Diagnostic value of multislice computed tomography for pancreas divisum: assessment with oblique coronal reconstruction images

OBJECTIVES: To assess the capabilities of high-resolution oblique coronal reconstruction images obtained by multislice computed tomography (CT) in diagnosing pancreas divisum. METHODS: This study included 11 patients with and 53 without pancreas divisum confirmed by direct cholangiopancreatography. Two blinded readers retrospectively interpreted oblique coronal reconstruction images with 0.5-mm continuous slices generated from isotropic or nearly isotropic pancreatic phase images with the scrolling mode and assessed the continuity of the ventral pancreatic duct, dorsal pancreatic duct, and main pancreatic duct in the body. The results were correlated with the findings of direct cholangiopancreatography. Other abnormal findings of the pancreatobiliary region on CT were also recorded in patients with pancreas divisum. RESULTS: The sensitivity and specificity of CT for diagnosing pancreas divisum were 100% and 89%, respectively. Computed tomography demonstrated all associated pancreatobiliary diseases. CONCLUSION: High-resolution oblique coronal reconstruction images allow us to make a diagnosis of pancreas divisum by depicting the continuity of the pancreatic ducts.     

Pancreas divisum: depiction with multi-detector row CT

PURPOSE: To retrospectively evaluate contrast material-enhanced multi-detector row computed tomography (CT) in the depiction of pancreas divisum. MATERIALS AND METHODS: This study was approved by the investigational review board. Seventy-seven patients (46 men and 31 women; mean age, 51 years) underwent CT with a four-detector row scanner and endoscopic retrograde pancreatography (ERP). Section thickness was 3.2 mm, and the reconstruction interval was 3 mm. Two radiologists independently evaluated the CT data sets with picture archiving and communication system (PACS) workstations equipped with software for two- and three-dimensional postprocessing reformations; the radiologists were blinded to the clinical and ERP data. Pancreas divisum was diagnosed at CT if what the authors termed the "dominant dorsal duct sign" (the caliber of the dorsal duct was larger than that of the ventral duct) was present and if the dorsal and ventral ducts did not appear to communicate with each other at cine review of images. ERP findings were used as the standard of reference for determining the performance (sensitivity, specificity, positive and negative predictive values) of the radiologists' CT interpretations. Interobserver agreement was measured by using kappa statistics. RESULTS: For four of the 77 patients (5%), both radiologists considered that depiction of the pancreatic duct on CT images was not sufficient to enable evaluation of ductal anatomy. These patients were excluded from further analysis. In the remaining 73 patients, ERP demonstrated pancreas divisum in 10 (14%); both observers made the correct diagnosis in nine of these patients. In addition, one radiologist had one false-positive interpretation, whereas the other radiologist had two false-positive interpretations. Thus, for observer 1, the calculated sensitivity was 90% (95% confidence interval [CI], 60%-98%) and the specificity was 98% (95% CI, 91%-100%). For observer 2, sensitivity was 90% (95% CI, 60%-98%) and specificity was 97% (95% CI, 89%-99%). Interobserver agreement was excellent (kappa = 0.93). CONCLUSION: CT scans obtained with multi-detector row scanners and interpreted with PACS workstations enable depiction of pancreas divisum. This assessment is possible only when the pancreatic duct is visualized.     

Pancreas. Part I: congenital changes, acute and chronic pancreatitis

The pancreas develops from ventral and the dorsal buds, which undergo fusion. Failure to fuse results in pancreas divisum, which is defined by separate pancreatic ductal systems draining into the duodenum. Risk of developing pancreatitis is increased in pancreas divisum because of insufficient drainage. MR cholangiopancreatography (MRCP) is the technique of choice for detecting pancreas divisum non-invasively. Annular pancreas is the result of incomplete rotation of the pancreatic bud around the duodenum with the persistence of parenchyma or a fibrous band encircling (and sometimes stenosing) the duodenum. Acute pancreatitis is usually caused by bile duct stones or alcohol abuse. The Atlanta classification differentiates between mild acute and severe acute pancreatitis associated with organ failure and/or local complications such as necrosis, abscess or pseudocyst. Contrast-enhanced multi-detector row CT is the method of choice to assess the extent of disease. Balthazar et al.'s CT severity index assesses the risk of mortality and morbidity. In acute pancreatitis, the role of MRCP is mainly limited to finding bile duct stones in patients with suspected biliary pancreatitis. Chronic pancreatitis results in relentless and irreversible loss of exocrine (and sometimes endocrine) function of the pancreas. MDCT even shows subtle calcifications. MRCP is the method of choice for non-invasive assessment of the duct. Inflammatory pseudotumor in chronic pancreatitis and groove pancreatitis are difficult to differentiate from pancreatic cancer. In these cases, multiple imaging methods such as MDCT, MRI and endosonography including biopsy may be used to make a diagnosis.     

Pankreas — Teil I

The pancreas develops from ventral and the dorsal buds, which undergo fusion. Failure to fuse results in pancreas divisum, which is defined by separate pancreatic ductal systems draining into the duodenum. Risk of developing pancreatitis is increased in pancreas divisum because of insufficient drainage. MR cholangiopancreatography (MRCP) is the technique of choice for detecting pancreas divisum non-invasively. Annular pancreas is the result of incomplete rotation of the pancreatic bud around the duodenum with the persistence of parenchyma or a fibrous band encircling (and sometimes stenosing) the duodenum. Acute pancreatitis is usually caused by bile duct stones or alcohol abuse. The Atlanta classification differentiates between mild acute and severe acute pancreatitis associated with organ failure and/or local complications such as necrosis, abscess or pseudocyst. Contrast-enhanced multi-detector row CT is the method of choice to assess the extent of disease. Balthazar et al.’s CT severity index assesses the risk of mortality and morbidity. In acute pancreatitis, the role of MRCP is mainly limited to finding bile duct stones in patients with suspected biliary pancreatitis. Chronic pancreatitis results in relentless and irreversible loss of exocrine (and sometimes endocrine) function of the pancreas. MDCT even shows subtle calcifications. MRCP is the method of choice for non-invasive assessment of the duct. Inflammatory pseudotumor in chronic pancreatitis and groove pancreatitis are difficult to differentiate from pancreatic cancer. In these cases, multiple imaging methods such as MDCT, MRI and endosonography including biopsy may be used to make a diagnosis.     

Pancreas. Congenital changes, acute and chronic pancreatitis

The pancreas develops from ventral and dorsal buds, which undergo fusion. Failure to fuse results in pancreas divisum, which is defined by separate pancreatic ductal systems draining into the duodenum. Risk of developing pancreatitis is increased in pancreas divisum. MR cholangiopancreatography (MRCP) is the technique of choice for detecting it non-invasively. Annular pancreas is the result of incomplete rotation of the pancreatic bud around the duodenum with the persistence of parenchyma or a fibrous band encircling (stenosing) the duodenum. Acute pancreatitis is usually caused by bile duct stones or alcohol abuse. Contrast-enhanced multi-detector row CT is the method of choice to assess the extent of this disease. In acute pancreatitis, the role of MRCP is mainly limited to finding bile duct stones in patients with suspected biliary pancreatitis. Chronic pancreatitis results in relentless and irreversible loss of exocrine (and sometimes endocrine) function of the pancreas. MDCT even shows subtle calcifications. MRCP is the method of choice for non-invasive assessment of the duct. Inflammatory pseudotumor in chronic pancreatitis and groove pancreatitis are difficult to differentiate from pancreatic cancer. In these cases, multiple imaging methods such as MDCT, MRI and endosonography including biopsy may be used to make a diagnosis.     

Pancreatic pseudotumor in pancreas divisum: CT characteristics

We report a case in which a focally spared area of pancreatic tissue in a gland otherwise replaced by fat created a "pseudomass" mimicking neoplasm on sonography and CT. The "pseudomass" appearance was related to the anomalous ductal anatomy in pancreas divisum. The spared area of pancreas creating a "pseudomass" was drained by the dorsal duct and the remainder of the pancreas that had undergone relative fatty replacement was drained by the ventral duct.     

Pancrease divisum: CT and ERCP findings

A case of pancreas divisum diagnosed by CT is reported. ERCP via the major pipilla revealed a very short pancreatic duct, which appeared to be abruptly interrupted by a tumor. CT, however, demonstrated two definite pancreatic moieties separated by a fat cleft, indicating the presence of pancreas divisum.     

Computed tomography findings in pancreas divisum

In 29 patients with abdominal pain the diagnosis of pancreas divisum (PD) was verified by endoscopic retrograde pancreatography (ERP) via both the major and the minor papilla. Computed tomography (CT) was done in all patients to evaluate contour, volume, antero-posterior diameters and attenuation values of the gland in comparison with a normal reference series. Also, the validity of the CT grading of pancreatitis was assessed in comparison with ERP grading. Patients with PD had an increased cranio-caudal diameter of the pancreatic head (p less than 0.001). Further, the main pancreatic duct was visualized more often in patients with PD (p less than 0.01), who also had an increasing frequency of pancreatic calcifications (p less than 0.05). Otherwise there were no differences compared with the normal series. The observed reduction in the volume of the gland in patients with marked pancreatitis at ERP seemingly reflected the severity of inflammation. No cleavage between the dorsal and ventral anlage was identified. CT was found to be too unspecific to be of any use in grading of pancreatitis. In conclusion, CT findings in patients with PD are sparse, unspecific and preferably a reflection of pancreatitis, if present. ERP remains the 'gold standard' for the diagnosis.     

Entwicklungsanomalien und kongenitale Erkrankungen des Pankreas

Summary Developmental anomalies of the pancreas result from fusion failure between the dorsal and ventral pancreatic ducts (pancreas divisum) or from rotational failure of the ventral bud (pancreas anulare). These variations and anomalies of the ductal anatomy can be asymptomatic throughout life or can cause varying symptoms in different age periods. Pancreas divisum and pancreas anulare can be confirmed exclusively by means of pancreatography. Congenital disorders of the pancreas derive from genetic defects involving different organ systems, which usually dominanate the clinical symptoms. Developmental anomalies and congenital disorders of the pancreas lead to varying morphological alterations of the organ which can be assessed by means of modern imaging. Eingegangen am 19. April 1996 Angenommen am 23. April 1996     

胰管内乳头状黏液性肿瘤的CT表现与临床、病理对照

目的 探讨胰管内乳又状黏液性肿瘤的CT特点，并与临床、病理对照，提高该病的诊断正确率。方法 回顾性分析经手术病理证实的8例胰管内乳头状黏液性肿瘤的CT表现，其中男6例，女2例，平均54岁。术前8例均行CT平扫及增强检查，5例行内镜逆行胰胆管造影（ERCP）检查，8例患者亦进行了B超检查，1例行MR检查。结果 CT检查发现胰头部囊实性混合肿块6例，胰头颈体部低密度肿块1例，胰腺体积增大1例，肿块最大径5．6～9．5cm不等，增强后表现为不均匀强化，6例肿块边界尚清晰，1例病灶与胃后壁紧密粘连。8例均有不同程度的胰管扩张，无一例出现远处转移。5例ERCP检查，发现十二指肠乳头增大和黏液溢出者3例，胰头体部胰管中断1例，4例全程胰管扩张。结论 胰腺导管内乳头状黏液性肿瘤的CT表现有一定的特点；CT结合ERCP有助于该病的诊断和指导治疗。     

Focal inflammation in the embryological ventral pancreas: assessment using CT and MRI

AIM: To identify the characteristic computed tomography (CT) and magnetic resonance imaging (MRI) findings of nonuniform inflammation between the posterior aspect of the head and the remainder of the pancreas. MATERIALS AND METHODS: Two radiologists retrospectively evaluated images of 19 patients in whom the degree of attenuation in the CT images and/or the signal intensity in the MRI images differed between the posterior aspect of the head (ventral primordium) and the remainder of the pancreas (dorsal primordium) due to benign disorders other than uneven fatty replacement. Multiphase, contrast-enhanced CT examinations were performed in 17 patients. In five, T1- and T2-weighted images with and without fat suppression were obtained using a 1.5 T superconducting MRI system. RESULTS: The lesions were localized in the posterior aspect of the head in 17 patients. In two patients, the lesions occupied the posterior aspect of the head and extended to the neck. The lesions exhibited the following findings: inhomogeneous hypoattenuation (with spotty areas of relatively well-maintained contrast enhancement) during the pancreatic phase (17/17) and no intense peripheral enhancement or central necrotic areas (17/17) in CT images, hypointensity in T1-weighed images (5/5), hyperintensity in T2-weighed images (4/5), no vascular invasion (19/19), failure to depict the entire course of Wirsung's duct (17/19), and calcification (13/19). Santorini's ducts were depicted in all but three patients. CONCLUSION: Focal inflammation in the embryological ventral pancreas exhibits a unique anatomical distribution and characteristic findings.     

Mucin-hypersecreting carcinoma of the pancreas

Five cases of prominent, diffuse dilatation of the main pancreatic duct caused by mucin-hypersecreting carcinoma are reported. Adenocarcinoma was noted mainly within one markedly dilated main pancreatic duct. On endoscopic retrograde pancreatograms, dilated main pancreatic ducts with amorphous or well-defined filling defects resulting from mucin (five patients) or tumor (one patient) were noted. The proximal portion of the main pancreatic duct alone was delineated in three cases because of reflux of contrast material as a result of the presence of excessive mucin and a patulous orifice of the papilla of Vater (major duodenal papilla). Diffuse dilatation of the main pancreatic duct was demonstrated or suggested on computed tomographic (CT) and ultrasound scans. Four patients who underwent operations are alive and free from carcinoma (mean, 50 months after diagnosis). Whenever prominent, diffuse dilatation of the main pancreatic duct is encountered on CT or ultrasound scans, endoscopic retrograde pancreatography is mandatory to permit confirmation or ruling out of mucin-hypersecreting carcinoma of the pancreas.     

Pancreas divisum and santorinicele: assessment by dynamic magnetic resonance cholangiopancreatography during secretin stimulation

PURPOSE: To evaluate the usefulness of MRCP, before and after secretin administration, in diagnosing Santoriniceles in patients with pancreas divisum. MATERIAL AND METHODS: One hundred and eight patients with suspected pancreatic disease, underwent dynamic magnetic resonance cholangiopancreatography (MRCP) before and after secretin administration (S-MRCP). S-MRCP images were evaluated for presence/absence of pancreas divisum, Santorinicele; size of the main pancreatic duct and of the Santorinicele. The onset of duodenal filling was calculated on dynamic S-MRCP images. S-MRCP findings were compared to endoscopic retrograde cholangiopancreatography (ERCP) ones (39/108). RESULTS: Pancreas divisum (PD) was detected in 6/108 patients (6%) at MRCP, and in 16/108 patients (14%) at S-MRCP. ERCP confirmed the diagnosis in 12/16 patients, with 1 false positive. 3 patients did not undergo ERCP. Santorinicele was detected in 4/108 (3%) patients at MRCP and in additional 4/108 (3%) patients at S-RMCP, only in patients with PD. Santoriniceles were confirmed in 7/8 patients at ERCP; in 1/8 patient CPRE was unsuccessful. The duct of Santorini was significantly larger (p< 0.05), in the pancreatic head, in patients with PD and Santorinicele (3.6 mm) compared to those with PD only (2.2 mm). A significant reduction in size of the pancreatic duct (26%) and of the Santorinicele (63%) was observed after sphincterotomy. The onset of duodenal filling was significantly delayed in patients with Santorinicele (2.1 vs 1.3 minutes)(p<0.05). CONCLUSIONS: S-MRCP helps to identify patients with pancreas divisum and Santorinicele, a known cause of impeded pancreatic outflow which benefits from endoscopic treatment.     

胰胆管合流异常的CT诊断(附3例报告)

目的：探讨CT诊断胰胆管合流异常的可能性。方法：结合正常胆管、胰管汇合部解剖,复习3例胰胆管合流异常病人的CT表现。结果：正常情况下,胆总管与主胰管在十二指肠壁内汇合。胰胆管合流异常时,可见两在十二指肠壁外直接汇合,此为直接征象;或是胆总管与主胰管先呈“双管征”样排列,在其后的断层图像上则成为一个管道,虽未看到直接汇合,但实际上已经汇合,此为间接征象。结论：CT同样可以诊断胰胆管合流异常。     

Severe chronic pancreatitis versus suspected pancreatic disease: dynamic MR cholangiopancreatography after secretin stimulation

PURPOSE: To assess whether secretin stimulation improves visualization of the pancreatic ducts at magnetic resonance (MR) cholangiopancreatography (MRCP) in patients with severe chronic pancreatitis or suspected pancreatic disease. MATERIALS AND METHODS: Thirty-one patients (group 1) with chronic pancreatitis and 84 patients (group 2) with clinical and/or laboratory findings suggestive of pancreatic disease who did not have ductal alterations at ultrasonography (US) and/or computed tomography (CT) underwent MRCP before and up to 10 minutes after secretin stimulation. Size of the main pancreatic duct (head, body, tail) and duodenal filling before and after secretin stimulation were measured quantitatively. Image quality, number of main pancreatic ductal segments visualized, visualization of side branches, ductal narrowing, endoluminal filling defects, and presence of pancreas divisum were analyzed qualitatively. RESULTS: In both groups, the size of the main pancreatic duct increased significantly 3 minutes after secretin stimulation. Reduced duodenal filling was detected in patients with severe chronic pancreatitis (P < .001). The number of segments of the main pancreatic duct visualized improved from 85 (91%) to 93 (100%) of 93 in group 1 and from 164 (65%) to 245 (97%) of 252 (P < .001) in group 2. Visualization of side branches improved from 22 (71%) to 31 (100%) of 31 in group 1 and from three (4%) to 53 (63%) of 84 (P < .001) in group 2. Pancreas divisum was visualized in one additional patient in group 1 and in six additional patients in group 2. CONCLUSION: The administration of secretin improves visualization of the pancreatic ducts and helps in the evaluation of exocrine reserve.     

Bilobular pancreas: another variant of the divided pancreas?

BACKGROUND: Pancreas divisum is the most common anomaly of the pancreas. This anomaly has been known as a possible cause of recurrent pancreatitis. CASE REPORT: We performed computerized tomography (CT) of the abdomen in 5 children in whom a divided pancreas was confirmed using endoscopic cholangiopancreatography. In a girl, who had three episodes of severe acute pancreatitis, a CT examination confirmed a completely divided embryonal dorsal and ventral primordium. We named this variant of the divided pancreas the "bilobular pancreas". Contrary to the remaining 4 children in whom the control of the number and severity of attacks, as well as the control of pancreatic pain were achieved by pharmacotherapeutics and an adequate diet, in the reported patient sphincteroplasty of the papilla duodeni minor resulted in a full control of the disease. CONCLUSION: The paper discussed the possibility that the variant of the divided pancreas, with anatomically completely separated ventral and dorsal pancreas and their ductal systems, is the key factor that determines the severity of pancreatic disease and an indication for sphincteroplasty of the papilla duodeni minor as the major therapeutic method.     

CT在胰管结石诊断及治疗中的作用（附12例报告）

目的探讨CT在胰管结石的诊断和治疗中的作用。方法回顾性分析近10年我院收治的12例胰管结石临床资料。结果所有病例均通过CT对结石的部位及胰管扩张的程度可清晰显示。12例中,有7例行手术治疗,其中有1例位于胰头处行胰十二指肠切除术,其余6例行胰管空肠吻合术：5例行保守治疗。所有患者于治疗后症状不同程度缓解。结论CT可准确定位胰管结石并能清晰显示胰管扩张的程度,对手术办式的选择有指导作用。     

HASTE MR cholangiopancreatography in the evaluation of intraductal papillary-mucinous tumors of the pancreas

PURPOSE: The aim of this study was to determine the usefulness of MR cholangiopancreatography (MRCP) of intraductal papillary-mucinous tumors. METHOD: Thirteen patients with intraductal papillary-mucinous tumors were examined by breath-hold MRCP using a half-Fourier acquisition single-shot turbo spin echo (HASTE) sequence with a body phased-array coil. RESULTS: Endoscopic retrograde cholangiopancreatography (ERCP) and MRCP completely imaged the entire main pancreatic duct in 12 and in all 13 patients, respectively. ERCP demonstrated the whole opacification of the cystic lesion in only one patient. MRCP depicted the whole of the cystic lesion in all 11 patients who had cystic lesions. ERCP and MRCP source images depicted a communicating duct between the main pancreatic duct and the cystic lesion in 8 and in all 11 patients, respectively. ERCP depicted papillary projections in the main pancreatic ducts in two patients. MRCP source images depicted papillary projections in the main pancreatic ducts or cystic lesions in five patients. CONCLUSION: MRCP may be more useful to reveal the main pancreatic duct, cystic lesion, communicating duct between the main pancreatic duct and cystic lesion, and papillary projections than ERCP in patients with intraductal papillary-mucinous tumors of the pancreas.     

CT pancreatogram in carcinoma of the pancreas and chronic pancreatitis

CT has made it possible to determine the contour of the pancreatic duct, to measure its caliber, and to detect dilatation of the duct. CT scans of 75 patients with pancreatic carcinoma and of 45 patients with chronic pancreatitis were obtained. Dilatation of the pancreatic duct was seen in 56% of patients with carcinoma, and in 70% of those with tumors confined to the pancreatic head and body. Smooth dilatation (43%) or beaded dilatation (40%) were most commonly associated with carcinoma. Ductal dilatation was present in 58% of the patients with chronic pancreatitis, and irregular dilatation was seen in 73% of the patients in this group. About half of the patients who had irregular dilatation had calculi within the ducts. The duct contour was similar to that seen in carcinoma in 27% of the cases of chronic pancreatitis. There was a significant difference in the caliber of the duct (P = .01) with larger ducts seen in patients with carcinoma. The width of the pancreatic gland (P = .005) and the ratio of duct caliber to gland width differed (P = .001) between the two diseases: the gland was wider in cases of chronic pancreatitis, and the ratio of duct to gland was larger in cases of carcinoma. Eight cases of dilatation of the duct with no detectible pancreatic mass were seen in a subgroup of 13 patients who had small carcinomas of the pancreas (tumor size of 3 cm or less). Our findings indicate that a dilated pancreatic duct with a smooth contour and a ratio of duct to total gland width of 0.50 or greater suggests carcinoma as the underlying pathology.     

Autoimmune pancreatitis: imaging features

PURPOSE: To retrospectively determine imaging findings in patients with autoimmune pancreatitis. MATERIALS AND METHODS: Twenty-nine patients (25 male and four female; mean age, 56 years; range, 15-82 years) with histopathologic diagnosis of autoimmune pancreatitis were examined. Data were reviewed by two radiologists in consensus. Imaging findings for review included those from helical computed tomography (CT), 25 patients; magnetic resonance (MR) imaging with MR cholangiopancreatography (MRCP), four patients; endoscopic ultrasonography (US), 21 patients; endoscopic retrograde cholangiopancreatography (ERCP), 19 patients; and percutaneous transhepatic cholangiography, one patient. Images were analyzed for appearances of pancreas, biliary and pancreatic ducts, and other findings, such as peripancreatic inflammation, encasement of vessels, mass effect, pancreatic calcification, peripancreatic nodes, and peripancreatic fluid collection. Follow-up images were available in nine patients. Serologic markers such as serum immunoglobulin G (IgG) and antinuclear antibody levels were available in 12 patients. RESULTS: CT showed diffuse (n = 14) and focal (n = 7) enlargement of pancreas. Seven patients had minimal peripancreatic stranding, with lack of vascular encasement, calcification, or peripancreatic fluid collection. Nine patients had enlarged peripancreatic lymph nodes. MR imaging showed focal (n = 2) and diffuse (n = 2) enlargement with rimlike enhancement in one. MRCP revealed pancreatic duct strictures in two and sclerosing cholangitis-like appearance in one. Endoscopic US showed diffuse enlargement of pancreas with altered echotexture in 13 patients and focal mass in the head in six. ERCP showed stricture of distal common bile duct in 12 patients, irregular narrowing of intrahepatic ducts in six, diffuse irregular narrowing of pancreatic duct in nine, and focal stricture of proximal pancreatic duct in six. Serologic markers showed increased IgG and antinuclear antibody levels in seven of 12 patients. At follow-up, CT abnormalities and common bile duct strictures resolved after steroid therapy in three patients. CONCLUSION: Features that suggest autoimmune pancreatitis include focal or diffuse pancreatic enlargement, with minimal peripancreatic inflammation and absence of vascular encasement or calcification at CT and endoscopic US, and diffuse irregular narrowing of main pancreatic duct, with associated multiple biliary strictures at ERCP.