Percutaneous drainage of pancreatic and peripancreatic fluid collections

Radiographically guided therapeutic percutaneous catheter drainage was used to manage 25 patients with 27 pancreatic and peripancreatic fluid collections. Nine of 11 (82%) noninfected and 11 of 16 (69%) infected collections were successfully managed with percutaneous drainage. Overall, eight complications and four deaths occurred in this group of patients. The morbidity and mortality in this series is somewhat higher than that previously reported in the radiologic literature. A discussion of the guidelines for percutaneous drainage is presented.     

MR imaging for blunt pancreatic injury

Objective

To study the MR imaging features of blunt pancreatic injury.

Materials and methods

Nine patients with pancreatic injury related to blunt abdominal trauma confirmed by surgery performed MR imaging. Two abdominal radiologists conducted a review of the MR images to assess pancreatic parenchymal and pancreatic duct injury, and associated complications.

Result

Diagnostic quality MR images were obtained in each of the nine patients. In the nine patients, pancreatic fracture, laceration and contusion were depicted on MR imaging in five, one and three patients, respectively. There were six patients with pancreatic duct disruption, eight patients with peripancreatic fluid collections, and four patients with peripancreatic pseudocyst or hematoma, respectively. All of the MR imaging findings was corresponded to surgical findings.

Conclusion

MR imaging is an effective method to detect blunt pancreatic injury and may provide information to guide management decisions.     

Radiologic diagnosis following pancreas transplantation

Technical complications are relatively common after pancreatic transplantation, and most require radiological evaluation. Ultrasonography and computed tomography are helpful in the identification of peripancreatic and intra-abdominal fluid collections. Sterile fluid collections can be effectively treated by percutaneous catheter drainage, whereas most intra-abdominal infections require surgical intervention. Angiography is performed primarily for diagnosis of vascular thrombosis. Recent results suggest that magnetic resonance imaging may be a useful non-invasive method for the detection of pancreatic transplant rejection. Further imaging studies are needed to better define the development of progressive fibrotic atrophy in long-term functioning pancreatic transplants.     

Pancreas bifidum: an extremely rare cause of acute pancreatitis

A wide spectrum of anomalies of the pancreas, the pancreatic ductal system and the biliary tree are commonly encountered at radiologic evaluation. Pancreas bifidum, also known as bifid pancreas or fish-tail pancreas, is an extremely rare congenital branching anomaly of the main pancreatic duct characterized by its duplication. These 2 separate ducts are laid from the pancreatic tail to neck and they generally join at the pancreas body-tail draining via the major papilla; the pancreatic parenchyma is also bifurcated with separated dorsal and caudal buds. The clinical impact of this condition is not well established: although some authors sustained that probably does not cause or contribute to abdominal pain or overt pancreatic diseases, others argued that could be considered as a possible cause of acute pancreatitis.We herewith describe the case of a 51-year-old woman presenting to our hospital with epigastric pain, nausea, and vomiting. Biochemical tests were suspicious for acute pancreatitis. Ultrasound examination was negative. MRI, including MR cholangiopancreatography revealed bifid pancreas characterized by duplication of the main pancreatic duct with 2 separate ducts that join at the pancreas head and draining via the minor papilla. On T2-weighted images the ventral bud of the pancreas was enlarged and characterized by slightly hyperintensity without peripancreatic fluid collections. The MRI findings were consistent with acute pancreatitis limited to the ventral bud of a bifid pancreas. Patient was treated with intravenous fluid resuscitation, pain control and institution of early enteral nutrition and discharged on the seventh day after admission.     

The role of percutaneous aspiration in the diagnosis of pancreatic abscess

Percutaneous aspiration should be performed on pancreatic/peripancreatic fluid collections when an abscess is suspected. Thirty-one percutaneous aspirations were performed on 21 such patients and seven (33%) proved to have an abscess. A Gram stain after the aspiration is important, as it can make an immediate diagnosis of an abscess. By helping make an early diagnosis, percutaneous aspiration might reduce the high mortality rate associated with a pancreatic abscess while avoiding surgery in those who have sterile fluid collections. Two complications (6%) occurred: superinfection of a pseudocyst and a hemoperitoneum.     

Pancreatic transplants: CT with clinical and pathologic correlation

A retrospective evaluation of 68 CT scans in 17 patients with pancreatic allografts was performed with clinical and pathologic correlation to better define the nature of abnormalities detected with CT and the role of CT in patient treatment. Patients with clinical complications demonstrated variable degrees of pancreatic inhomogeneity and peripancreatic inflammation on CT scans. These findings were similar in appearance to pancreatitis in the native gland. Most patients proved to be undergoing acute rejection. However, these findings were not specific and were also seen with peripancreatic infection, hemorrhage, and exocrine anastomotic leaks. No CT changes were detected in two of three patients with late rejection. Thus, CT was not helpful in the diagnosis of pancreatic rejection. The most beneficial role of CT was in the detection of intraabdominal fluid collections, including abscesses, hematomas, and pseudocysts. Percutaneous aspiration was invaluable in the distinction between infected and sterile fluid collections; however, percutaneous drainage was of limited use in treatment.     

Percutaneous drainage of abdominal abcess

The mortality in undrained abdominal abscesses is high with a mortality rate ranging between 45 and 100%. The outcome in abdominal abscesses, however, has improved due to advances in image guided percutaneous interventional techniques. The main indications for the catheter drainage include treatment or palliation of sepsis associated with an infected fluid collection, and alleviation of the symptoms that may be caused by fluid collections by virtue of their size, like pancreatic pseudocele or lymphocele. The single liver abscesses may be drained with ultrasound guidance only, whereas the multiple abscesses usually require computed tomography (CT) guidance and placement of multiple catheters. The pancreatic abscesses are generally drained routinely and urgently. Non-infected pancreatic pseudocysts may be simply observed unless they are symptomatic or cause problems such as pain or obstruction of the biliary or the gastrointestinal tract. Percutaneous routes that have been described to drain pelvic abscesses include transrectal or transvaginal approach with sonographic guidance, a transgluteal, paracoccygeal-infragluteal, or perineal approach through the greater sciatic foramen with CT guidance. Both the renal and the perirenal abscesses are amenable to percutaneous drainage. Percutaneous drainage provides an effective and safe alternative to more invasive surgical drainage in most patients with psoas abscesses as well.     

Computed tomography of pancreatic abscesses

Computed tomography (CT) was used as the primary diagnostic tool in 10 cases of pancreatic abscess and seven cases of infected pseudocyst. Pancreatic gas collections were the only definitive feature of infection and were seen in five cases (29%). An equally common finding was poorly defined nonencapsulated peripancreatic fluid collections or mottled mass density. It was not possible to distinguish infected from noninfected pseudocysts or peripancreatic fluid collections by other CT criteria. Diagnostic percutaneous needle aspiration is indicated in patients with pancreatic pseudocyst or fluid collections with persistent fever or leukocytosis. CT is also useful in the preoperative evaluation of multiple abscesses and of recurrent abscesses after surgery.     

Ultrasound and computed tomography in the evaluation of pancreatic transplantation

Both ultrasound and computed tomography are useful imaging modalities in the evaluation of pancreatic transplants and their complications. Ultrasound and computed tomography are most valuable in the detection of peripancreatic fluid collections, although some parenchymal abnormalities can occasionally be detected. Directed diagnostic aspiration is useful in determining the etiology of peripancreatic and other peritoneal fluid collections. The role of percutaneous catheter drainage in the management of these complex patients is not yet clearly defined.     

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。     

Infection of pancreatic pseudocyst demonstrated on PET/CT using 18F-fluorodeoxyglucose-labeled autologous leucocytes

Labeled leukocyte scintigraphy has been used as an indicator of pancreatic necrosis in patients with acute pancreatitis and proposed for the detection of infection in peripancreatic fluid collections. The authors present a PET/CT scan showing abnormal uptake of 18F-Fluorodeoxyglucose-labeled autologous leukocytes in a pancreatic pseudocyst, from which aspirated fluid subsequently showed growth of Pseudomonas aeruginosa.     

Percutaneous management of lymphatic fluid collections

Eight lymphatic fluid collections were drained percutaneously. There were no immediate or late complications. Seven patients had follow-up; 1 required surgical drainage of a residual or recurrent lymphocele, and another had reaccumulated fluid in a lymphocele which was detected on autopsy. The remaining lymphatic collections responded to percutaneous drainage. Percutaneous drainage is safe and can be an effective tool in the management of lymphatic collections.     

The revised Atlanta classification of acute pancreatitis: its importance for the radiologist and its effect on treatment

An international working group has modified the Atlanta classification for acute pancreatitis to update the terminology and provide simple functional clinical and morphologic classifications. The modifications (a) address the clinical course and severity of disease, (b) divide acute pancreatitis into interstitial edematous pancreatitis and necrotizing pancreatitis, (c) distinguish an early phase (1st week) and a late phase (after the 1st week), and (d) emphasize systemic inflammatory response syndrome and multisystem organ failure. In the 1st week, only clinical parameters are important for treatment planning. After the 1st week, morphologic criteria defined on the basis of computed tomographic findings are combined with clinical parameters to help determine care. This revised classification introduces new terminology for pancreatic fluid collections. Depending on presence or absence of necrosis, acute collections in the first 4 weeks are called acute necrotic collections or acute peripancreatic fluid collections. Once an enhancing capsule develops, persistent acute peripancreatic fluid collections are referred to as pseudocysts; and acute necrotic collections, as walled-off necroses. All can be sterile or infected. Terms such as pancreatic abscess and intrapancreatic pseudocyst have been abandoned. The goal is for radiologists, gastroenterologists, surgeons, and pathologists to use the revised classifications to standardize imaging terminology to facilitate treatment planning and enable precise comparison of results among different departments and institutions.     

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。     

Acute pancreatitis and its complications. Computed tomography and sonography

Acute pancreatitis is a clinical diagnosis. In most patients with uncomplicated acute pancreatitis, there is no need for radiologic confirmation or work-up. However, in some patients, the diagnosis may be in doubt, or associated abnormalities or complications of acute pancreatitis may be suspected by the patient's protracted course or severity of disease. In these patients, radiology can be extremely helpful. CT is the best single radiologic imaging modality to evaluate these patients. With modern scanners, there are no failures, and CT provides a complete view of the pancreas and peripancreatic tissues, despite overlying bowel gas or other anatomic features that may limit the sonographic evaluation. Sonography may be helpful in evaluating possible biliary complications of acute pancreatitis, in evaluating thin patients with a good sonic window to the pancreas, or in evaluating patients who have a clearly defined complication such as a large pseudocyst. Sonography is also helpful for serial studies following the size of the fluid collection. The complications of pancreatitis include fluid collections and pseudocysts, which may become infected or develop bleeding within them, vascular complications including occlusion of the splenic vein with secondary development of varices, pancreatic ascites, and pancreatic abscess. While these complications can be evaluated by various radiologic methods, they are most effectively evaluated by CT. However, for some cases in which the cause of a cystic mass is in doubt or for cases of suspected pancreatic abscess, radiologic studies may be unable to provide a definitive diagnosis. In these cases, percutaneous needle aspiration will assist in the diagnosis.     

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。     

Blunt pancreatic trauma: evaluation with MDCT technology

The purpose of this paper is to determine the relative frequency of multi-detector CT (MDCT) findings of pancreatic injury in blunt trauma and to determine their diagnostic accuracy in predicting main pancreatic duct injury. Fifty-three patients (31 male, 22 female; mean 44.1 years) with blunt trauma and admission MDCT findings suspicious for pancreatic injury or who underwent MDCT and had a discharge diagnosis of pancreatic trauma were included in this study. Two radiologists reviewed all images and recorded findings suspicious for pancreatic injury, which were subsequently compared to surgical findings to generate diagnostic accuracy. MDCT imaging findings suggestive of pancreatic injury included low attenuation peripancreatic fluid (n?=?51), hyperattenuating peripancreatic fluid (n?=?13), pancreatic contusion (n?=?7), active hemorrhage (n?=?2), and pancreatic laceration (n?=?16). Diagnostic accuracy of the various imaging findings varied for diagnosing main duct injury; there were highly sensitive, nonspecific imaging findings such as the presence of low attenuation peripancreatic fluid (sensitivity, 100 %; specificity 4.9 %) as well as insensitive, specific findings such as visualizing a pancreatic laceration involving >50 % of the parenchymal width (sensitivity, 50 %; specificity, 95.1 %). In the setting of blunt abdominal trauma, MDCT imaging findings can be grouped into two categories for determining integrity of the main pancreatic duct: indirect, highly sensitive but nonspecific findings and direct, specific but insensitive findings. Awareness of the clinical implications of the various MDCT imaging findings of pancreatic trauma is useful in interpreting their significance.     

Groove pancreatic carcinomas: radiological and pathological findings

The aim of this study was to clarify the characteristics of pancreatic head carcinomas mainly invading the groove between the duodenum and the pancreatic head. Nine patients with pathologically proven pancreatic head carcinomas underwent thin-slice dynamic CT, MR imaging, duodenal endoscopy, and angiography (seven patients). Plate-like masses within the groove region were seen in all cases, which showed hypointensity on T1-weighted images and slight hyperintensity on T2-weighted MR images. The masses appeared hypovascular in the early phase and delayed enhancement in the late phase of dynamic CT and MR imaging. On MR cholangiopancreatography, stenosis of intrapancreatic common bile duct was seen in all patients, whereas stenosis of the main pancreatic duct was seen in only three cases. Endoscopy revealed luminal narrowing of the duodenum in all patients, and duodenal mucosal biopsy demonstrated adenocarcinoma in seven patients. Abdominal arteriography showed serrated encasement of peripancreatic arteries in seven patients who received angiographic examinations. The CT and MR imaging findings of groove pancreatic carcinomas resemble those of groove pancreatitis. Differential diagnosis may be achieved by the pathological diagnosis of a biopsy specimen of the duodenal mucosa and arterial encasement on arteriography.     

The halo sign and peripancreatic fluid: useful CT signs of hypovolaemic shock complex in adults

AIM: To report two new, useful computed tomography (CT) signs of the hypovolaemic shock complex (HSC) in adults admitted after blunt abdominal trauma: the halo sign (ring of fluid around a collapsed intra-hepatic inferior vena cava (IVC)), and peripancreatic retroperitoneal fluid. MATERIALS AND METHODS: CT images of 498 consecutive patients admitted after blunt abdominal trauma were reviewed, of which 27 had CT signs of the HSC. The CT images of these 27 patients were analysed. A control group of 101 patients examined using CT for suspected blunt abdominal trauma who did not have the HSC were chosen for comparison. RESULTS: The most common features involved the vascular compartment: diminished IVC diameter n = 27 a positive halo sign n = 21 diminished anteroposterior diameter of the aorta n = 13 and abnormal vascular enhancement n = 10. Peripancreatic retroperitoneal fluid in the absence of pancreatic injury, pancreatitis or pancreatic disease was observed in eight patients. Hollow visceral abnormalities included: diffuse increased mucosal enhancement of both the small and large bowel n = 19 diffuse thickening of the small bowel wall n =11 and small bowel dilatation n = 7. Solid visceral abnormalities included both decreased and or increased enhancement. Several concomitant intra- and extra-abdominal injuries were also identified. CONCLUSION: In the setting of blunt abdominal trauma, early abdominal CT can show diffuse abnormalities due to the HSC, which occasionally may alert clinicians of unsuspected shock. Recognition of these signs as distinguished from injured viscera is important in order to avoid unnecessary laparotomy. Two new signs are described: the halo sign and peripancreatic retroperitoneal fluid.