Lymphoepithelial cyst of the pancreas

OBJECTIVES: We surveyed a "population" of younger men (20 to 49 years old) for lower urinary tract symptomatology and for symptomatology associated with prostatitis. METHODS: A National Guard unit was surveyed by mail with a 58-question urinary symptom questionnaire. Surveys were returned anonymously by mail. RESULTS: International Prostate Symptom Score (IPSS) of 8 or greater was seen in 5% of men in their 20s and rose to 15% of those in their 40s. Approximately 5% (0% to 7%) reported a history of prostatitis. Caffeine caused symptoms in 2% to 13%, while exercise and smoking were not associated with symptoms. Individual prostatitis symptoms were only seen occasionally across this age group. CONCLUSIONS: As measured by the IPSS, urinary symptoms increased during the 20 to 49-year age period. A history of prostatitis in much less common than most nonpopulation studies suggest.     

Imaging of spinal intradural arachnoid cysts: MRI, myelography and CT

Imaging studies in eight patients with surgically-confirmed spinal arachnoid cysts were analyzed retrospectively. All patients had preoperative MRI of the spine and seven preoperative myelography with postmyelographic CT. In all cases the correct diagnosis could be made preoperatively on the basis solely of MRI. The diagnosis could also be established from myelography and postmyelographic CT in six of the seven cases. In one case myelography and CT simply demonstrated an intradural extramedullary mass.     

Virtual colonoscopy using CT and MRI

PURPOSE: To evaluate experimentally and in patients the sensitivity and effective dose of virtual electron-beam tomography (EBT) colonoscopy for detecting small colon tumors and to compare the methods and results with virtual colonoscopy using spiral CT and MR imaging in a review of the literature. MATERIALS AND METHODS: Six polyps with diameters between 3 and 12 mm were created and randomly placed in resected pig colon. After distension with air, the pig colon was scanned with continuous volume scanning (CVS, 3 mm collimation) and a pitch of 0.4, 0.8 and 1.5. Twenty patients positive for the fecal blood test were examined after rectal CO2 insufflation and i.v. administration of 1 mg glucagon. A 13 s CVS scan was used to cover the entire colon within one breath-hold. 3D volume-rendered fly-throughs were evaluated by two independent radiologists. Effective dose equivalent was estimated using an Alderson phantom equipped with thermoluminescence dosimeters. RESULTS: In the tumor model, all polyps were detectable at a pitch of 1.5. A further reduction of the pitch ratio did not improve the conspicuity of the polyps. In patient studies, all tumors (n = 4) and polyps (n = 3) were correctly identified on 3D fly-throughs. Two false positive results were obtained. Effective dose equivalent was calculated at 3.2 mSv per scan. CONCLUSIONS: Our preliminary results indicate that virtual EBT colonoscopy holds promise for fast screening for colon polyps. The best technique for virtual colonoscopy (Spiral CT, EBT, MRI) has not yet been determined and the future role of virtual colonoscopy must still be defined.     

CT and US of the pancreas

The diagnostic capabilities of pancreatic imaging continue to improve with technological advancements in computed tomography (CT), ultrasound (US), and magnetic resonance imaging (MRI). To update the practicing radiologist, this article summarizes the current literature on pancreatic imaging, with particular emphasis on CT and US. Pertinent clinical considerations of the disease entities are included, along with illustrative material from the authors' experience.     

Bilateral synovial coracoclavicular joints: MRI demonstration

Bilateral coracoclavicular joints, an anatomical variation, are described by radiography and MRI. MRI enabled precise identification of the nature of these joints. They were true synovial joints with cartilage and synovial fluid. To the best of the authors' knowledge, this is the first demonstration of such joints by MRI.     

Primary choriocarcinoma of the stomach and pancreas: CT findings

In this report we present the CT findings of two non-gestational, extragonadal choriocarcinomas, one arising within the stomach and one in the pancreas. These are rare tumours and a pancreatic primary site has not been previously described.     

Horseshoe lung: demonstration by electron-beam CT

Horseshoe lung is a rare pulmonary anomaly characterized by fusion of the posterobasal portions of the right and left lungs behind the pericardial reflection, anterior to the aorta. The majority of reported cases occur in conjunction with scimitar syndrome, including hypoplasia of the right lung, anomalous right pulmonary venous return and systemic arterial supply to the lung. Horseshoe lung is usually diagnosed on pulmonary arteriography when the right inferior pulmonary artery crosses the midline and extends to the left lung base. Bronchography is also diagnostic when the branch of horseshoe portion arises from the right bronchus and passes within the lung parenchyma to midline of the lung tissue. The only described CT finding of horseshoe lung is the contiguity of the right and left lungs behind the heart. Most cases are infants under 12 months of age and CT images are severely hampered by respiration motion artefacts. Such artefacts are minimized by using electron-beam computed tomography, allowing a more detailed CT appearance of horseshoe lung in this case.     

Macrocystic serous cystadenoma of the pancreas: CT and endosonographic features

Defects in stomatin, alpha-adducin, and beta-adducin have been implicated in erythrocyte disorders of cation permeability. We performed linkage analysis of the genetic loci for these proteins in a large kindred with xerocytosis (dehydrated hereditary stomatocytosis). Using polymerase chain reaction-based genotyping techniques, all three loci are excluded as disease gene candidates.     

Leiomyosarcoma of the maxillary sinus: CT and MRI findings

This report describes the CT and MRI appearances of a leiomyosarcoma of the maxillary sinus. CT showed frank bony destruction, no calcification and a low attenuation area within the mass. MRI showed intermediate intensity on T1 weighted images, intermediate to slightly high signal intensity on T2 weighted images and moderate inhomogeneous enhancement. Precise identification of the extent of the tumour, especially of orbital invasion, is of utmost importance because local recurrence is common after the resection of leiomyosarcomas.     

Lymphoepithelial tumor of the skin

We celebrate in 1998 the centenary of the discovery of the Golgi apparatus. Neurones have played a special role in the history of this cell organelle, primarily because the endocellular apparatus was discovered in nerve cells by Camillo Golgi when he was studying the cerebellum of an owl. In the following years, the apparatus of the nerve cell represented the prototype of this cell component which, however, was soon also detected in many other cell types. During the 1920s and 1930s the original idea of a Golgi endocellular "network" was refused and research was focused on the constituents and function of the organelle, using various tissues and techniques. However, the real existence of the apparatus was seriously questioned until the organelle was finally identified by electron microscopy in the mid-1950s. The studies performed on nerve cells during these decades is briefly reviewed here.     

Giant adrenal myelolipomas: CT and MRI findings

A beta (beta/A4) is the major constituent of brain amyloid in Alzheimer's disease (AD), Down's syndrome (DS) and normal aged persons. This protein is presumably derived by normal proteolysis from a precursor protein (APP). In this study, C-terminal fragments of APP in a Tris/Triton soluble fraction were partially purified from DS brain by heparin-affinity and reverse phase chromatography, and analyzed by N-terminal amino acid sequencing after SDS polyacrylamide gel electrophoresis and Western blotting. We found at least six different C-terminal fragments including those with the entire A beta region. These results suggest that secretory processing of APP is heterogeneous and generates amyloidogenic C-terminal fragments.     

Acinic cell Carcinoma of the parotid gland: CT and MRI

Skin permeation of amino acids through excised rat skin was measured at various pH values. The permeabilities varied with the donor pH and amino acid, indicating that each ionic species of amino acid may have a different permeability. The permeability coefficient of each ion was estimated from the permeability-pH profiles using the dissociation constants. The estimated values for mono-cation and uncharged zwitterion were not dependent on the lipophilicity but on the size of the amino acid, suggesting a porous mechanism of transport. The permeability coefficient was highest for di-cation, followed by mono-cation, positively charged, uncharged and negatively charged zwitterions. The electrical potential difference across the skin was too small to affect the permeation of ions. The permselective property of skin thus seems to be determined by the difference of diffusivity in aqueous pores of skin due to the hydration of ions and other factors.     

CT and MRI of the male genital tract: radiologic-pathologic correlation

Technical advances in magnetic resonance imaging (MRI), notably in high-resolution MRI, have opened up new diagnostic applications in male pelvic pathology. A major indication is the preoperative staging of prostate cancer, where MRI is more reliable than other imaging modalities in differentiating between localized and advanced disease. In monitoring local recurrence after radical prostatectomy MRI is also valuable in differentiating scar tissue from new growth. In benign prostate disease, MRI effectively displays the congenital cysts that may be associated with infertility. Other disease, however - notably benign prostatic hyperplasia - is generally an incidental finding. Ultrasound remains the imaging modality of choice for evaluation of pathologies of the penis, testis and scrotum, e. g. in differentiating malignant from benign scrotal masses or in diagnosing acute scrotum due to testicular torsion or rupture. In isolated cases, MRI is also a valuable diagnostic aid in conditions of these organs, e. g. in the preoperative localization of ectopic testes in cryptorchidism or if US findings are equivocal.     

MRI cholangiopancreatography in the pathology of the bile ducts and pancreas

MR cholangiopancreatography (MRCP) is a recent and exciting imaging modality that allows visualization of bile and pancreatic ducts without morbidity. Although the technique of MRCP is in its early stages of development and MRCP technology is progressing MRCP will undoubtedly replace traditional techniques such as diagnostic ERCP. This article describes MRCP findings in bile or pancreatic duct diseases, analyzes the accuracy of MRCP in these diseases, and discusses the potential role of MRCP in evaluating the pathology of the biliary tract and pancreas.     

CT scan and metrizamide CT cisternography in arachnoid cysts of the middle cranial fossa: classification and pathophysiological aspects

Thirty-one cases of arachnoid cysts of the middle cranial fossa were investigated by CT scan, 7 of them undergoing additional metrizamide CT cisternography. In this paper we analyze and correlate the different findings from these two examinations and propose a classification of arachnoid cysts of the middle cranial fossa into three basic types. Pathophysiological and surgical implications are discussed.     

CT characteristics of metastatic disease of the pancreas

Contrast material-enhanced computed tomographic (CT) scans obtained over a 10-year period in 66 patients with metastases to the pancreas were retrospectively reviewed. The primary tumors most commonly responsible for these metastases were renal cell carcinoma (30.3%) and bronchogenic carcinoma (22.7%). Metastases showed no predilection for any particular part of the pancreas. The majority (75.8%) of metastases appeared as tumors with discrete margins, and most of these tumors were round or ovoid with smooth borders. Over three-fourths of the lesions demonstrated enhancement (usually heterogeneous). Vascular involvement was uncommon. In those patients in whom pancreatic metastases were discovered some time after the primary tumor was identified, the interval ranged from 2 to 295 months, with the longest mean interval (120.2 months) being associated with metastatic tumors from renal cell carcinoma. The appearance of these tumors at CT--predominantly hyperattenuating masses, often with nonenhancing internal components--was similar to that of primary renal cell carcinoma. In most pancreatic metastases, however, clinical information in conjunction with CT characteristics such as multiplicity of tumors or hypervascularity permit differentiation of metastases from primary neoplasm. When diagnosis of a pancreatic neoplasm is uncertain, percutaneous biopsy often permits histologic confirmation of the tumor type.     

The size of acoustic neuromas: CT and MRI

The growth rate of acoustic neuromas is very variable: some tumours grow rapidly, some do not grow and some even get smaller. When making treatment decisions, it may be important to have an idea of the growth rate of the individual tumour, and this is only possible when there are comparable examinations. We performed both CT and MRI on 15 patients. Two radiologists estimated the size of their acoustic neuromas. There was a significant difference between the two examiners' calculations of tumour volumes on CT and between the first examiner's CT and MRI volume calculations. No difference was found between the two MRI volume estimations or the second examiner's estimation of volumes on CT and MRI. Measurements of the maximal tumour diameter along the pyramid showed good concordance. We conclude that measurement the size of acoustic neuromas is reproducible with MRI and the measurement of the maximal tumour diameter is in practice a better parameter for comparison than calculation of real volume.     

Dacryocystography using CT and MRI. Comparative study apropos of 13 clinical cases

Magnetic Resonance Imaging of a dacryocystography and a watersoluble computed tomographic dacryocystography were compared in 13 prospective cases after facial traumas, infections or without previous history. All had either watering eyes, ephiphora or dacryocystitis. This study demonstrated the superiority of computed tomography which must be used in first intention for complexe problems of the lacrimal drainage system. Only tumoral pathology (very rare) requires Magnetic Resonance Imaging. Combined computed tomography and dacryocystography in the same time provide diagnostic precision and less radiation. Confortable for the patient by helicoidal acquisition, computed tomography is cheaper than a Magnetic Resonance Imaging.