the clinical significance of our findings.

SOLID PSEUDOPAPILLARY TUMOR OF THE PANCREAS:CLINICAL AND COMPUTED TOMOGRAPHIC FINDINGS WITH PATHOLOGIC CORRELATION IN 21 CASES

Objective To correlate the clinical and imaging features of the solid pseudopapillary tumor (SPPT) of the pancreas with the pathologic diagnosis. Methods The computed tomographic findings in 21 patients (18 women and 3 men) with pathologically proven solid pseudopapillary tumor of the pancreas were reviewed retrospectively. Two radiologists reviewed images for location, size and morphology, capsule and margin, density, enhancement pattern, calcification, dilatation of pancreatic duct, lymphadenopathy, vascular invasion, distant metastasis, and recurrence. Results On CT, the lesion presented as solitary, round (28.57%), oval (57.14%), or lobulated (14.28%) mass in pancreatic head (47.62%) with complete capsule (85.71%). Lesions smaller than 4cm in maximum diameter (47.62%) presented as predominantly solid mass whereas lesions greater than 4cm in diameter (52.28%) presented as heterogenous mass. On contrast administration, the viable solid portion of the tumor showed mild peripheral enhancement in arterial phase [enhancement degree<20Hounsfield unit (HU)] with progressive fill in during the portal and hepatic parenchyma phase (enhancement degree 20-40HU). Eighteen lesions (85.7%) had complete capsule. Two lesions (9.5%) had areas of high density (>60HU) on plain CT which due to hemorrhage. Dilatation of the pancreatic duct was rare (25%), and distant metastasis, regional lymphadenopathy, and tumor recurrence were absent. Nine patients (42.85%) had an abdominal CT follow-up for 24.55months (range, 2-60months) post-surgery without recurrence or distant metastasis. Conclusion Solid pseudopapillary tumor of the pancreas usually occurs in young females in the pancreatic head or tail. On CT, they manifest as moderate vascular mixed tumor, progressive enhancement of the viable solid portion, distinct tumor margin with capsule formation, and absence of regional lymphadenopathy.

术前CT评价壁外血管侵犯情况对胃癌患者预后的评估价值

目的探讨术前CT评价壁外血管侵犯情况对胃癌患者预后的评估价值。方法选择2016年1月-2018年12月于我院接受胃癌根治术的患者作为研究对象,术前进行CT检查并评价患者壁外血管侵犯情况,术后随访患者总生存期(OS)和无病生存期(DFS),采用K-M曲线及Log-rank检验分析壁外血管侵犯情况与患者OS、DFS的关系,采用COX回归模型分析患者OS和DFS的影响因素。结果肿瘤直径≥5 cm、TNMⅢ期胃癌患者术前CT评价壁外血管侵犯的发生率明显高于肿瘤直径<5 cm、TNMⅠ~Ⅱ期胃癌患者(χ^(2)=7.745、7.011,P<0.05);与术前CT评价壁外血管未侵犯的胃癌患者比较,壁外血管侵犯的胃癌患者DFS和OS均明显缩短(χ^(2)=6.245、5.388,P<0.05);壁外血管侵犯、TNM分期是胃癌患者DFS的影响因素,壁外血管侵犯、肿瘤直径、TNM分期是胃癌患者OS的影响因素。结论术前CT评价壁外血管侵犯情况对胃癌患者预后评估有较大的临床价值。

IMAGING EVALUATION OF SEROUS CYSTADENOMAS AND MUCINOUS CYSTIC TUMORS OF THE PANCREAS

Objective To evaluate imaging features of the serous cystadenomas and mucinous cystic tumors of the pancreas. Methods The imaging findings in 59 patients with pathologically proven serous cystadenomas (SCs), mucinous cystadenomas (MCs), and mucinous cystadenocarcinomas (MCCs) of the pancreas were reviewed for location, thickness of septa or the cyst wall, number of cysts, diameter of the largest cyst, lesion calcification, presence of mural node or solid enhancing component, dilatation of the main pancreatic duct (MPD), lesion communication with MPD, invasion of surrounding organs, and regional lymphadenopathy.Results The characteristic imaging feature of SCs was that of microcystic lesion with >6 cysts, the diameter of the largest cyst being <2 cm. Mucinous cystic tumors (MCTs) including MCs and MCCs were that of macrocystic lesion with <6 cysts, the diameter of the largest cyst being >2 cm. MCs was that of a lesion with smooth and regular cyst wall and septa, the wall/septa thickness being <0.3 cm. MCCs was that of a cystic lesion with thick irregular septa, presence of mural node or solid enhancing component, invasion of surrounding structures. These findings were of statistical significance. Conclusion SCs, MCs, and MCCs have characteristic imaging features. Analysis of the number of cysts, septation features, mural node or solid enhancing component, diameter of the largest cyst, dilatation of the pancreatic duct, and invasion of surrounding structures often can successfully subtype tumors into benign SCs or potentially malignant MCs or malignant MCCs.

胰腺黏液性囊性肿瘤的不典型CT表现及鉴别诊断

目的 探讨胰腺黏液性囊性肿瘤(MCN)的不典型CT表现及鉴别诊断。方法 选取经病理诊断为胰腺MCN而术前影像表现不典型的17例患者资料,总结分析其临床症状、CT表现及术前诊断等。结果 17例患者中伴有临床症状13例,术前CT检查发现病变位于胰腺头颈部7例,体尾部10例;单囊单房样5例,多囊单房样3例,伴有明显实性成分7例,囊壁增厚6例,瘤内出血3例、伴有胰管和(或)胆管扩张8例、周围脂肪间隙模糊/淋巴结肿大/血管侵犯等侵袭性征象5例。CT术前诊断为囊腺瘤4例,囊腺瘤/囊肿2例,胰腺恶性肿瘤(胰腺癌/囊腺癌/转移)3例,实性假乳头状瘤/导管内乳头状黏液性囊腺瘤1例,囊(实)性肿物7例。结论 胰腺MCN不典型表现多种多样,良性胰腺MCN可伴有明显实性成分,囊壁增厚、瘤内出血、胰管扩张、周围脂肪间隙模糊/淋巴结肿大/血管侵犯等不典型侵袭性特征,恶性胰腺MCN可无侵袭性间接征象、无肿瘤标记物升高等。认识其不典型的影像学表现有利于为临床诊治提供更准确的诊断依据。

胰腺实性假乳头状瘤CT和MRI诊断

目的探讨胰腺实性假乳头状瘤(SPT)的CT和MRI表现。方法回顾性分析9例病理证实的胰腺SPT的CT和MRI表现。结果肿瘤囊实性比例相当4例,实性和囊性为主各4例和1例。CT平扫囊性呈低密度,实性呈等低密度。钙化2例。MRI上实性结构T1WI低信号,T2WI高信号。动脉期实质部分不同程度强化,门脉期及延时期持续强化。病灶包膜完整,延迟强化。结论胰腺SPT影像学表现有一定的特征。当胰腺出现包膜清晰的囊实性肿瘤,实质部分呈不同程度强化时,结合病人的临床资料,应考虑胰腺SPT的诊断。

多层螺旋CT胰腺增强扫描:扫描方案的选择及对胰周血管的评价

目的:通过胰腺同层动态增强扫描,获得感兴趣区的时间-密度曲线,确定胰腺增强扫描的最佳延迟时间,并应用此扫描方案分析胰周血管的显示率。方法:①随机选择20例无胰腺疾病的患者进行胰腺同层动态增强扫描,获得感兴趣区的强化峰值及到达峰值时间;②随机选择40例无胰腺疾病的患者进行胰腺三期增强扫描,分析胰周血管的显示率。结果:①腹主动脉强化峰值时间约为30s,平均强化峰值为350.3HU,20s时平均CT值为316.7HU;门静脉强化峰值时间约为45s,胰腺实质强化峰值时间约为40s,肝脏实质强化峰值时间约为55s,曲线到达峰值后75s内处于平台期;②胰周主要动脉(CA、HA、SA、SMA)的显示率为100%(40/40),除AIPDA以外的其它胰周小动脉显示率为75%～100%。胰周主要静脉(PV、SV、SMV)的显示率为100%(40/40),除AIPDV以外的其它胰周小静脉显示率为75%～100%。结论:在注射剂量100ml,注射流率4ml/s时,建议多层螺旋CT胰腺增强扫描的延迟时间分别为动脉期20s,胰腺实质期45s,门静脉期或肝脏期70s。

多排螺旋CT三期增强扫描术前评价胰腺癌可切除性的手术对照研究

目的探讨多排螺旋CT(MDCT)三期增强扫描术前观察胰周主要血管侵犯并评价肿瘤可切除性的价值。方法回顾分析25例MDCT三期增强的图像资料,分析三期增强扫描胰腺癌与正常胰腺的密度差及胰周主要动静脉是否受侵等,并与手术结果进行对照。结果 25例胰腺癌病例中,胰头部17例,体部6例,胰尾部2例。肿瘤直径≤2cm的小胰腺癌2例,>2cm的胰腺癌23例。25例胰腺癌均行手术治疗,其中12例行胰十二指肠切除术,13例行姑息性手术或剖腹探查,4例(9支)误判不可切除,3例(8支)误判可切除。MDCT动脉期利于观察动脉血管的受累情况及进行CT血管造影(CTA)成像,可以较好地评估肿瘤对胰周动脉的侵犯情况;在胰腺期,胰腺肿块与正常胰腺存在最大密度差,此期最易发现胰腺肿块;在肝脏期,肝脏实质与转移瘤密度差最大,易于病灶的显示与定性诊断。结论 MDCT增强扫描对胰腺癌的诊断及评估胰周主要动静脉受侵情况有重要价值,结合各项其他标准,有利于术前评估肿瘤的可切除性。

胰腺黏液性囊性肿瘤和浆液性囊腺瘤的多层CT对比研究

探讨多层CT在胰腺黏液性囊性肿瘤和浆液性囊性腺瘤诊断和鉴别诊断中的价值。方法 回顾性分析于2003年5月至2009年12月在我院经手术病理证实的黏液性囊性肿瘤患者（19例）和胰腺浆液性囊腺瘤（13例）的多层CT图像。图像分析包括肿瘤位置、形态、囊腔直径、囊壁、分隔、钙化、实性成份、胰腺萎缩、主胰管扩张、边界情况等。结果 胰腺黏液性囊性肿瘤与胰腺浆液性囊腺瘤囊腔直径大小比较有统计学意义（P=0.009）；囊腔直径大于2 cm多见于黏液性囊性肿瘤，与浆液性囊腺瘤之间差异统计学意义（P=0.01）；肿瘤实性成分多见于浆液性囊腺瘤，与粘液性囊性肿瘤比较有统计学意义（P=0.029）。结论 多层 CT在胰腺黏液性囊性肿瘤和浆液性囊性腺瘤诊断和鉴别诊断中具有重要的临床价值。

胰周小静脉的观察在胰腺癌分期中的价值

目的 探讨胰周小静脉在胰腺癌分期中的作用。方法 对正常组 3 0例及胰腺癌 44例行螺旋CT双期扫描 ,即胰腺期和肝脏期 (注射对比剂后 3 5s和 70s)扫描。统计正常组胰腺期及肝脏期胰周小静脉的显示率 ,观察胰腺癌病例胰周小静脉扩张情况及其他改变。结果 正常组胰周小静脉的显示率为 73 %～ 90 % ,胰腺期优于肝脏期 ;胰周小静脉扩张者占不可切除性肿瘤的 41% (13 /3 2 )。结论 胰周小静脉的显示率胰腺期优于肝脏期 ,胰周小静脉的扩张可作为胰腺癌不可切除的重要参考。

胰腺实性假乳头状瘤的多层螺旋CT表现与病理对照

目的分析胰腺实性假乳头状瘤(SPTP)的MSCT表现。方法分析19例SPTP患者的MSCT双期或三期增强扫描CT表现,并与手术病理结果对照分析。结果 SPTP为胰腺单发外突性生长肿瘤,12例呈分叶状,6例呈卵圆形,1例呈类圆形。10例最大径≥5.0cm,17例见完整包膜,1例未见包膜,1例包膜破裂、不完整,4例见壁结节。肿瘤呈多囊实性混杂病变,增强后肿瘤实性部分动脉期轻、中度强化,门脉期呈渐进性延迟强化。2例伴出血,7例伴钙化,1例伴胰管扩张。18例镜下可见假乳头状结构以及出血坏死囊变,病理证实1例肠系膜区淋巴结转移,2例脉管浸润,3例胰腺周围正常组织受侵,1例十二指肠受侵。结论 SPTP的MSCT表现具有一定的特征性,平扫及多期增强扫描有助于诊断及鉴别诊断。

多层螺旋CT探讨血管集束征对周围型小肺癌的诊断价值

目的探讨血管集束征对周围型小肺癌的诊断价值。方法对52例周围型小肺癌和22例肺良性结节行多层螺旋CT高分辨薄层扫描,并按血管走行方向做多平面重建(MPR),重点观察血管集束征的CT表现,最后与病理结果对照。结果血管集束征在周围型小肺癌的出现率为88.5%(46/52),肺良性结节出现率为18.2%(4/22),二者之间有非常显著差异性(P<0.001)。结论多层螺旋CT高分辨薄层扫描结合(MPR)能较好地显示血管与肿瘤的关系,血管集束征是周围型小肺癌的重要CT征象。

胰腺实性-假乳头状瘤的CT诊断

目的:探讨CT对胰腺实性-假乳头状瘤的诊断价值。方法:回顾性分析经手术病理证实的7例胰腺实性-假乳头状瘤的CT表现,包括肿瘤的部位、大小、形态、密度及强化特征。结果:7例肿瘤位于胰头2例,胰体尾部4例,异位胰腺1例。7例瘤体均为囊、实混合性,1例肿瘤内有出血灶,3例肿瘤有钙化,增强后实质部分均有强化,囊性部分无强化。结论:胰腺实性-假乳头状瘤有相对特征性CT表现,CT对确定手术方案有重要价值。

胰腺实性-假乳头状瘤的影像学表现和鉴别诊断

目的:胰腺实性-假乳状瘤是一种好发于年轻妇女少见的低度恶性肿瘤,Frantz于1959年首先报道了本病,其组织发生来源尚未确定。文中探讨胰腺实性-假乳头状瘤的影像学表现,提高对该病的认识和诊断水平。方法:回顾分析经手术及病理证实的5例胰腺实性-假乳头状瘤的临床及影像资料。结果:5例患者均为年轻女性,表现为胰腺区巨大囊实性肿块,包膜大多完整,增强后强化明显,与胰腺分界清晰。胰腺实性-假乳头状瘤在T1WI、T2WI上呈混杂信号,肿块体积均较大,邻近结构受压移位。造影增强后肿瘤实质动脉期呈轻度强化,门静脉期呈明显强化,囊性部分增强前后均呈低密度。1例肿块内伴有条状钙化;1例伴有胰管轻度扩张;5例均未见肝内外胆管扩张。结论:胰腺实性-假乳头状瘤的影像表现有一定特征,结合临床特征,可与其它有类似影像学表现的胰腺肿瘤相鉴别。

胰腺导管内乳头状粘液性肿瘤的影像分析

目的探讨胰腺导管内乳头状粘液性肿瘤(intraductal papillary mucinous neoplasm, IPMN)的CT及MRI表现和诊断价值。方法回顾分析经手术或超声内镜下活检病理证实的48例IPMN,探讨CT及MRI的影像表现和诊断价值。结果IPMN的特征性表现为胰腺囊性病灶与主胰管相通,可分3型;1)主胰管型4例(2例恶性),表现为主胰管弥漫性或节段性扩张;2)分支胰管型23例(8例恶性),表现为胰腺分支胰管扩张,多位于胰头钩突部,可呈单囊或多囊形,和主胰管相通,恶性者可见分隔、壁结节;3)混合型21例(12例恶性),该型同时具有分支胰管、主胰管扩张的特点。IPMN诊断敏感性MRI及CT分别为90.9%(20/22)、77.3%(17/22),诊断特异性分别为88.5%(23/26)、76.9%(20/26),统计学无差异( P >0.05)。MRCP对IPMN与胰管相通的显示率高达93.7%(45/48),明显高于CT(79.2%,38/48),统计学有差异( P <0.05)。参考2012年新版IPMN诊治共识指南中的高危特征,良、恶性IPMN出现强化的实性成分分别为3/26 vs 13/22,其中1例良性IPMN壁结节及10例恶性IPMN壁结节大于10mm;主胰管直径大于10mm分别为2/26 vs 8/22,统计学有差异( P <0.05)。结论胰腺导管内乳头状粘液样瘤的影像表现有一定特征性,影像学诊断对其良恶性判断、临床治疗方案制定及随访具有重要价值。

多层螺旋CT对胰周血管的显示研究

目的 探讨多层螺旋CT对胰腺周围血管的显示能力。方法 将225例接受上腹部增强CT的患者的扫描资料分别按动脉期和门脉期薄层重建，使用容积再现（VR）和多层面容积重建（MPVR）进行血管成像，观察两种成像方式对胰腺周围动脉、静脉的显示情况。结果 多层螺旋CT对正常胰腺周围大动脉（腹腔干，肝总动脉，脾动脉，胃十二指肠动脉，肠系膜上动脉）的显示率为100％，对小动脉（胰背动脉，胰横动脉，胰大动脉，胰尾动脉，胰十二指肠上动脉，胰十二指肠下动脉）的显示率为33．8％～96．0％。所显示的胰背动脉起源变异较多，胰背动脉起源于脾动脉，肝总动脉，腹腔干，肠系膜上动脉的比例分别为55．1％、9．7％、10．6％和24．5％。对胰腺周围大静脉（脾静脉，肠系膜上静脉，门静脉主干）的显示率为100％；胰头部小静脉（胰十二指肠上前静脉，胃结肠干及其属支）的显示率为85．3％和77．3％。对于胰腺周围小血管，MPVR较VR具有较强的显示能力。结论 多层螺旋CT对胰腺周围大血管具有可靠、稳定的显示率；对胰腺周围小血管也具有一定的显示能力。

多层螺旋CT胰周血管成像在胰腺癌手术治疗中的应用价值

目的探讨多层螺旋CT胰周血管成像在胰腺癌手术治疗中的指导价值。方法回顾性分析2010年3月—2015年2月收治的经手术病理证实的胰腺癌48例的临床资料,观察多层螺旋CT影像学表现,评估多层螺旋CT胰周血管成像在胰腺癌手术治疗中的指导价值。结果多层螺旋CT胰周血管成像技术评估手术切除可行性与手术结果可行性的符合率为95.83%。结论多层螺旋CT胰周血管成像在胰腺癌手术治疗中具有较高的指导价值。

CT对胰腺实性假乳头状瘤的诊断价值

目的:研究胰腺实性假乳头状瘤的CT表现,提高CT对该病的诊断水平。方法:回顾分析7例经病理证实的胰腺实性假乳头状瘤的CT表现。结果:7例患者均为女性。CT表现为囊实性肿块,边界清楚,5例位于胰头部,1例位于胰体,1例位于胰腺尾部;其中2例肿块内可见钙化;所有病例胰管、胆管均未见扩张。增强后肿块囊壁及实性部分明显强化,无局部浸润或淋巴结转移。结论:胰腺实性假乳头状瘤好发于年轻女性,CT表现具特征性,结合临床特征可在术前作出诊断。

胰腺实性假乳头状瘤的CT和MRI诊断

目的探讨胰腺实性假乳头状瘤的CT和MRI表现,提高对该病的诊断水平。方法回顾性分析8例经手术病理证实的胰腺实性假乳头状瘤患者的CT和MRI资料,4例患者均行CT平扫及增强,5例行MRI扫描。结果5例患者为青春期或青年女性,1例为中年女性,2例为中年男性,均无黄疸。1例肿瘤以囊性成分为主,5例实、囊成分比例相仿;2例以实性成分为主。肿瘤在CT平扫表现为混杂密度团块影,MRI表现为T1WI低或混杂信号,T2WI高信号或混杂信号,增强后肿瘤实性部分可见延迟强化,囊性部分无强化。7/8例无胰管或胆管扩张。结论胰腺实性假乳头状瘤的CT和MRI表现有一定特征,结合临床,可与其它胰腺肿瘤相鉴别。