Pancreatic pseudotumors: Computed tomography

Although pancreatic disease is suspected initially by historical or biochemical findings, the nature of the pathologic process in the past was frequently established only through invasive procedures. Inferences can be drawn from routine roentgenologic examinations, but visualization of the pancreas has only recently been achieved. Of the currently available noninvasive imaging procedures, computed tomography, in our opinion, is the screening procedure of choice. Care in the interpretation of pancreatic masses must be exercised since some of the findings can be attributed to anatomic variants, normal adjacent structures, or other neighboring pathologic processes.     

螺旋CT 多期增强扫描诊断胰腺癌的价值

目的 比较二期和三期增强扫描在胰腺癌发现和诊断上的差异探索建立最佳扫描常规。方法 ４２例胰腺癌病人分为：Ａ组２６例,行三期扫描。分别为增强后平均延迟２８ｓ为动脉期,１０５ｓ为门脉期和３００ｓ为延迟平衡期。Ｂ组１６例,行二期扫描,分别延迟２８ｓ为动脉期和１３０ｓ为门脉期。比较各期扫描正常胰腺组织与肿瘤的密度差异和肝转移瘤的发现率,结果 门脉期扫描胰腺和癌肿的密度差别最显著,门脉后期显示肝转移瘤最清楚     

Pancreatic carcinoid tumor with obstructive pancreatitis: multislice helical CT appearance: case report

Carcinoid tumor of the pancreas is rare. Moreover, obstructive pancreatitis secondary to a pancreatic carcinoid tumor is extremely rare. We report a case of pancreatic carcinoid tumor in a 50-year-old male who presented with pancreatitis. On multislice helical computed tomography, the main pancreatic duct was obstructed by a small round tumor, and the main pancreatic duct proximal to the tumor was dilated. The correlation between the main pancreatic duct and the tumor was well depicted on minimum intensity projection image. This is the first report of multislice helical computed tomorgraphic and minimum intensity projection image findings of a pancreatic carcinoid tumor presenting with pancreatitis     

Pancreatic metastasis of renal cell carcinoma: multidetector CT findings

Pancreatic metastasis of renal cell carcinoma is more prevalent than the rates reported in the literature before the development of multidetector computed tomography (MDCT). These lesions are usually asymptomatic and used to be an incidental finding detected on radiological follow-up of these patients. If they are not associated with extrapancreatic involvement, they show an excellent response to surgical treatment. Thus, radiologists should be aware of the radiological characteristics of this condition to allow detection at an early stage. In this article we review the MDCT features of four cases of pancreatic metastasis of renal cell carcinoma to familiarize radiologists with this entity and the most suitable study method for its detection. The main imaging findings observed were hypervascular lesions in arterial phase of biphasic studies, hence the detection of these lesions is performed better during the early phase scanning.     

Focal fatty sparing of the pancreatic head in cystic fibrosis: CT findings

The most common imaging appearance of the pancreas in cystic fibrosis is diffuse, complete fatty replacement. We present a case of complete fatty replacement of the pancreatic body and tail with total sparing of the pancreatic head. To our knowledge, this pattern of fatty sparing and its associated computed tomographic appearance have not been previously reported in cystic fibrosis.     

CT depiction of small arteries in the pancreatic head: assessment using coronal reformatted images with 16-channel multislice CT

Background To assess the capabilities of 16-channel multislice CT in acquiring almost exclusively arterial-phase images of the pancreas and depicting small pancreatic arteries in coronal reformatted images. Materials and methods In 45 consecutive patients, arterial-phase contrast enhancement was measured in the aorta and its branches, portal venous system, and pancreas. Coronal reformatted images of 1.2- or 1.3-mm slice thickness at 0.8- or 0.9-mm intervals were generated from axial images acquired with 0.5-mm collimation. Two radiologists evaluated the quality of imaging in the arterial phase and the visibility of the pancreatic arteries in coronal reformatted images. Results Mean enhancement in the aorta and its branches was greater than 300 HU, while that in the portal venous system and pancreas was less than 100 HU. The images were judged to be suitable for delineating the pancreatic arteries in all patients. The following arteries were visualized: anterior superior pancreaticoduodenal (39 patients), posterior superior pancreaticoduodenal (41), anterior inferior pancreaticoduodenal (39), posterior inferior pancreaticoduodenal (33), dorsal pancreatic (42), its right branch (34), and transverse pancreatic (37). Conclusion Multislice CT can depict small pancreatic arteries using coronal reformatted images generated from almost exclusively arterial-phase axial images acquired with 0.5-mm collimation.     

螺旋CT双相扫描对胰腺癌可切除性的评价

目的前瞻性评价双相螺旋CT（HCT）术前预测胰腺癌可切除性的诊断价值。方法应朋对比剂增强HCT对57例疑似胰腺癌病例进行双相扫描,并对其中28例手术病理证实的胰腺癌病人的术前诊断和分期进行研究。结果28例胰腺癌经外科探查,17例进行根治性切除,7例进行姑息手术。可切除性的阳性预测值为70．8％。7例CT发现可切除的病例,因血管侵犯（5例）、淋巴结转移（2例）,术中未能切除。HCT作为判定胰腺癌可切除性的总的精确率为75％（21／28）。结论双相HCT扫描技术是胰腺癌术前分期和可切除性判断的一项有用方法。     

Pancreatic schwannoma: CT findings

Schwannomas of the pancreas are rare tumors. We report a case of solitary schwannoma of the pancreas without von Recklinghausen disease. A 72−year-old man underwent routine abdominal ultrasound before cholecystectomy because of chronic cholecystitis and multiple gallstones, and ultrasound showed a small solitary tumor in the pancreas. Spiral computed tomography showed a 1.0−cm, well-defined homogeneous hypodense lesion with mild inhomogeneous enhancement and peripheral enhancement at the junction between the head and body of the pancreas. These computed tomographic findings are different from those in previous reports.     

多层螺旋CT评价侵犯胰周血管的胰腺癌的可切除性

目的探讨多层螺旋CT（MSCT）评价侵犯胰周血管的胰腺癌的可切除性。方法收集经手术病理证实的胰腺导管细胞癌66例,根据MSCT所示的胰腺癌肿块与胰周血管之间的关系（累及血管周长、血管变形和狭窄的程度、累及血管纵轴的长度）预设五组指标判断胰周血管侵犯时胰腺癌的可切除性,计算各组指标的敏感性、特异性、准确性、假阴性、假阳性、阳性预测值及阴性预测值,并比较各组之间的差异。结果本组中行胰头十二指肠切除术（Whipple）30例;胰体尾切除17例,内引流17例,剖腹探查2例。手术探查无血管侵犯34例,血管侵犯32例。与手术病理结果对比,第一组各项指标均为优,第二组、第三组及第五组的假阴性或假阳性较高,第四组的敏感性及准确性大大低于第一组：结论综合血管受侵的周长、血管变形或狭窄程度及血管纵轴受累的长度,MSCT可用于术前评价胰腺癌的可切除性．     

Pancreatic cavernous hemangioma: CT,MRI, US,and angiography characteristics

A large pancreatic cavernous hemangioma was found in a 30-year-old man with abdominal distention. Plain and contrast-enhanced computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US), and angiography were performed prior to operation. Contrast-enhanced CT and angiography showed a large poorly enhanced hypovascular tumor at the head of the pancreas. But MRI and US disclosed findings compatible with a cavernous hemangioma.     

The accuracy of Multi-detector row CT for the assessment of tumor invasion of the mesorectal fascia in primary rectal cancer

PURPOSE: To evaluate the accuracy of Multi-detector row CT (MDCT) for the prediction of tumor invasion of the mesorectal fascia (MRF). MATERIALS AND METHODS: A total of 35 patients with primary rectal cancer underwent preoperative staging magnetic resonance imaging (MRI) and MDCT. The tumor relationship to the MRF, expressed in 3 categories (1--tumor free MRF = tumor distance > or = 1 mm; 2--threatened = distance < 1 mm; 3--invasion = distance 0 mm) was determined on CT by two observers at patient level and at different anatomical locations. A third expert reader evaluated the MRF tumor relationship on MRI, which served as reference standard. Receiver operating characteristic curves (ROC-curves) and areas under these curves (AUC) were calculated. The inter-observer agreement of CT was determined by using linear weighted kappa statistics. RESULTS: The AUC of CT for MRF invasion was 0.71 for observer 1 and 0.62 for observer 2. The inter-observer agreement was kappa = 0.34. The performance of CT at mid-high rectal levels was statistically significant better compared to low anterior (obs.1: AUC = 0.88 vs. 0.50; obs 2: AUC = 0.84 vs. 0.31; P < or = 0.040). CONCLUSION: Multi-detector row CT has a poor accuracy for predicting MRF invasion in low-anterior located tumors.The accuracy of CT significantly improves for tumors in the mid-high rectum. There is a high inconsistency among readers.     

胰腺CT:水与1.5%泛影葡胺充盈胃肠道对胰腺显示的比较

122例胰腺CT随机分成四组,分别在用或不用654—2的情况下口服水或1.5%泛影葡胺。结果表明:在用或不用654—2的情况下水对胰头显示优片率分别为87.1%,53.3%,两者有极显著性差别((P<0.01)。1.5%泛影葡胺对胰头显示优片率分别为77.4%,46.7%,两者有显著性差别(0.05相似文献   

胰腺癌CT征象探讨

目的 对胰腺癌的CT征象进行探讨。方法 收集经手术病理证实的胰腺癌18例,其中胰头癌13例,胰体癌3例,胰尾癌2例,就其CT征象进行分析,同时又收集手术病理证实的壶腹癌7例,十二指肠乳头癌5例,胆总管远端癌4例,胰头部炎性肿块3例作为鉴别诊断,全部病例均采用型高分辨率CT机作增强前后扫描,对兴趣区作3－5mm薄层和动态扫描,并分别摄取动脉期及静脉期相。结果 胰腺肿块呈低密度,胰头静脉弓扩大,胰后脂肪间隙模糊,肿块远端的胰腺组织不同程度稀疏,萎缩,肠系膜上动脉增粗,胆总管远端和主胰管远端间距分离,为胰腺癌较具特征的表现,结论 高分辨率CT薄层和动态扫描是发现胰腺癌的有效方法。     

经动脉插管双期螺旋CT扫描评价胰头癌的可切除性

目的：采用经动脉插管双期螺旋CT扫描的方法，对胰头癌的可切除性进行评价。方法；对18例胰头癌行经动脉插管后双期螺旋CT增强扫描，动脉期扫描时间为10s，门静脉期50s，扫描速度2.5ml/s，造影剂为欧乃派克300或优维显30030ml，用0．9％生理盐水稀释至100ml，通过留置导管注入造影剂于肠系膜上动脉。扫描结果和经静脉双期扫描进行对比。结果：18例胰头癌，可行根治切除3例，不可根治切除15例。对于3例可行根治切除的，两种方法均做出了正确判断，15例不可根治手术者经动脉插管双期螺旋CT扫描作出了正确判断，而经静脉双期扫描只正确判断了12例。估计手术无法切除率经动脉双期扫描为83％（15／180，经静脉双期扫描为67％（12／18）。在判断胰周血管是否受侵的准确性方面，经动脉插管法优于静脉法。结论：经动脉插管双期螺旋CT扫描能够较经静脉双期扫描更准确地评价胰头癌的情况，有利于肿瘤可切除性的评价。     

CT appearance of incidental pancreatic lipomas: a case series

Pancreatic lipomas are rare benign lesions, with only 15 examples documented in the current literature. We describe five cases of intrapancreatic lipomas from a single institution, all incidentally found using computed tomography within a 14-month period. Computed tomography depicted lipomas as homogeneous, nonenhancing, well-marginated lesions with a density coefficient consistent with adipose tissue.     

CT appearance of primary pancreatic lymphoma

Primary lymphoma of the pancreas is a rare neoplasm that may resemble pancreatic carcinoma on CT scans. Two cases with CT findings are presented.     

Computed tomography of carcinoma in the pancreatic head

Computed tomographic findings in patients with localized and extensive pancreatic head cancer were studied. Widening of the pancreatic duct existed in both groups; mass shadow was hardly detected in localized and rather easily detected in extensive cancer; duodenal invasion and obliteration of fat planes were found only in extensive type; enlargement of the pancreas was a confusing factor of tumor detection in localized type; atrophy of the pancreatic body and tail was a most favorable indirect sign in extensive cancer.     

Intraductal papillary mucinous neoplasms of the pancreas: correlation of helical CT and dynamic MR imaging features with pathologic findings

BACKGROUND: We assessed the imaging features of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas paying special attention to underlying pancreatic fibrosis on three-phase helical computed tomography (CT) and dynamic magnetic resonance (MR) imaging. METHODS: Sixteen patients with histopathologically proven IPMNs underwent three-phase helical CT and dynamic MR imaging. RESULTS: IPMNs were seen as a cluster of cyst-like structures in branch duct (n = 5) and combined types (n = 10), and as a fusiform appearance in the main duct type (n = 1). IPMN shape was most easily visualized at the portal venous dominant phase or delayed phase owing to rim-like enhancement of the dilated ducts. Pathologically mild to severe fibrosis was seen on this enhanced rim replacing the surrounding pancreatic parenchyma. Communication between the dilated branch ducts and main pancreatic duct was identified in 15 patients on helical CT and 14 patients on dynamic MR imaging. In patients with fibrosis of pancreatic parenchyma surrounding this, communication was most easily visualized at the later phase on CT and MR imaging. Adenocarcinomas were depicted as papillary projections in eight of nine patients on CT and MR imaging. Invasion of the pancreatic parenchyma was seen in five of six patients as a solid mass in the pancreatic parenchyma. These masses were most easily visualized at the arterial dominant phase on both CT and MR imaging. CONCLUSION: Three-phase helical CT and dynamic MR imaging were useful in the diagnosis of IPMN of the pancreas.     

CT evaluation of the resectability of gastric cancer postchemotherapy

Background: To determine the accuracy of CT in the postchemotherapy assessment of resectability of gastric cancer. Methods: Thirty patients deemed to have unresectable gastric cancer on CT were studied. This was verified at laparotomy in 10 of these patients. Following initial assessment, all received three to eight cycles of chemotherapy aiming for disease control and potential resection. Serial CT examinations, endoscopy, and biopsy were performed after the fourth, sixth, and eighth cycle of treatment. The primary tumor and lymph nodes seen on CT were compared with operative findings. Results: After completion of chemotherapy, CT findings were correct in 23 patients. Fourteen of them had operable tumors and nine were inoperable. However, the CT findings were either equivocal or incorrect in the remaining seven patients. Conclusion: Chemotherapy is now able to downstage a previously inoperable gastric cancer, and CT is an accurate method in identifying those patients who can proceed to resection. Received: 24 October 1994/Accepted after revision: 6 April 1995     

A new method for the diagnosis of acute hemorrhagic-necrotizing pancreatitis using contrast-enhanced CT

Twenty-eight consecutive patients with a first attack of alcohol-induced pancreatitis were studied using contrast-enhanced CT. The findings on CT were then related to the course of the disease. The patients with acute hemorrhagic-necrotizing pancreatitis showed significantly lower enhancement values of the pancreatic parenchyma than those with milder forms of the disease.The next 20 patients with severe pancreatitis were scanned using a slightly modified procedure. The enhancement values were calculated and plotted on the graphs for the 2 former groups.Two categories of pancreatic enhancement were found: low enhancement and high enhancement. In all 10 patients with low-enhancement values surgery revealed hemorrhagic-necrotizing pancreatitis. In the 10 patients with highenhancement values conservative treatment was continued, and the clinical course was nonfulminant in all of them.