Obliteration of the fat surrounding the celiac axis and superior mesenteric artery is not a specific CT finding of carcinoma of the pancreas

Partial or complete obliteration of the fat surrounding the celiac axis and superior mesenteric artery on CT is considered so characteristic of pancreatic carcinoma that many consider it diagnostic. However, this finding may be present on CT scans of some treatable tumors. During a 2-year period, we retrospectively collected 10 cases of nonpancreatic tumors that obliterated the fat surrounding the celiac axis and/or superior mesenteric artery. Four patients had metastatic disease, three had lymphoma, two had primary small-bowel adenocarcinoma, and one had a diffuse retroperitoneal endocrine tumor. The scans were analyzed for presence, location, and morphology of the mass and biliary and/or pancreatic ductal dilatation. Of the patients with metastatic disease, three had focal, retropancreatic, periceliac masses without ductal dilatation. One had an infiltrative retroperitoneal process enveloping the pancreas and causing biliary dilatation. Of the patients with lymphoma, two had focal masses in the mesenteric root without ductal dilatation, and one had an infiltrative retroperitoneal process. Of the two patients with primary carcinoma of the small bowel, one had a mesenteric mass without ductal dilatation and the other had an infiltrative retroperitoneal process enveloping the pancreatic head and obstructing the ducts. The patient with the neuroendocrine tumor had an infiltrative retroperitoneal process enveloping the pancreas without ductal dilatation. Obliteration of the fat surrounding the celiac axis and superior mesenteric artery is not a specific CT finding of carcinoma of the pancreas. One cannot rely solely on its presence for the diagnosis of pancreatic carcinoma but should use other important findings such as a focal pancreatic mass and ductal dilatation.     

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.     

The superior mesenteric artery fat plane: is obliteration pathognomonic of pancreatic carcinoma?

Obliteration of the fat plane surrounding the superior mesenteric artery has been described as characteristic of pancreatic carcinoma. To determine the specificity of this and other computed tomography findings in the pancreas and peripancreatic region, scans of 86 patients were reviewed without clinical history. Diagnoses included pancreatitis (26 patients); pancreatic adenocarcinoma (14 patients); lymphoma (17 patients); metastatic nonpancreatic carcinoma (14 patients); and normal findings (15 patients). Confluent adenopathy could not be reliably differentiated from a pancreatic mass except when adenopathy separated the common bile duct from the duodenum. Retrocrural adenopathy was unusual with pancreatic carcinoma. The fat plane surrounding the superior mesenteric artery was obliterated with pancreatic carcinoma (36%), nonpancreatic carcinoma (29%), and lymphoma (24%), but not with pancreatitis, although perivascular edema was seen in 19%. Evaluation of the celiac axis was less rewarding. Obliteration of the superior mesenteric artery fat plane is a sign of malignancy, but it is not specific for pancreatic carcinoma. We propose that the superior mesenteric artery origin be considered within a paraaortic space, separate from the anterior pararenal space. This explains its characteristic lack of involvement by pancreatitis.     

胰腺癌胰周淋巴结转移分布特征的螺旋CT表现

目的:胰腺癌胰周淋巴结转移的分布特征及螺旋CT影像表现。方法:搜集经手术病理诊断为原发性胰腺癌45例,所有病例均经手术病理或影像标准诊断有胰周淋巴结转移。根据本组45例病例CT所反映的肿大淋巴结的分布情况,将胰周淋巴结分为8组。设定淋巴结的短径≥1.0cm为淋巴结转移阳性的影像表现。统计阳性淋巴结的出现率,重点观察淋巴结转移的部位、大小、数目、形态、密度、强化情况。结果:本组45例胰腺癌中,共计89个部位观察到淋巴结转移胰周转移淋巴结以腹腔动脉干组46.7%(21例),肠系膜根部组46.7%(21例),腹主动脉周围组35.6%(16例)为最多,胃周11.1%(5例)及脾动脉-脾门组13.3%(6例)最少。结论:胰腺癌转移所致肿大淋巴结主要分布在腹腔干、肠系膜根部以及腹主动脉周围。螺旋CT扫描检查可以较准确显示胰腺癌胰周淋巴结的转移情况。     

胰腺癌侵犯胰周主要血管的CT表现分析

目 的分析多层螺旋CT(MSCT)胰腺检查，胰腺癌侵及胰周主要动、静脉的不同CT表现特征。方法 MSCT诊断胰腺癌68例患者中，33例行手术治疗(其中12例行胰十二指肠切除术，21例剖腹探查发现不可切除)，病理结果均证实为胰腺导管细胞癌。术中由手术者仔细探查胰周主要血管[肠系膜上动脉(SMA)、腹腔干(CA)、肝动脉(HA)、肠系膜上静脉(SMV)及门静脉主干(PV)]。结果 165支受检血管中，手术探查发现103支血管未受侵犯，其余62支血管受侵，MSCT术前检查，8．1％(5／62)受侵血管误判为未受侵犯(假阴性)。其余受侵的胰周主要动、静脉(57支)具有不同的CT表现特征：胰周主要动脉受侵时，均被肿瘤包绕大于管周的1／2或完全包埋于肿瘤中。胰周主要静脉受侵时，部分静脉血管被肿瘤包绕小于管周的1／2：SMV为4支(4／17)，PV为2支(2／13)，但同时均出现管壁受浸润或管腔狭窄或管腔形态改变；胰周静脉受侵犯时出现管腔狭窄或闭塞的机会较胰周动脉大：SMV为11支(11／17)，PV为12支(12／13)，而CA为3支(3／8)，HA为4支(4／7)，SMA为4支(4／12)；胰周静脉受侵犯时管壁呈浸润性改变的比例较胰周动脉高：SMV为11支(11／17)，PV为7支(7／13)，而CA为3支(3／8)，HA为2支(2／7)，SMA为6支(6／12)。结论 胰周动、静脉受侵及时，其CT表现具有不同特征。     

CT appearance of diffuse mesenteric edema

The extent of pathologic processes involving the mesentery is frequently difficult to assess by clinical examination and standard radiography. Contrast studies of the gastrointestinal tract only identify the effect of these processes on adjacent opacified bowel loops and frequently underestimate the extent of mesenteric pathology. Computed tomography has previously been used to characterize various mesenteric abnormalities, most often secondary to malignant or inflammatory disease. We report the characteristic CT appearance of diffuse mesenteric edema in 14 patients. Eleven patients had documented hypoalbuminemia, two patients superior mesenteric vein thrombosis, and one patient cirrhosis. The CT findings that allowed confident diagnosis of this entity include increase in density of the mesenteric fat, poor definition of segmental mesenteric vessels, relative sparing of the retroperitoneal fat, and association with subcutaneous edema.     

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。     

Case report. Unusual presentation of a pancreatic mass in an infant: pancreatic haemangioendotheliomatosis

Primary pancreatic tumours are extremely rare in children. We report a case of a 5-month-old male with a diffuse invasive tumour of the head of the pancreas. The tumour demonstrated peripancreatic extension into the porta hepatis, which occluded the portal vein and invaded the superior mesenteric artery. It was found to be haemangioendotheliomatosis of the pancreas. Imaging, pathological findings and a brief relevant classification of haemangioma are discussed.     

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     

Local extension of pancreatic carcinoma: assessment with thin-section helical CT versus with breath-hold fast MR imaging--ROC analysis.

PURPOSE: To compare contrast material-enhanced thin-section helical CT with breath-hold contrast-enhanced MR imaging for sensitivity in the detection of pancreatic adenocarcinoma and for accuracy in local tumor staging. MATERIALS AND METHODS: Fifty-seven patients (37 men, 20 women aged 42-28 years) suspected of having pancreatic adenocarcinoma were examined. The final diagnosis was confirmed at surgery to be pancreatic cancer in 31 patients; the other 26 patients were deemed not to have pancreatic cancer. All patients underwent both CT and MR imaging (turbo spin-echo and fast low-angle shot) studies. Image quality and pancreatic enhancement were subjectively evaluated. All CT scans and MR images were assessed by two independent observers by using a five-point scale for the detection of tumor and of invasion into the peripancreatic tissue, portal vein, and/or peripancreatic artery. Receiver operating characteristic curves for CT and MR imaging were analyzed. RESULTS: At visual analysis, pancreatic enhancement at CT and at MR imaging was comparable, but depiction of vessels was superior at helical CT. Detectability of tumor was comparable. Helical CT was significantly superior to MR imaging in diagnostic imaging of invasion into the peripancreatic tissue, portal vein, and/or peripancreatic artery (P < .01). CONCLUSION: Thin-section dynamic CT is more sensitive than MR imaging for detection of peripancreatic and vascular invasion in patients with pancreatic cancer.     

Multi--detector row helical CT of the pancreas: effect of contrast-enhanced multiphasic imaging on enhancement of the pancreas, peripancreatic vasculature, and pancreatic adenocarcinoma.

PURPOSE: To determine the optimal phase for enhancement of the normal pancreas and peripancreatic vasculature and the maximal tumor-to-pancreatic parenchymal enhancement difference by using multiphase, contrast material-enhanced, multi-detector row helical computed tomography (CT). MATERIALS AND METHODS: Forty-nine patients with a normal-appearing pancreas but suspected of having pancreatic abnormality and 28 patients with proved pancreatic adenocarcinoma underwent multiphase, contrast-enhanced, multi-detector row CT during the arterial phase (AP), pancreatic parenchymal phase (PPP), and portal venous phase (PVP). Attenuation values of the normal pancreas, pancreatic adenocarcinoma, celiac and superior mesenteric arteries, and superior mesenteric and portal veins were measured during all three imaging phases. Quantitative analysis of these measurements and subjective qualitative analysis of tumor conspicuity were performed. RESULTS: Maximal enhancement of the normal pancreatic parenchyma occurred during the PPP. Maximal tumor-to-parenchyma attenuation differences during the PPP and PVP were equivalent but greater than that during the AP. Subjective analysis revealed that tumor conspicuity during the PPP and PVP was equivalent but superior to that during the AP. Maximal arterial enhancement was seen during the PPP, and maximal venous enhancement was seen during the PVP. CONCLUSION: A combination of PPP and PVP imaging is sufficient for detection of pancreatic adenocarcinoma, because it provides maximal pancreatic parenchymal and peripancreatic vascular enhancement. AP imaging can be reserved for patients in whom CT angiography is required.     

胰腺癌可切除性的CT研究

４３例胰腺癌均经手术和／或病理证实，其中１０例经胰十二指肠切除术切除。本文复习ＣＴ所见，初步认为下列表现是胰腺癌不可切除的ＣＴ征象：（１）胰头癌距肝门的距离少于４ｃｍ；（２）肠系膜上动脉、下腔静脉、腹主动脉、胃、肝、脾、左肾及较大范围的肠系膜上静脉浸润；（３）肝转移。腹水、肠系膜上动脉周围脂层的单纯消失均不是判断不可切除的可靠征象。     

Pancreatic portal cavernoma in patients with cavernous transformation of the portal vein: MR findings

The purpose of the article was to prospectively evaluate the MR findings of pancreatic portal cavernoma in a consecutive series of patients with cavernous transformation of the portal vein. This study was approved by the review board of our institution, and informed consent was obtained. The clinical and biological data and the MR imaging for 20 patients (11 female, 9 male; median age, 49 years) with cavernous transformation of the portal vein and no evidence of previous pancreatic disease were reviewed. The presence of pancreatic portal cavernoma (defined as intra- and/or peripancreatic portal cavernoma), morphological changes in the pancreas, biliary and ductal pancreatic abnormalities, and extension of the portal venous thrombosis were qualitatively assessed. Fifteen patients (75%) had pancreatic portal cavernoma with collateral formation in the pancreas and/or collaterals around the pancreas seen on dynamic contrast-enhanced MR sequences: three patients had both intra- and peripancreatic portal cavernoma, six had intrapancreatic portal cavernoma alone and six had peripancreatic portal cavernoma only. The presence of intra- or peripancreatic portal cavernoma was significantly associated with extension of the thrombosis to the splenic and superior mesenteric veins (p = 0.05). Morphological changes in the pancreas, heterogeneity on T2-weighted sequences and main ductal pancreatic abnormalities were seen in two, four and two patients, respectively. All these patients had intrapancreatic portal cavernoma. Bile duct dilatation was observed in 13 (65%) patients: among them three had extrahepatic dilatation only and these three patients had associated intrapancreatic portal cavernoma. In patients with cavernous transformation of the portal vein, intra- or peripancreatic portal cavernoma is common. In conclusion, intra- or peripancreatic portal cavernoma was only observed in patients with extension of the thrombosis to the splenic vein and/or the superior mesenteric vein.     

肠系膜上动脉梗死的CT表现

目的：探讨肠系膜上动脉栓塞的CT表现特点。方法：搜集肠系膜上动脉栓塞病例6例，男4例，女2例，平均年龄63岁，其中5例手术证实，1例DSA证实。6例均行腹部平扫加增强CT扫描。结果：肠系膜上动脉内充盈缺损6例，肠壁增厚4例，肠系膜增厚、血管增粗3例，肠腔扩张、肠壁薄纸样改变2例；腹腔积液2例。结论：多层螺旋CT是诊断肠系膜上动脉栓塞的一种有效且无创伤的影像检查方法，可以明确阻塞动脉的部位及范围，对手术较有指导价值。     

The local spread of lower bile duct cancer: evaluation by thin-section helical CT

This study illustrates the local spread of lower bile duct cancer with thin-section helical CT in correlation with the surgical and pathological findings. Pathologically, 16 patients had pancreatic invasion, 4 had small bowel mesentery invasion, 7 had extrapancreatic nerve plexus invasion, and 3 patients had vascular invasion. On thin-section helical CT, pancreatic invasion was correlated to the clarity or non-clarity of the bile duct mass-pancreas border and the presence of an intrapancreatic mass. Cases with small bowel mesentery and extrapancreatic nerve plexus invasion showed mass or stranding around the superior mesenteric artery and/or inferior pancreatoduodenal artery. Vascular invasion was seen as tumor contiguity to these vessels. Received: 28 September 1998; Revised: 30 December 1998; Accepted: 2 April 1999     

Pancreatic clefts caused by penetrating vessels: a potential diagnostic pitfall for pancreatic fracture on CT

The diagnosis of pancreatic fracture using computerized tomography (CT) is made by identifying a linear defect in the pancreas, often with a variable amount of peripancreatic fluid. However, the fat surrounding arterial and venous vessels which penetrate the pancreas can give a very similar CT appearance – a previously unreported finding. This report describes the CT appearance of such defects as well as the macroscopic and microscopic analysis of the vessels penetrating the pancreas in a cadaver having this CT finding.     

胰腺癌CT征象及手术切除性估价的探讨（附67例分析）

分析了６７例经手术及病理学证实的胰腺癌的ＣＴ征象。胰腺轮廓局限性增大５０例（７４．６％），８例（１１．９％）显示向肠系膜侵犯的线条状影，等密度或均匀低密度病灶４１例（６１．２％）。受累血管以下腔静脉、肠系膜上动、静脉及腹主动脉为多（９４．８％）。脾脏增大１５例，继发假性囊肿１１例。讨论了早期胰腺癌诊断的难点和可能性，总结了胰腺癌继发囊肿的ＣＴ特征，对胰腺癌手术切除性的ＣＴ标准进行了评估。     

双源CT双期增强血管成像对急性肠缺血的诊断

目的:探讨双源CT(DSCT)双期增强扫描血管成像对急性肠缺血(acute mesenteric ischemia,AMI)患者的诊断价值。方法:回顾性分析经手术或介入治疗证实的26例AMI患者的DSCT资料。所有患者均行DSCT双期增强扫描即动脉期和门静脉期血管成像。结果:肠系膜上动脉栓塞8例,肠系膜上动脉血栓形成4例,肠系膜上静脉血栓形成14例。CT直接征象为肠系膜血管内低密度充盈缺损,受累血管腔闭塞(17例)或重度狭窄(9例)。间接征象:肠壁增厚(21例),肠管扩张、肠腔内积液积气(18例),肠壁强化程度降低(7例),肠壁积气(5例),肠系膜脂肪水肿及渗出(19例),"缆绳征"14例,腹腔积液12例。结论:DSCT增强扫描及双期血管成像可清楚显示AMI血管阻塞的部位、范围、程度及继发改变,对明确诊断和指导治疗具有较高的应用价值。     

螺旋CT双期扫描技术及其在胰腺癌诊断中的价值

目的：探讨螺旋CT双期扫描技术及其对胰腺癌的诊断价值。方法：正常人60例及胰腺癌44例分两组行螺旋CT双期扫描：A组40例,分动脉期和门动脉期（注射对比剂后20s和60s）扫描;B组64例,分胰腺期和肝脏期（注射对比剂后35s和70s)扫描。分别测定各期胰腺、病灶及胰周大血管的CT值,计算胰腺期及肝脏期胰周小静脉的显示率,并行统计学处理,对扫描时相的比较采用方差分析及q检验处理,对胰周小静脉的显示率采用x^2检验分析。结果：正常组,胰腺在胰腺期的增强值高于其他3期（F＝13．45,P＜0．0001）胰周大血管在胰腺期显示良好。胰周小静脉的显示率,胰腺期优于肝脏期（x^2=4．44,12．38,4．81,P＜0．05）;异常组,胰腺与病灶的增强差值,胰腺期明显大于其他3期（F＝14．90,P＜0．0001）,发现小胰腺癌4例。胰周大血管受侵者占不可切除性肿瘤的54％（19／35）,胰周小静脉迂曲扩张者占42％（10／42）。肝转移灶占37％（13／35）。结论：胰腺螺旋CT双期扫描宜分为胰腺期和肝脏期,该技术在胰腺癌的诊断中具有非常重要的临床价值。     

多排螺旋CT曲面重建在胰腺和胰周病变中的应用

目的　探讨多排螺旋CT曲面重建在胰腺及胰周病变中的应用价值。方法　对胰腺和胰周病变的患者共 17例采用多排螺旋CT扫描上腹部 (5例单纯平扫 ,11例平扫 增强 ,1例行静脉CT胆道造影 ) ,其中胰腺癌 4例 ,胆总管结石 3例 ,慢性胰腺炎伴假性囊肿 3例 ,真性囊肿合并慢性胰腺炎及胆道梗阻 1例 ,囊腺瘤 1例 ,胰岛细胞瘤 1例 ,胰周淋巴结肿大 3例和 1例脾动脉瘤。由操作者经特定的解剖结构和病变画线做曲面重建。结果　多排螺旋CT可获得高质量的曲面重建图像 ,跟踪显示胰胆管或胰周血管 ,和清晰显示病灶与胰腺、胰胆管和胰周血管的关系。结论　多排螺旋CT薄层扫描能获得胰腺高质量曲面图像 ,提供独特的解剖信息和相关病理征象 ,有助于胰腺和胰周病变的诊断及局部侵犯的评价 ,指导临床治疗方案的选择与实施。