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。     

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.     

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.     

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.     

CT assessment of the inferior peripancreatic veins: clinical significance

OBJECTIVE: The purpose of this study was to evaluate and clarify the clinical significance of CT scans of the inferior peripancreatic veins. MATERIALS AND METHODS: Forty-three patients with suspected pancreatic disease underwent three-phase helical CT (collimation, 5 mm; reconstruction, 2.5 mm; scan delay, 30, 60, and 150 sec). The frequency of visualization on CT of the anterior and posterior inferior pancreaticoduodenal veins, inferior pancreaticoduodenal vein, and first jejunal trunk was assessed and correlated with angiographic and pathologic findings. RESULTS: The frequency of visualization of normal inferior peripancreatic veins in patients (n = 22) with a normal portomesenteric vein was 36% for the anteroinferior pancreaticoduodenal vein, 36% for the posteroinferior pancreaticoduodenal vein, 59% for the inferior pancreaticoduodenal vein, and 100% for the first jejunal trunk. The smaller inferior peripancreatic veins were frequently not visualized when normal. In patients (n = 13) with pancreatic carcinoma involving the portosuperior mesenteric vein, all of the inferior peripancreatic veins were dilated and easily recognizable. When the tumor did not involve the portosuperior mesenteric vein but did involve the anteroinferior pancreaticoduodenal, posteroinferior pancreaticoduodenal, and inferior pancreaticoduodenal veins (n = 8), some of the other peripancreatic veins (first jejunal trunk, anterior and posterior superior pancreaticoduodenal veins, and gastrocolic trunk) were dilated. Dilatation indicated tumor extension to the third portion of the duodenum. In patients (n = 7) with involvement of the inferior pancreaticoduodenal vein, the first jejunal trunk, or both without the involvement of the portosuperior mesenteric vein, dilatation of the other peripancreatic veins (anteroinferior pancreaticoduodenal vein, posteroinferior pancreaticoduodenal vein, anterosuperior pancreaticoduodenal vein, posterosuperior pancreaticoduodenal vein, and gastrocolic trunk) indicated tumor invasion of only the second portion of the extrapancreatic nerve plexus (n = 4) and tumor invasion of both the second portion of the extrapancreatic nerve and the mesenteric root (n = 3). CONCLUSION: Dilatation of peripancreatic veins with nonvisualization of inferior peripancreatic veins suggests tumor invasion of peripancreatic tissue.     

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。     

食管癌侵犯气管-支气管和下肺静脉的术前CT探讨

目的探讨术前CT检查判断食管癌外侵气管-支气管和下肺静脉的价值.方法 30例经病理学检查确诊的食管癌患者进行术前的CT检查及分析.气管-支气管受侵判别标准气管-支气管有明显移位、受压并有管壁不规则变形或有肿物凸入气管、支气管腔内为受侵,否则为未受侵.肿瘤包绕下肺静脉或肿瘤与下肺静脉分界不清时,考虑为下肺静脉受侵.结果 30例食管癌患者气管-支气管受侵CT诊断的敏感性、特异性及准确性分别为100.00%、88.00%及90.00%;下肺静脉受侵的敏感性、特异性及准确性分别为100.00%、92.86%及93.33%.结论术前CT检查判断食管癌有否外侵气管-支气管及下肺静脉价值较大.     

Preoperative evaluation of local invasion and metastatic lymph nodes of colorectal cancer and mesenteric vascular variations using multidetector-row computed tomography before laparoscopic surgery

OBJECTIVE: To evaluate local invasion and lymph nodes metastasis of colorectal cancer and mesenteric vascular variations using multidetector-row computed tomography (MDCT) before laparoscopic colorectal surgery. METHODS: Fifty-one patients with colorectal cancer underwent MDCT. The evaluation items were as follows: (1) local invasion; (2) detected lymph nodes evaluated by short-axis diameter, long-axis diameter, short/long axis diameter ratio, and computed tomography (CT) attenuation; and (3) visualization of mesenteric artery and vein by 3-dimensional-CT angiography. RESULTS: First, in the evaluation of local invasion, overall accuracy was 94.1%. Second, the point of 0.8 or greater in short/long-axis diameter ratio was best index for the diagnosis of metastatic lymph nodes. Using this index, the accuracy of the diagnosis per node was 80.5%. Third, 3-dimensional-CT angiography correctly demonstrated variations of the mesenteric artery and vein. CONCLUSIONS: The MDCT was effective for evaluation of local invasion and lymph nodes metastasis of colorectal cancer and mesenteric vascular variations before laparoscopic surgery.     

Preoperative assessment of vascular invasion in exocrine pancreatic cancer by multidetector CT

Purpose

To evaluate multidetector CT (MDCT) signs of vascular invasion in pancreatic carcinoma.

Patients and methods

Retrospective review of preoperative dynamic MDCT of 42 patients with pathologically proven pancreatic carcinoma.

Results

Surgically confirmed invaded vessels were 19 arteries and 33 veins. Multiple signs of vascular invasion were assessed.

Conclusion

Significant advances have been made in the ability of MDCT to visualize pancreatic cancer and to stage disease when close attention is paid to technique with special attention to multiple signs of vascular invasion.     

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。     

CT Angiography for Living Kidney Donors: Accuracy, Cause of Misinterpretation and Prevalence of Variation

OBJECTIVE: To determine the accuracy of the use of multi-detector row CT (MDCT) to predict vascular anatomy in living kidney donors and to reveal the prevalence of vascular variations in a Korean population. MATERIALS AND METHODS: A total of 153 living kidney donors that had undergone preoperative CT and nephrectomy, either with open or laparoscopic surgery, were selected retrospectively. The initial CT results were compared with the surgical findings and repeated review sessions of CT scans were performed to determine the causes of mismatches in discordant cases. RESULTS: The accuracy of CT angiography was 95% to predict the number of renal vessels. Four arteries and two veins were missed during the initial CT interpretation due to perception errors (for two arteries and two veins) and technical limitations (two arteries). The prevalence of multiple renal arteries and veins, early branching of a renal artery and late confluence of a renal vein were 31%, 5%, 12%, 17%, respectively. The circumaortic renal vein and the bilateral inferior vena cava were found in two cases each (1.3%). One case (0.7%) each of a retroaortic renal vein and a supradiaphragmatic originated renal artery were found. CONCLUSION: MDCT provides a reliable method to evaluate the vascular anatomy and variations of living kidney donors.     

Comparing contrast-enhanced breath-hold MR angiography and conventional angiography in the evaluation of mesenteric circulation

OBJECTIVE: Our aim was to compare the results of gadolinium-enhanced breath-hold MR angiography with those of conventional angiography for the study of mesenteric circulation. SUBJECTS AND METHODS: MR angiography and digital subtraction angiography were prospectively performed in 33 patients referred for hepatic, pancreatic, or mesenteric disease. MR angiography was performed with four three-dimensional acquisitions at 0, 30, 60, and 90 sec after injection of 0.1 mmol/kg of gadolinium. Selective conventional angiography was used as the standard of reference. RESULTS: A pure arterial angiogram (one on which veins could not be visualized) was obtained in 27 patients during the second or third acquisition. By subtracting the arterial phase from an arteriovenous phase (third or fourth acquisition) we obtained a pure venous angiogram (one on which arteries could not be visualized) in 28 patients. Agreement was good or excellent for the hepatic artery (kappa = 0.78), the superior mesenteric artery (kappa = 0.65), the splenic artery (kappa = 0.70), the portal vein (kappa = 1.0), the superior mesenteric vein (kappa = 0.88), and the splenic vein (kappa = 0.75). Agreement was poor, and vessels were better shown by conventional angiography, for the intrahepatic arteries (kappa = 0.006) and the branches of the superior mesenteric artery (kappa = 0.14). MR angiography and conventional angiography revealed 29 and 27 portosystemic collaterals, respectively. CONCLUSION: Dynamic breath-hold contrast-enhanced MR angiography compared favorably with conventional angiography in preoperative assessment of the proximal mesenteric arteries and in the evaluation of portal hypertension; however, conventional angiography is still necessary to evaluate distal arteries.     

Computed tomography of peripancreatic fat planes

Obliteration of peripancreatic fat planes usually is considered an indicator of peripancreatic tumour infiltration in the presence of a malignant mass, or of inflammation of peripancreatic tissues in patients with pancreatitis. However, absence of peripancreatic fat planes also may be found in patients without evidence of pancreatic disease. Hence, CT scans of 125 patients without clinical or computed tomographic evidence of pancreatic disease were evaluated to assess normal variations in the anatomy of the pancreas and its relation to surrounding vessels and bowel loops. The fat plane separating the superior mesenteric artery from the pancreas was preserved in 100% of patients. Conversely, fat planes between the pancreas and the superior mesenteric vein, inferior vena cava, and adjacent bowel loops were partially or totally obliterated in 13% to 50% of patients. It is concluded that the absence of fat around the superior mesenteric artery is highly suggestive of pathologic changes of the pancreas, while the lack of fat planes between the pancreas and other splanchnic vessels or bowel loops frequently is normal, and therefore, is an unreliable sign of pancreatic disease. The applications of these findings to the assessment of tumour resectability by CT, and to CT scanning techniques, are discussed.     

Septic thrombosis of the portal vein due to peripancreatic ligamental abscess

Septic thrombus formation of both the main portal vein and its intrahepatic branches were observed on CT in a patient with peripancreatic abscess. The septic thrombosis of portal vein (STPV) extended from the level of porta hepatis into the intrahepatic branches, but the portal vein and superior mesenteric vein at the level of pancreatic head were preserved with no evidence of thrombosis angiographically. The gas-containing abscess near the head of the pancreas extended toward the hepatic hilum and surrounded the portal vein and its branches on CT. It was concluded that these thrombi of portal vein branches at porta hepatis and intrahepatic branches were caused by extensions of peripancreatic abscess via the hepatoduodenal ligament and ligamentum teres. Computed tomography was useful in depicting the ligamentous spread of peripancreatic abscess resulting in STPV. Received: 29 September 1997; Revision received: 13 February 1998; Accepted: 16 February 1998     

Median arcuate ligament syndrome: multidetector computed tomography findings

OBJECTIVE: We aimed to describe the clinical and multidetector computed tomography (MDCT) angiography findings of celiac, mesenteric, and renal artery entrapment by the median arcuate ligament. MATERIALS AND METHODS: Patients (n = 453) who underwent MDCT abdominal aorta angiography in a period of 3 years were retrospectively reviewed for vascular compression by median arcuate ligament known as median arcuate ligament syndrome. The MDCT examinations were performed with 16-slice (n = 292) and 64-slice scanners (n = 161). The median arcuate ligament itself and adjacent vascular branches of abdominal aorta were assessed for compression by 2 different radiologists who are experienced on MDCT angiography more than 3 years. Both axial, multiplanar reformatted images and 3-dimensional angiographies were used for interpretation. RESULTS: Twelve patients were found to have clinically significant vessel entrapments by median arcuate ligament; 6 of them with celiac artery, 4 of them with renal artery, and 2 of them with both celiac and mesenteric artery involvement. Patients with celiac and mesenteric vessel entrapments presented with epigastric pain. All patients with renal artery entrapment had resistant hypertension. The MDCT showed the proximal narrowing caused by compression of median arcuate ligament. The proximal portions of renal arteries pulled down and in toward the aorta, with mild to moderate narrowing. CONCLUSIONS: The MDCT exanimation with multiplanar images and 3-dimensional angiography is a noninvasive imaging technique that can be used with high accuracy in the diagnosis of median arcuate ligament syndrome.     

Current development of cardiac imaging with multidetector-row CT

Multidector-row CT (MDCT) with retrospective ECG gating allows scanning the entire heart with 1.25 mm slice thickness and 250 ms effective exposure time within 35 s investigation time. The resulting images allow for an accurate high-resolution assessment of morphological detail of both the coronary arteries and the cardiac chambers. Performing a contrast-enhanced MDCT angiography (MD-CTA) in addition to a non-enhanced scan for the detection and quantification of coronary calcifications may be indicated in patients with atypical chest pain and in young patients with high cardiovascular risk. This group of patients may show non-calcified plaques as the first sign of their coronary artery disease. As the proximal part of the coronary arteries is well displayed by MD-CTA it also helps to delineate the course in anomalous coronary vessels. Additional information is drawn from the preoperative use of MD-CTA do determine the distance of the left internal mammarian artery to the left anterior descending coronary artery prior to minimal invasive bypass grafting. Additional indications for MD-CTA are the non-invasive follow up after venous bypass grafting, PTCA, and coronary stent interventions. MD-CTA allows following the course of the coronary vessels to the level of third generation coronary segmental arteries. A definite diagonis to rule out coronary artery disease can be reliably made in vessels with a diameter of 1.5 mm or greater. With MDCT a number of different atherosclerotic changes can be observed in diseased coronary arteries. Non-stenotic lesions may show tiny calcifications surrounded by large areas of irregularly distributed soft tissue. Calcifications in this type of atherosclerotic coronary artery wall changes appear as 'the tip of iceberg'. Heavy calcifications usually tend to be non-stenotic because of vessel remodelling resulting in a widening of the coronary vessel lumen. Therefore, heavy calcifications appear to ack like an 'internal stent' for a coronary vessel segment. Humps of soft tissue either with or without calcifications are more likely to cause significant coronary artery disease and correlate with stenoses of >50% on selective coronary catheter. These humps consist of well-defined soft tissue in the coronary artery wall. The density of this soft tissue may vary between 30-70 HU. In cases where a coronary vessel is occluded by thrombotic material, a typical sign is found with enlargement of the coronary vessel, a hypodense center and a hyperdense rim. Vessel occlusion without thrombus may also appear within a collapsed and dense lumen. In addition to the investigation of the coronary arteries, CTA with MDCT is well suited to assess the presence and morphology of myocardial scars and aneurysms, intracardial tumors and thrombi.     

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.     

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     

Vascular encasement by pancreatic cancer: correlation of CT findings with surgical and pathologic results

PURPOSE: The purpose of this study was to correlate thin-slice high-resolution helical CT findings of arterial and venous involvement in pancreatic cancers with surgical and histopathologic results. METHOD: Forty-eight patients with pancreatic cancer underwent preoperative thin-slice high-resolution helical CT, followed by surgical dissection of the pancreatic vessels during curative or palliative surgery. Major vessels running within 1 cm from the tumor margin were evaluated. CT appearance was graded on a 0-4 scale (0: none, 1: <24%, 2: 25-49%, 3: 50-74%, 4: 75-100%) by circumferential contiguity of tumor to vessels. Resected specimens were available from 26 patients. RESULTS: Surgical correlation of CT findings was available in 89 veins and 83 arteries, and both surgical and histologic correlation was available for 42 veins and 29 arteries. At surgical observation, 29 of 35 veins (82.9%) evaluated as CT grade 3 or 4 were found to be involved, whereas only 18 of 30 arteries (60%) evaluated as CT grade 3 or 4 were proved to be involved. On microscopic observation, tumor invasion to the portal venous systems was confirmed in 15 of 42 (35.7%) vessels, and this invasion was depicted as from CT grades 1 to 4. In arteries, tumor invasion was seen in 3 of 29 vessels (10.3%), all of which were graded as 3 or 4 by CT. CONCLUSION: The grading system of vascular invasion should differ between arteries and veins. Involvement of the venous system exceeding one-half circumference of the vessels (grade 3 or 4) was suggestive of vascular invasion; however, this criterion was not always satisfactory for the evaluation of tumor invasion in the arterial system.     

MDCT in Pancreatic adenocarcinoma: prediction of vascular invasion and resectability using a multiphasic technique with curved planar reformations

OBJECTIVE: The objective of our study was to determine the negative predictive value of MDCT with curved planar reformations for detecting vascular invasion and predicting overall resectability in patients with pancreatic adenocarcinoma. MATERIALS AND METHODS: Imaging findings related to vascular invasion and overall tumor resectability in 25 patients who underwent contrast-enhanced biphasic MDCT evaluation were correlated with actual vessel invasion and overall resectability determined at surgery and pathologic examination. The presence of vascular invasion was assessed in 110 major peripancreatic vessels in 22 patients who underwent resection. RESULTS: On MDCT, 23 (92%) of 25 patients were deemed to have resectable pancreatic adenocarcinoma. The tumors in the remaining two (8%) were considered not resectable because of the presence of vascular invasion (which was confirmed in only one patient at surgery). Of those 23 patients deemed to be candidates for curative resection on the basis of MDCT results, 20 were found to have resectable adenocarcinoma at time of surgery, yielding a negative predictive value for MDCT of 87% (20/23 patients) for overall resectability. In the other three patients, adenocarcinoma was deemed to be unresectable because of small metastases to the liver (two patients) or to the peritoneum (one patient) discovered at surgery. For detection of vascular invasion, MDCT yielded a negative predictive value of 100% (108/108 vessels) with no false-negative findings and an accuracy of 99% (109/110 vessels) with 108 true-negative findings, one true-positive finding, and one false-positive finding. CONCLUSION: Our preliminary data on MDCT show that the technique has excellent negative predictive value for vascular invasion and good negative predictive value for overall tumor resectability in patients with pancreatic adenocarcinoma, suggesting an improvement over previous results reported using single-detector CT. The problem of undetected micrometastases to the liver and peritoneum remains.