Complications of endoscopic retrograde cholangiopancreatography: spectrum of abnormalities demonstrated with CT.

Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive procedure that is performed to diagnose and treat pancreatic and biliary disease. In approximately 5%-10% of cases, the procedure itself causes adverse events. Diagnosis and management of ERCP-induced complications are performed with clinical, laboratory, and radiologic procedures. Evaluation of the type and severity of the complication is necessary and is successfully performed with computed tomography (CT). The most common causes of post-ERCP pain are acute pancreatitis and duodenal perforation. In severe pancreatitis, the pancreas is enlarged and enhances heterogeneously at CT. Pancreatic enhancement is diminished in areas of glandular necrosis. In duodenal perforation, CT may reveal extraluminal air or fluid. CT findings of acute duodenal hemorrhage are duodenal wall thickening and a high-attenuation mass in the duodenal wall. In infection, the bile ducts can be dilated and the attenuation of the bile can be increased at CT. Abscesses appear as hypoattenuating masses with enhancing capsules. CT findings of stent migration are an atypical location of the stent and bowel impaction. Other complications of ERCP are those related to endoscopy and include esophageal, liver, and splenic injury.     

Acute pancreatitis: assessment of severity with clinical and CT evaluation

Treatment of patients with acute pancreatitis is based on the initial assessment of disease severity. Severe pancreatitis occurs in 20%-30% of all patients with acute pancreatitis and is characterized by a protracted clinical course, multiorgan failure, and pancreatic necrosis. Early staging is based on the presence and degree of systemic failure (cardiovascular, pulmonary, renal) and on the presence and extent of pancreatic necrosis. Individual laboratory indexes (markers of pancreatic injury, markers of inflammatory response), while promising, have not yet gained clinical acceptance. Numeric grading systems with sensitivities of about 70% are commonly used today as indicators of organ failure and disease severity. Contrast material-enhanced computed tomography is used in addition to help evaluate local pancreatic morphology and the presence and extent of pancreatic necrosis. Advantages and limitations of the clinical, laboratory, and imaging prognostic indexes are analyzed and discussed.     

Pancreatic abscess: predictive value of early abdominal CT

The value of a recently reported grading system of early abdominal computed tomography (CT) for predicting development of pancreatic abscess in patients with acute pancreatitis was reassessed. When the previously described CT grading system was used in another patient population, it did not demonstrate the same degree of prognostic value of baseline CT. In this series pancreatic abscess occurred in only eight of 29 patients (28%) with grade E CT scans (with grade E representing the most severe involvement), compared with 60% in the previous series. Of 44 patients with either grade D or E baseline CT scans, abscesses developed in only 30%, with a minimum clinical follow-up of 3 months. A second grading system, which used a semiquantitative analysis of the degree of peripancreatic inflammation (a "CT severity score"), also did not strongly correlate with the future risk of abscess, The authors conclude that early abdominal CT should be performed selectively in patients with acute pancreatitis and reserved for patients who are either diagnostic dilemmas or who fail to respond to supportive treatment and have clinically suspected surgical complications such as pancreatic abscess.     

Non-traumatic abdominal emergencies: imaging and intervention in acute pancreatic conditions

Pancreatic emergency, unrelated to traumatic events, can occur as a consequence of the more significant pancreatic pathologies (acute and chronic pancreatitis, tumors) or of the interventional or surgical treatment carried out as therapy for the above-mentioned lesions. Acute pancreatic conditions are represented by pancreatic infections, the involvement of organs, structures, and adjacent spaces within the pancreatic disease, and, lastly, vascular complications. Acute pancreatic conditions are common in pancreatic diseases and can be catastrophic; even if there is a gamut in the severity of clinical presentation, each can be potentially life threatening. Immediate radiological detection of the lesions together with a correct therapeutic percutaneous radiological approach whenever an interventional procedure is preferable to surgery or, when performed before surgery, whenever it can optimize its results, is of fundamental importance in the management of these patients. This article focuses on the essential role of radiology and the integration of imaging and intervention in acute pancreatic conditions.     

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.     

Acute pancreatitis: interobserver agreement and correlation of CT and MR cholangiopancreatography with outcome.

PURPOSE: To assess the correlation between and the interobserver agreement of contrast medium-enhanced computed tomography (CT) and nonenhanced and contrast-enhanced magnetic resonance (MR) imaging findings in patients with acute pancreatitis and to correlate these findings with outcome. MATERIALS AND METHODS: Two blinded reviewers separately assessed contrast-enhanced CT and nonenhanced and contrast-enhanced MR images in 30 patients with acute pancreatitis and established a severity index based on the presence of peripancreatic fluid collections and pancreatic necrosis. The Spearman rank correlation coefficient and weighted kappa statistic were used to assess the correlation between each imaging technique and the interobserver agreement, respectively. Correlation between hospitalization days, morbidity, and severity indexes were assessed by using linear correlation. RESULTS: A strong correlation existed for both reviewers when comparing contrast-enhanced CT with nonenhanced (r = 0.82, 0.79) or contrast-enhanced (r = 0.82, 0.79) MR cholangiopancreatography or when comparing nonenhanced and contrast-enhanced MR cholangiopancreatography (r = 0.99, 1.00). The interobserver agreement in staging was stronger with nonenhanced (kappa = 0.76) and contrast-enhanced (kappa = 0.78) MR cholangiopancreatography than with contrast-enhanced CT (kappa = 0.70). There was no linear correlation between the severity index for contrast-enhanced CT and outcome, while there was a linear correlation between nonenhanced or contrast-enhanced MR cholangiopancreatographic staging and the patient morbidity rate. CONCLUSION: MR cholangiopancreatography could be an alternative to contrast-enhanced CT for the initial staging of acute pancreatitis.     

急性胰腺炎严重指数对临床预后的评估价值

目的：综合ＣＴ影像提出急性胰腺炎严重指数（ＡＰＳＩ）的评估方法并测定其敏感性,提高ＣＴ影像对急性胰腺炎预后评估的准确率。材料与方法：Ｑ发 胰腺炎患者６５例,以住院时间及禁食时间为应变量（Ｙ）、胰腺肿大、胰周和／或腹腔内渗出液及胰腺坏死情况作为自变量（Ｘ）,用多元线性回归分析法对ＡＰＳＩ、ＣＴ严重（ＣＴＳＩ）及简化急症生理（ＳＡＰ）计分法进行比较。并分析此三者对并发症发生率和死亡率的预评价值。结果：     

Hodgkin's disease: a quantitative evaluation by computed tomography of tumor burden

A direct method for the evaluation by computed tomography (CT) of the neoplastic mass (tumor burden [TB]) has been adopted in 34 patients diagnosed with Hodgkin's disease in the early stage. Stressed are its prognostic value, and its correlation with the clinical and laboratory parameters usually adopted in the staging of the disease and in its follow-up. It is concluded that the CT-calculated TB is a reliable index showing good correlation with other commonly used prognostic parameters.     

Value of CT and clinical criteria in assessment of patients with acute pancreatitis

OBJECTIVE: To re-assess the value of CT and clinical criteria as prognostic and severity indicators in acute pancreatitis and the correlation between them. METHODS: Sixty-five cases with acute pancreatitis (AP) were included in the study. The hospitalization days, fevering days and overall complications were regarded as clinical endpoints for the patient group. CT criteria used for AP evaluation included Balthazar's plain CT scan score, CT severity index (CTSI) and London's pancreatic size index (PSI) score. Clinical criteria was Ranson score. The correlations between each criterion and the clinical endpoints, and the relation between CT and clinical criteria were analyzed. The power of each criterion and combination of CT and clinical criteria in predicting overall complications of AP were assessed and compared by using a receiver operative characteristic curve (ROC) analysis. RESULTS: The mean scores of PSI, Ranson among the three groups classified according to overall complications were significantly different. Except Balthazar's plain CT scan criterion, each criterion's mean score in-groups with local complications was significantly higher than that in-group without. The overall complications were significantly more in severe group than that in mild group classified according to each criterion except plain CT scan criterion. Mean days of hospital stay and fevering were significantly longer in severe group with Ranson score than that in mild group. PSI and Ranson score had a linear correlation with fevering days, and Ranson score had a linear correlation with hospitalization days. In CT criteria, only PSI had a linear correlation with Ranson score. The findings of plain CT scan was found to be some laggard compared with that of clinic. ROC analysis showed the largest A(Z) of Ranson score, and there was no A(Z) increase when CT criteria were added to clinical criteria. CONCLUSION: The predictive values of Ranson and PSI score in AP patients are superior to that of other criteria. CT criteria are superior to clinical criterion in predicting local complications, and short-term CT follow-up examination is important in the evaluation of AP.     

Gastroepiploic veins: CT appearance in pancreatic disease.

The frequency with which gastroepiploic vein (GEV) enlargement was seen on CT and its relevance to disease of the portal venous system associated with pancreatic disease were studied. We performed a retrospective study of 50 patients with proved pancreatic disease and another 50 patients without such disease. The CT examinations were done in incremental dynamic fashion after a bolus injection of contrast medium. Scans were evaluated for collateral channel formation, including GEV enlargement, and for involvement of the portal venous system by pancreatic disease. Part of the GEV arcade was visible in 36 patients without pancreatic disease, and on average measured 3.2 mm in diameter (range, 1-5.5 mm). GEV enlargement was visible in 62% of the patients with disease; 16% demonstrated a vessel 6 mm or more in diameter. Thirty-four percent of the patients with disease had portal venous complications: 26% had isolated splenic vein involvement, 2% had isolated portal vein involvement, and 6% had a combination of splenic and portal vein involvement. Of the patients with splenic vein disease, 81% had collateral channel formation, 50% of them demonstrating isolated GEV enlargement. Patients with splenic vein disease due to acute pancreatic disease had a much higher instance of GEV enlargement (83.3%). Collateral vessels are commonly seen on CT scans of patients with splenic vein disease and most often occur via enlarged GEVs. Acute pancreatic disease is frequently associated with GEV enlargement, suggesting that the latter represents an early response to splenic vein disease. In contrast, multiple collateral pathways tend to develop in patients with chronic pancreatic disease.     

Prognostic value of CT in the early assessment of patients with acute pancreatitis

OBJECTIVE: This study investigates the prognostic value of early CT in acute pancreatitis, the role of pancreatic necrosis as a indicator of prognosis, and the need for the routine use of IV iodinated contrast material in early CT to assess prognosis in these patients. MATERIALS AND METHODS: We conducted a retrospective review of 148 patients who underwent unenhanced and contrast-enhanced helical CT within 72 hr after onset of symptoms of a first episode of acute pancreatitis. Patients were classified by CT grade and grouped into two categories (mild: grades A, B, C; and severe: grades D and E) that were correlated with complications and death. In the grades including patients with pancreatic necrosis, it was also correlated with complications and death. RESULTS: All complications (n = 15) and deaths (n = 4) occurred in patients with a CT grade of severe disease; differences as compared with mild grade were significant (p < 0.001 and p < 0.03, respectively). CT grade had a sensitivity and specificity of 100% and 61.6%, respectively, for predicting morbidity and 100% and 56.9% for predicting mortality. The 13 patients with necrosis were all in the severe group (p < 0.001). Necrosis detection on early CT had a sensitivity and specificity of 53.3% and 90.2%, respectively, for predicting morbidity and 75% and 83.8% for mortality. CONCLUSION: Early unenhanced CT alone was a good indicator of severity of acute pancreatitis in our selected population. CT grade was sensitive for predicting outcome in acute pancreatitis. Pancreatic necrosis, estimated on early, contrast-enhanced CT and seen only in patients having severe disease, was a specific predictor of morbidity and mortality. These findings lead us to suggest that the use of iodinated contrast material to assess necrosis can be reserved for only those patients classified as having severe disease on unenhanced CT.     

急性胰腺炎预后的CT研究进展

急性胰腺炎(AP)早期是诊断与治疗的关键时期,早期影像诊断可对预后进行推测并判断一些重要并发症出现的可能性。目前,CT检查为早期AP最重要的影像检查技术,已建立多种评分系统进行AP严重度的评估,其中应用最广泛的是CT严重度指数(CTSI)及修订的CTSI(MCTSI)。CT评分可较好地预测预后,甚至判断是否出现器官衰竭。CECT所见的低强化及CTP显示的灌注减低是预示胰腺梗死的较好指标,但CT难以预测AP是否出现血管并发症及合并感染。     

胰腺癌:MRI检查技术和诊断

胰腺癌的患病率呈上升趋势。更重要的是胰腺癌早期没有症状，恶性程度高，发展快，侵及范围广，病死率高。外科手术切除是胰腺癌治疗的有效手段，胰腺癌的检测和分期是MRI的重要课题。近年来，MRI技术的发展可以较全面地评价胰腺及胰腺病变，这些技术包括屏气T1加权成像及其脂肪抑制，T2加以成像及其抑制、Gd-DTPA,动态增强、MRCP和MRA，这些脉冲序列各自有其不同的组织对比机制，而且是相互补充的。其中Gd-DTPA动态增强MRI是检测胰腺癌最可靠，应用最广的技术，它们的联合应用，在检测胰腺癌，特别是局限于胰腺内的小部肿，优于螺旋CT；在胰腺癌的分期中，动态增强MRI在确定肿瘤的局部侵犯和肝转移上优于螺旋CT，对血管的侵犯的判断两者相似。     

Prospective evaluation of nonenhanced MR imaging in acute pancreatitis

PURPOSE: To compare the value of nonenhanced (NE) magnetic resonance imaging (MRI) (NE-MRI) with contrast-enhanced (CE) computed tomography (CT) (CE-CT) scan in assessing acute pancreatitis (AP) and in evaluating the severity index (SI) with clinical outcome. MATERIALS AND METHODS: Patients with AP were prospectively investigated by CE-CT scan and NE-MRI on admission. MRI was performed with fat-saturated T1-weighted imaging, T2-weighted imaging, and MR cholangiopancreatography (MRCP). Balthazar's grading system was used to evaluate the NE-MRI severity index (CTSI, MRISI) and it was compared to the clinical outcome. RESULTS: A total of 90 patients (median age = 55 years) were included in the study. AP was of biliary etiology in 37 patients (41%). On admission, AP was assessed as grade III by CTSI in four patients (4%), whereas 19 patients were classified grade III by MRISI. The coefficient correlation between CTSI and MRISI was good, with r = 0.6 (P < 0.001). Considering CE-CT scan as the gold standard, sensitivity (Sn), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) of NE-MRI for detecting severe AP based on imaging criteria were 100%, 82.6%, 100%, and 21%, respectively. NE-MRI discriminates normal pancreatic parenchyma from edema and necrosis with a correlation between morbidity (P < 0.008). CONCLUSION: NE-MRI seems to be a reliable method of staging AP severity in comparison to CE-CT scan.     

The clinical significance of acute pancreatic hemorrhage

Computed tomography (CT) has the ability to demonstrate acute hemorrhage both within the pancreatic parenchyma and the adjacent retroperitoneal spaces. It was found that during the acute phase of pancreatic hemorrhage (about 1-7 days) the CT number of hemorrhage is significantly greater than that of the gland. At the present time the true incidence of pancreatic hemorrhage and the relation of the CT demonstration of hemorrhage to the clinical entity of hemorrhagic pancreatitis is unclear. The CT, laboratory, and clinical findings in eight patients with acute pancreatitis were analyzed to help answer these questions. This limited experience suggests pancreatic hemorrhage is more frequent than hemorrhagic pancreatitis as currently defined clinically.     

The value of CT for the diagnosis of acute diverticulitis

PURPOSE: In acute diverticulitis accurate diagnosis and staging are mandatory to decide on the treatment of the patient.The impact of computed tomography (CT) on the treatment of acute diverticulitis will be discussed. MATERIAL AND METHOD: CT is performed after distension of the distal colon by means of positive,water-soluble contrast media to depict intestinal perforation or penetration. Then intravenous contrast material is administered and spiral scanning is repeated to judge enhancement patterns of the abdominal structures/organs especially of the intestinal wall and to diagnose abscess formation. CT-morphologies of different stages of acute diverticulitis will be described. RESULTS: CT imaging is the only diagnostic method that in case of an acute diverticulitis combines safety with accuracy. On the one hand, it is fast and therefore safe with respect to patient control and on the other hand, it allows accurate staging of the inflammatory process reaching a sensitivity and specificity of up to 100%, each. CT is an appropriate tool to diagnose acute diverticulitis complicated by abscess formation, intestinal penetration or perforation and therefore has direct impact on the treatment of the patient. DISCUSSION: If acute diverticulitis is suspected CT is the method of choice for imaging because of its high impact on the choice of therapy and on the management of complications.     

CT引导下125I放射性粒子植入治疗胰腺癌的疗效评价

目的探讨CT引导下~(125)I放射性粒子植入治疗胰腺癌的近期疗效。方法15例胰腺癌患者均有典型的CT特征并经穿刺活检后病理证实。采用CT引导下经皮穿刺将~(125)I放射性粒子均匀置入肿瘤内进行组织间放疗。结果粒子植入后1个月CT复查:完全缓解(CR)5例,部分缓解(PR)6例,稳定(SD) 2例,进展(PD)2例,总有效率86.7%;3个月:CR 5例,PR 5例,SD 2例,PD 3例。总有效率80%。除1例出现胰瘘,无急性胰腺炎、出血等严重并发症,结论CT引导下~(125)I放射性粒子植入治疗胰腺癌具有近期疗效好、创伤小、并发症少等优点。     

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.     

Peripancreatic vascular abnormalities complicating acute pancreatitis: contrast-enhanced helical CT findings

OBJECTIVE: To determine the prevalence and morphologic helical computed tomography (CT) features of peripancreatic vascular abnormalities in patients with acute pancreatic inflammatory disease in correlation with the severity of the pancreatitis. MATERIALS AND METHODS: One hundred and fifty-nine contrast-enhanced helical CT scans of 100 consecutive patients with acute pancreatitis were retrospectively and independently reviewed by three observers. CT scans were scored using the CT severity index (CTSI): pancreatitis was graded as mild (0-2 points), moderate (3-6 points), and severe (7-10 points). Interobserver agreement for both the CT severity index and the presence of peripancreatic vascular abnormalities was calculated (K-statistic). Correlation between the prevalence of complications and the degree of pancreatitis was estimated using Fisher's exact test. RESULTS: The severity of pancreatitis was graded as mild (n = 59 scans), moderate (n = 82 scans), and severe (n = 18 scans). Venous abnormalities detected included splenic vein (SV) thrombosis (31 scans, 19 patients), superior mesenteric vein (SMV) thrombosis (20 scans, 14 patients), and portal vein (PV) thrombosis (17 scans, 13 patients). Arterial hemorrhage occurred in five patients (6 scans). In our series, no cases of arterial pseudoaneurysm formation were detected. The interobserver agreement range for scoring the degree of pancreatitis and the overall presence of major vascular abnormalities was 75.5-79.2 and 86.2-98.8%, respectively. The presence of the vascular abnormalities in correlation with the severity of pancreatitis was variable. CONCLUSION: Vascular abnormalities are relatively common CT findings in association with acute pancreatitis. The CT severity index is insufficiently accurate in predicting some of these complications since no statistically significant correlation between their prevalence and the severity of pancreatitis could be established.     

Amebic liver abscess: Clinico-radiological findings and interventional management

In its classic form, amebic liver abscess (ALA) is a mild disease, which responds dramatically to antibiotics and rarely requires drainage. However, the two other forms of the disease, i.e., acute aggressive and chronic indolent usually require drainage. These forms of ALA are frequently reported in endemic areas. The acute aggressive disease is particularly associated with serious complications, such as ruptures, secondary infections, and biliary communications. Laboratory parameters are deranged, with signs of organ failure often present. This form of disease is also associated with a high mortality rate, and early drainage is often required to control the disease severity. In the chronic form, the disease is characterized by low-grade symptoms, mainly pain in the right upper quadrant. Ultrasound and computed tomography (CT) play an important role not only in the diagnosis but also in the assessment of disease severity and identification of the associated complications. Recently, it has been shown that CT imaging morphology can be classified into three patterns, which seem to correlate with the clinical subtypes. Each pattern depicts its own set of distinctive imaging features. In this review, we briefly outline the clinical and imaging features of the three distinct forms of ALA, and discuss the role of percutaneous drainage in the management of ALA.