Innocuous gas collections in pancreatic allografts demonstrated by computed tomography

Over a 4-year period, 6 pancreatic abscesses were found in 37 patients who had combined renal and segmental pancreatic transplants. An additional 4 patients who were nontoxic at the time of their computed tomographic (CT) examinations had innocuous gas collections, either in the pancreatic allograft or the surrounding peripancreatic tissue. The possible etiology of this gas formation is discussed. These collections do not have the same ominous clinical significance as would be expected in abscess formation. Radiological evaluation should include examination of the gastrointestinal tract and voiding cystograms to detect fistula formation. Simultaneous percutaneous aspiration of this area should be performed to rule out an infective process. If this is negative in a nontoxic transplant patient, the radiologist will be in a position to obviate unnecessary surgical intervention.     

Pancreatic transplants: secretin-stimulated MR pancreatography

Background

Our study was aimed to evaluate the functional status of pancreatic transplants using dynamic MR pancreatography after secretin stimulation.

Methods

Thirteen asymptomatic patients previously submitted to isolated pancreas (n = 6) or combined kidney–pancreas (n = 7) transplantation, with enteric-portal pancreatic drainage, underwent MR examination at 1.5 T using a phased-array coil. After the acquisition of axial and coronal T1- and T2-weighted sequences, dynamic MR pancreatography was performed using a coronal breath-hold, thick-slab (40–60 mm), single-shot T2-weighted fast spin-echo sequence. After the intravenous administration of secretin (Secrelux^®, Sanochemia; 1 cU/kg body/weight), a single-slice image acquisition was repeated every 30 s up to 15 min. We estimated the calibre changes of the pancreatic ductal system and the filling of the donor’s duodenum on the basis of pancreatic secretion after secretin stimulation, also evaluated by using a mean signal intensity/time histogram in a chosen region of interest including the transplanted pancreas and the connected small bowel.

Results

All patients well tolerated the examination, and no side effects were reported after secretin administration. In 12/13 cases, a significant increase (more than 1 mm) in the diameter of the mean pancreatic duct was observed after secretin stimulation; in all patients, a noticeable filling of the duodenal graft was demonstrated during dynamic MR pancreatography on both qualitative and quantitative analyses.

Conclusions

Dynamic MR imaging after secretin administration allows non-invasive evaluation of exocrine function of the pancreatic transplants and could be used to differentiate patients with graft rejection from those with normal graft function.

     

Ultrasonic characteristics of pancreatic tumors

The ultrasonic features of 40 pancreatic tumors were analyzed. The tumors were categorized by texture, attenuation, shape, size, and location. Secondary effects of pancreatic duct visualization, biliary stasis, splenic vein involvement, metastases, and ascites were reviewed. Thirty of thirty-one adenocarcinomas had a similar ultrasonic texture consisting of a background of faint, low-level echoes with varying amounts of superimposed coarse echoes. Tumors are detectable prior to enlargement or distortion of the pancreas. Secondary features were present in 94% of the adenocarcinomas. Significant information regarding the possibility and complexity of resection can be provided.     

Lymphoepithelial cyst of the pancreas

Lymphoepithelial cyst of the pancreas is a rare lesion which may mimic a pancreatic pseudocyst or mucinous cystic neoplasm. To our knowledge, this lesion has never been reported in the radiologic literature. We present a patient with lymphoepithelial cyst of the pancreas, and we discuss the radiographic and pathologic findings.     

Agenesis and pseudo-agenesis of the dorsal pancreas

Agenesis of the dorsal pancreatic anlage is a very unusual congenital anomaly. The case reported appears to be accompanied by hypertrophy of the ventral gland. Atrophy of the pancreas following an episode of acute pancreatitis is also very unusual. When the atrophy spares the uncinate process, it may also resemble agenesis of the dorsal gland.     

Angiographic evaluation of the abnormal endoscopic pancreatogram

Out of 1,269 pancreatograms, 122 were abnormal. Angiography was performed in these patients. Fifty-five were found to have pancreatic carcinoma. In the remaining 67 patients a false positive angiographic diagnosis of either chronic pancreatitis or pancreatic cancer was made in 11%. In one patient a hemangioma was diagnosed as a pancreatic cyst. The remaining 58 patients all had normal pancreatic angiograms in spite of gross ductal abnormality on endoscopic retrograde cholangiopancreatography (ERCP). All these patients were followed for an average of 19 months and showed no clinical evidence of pancreatic disease. It is suggested that angiography should be considered a complementary examination to ERCP and is particularly useful to exclude carcinoma when the pancreatogram is abnormal.     

Intraductal papillary carcinoma of the pancreas

We report a case of intraductal papillary adenocarcinoma of the distal pancreatic duct. Although a rare subgroup of exocrine pancreatic tumors, their diagnosis is an important one in view of their favorable prognosis with pancreatectomy. Because of the established behavior of villous tumors of the colon, to which they are similar histologically, these tumors should be resected, even if biopsy shows benign disease. Patients should be followed radiologically for recurrence or the development of new adenoma following resection.     

Isolated ventral pancreatitis in an alcoholic with pancreas divisum

An alcoholic with no history of clinical pancreatitis was found to have pancreas divisum and marked changes of chronic pancreatitis isolated to the ventral pancreas. Pancreas divisum has been suggested to cause recurrent pancreatitis in some patients. Gross and histologic changes of pancreatitis in only the dorsal pancreas of surgically resected specimens from patients with pancreas divisum is thought to support the concept that obstruction at the minor papilla produces dorsal pancreatitis. Alternative explanations for the occurrence of segmental pancreatitis and the possible synergistic role of ethanol and bile are reviewed.     

Age-related morphology of the normal pancreas on computed tomography

Abdominal computed tomographic scans were performed on a group of 360 patients between the ages of 20 and 80 years. The anteroposterior diameter of the pancreatic head, body, and tail, the age-related ratio of vertebral body-pancreas diameter, and the external and internal contours of the organ were analyzed. The age-related changes in the pancreas were compared with known anatomical findings.     

Macrocystic serous cystadenoma of the pancreas:CT and endosonographic features

Recently, the term ``serous cystadenoma' has been adopted in the pathological community to qualify the so-called microcystic adenoma of the pancreas. This change in terminology was based on the emergence of a new type of serous cystadenoma of the pancreas, i.e., the macrocystic variant. We report one case of pathologically proven macrocystic serous cystadenoma of the pancreas for which the diagnosis of mucinous cystadenoma was suggested preoperatively. This rare but benign macrocystic variant exhibits radiological features similar to those of mucinous cystadenoma. In addition, inflammatory changes and foci of hemorrhage within the tumor may simulate mucinous cystadenocarcinoma. RID="ID="<e5>Correspondence to:</e5> P. Soyer Received: 25 August 1997/Accepted: 8 October 1997     

Psoas muscle pancreatic pseudocyst: CT-US diagnosis and percutaneous drainage

We present 2 cases of psoas muscle pancreatic pseudocysts. In both cases there was no clinical or laboratory evidence of recent acute pancreatitis. The route of extension for the pseudocyst from the pancreas to the psoas was the perirenal space. In both cases the diagnosis was made on the basis of imaging studies and the pseudocysts resolved with percutaneous drainage only.     

Pancreatic lesions and transfascial perirenal spread: Computed tomographic demonstration

Computed tomographic (CT) findings in 105 cases of pancreatitis and 107 cases of pancreatic carcinoma were analyzed retrospectively to determine the occurrence and roentgenologic signs of penetration of the anterior renal fascial planes in relation to clinical symptoms. In pancreatitis, the perirenal fat was infiltrated in 7% to variable extents by extrapancreatic fluid collections, either as asymptomatic fluid lying alongside renal fascial planes and perirenal septa (5 cases) or as well-circumscribed fluid collections causing clinical symptoms (2 cases). In pancreatic carcinoma the occurrence of retropancreatic extension to a perirenal space was rarer (3%). Distinction on CT between perirenal involvement from the pancreas and primary adrenal or renal lesions with anterior spread can prevent unnecessary surgery.     

Papillary cystic neoplasm of the pancreas: Radiological findings

We report a series of 10 papillary cystic neoplasms of the pancreas evaluated in our institution. The lesions are analyzed in retrospect to define the existence of eventual specific imaging patterns as well as to point out the existing problems of differential diagnosis versus other pancreatic tumors.     

Carcinoid tumors of the pancreas: CT findings

Computed tomographic (CT) and ultrasound (US) findings in four cases of carcinoid tumors of the pancreas are reported. Differential diagnosis with other endocrine and nonendocrine pancreatic tumors is discussed. CT and US techniques play an important role in diagnosis, prognosis, and treatment of these tumors.     

Branch duct IPMTs: value of cross-sectional imaging in the assessment of biological behavior and follow-up

Branch duct intraductal papillary mucinous tumors (IPMTs) are increasingly being described and represent a challenge for the physician. Recent imaging modalities, especially computed tomography and magnetic resonance, allow for a correct diagnosis, but IPMTs can manifest with different degrees of cellular atypia so it is very important to be able to establish the biological behavior of the lesion. Sixty-five patients were included in this study: 29 of them underwent surgery, and the other 36 were followed with cross-sectional imaging. Among patients who underwent surgery, 11 had benign lesions and 18 had malignant lesions. Overall sensitivity, specificity, and accuracy in the diagnosis of malignancy for all the cross-sectional imaging techniques were 61%, 81%, and 69%, respectively. Among patients who were followed and had a magnetic resonance cholangiopancreatographic diagnosis of branch duct IPMT with imaging features indicative of benignity, only two showed modifications over the follow-up period. Even considering some important biases (small number of patients and relatively short follow-up), interesting conclusions can be drawn: the imaging diagnosis of malignancy can be trusted, whereas that of benignity cannot be relied upon, but if the signs of malignancy are absent, the slow growth of the lesions justifies watchful follow-up in the correct clinical setting.     

CT diagnosis of splenic vein occlusion: imaging features,etiology, and clinical manifestations

Background Previous reports have described the computed tomographic (CT) appearance of collateral veins following splenic vein occlusion (SVO). This retrospective study was performed to determine the etiology, clinical manifestations, and accuracy of CT diagnosis in patients with this entity.Methods A computer search of radiology reports for a 1-year period found 52 patients with SVO diagnosed by absence of visualization of the splenic vein accompanied by the formation of the expected perigastric collateral veins. Clinical data were reviewed for sequela of SVO and clinical impact of the diagnosis.Results In 12 cases, other studies confirmed the CT diagnosis of SVO. In no case was the CT diagnosis proved to be incorrect by other imaging studies. Angiographic records found five additional cases with SVO not diagnosed by CT, but two of five had convincing CT evidence of SVO noted upon reevaluation by the authors. Review of clinical data showed heme-positive stool in six, of which three had significant gastrointestinal hemorrhage. Splenic infarction occurred in two cases.Conclusions Our data indicate that SVO is more common than previously suspected and usually remains clinically silent, but CT appears to be highly specific and fairly sensitive for its diagnosis.     

Pancreatic duct diameter: Sonographic measurement in normal subjects

In a prospective ultrasonic study of the pancreatic duct, 233 sonograms were obtained from 49 normal subjects. The duct in the regions of the head-neck and body was measured in the transverse/oblique planes. The mean diameter of the duct in the area of the head-neck was 3 mm; in the body proximal and distal to the neck, duct diameters were 2.1 and 1.6 mm, respectively.     

Non-beta islet cell tumor calcification associated with Zollinger-Ellison syndrome and multiple endocrine adenomatosis

The radiographic triad of a calcified pancreatic mass, duodenal ulcers, and nephrocalcinosis should suggest the Zollinger-Ellison syndrome as part of the multiple endocrine adenomatosis complex. The clinical and radiographic features of the entity are described in this case report.     

Cystic tumors of the pancreas: Evaluation by ultrasonography and computed tomography

The personal series of 30 cystic tumors of the pancreas [12 serous cystic tumors (SCT) and 18 mucinous cystic tumors (MCT)] is presented. All neoplasms were evaluated with ultrasonography (US) 28 of 30 with computed tomography (CT); the tumoral histotype could be correctly defined in 73% of cases (seven of 12 SCT and 15 of 18 MCT). Percutaneous fine-needle aspiration (FNA) with diagnostic aims (preparation of cytological smears and/or biochemical assays) was performed in only 10 of 30 cases, yielding a 100% sensitivity; on the whole, the combined use of imaging modalities and FNA allowed correct characterization of the cystic tumors in 27 of 30 cases (90%). The usefulness of a precise diagnostic workup of these neoplasms is emphasized, due to their prognostic and therapeutic outcome.     

Magnetic resonance imaging of the pancreas with gadolinium-DTPA

Gadolinium (Gd)-DTPA was evaluated as a contrast agent for magnetic resonance (MR) imaging of the pancreas at 1.5T. Twenty-five patients were imaged with identical gradient-echo (GE) (TR 47, TE 13, 80° pulse angle) and spinecho (SE) (TR 300, TE 15) MR sequences prior to and following an intravenous bolus of 0.1 mmol/kg Gd-DTPA. Marked pancreatic enhancement was demonstrated on dynamic sequential breath-hold GE images obtained immediately following the Gd-DTPA bolus (116% mean enhancement over pre-Gd-DTPA images). Enhancement decreased but persisted on the SE images obtained approximately 5 and 15 min following the Gd-DTPA bolus (65 and 60% mean enhancement, respectively). Five of the patients had a pancreatic mass. In these five patients, the enhancement of pancreatic tissue resulted in improved conspicuity of the mass. These initial results suggest that pancreatic enhancement occurs following an intravenous bolus of Gd-DTPA and has the potential to improve MR visualization of pancreatic masses.