16层螺旋CT兼容性血管成像对胰腺癌胰周主要血管侵犯的诊断价值

目的探讨16层螺旋CT兼容性血管成像对胰腺癌胰周主要血管侵犯的诊断及其价值。方法对48例胰腺癌患者采用MSCT肝脏兼容性双期增强扫描方式,以多平面容积重建(MPVR)、容积重建(VR)血管成像技术,行胰周主要动脉、门静脉血管成像,并多角度观察胰周主要动脉、静脉血管的侵犯情况。结果胰腺癌胰周毗邻的动脉主干受侵30例,主要静脉受侵41例,胰周血管受侵的表现特征:1肿瘤压迫侵蚀局部血管弧形变扁,边缘轻度不规则;2血管僵直管腔狭窄变细,边缘毛糙或锯齿状改变;3孤立性或非孤立性脾静脉阻塞;4胰周侧支循环血管扩张迂曲;5胰周区域性门静脉高压。结论 MSCTA、CTPV对胰腺癌胰周主要血管侵犯的准确诊断和不可切除性评估提供较为可靠的依据。     

胰周血管受胰腺癌侵犯程度常被影像学低估的原因分析

目的 探讨胰周血管受侵程度被影像学低估的原因.方法 收集经手术病理证实或临床治疗证实的胰腺癌无远处转移患者76例,均行术前螺旋CT增强扫描,其中66例行MRI增强扫描并行三维血管重建,显示胰腺癌对周围血管的侵犯程度,把肿瘤对血管的侵犯程度分为0级、1级、2级、3级、4级.对术前评价可切除病例中的受侵犯的血管进行术中探查,并与手术结果对照.结果 39例中的138支血管受肿瘤侵犯达2级或以上,放弃手术,另37例术前评估有手术切除可能性,术中25例做了胰腺根治性切除,12例由于术前低估了1支或多支血管的受侵程度,仅做了肿块切除或姑息性治疗.此12例中有16支动脉血管及21支静脉血管受侵程度被低估,术中综合评估3级、4级的血管手术均无法切除,术中综合评估0级、1级的血管手术均顺利切除,评估为2级的血管受术者水平的影响而有部分切除.结论 术前用多层螺旋CT及MRI多期增强扫描并进行三维血管重建,评估动、静脉时使用不同的时像、不同的判定标准,可准确反映胰周血管受侵程度的准确信息.     

多层螺旋CT肠系膜血管成像的临床应用

目的:探讨多层螺旋CT肠系膜血管成像(MMSCTA)的临床应用价值。方法:对32例经证实的肠系膜血管病变患者进行多层螺旋CT(MSCT)检查,采用多种后处理技术(VR、MIP、MPR、CPR)进行肠系膜血管成像,观察肠系膜血管病变的情况。结果:32例患者中,肠系膜上动脉(SMA)栓塞2例,MMSCTA及DSA示SMA充盈缺损;SMA血栓形成1例,MMSCTA及DSA示SMA主干呈长条状充盈缺损;肠系膜上静脉(SMV)栓塞9例,MMSCTA示SMV充盈缺损7例,2例不显影;胰腺癌侵犯SMA、SMV者13例,MMSCTA示肠系膜血管被包埋,血管狭窄中断;SMA主干或分支狭窄伴软斑形成7例。结论:多层螺旋CT肠系膜血管成像是肠系膜血管病变的一种无创性有价值的检查方法。     

胰腺及胰周血管强化的多层螺旋CT研究

目的　探讨多层螺旋CT增强扫描胰腺及胰周血管强化的最佳时相及扫描方案。资料与方法　采用多层螺旋CT对 19例胰腺正常的患者行动脉期、胰腺期及门脉期三期扫描 ,比较胰腺、肠系膜上动脉 (SMA)和肠系膜上静脉 (SMV)在三期图像上的强化程度 ,以及观察胰周小血管的充盈显影情况。结果　胰腺期胰腺强化程度最大 ,高于动脉期和门脉期 (P <0 .0 0 1)。SMA于动脉期强化程度最大 ,其次为胰腺期 ,两者差别无统计学意义 (P >0 .0 5 ) ,但两者均高于门脉期 (P <0 .0 0 1)。SMV于胰腺期强化程度最大 ,高于动脉期和门脉期 (P <0 .0 5 )。胰腺期胰周小动脉和小静脉均能得到较好充盈显影。结论　胰腺及胰周血管在胰腺期获得最大程度强化和充盈显影 ,胰腺CT增强扫描最佳扫描方案为胰腺期和门脉期双期扫描。如需行CTA时 ,多层螺旋CT可行三期扫描     

多层螺旋CT血管造影对胰腺癌侵犯胰周血管的判断

目的:探讨多层螺旋CT血管造影对胰腺癌侵犯胰周血管的判断及其意义。方法:使用Toshiba Aquilion 16层螺旋CT对胰腺癌患者扫描后,进行动脉期和门脉期胰周主要血管CTA三维成像。以三维图像为主,对胰周血管是否受累进行判别及评价,并与手术对照。结果:其中手术病人42例,CTA显示血管受侵28例,术中所见血管受侵29例。CTA判断血管受侵敏感性为96.43%,特异性为85.71%,χ2=0.333,P=0.564>0.05,胰周血管是否受侵术前CTA判断与手术判断在统计学上没有差异。结论:术前CTA判断胰腺癌的胰周血管是否受侵对手术具有前瞻性指导意义。     

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。     

多层螺旋CT对肠扭转的诊断价值

目的探讨多层螺旋CT(MSCT)对肠扭转的诊断价值。方法收集急腹症MSCT双期增强扫描病例80例,其中10例患者图像经多平面重组(MPR)及肠系膜血管最大密度投影(MIP)处理,诊断为肠扭转。结果MSCT诊断10例肠扭转,主要征象有肠系膜血管“漩涡征”10例,肠管“漩涡征”5例,靶环征或双晕征5例,肠系膜上动脉、静脉(SMA、SMV)换位征3例,鸟喙征4例,SMV血栓形成2例,腹水征10例。诊断均经手术证实。结论MSCT双期增强扫描及多平面重组(MPR)与肠系膜血管最大密度投影(MIP)对肠扭转的诊断有重要价值。     

门静脉系统血栓的64层螺旋CT诊断价值

目的 探讨门静脉系统血栓(portal vein thrombosis,PVT)的64层螺旋CT表现特征.资料与方法 15例PVT行64层螺旋CT平扫和双期增强扫描,采用最大密度投影(MIP)、容积再现(VR)及多平面重组(MPR)观察其影像学特征.结果 15例中,血栓发生于门静脉(PV)主干13例,右支6例,左支7例,脾静脉(SV)3例,肠系膜上静脉(SMV)9例,其中血栓同时累及PV主干和SMV 8例,同时累及PV左右支、主干和SMV 4例,累及PV主干和右支6例,累及PV主干和左支6例,累及SV和SMV 2例,PV主干、SV、SMV三岔口处血栓1例.Yerdel分级:Ⅰ级1例,Ⅱ级10例,Ⅲ级3例,Ⅳ级1例;血栓呈高密度10例,等密度2例,低密度3例;血栓为部分偏心性栓塞12例,呈小条状、"柴捆"状;附栓管壁均连续光滑、无外突结节,局部PV管壁呈典型的线样"强化征"或"轨道征";出现食管胃丛及脾丛侧支循环12例,胆管丛及胆囊丛侧支循环4例,无一例出现肝动脉.门静脉瘘.结论 64层螺旋CT能够清晰、立体地显示PVT的部位、累及范围,具有特征性,是PVT重要的检查方法.     

胰腺癌血管侵犯的不同CT诊断标准的研究

目的:研究胰腺癌血管侵犯的不同CT诊断标准的优劣。材料和方法:回顾性收集我院经多层螺旋CT三期动态增强扫描并经手术病理证实为胰腺导管细胞癌的36例患者。CT轴位图像结合CTA(以MIP和VR方法重建)以及多平面重建(MPR)分别对这些血管以Loyer和Lu血管分级CT标准进行分级,并和手术结果进行对照,分别作出受试者工作特性曲线(ROC),比较曲线下面积的差异。另外,运用Lu的CT诊断标准分别评价胰周动脉和静脉受侵的准确性、灵敏度、特异度、阳性预测值、阴性预测值、Youden指数,研究Lu的CT诊断标准对动静脉分级的差异。结果:Loyer和Lu的CT诊断标准所得的灵敏度、特异度分别为84.5%、86.0%、81.4%、91.8%,两个诊断标准的ROC曲线下面积分别为0.886、0.912,经统计学检验无明显差异。应用Lu的CT诊断标准,胰周动静脉受侵的阳性预测值分别为57.1%和71.0%。结论:分别以Loyer和Lu血管分级CT标准对胰腺癌胰周血管侵犯进行分级,两者的诊断价值相同,Lu的CT诊断标准的最佳诊断分界点应在90°-180°之间,此外,它对胰周动脉的价值要比静脉差。     

胰源性区域性门静脉高压的多层螺旋CT表现

目的 分析胰源性区域性门静脉高压(pancreatogenic segmental portal hypertension,PSPH)的多层螺旋CT(MSCT)表现和特征.方法 对32例胰源性门静脉高压患者,使用16排多层螺旋CT行上腹部CT平扫、多期相增强扫描,采用多平面重组(MPR)、最大密度投影(MIP)、容积再现(VR)等图像后处理技术显示异常的脾静脉及侧枝血管情况.结果 脾静脉均有受压、血栓或受侵表现,孤立性脾静脉阻塞中,食管静脉(EV)、胃短静脉(SGV)、胃冠状静脉(CGV)、胃网膜静脉(GEV)、胃结肠干(GCT)曲张分别占9.37%,67.65%,65.63%,96.88%,28.13%;非孤立性脾静脉阻塞伴有肠系膜上静脉SMV阻塞时,其属支结肠右上静脉(RSCV)、胃结肠干(MCV)、胰十二指肠前上静脉(ASPDV)曲张例数分别为15.63%,18.75%,5.88%.同时伴门静脉海绵样变5例.结论 MSCT及图像后处理系统对PRPH诊断具有莺要价值.     

Assessment of vascular invasion in pancreatic carcinoma by MDCT

Background

Pancreatic cancer is one of the aggressive cancers with poor resectability and survival rates. The relationship to adjacent vessels must be assessed before deciding the choice of treatment.

Aim

Assessment of the MDCT signs of arterial and venous invasion in pancreatic carcinoma.

Subjects and methods

Total of 179 of the major peripancreatic vessels (CA; CHA; SMA; PV; SMV) in 47 patients who underwent surgery for pancreatic cancer after MDCT were assessed at surgery and compared with CT findings. Statistical analysis of the findings was done using Chi square test.

Results

115 vessels were not invaded at surgery, while the remaining 64 vessels were invaded (22 arteries and 42 veins). There was over all statistically significant difference between arterial and venous invasion regarding stenosis, occlusion, infiltration and circumferential involvement of the vessel wall.

Conclusion

Assessment of vascular invasion is crucial in the evaluation of resectability for pancreatic cancer. MDCT is an accurate diagnostic tool for peripancreatic vascular invasion in cancer pancreas.     

Pancreatic adenocarcinoma: the different CT criteria for peripancreatic major arterial and venous invasion

OBJECTIVE: To establish preliminarily the different diagnostic criteria for peripancreatic arterial and venous invasion in pancreatic carcinoma by comparing their multidetector-row computed tomography (MDCT) appearances with surgical exploration. METHODS: Among 101 patients with pancreatic carcinoma examined by MDCT, 54 candidates accepting surgery were preoperatively evaluated for vascular invasion based on CT signs (A-E): arterial embedment in tumor or venous obliteration; tumor involvement exceeding one-half of the circumference of the vessel; vessel wall irregularity; vessel caliber stenosis; teardrop superior mesenteric vein (SMV). The peripancreatic major vessels (n = 224) were examined carefully by surgeons during the operation. RESULTS: During surgical exploration, 78 vessels were found to be invaded. With sign A (B, C, or D) as the CT criterion for peripancreatic vascular invasion, the sensitivity of arterial and venous invasion was 66% (97%, 45%, or 41%) and 14% (49%, 63%, or 55%), respectively; the specificity of absence of arterial and venous invasion was 100% (91%, 99%, or 100%) and 100% (all 100%). In this study, there were 3 SMVs appearing teardrop (sign E), which were all confirmed to be invaded. CONCLUSIONS: It is recommended that the CT diagnostic criteria for arterial and venous invasion should be dealt with differently. The criteria of arterial invasion are the presence of sign A or the combination of sign B with one of signs C and D. The criteria of venous invasion are the presence of one of the following signs: sign A, sign B, sign C, sign D, and sign E.     

Pancreatic adenocarcinoma: signs of vascular invasion determined by multi-detector row CT

The purpose of this study was to analyse multi-detector row CT (MDCT) signs of peripancreatic arterial and venous invasion in pancreatic carcinoma. Among 101 patients with pancreatic carcinoma examined by MDCT, 54 candidates for surgery were pre-operatively evaluated for vascular invasion based on MDCT signs. The peripancreatic major vessels (including superior mesenteric artery, coeliac artery, common hepatic artery, superior mesenteric vein and portal vein) were examined carefully by surgeons during the operation. At surgical exploration, 78 of 224 vessels were invaded by tumour. The invaded peripancreatic major arteries (n = 29) and veins (n = 49) presented different MDCT signs: 43% of invaded veins (18/42, except for 7 occluded veins) were surrounded by tumour less than 50% of the vessel circumference compared with 97% (28/29) of the invaded arteries, which were surrounded by tumour more than 50% of the vessel circumference or were embedded in tumour (p<0.001). 69% (34/49) of the invaded veins had vascular stenosis or obliteration, compared with 41% (12/29) of the invaded arteries (p<0.05). Irregularity of the vein wall, 74% (31/42, except for 7 occluded veins); occurred more often than that of the artery wall, 45% (13/29) (p<0.05). In conclusion, the MDCT signs of peripancreatic arterial and venous invasion have different characteristics, which should be considered in pre-operative evaluation.     

肠系膜静脉结扎致急性肠缺血的多层螺旋CT研究

目的 探讨MSCT显示肠系膜静脉结扎致急性肠缺血的早期征象及其动态演化规律.方法 12只巴马猪,采用数字表法随机分成3个实验组(术后6、12、18 h组)和1个对照组,每组3只.实验组9只猪剖腹结扎肠系膜上静脉(SMV)主干远端空肠、回肠和回结肠支,分别于术前及术后6、12和18 h采用MSCT行平扫和增强后动脉、静脉和延迟期扫描.对照组3只猪仅剖腹分离暴露SMV,并于上述时间点进行扫描,比较手术前后肠系膜血管、肠道、腹腔形态的动态变化,结果与病理对照.结果 9只实验组猪均显示急性肠缺血病理改变,随时间延长,缺血进行性加重.CTA可准确显示SMV主干、大属支及其远端小分支直至肠壁边缘的直小静脉,显示SMV分支各结扎点.静脉堵塞性肠缺血的早期CTA改变为肠系膜上动脉痉挛、充盈欠佳、显影延迟和延长;SMV显影淡、延迟;肠壁增厚,系膜水肿,腹水,肠壁强化高于正常;随时间推移,出现肠壁变薄,肠腔扩张、积液,系膜水肿,腹水加重,肠壁强化减弱.结论 CTA能清晰显示肠系膜血管解剖、堵塞的静脉、早期肠缺血改变及其动态演化规律,于病变早期可靠地诊断静脉堵塞性肠缺血.     

CT criteria for venous invasion in patients with pancreatic head carcinoma

The purpose of the study was to evaluate CT criteria for venous invasion in patients with potentially resectable carcinoma of the pancreatic head, with surgical and histopathological correlation. In 113 patients evaluated with spiral CT for suspected pancreatic head carcinoma, several CT criteria for venous invasion were scored prospectively for the portal vein (PV) and the superior mesenteric vein (SMV): length of tumour contact with PV/SMV (0 mm, < 5 mm, > 5 mm); circumferential involvement of the vein (0 degree, 0-90 degrees, 90-180 degrees, > 180 degrees); degree of stenosis; irregularity of the vessel margin; and tumour convexity towards vessel. 65 patients underwent surgery. Pancreatic head carcinoma was proven and pathology of the vascular margin was obtained in 50 of these patients. CT findings for single and combined criteria were correlated with pathology in these 50 patients, 30 of whom showed venous ingrowth. Invasion was found in all cases with SMV narrowing (n = 7), PV contour involvement > 90 degrees (n = 6), PV narrowing (n = 5) and PV wall irregularity (n = 3). The vascular ingrowth rate was 88% (15/17) for tumour concavity towards the PV or SMV. Poor predictors of ingrowth were length of tumour contact with PV > 5 mm (78% ingrowth, 14/18) and contour involvement of the SMV > 90 degrees (83% ingrowth, 10/12). Absence of vascular ingrowth could not be predicted in 100%. In conclusion, CT criteria can predict a high risk of invasion in potentially resectable tumours. Narrowing of the SMV and the PV seems the most reliable criterion, as well as circumferential involvement of the PV > 90 degrees. The best combination of criteria was tumour concavity with circumferential involvement > 90 degrees (sensitivity 60% and positive predictive value 90%).     

胰腺无功能性内分泌肿瘤的螺旋CT诊断与鉴别诊断

目的:分析胰腺无功能性内分泌肿瘤螺旋CT多期扫描的表现,提高CT对无功能性胰腺内分泌肿瘤诊断的正确性。材料和方法:回顾性分析25例经穿刺及手术病理证实的胰腺无功能性内分泌肿瘤的薄层螺旋CT多期扫描资料。螺旋CT采用常规平扫和薄层三期动态增强扫描即动脉期、门脉期和延迟期,三期扫描延迟时间分别为25s,70s和120s。结果:25例患者共检出26个病灶,位于胰头部10个病灶,胰颈部5个病灶,胰体部3个病灶,体尾部4个病灶,胰尾部4个病灶,其中1例同时有两个病灶分别位于胰头和体尾部。肿瘤平均大小为4.0cm。14个病灶呈等密度;12个病灶呈略低密度,密度不均匀,其中可见更低密度灶;其中5个病灶内可见钙化。增强扫描动脉期共18个病灶明显强化,其中6个病灶均匀强化,12个病灶不均匀强化,6病灶呈中等程度强化,2个病灶动脉期轻度强化。3例肿瘤位于胰头者,2例出现了胆道和胰管扩张,胰体尾部萎缩,另1例仅出现胰管轻度扩张,1例肿瘤位于体部者出现远端胰管扩张伴实质萎缩。25例患者8例出现多发肝富血供转移灶,其中1例患者同时出现肺和脊柱的多发转移,无胰周及后腹膜淋巴结转移;3例出现肿瘤邻近血管的侵犯,其余为邻近血管推移受压改变。结论:无功能性胰腺内分泌肿瘤多较大,富血供,常见钙化,较少出现周围血管及胰胆管直接侵犯,较少出现后腹膜淋巴结转移及神经丛侵犯,根据有无肝脏及其他脏器转移、淋巴结转移及周围血管侵犯,进一步提示肿瘤的良恶性。     

急性肠系膜血管梗塞的CT表现

目的评价CT对急性肠系膜血管梗塞（AMI）的诊断价值。方法搜集AMI病例10例，男6例，女4例，平均年龄67．2岁。除1例在诊断次日死亡外，其余均经手术病理证实。其中肠系膜上动脉（SMA）梗塞4例，肠系膜上静脉梗塞（SMV）5例，肠系膜下静脉（IMV）梗塞1例。除1例行CT平扫外，其余9例均行CT平扫及增强扫描，详细分析其影像学表现。结果直接征象为血管内充盈缺损（8例）。间接征象包括肠腔扩张积液（4例）、肠壁增厚（6例）、薄纸样肠壁（4例）、缆绳征（5例）、肠系膜积液（3例）、肠壁积气（2例）、门静脉积气（1例）及腹腔积液（3例）。结论CT是诊断急性肠系膜血管梗塞的一种快速、敏感、可靠及无创伤的影像学方法。     

Multislice helical CT of the pancreas and spleen

Multislice helical CT (MSCT) with its multidetector technology and faster rotation times, has led to new dimensions in spatial and temporal resolution in CT imaging. In contrast to single-slice CT, smaller slice collimations can be applied that lead to almost isotropic voxels and allow high quality multiplanar and 3-D image reconstructions. The high speed of multislice CT can be used to reduce the time needed to cover a given volume, to increase the spatial resolution along the z-axis by applying thinner slice collimations, and to cover longer anatomic volumes. The speed of MSCT allows organ imaging in clearly defined perfusion phases, e.g. the arterial, parenchymal, and portal venous perfusion phases. Contrast agents with higher iodine concentrations (400 mg iodine per ml compared with 300 mg iodine per ml) lead to higher contrast enhancement of the pancreas (arterial+portal venous phases), the kidneys (arterial+portal venous phases), the spleen (arterial phase), the wall of the small intestine (arterial+portal venous phases), the larger and smaller arteries (arterial phase), and the portal vein (portal venous phase). All of these advancements lead to improved visualization of small structures and of various pathologies, such as pancreatic tumors, liver metastases, vessel infiltration, and vascular diseases.