Louisa Azizi

MR Lymphography of Abdominal and Retroperitoneal Lymphatic Vessels

OBJECTIVE The abdominal and retroperitoneal lymphatic system is characterized by numerous anatomic variations. Our objective is to review MR lymphographic features of normal anatomy and abnormal conditions. CONCLUSION MR lymphography is a noninvasive technique that is well suited for the examination of abdominal and retroperitoneal lymphatic vessels.

Pouchography, CT, and MRI Features of Ileal J Pouch-Anal Anastomosis

OBJECTIVE Our objective is to describe pouchography, CT, and MRI features of the J-shaped pouch, both normal and with pouch-related complications. CONCLUSION Pouchography is performed before closure of the loop ileostomy to assess the integrity of the ileal pouch and anastomosis. CT and MRI can be performed when postoperative complications, such as small-bowel obstruction, pouchitis, leakage, abscess, intramural hematoma, desmoid tumor, or recurrent Crohns disease, are suspected.

Infected aortic aneurysms: CT features.

Infected aortic aneurysm is an uncommon life-threatening disease that exposes the patient to uncontrolled sepsis and aortic rupture. Infected aortic aneurysm is defined as a lesion of the arterial wall due to bacterial contamination. Two main routes have been described that can result in an infected aneurysm. The first route refers to cases in which there is a source of septic emboli or bacteremia. Endocarditis, in the preantibiotic era, was the classic source of septic emboli; intravenous drug abuse is the current leading cause. The second route refers to cases of extraaortic infection, such as spondylodiscitis, with secondary invasion of adjacent aorta. The most common organisms causing infected aortic aneurysms in recent years are Staphylococcus aureus, Salmonella, Escherichia coli, and Pseudomonas [1, 2]. Clinical diagnosis of infected abdominal aortic aneurysms is based on the presence of signs and symptoms of infection (fever, leukocytosis, and abdominal or back pain) combined with a pulsatile mass [2, 3]. Patients with such symptoms are often referred for computed tomography (CT) to exclude an abscess, diverticulitis, or other potential infectious focus. We present the CT features of infected aortic aneurysms including early-stage features, advanced-stage features, and complications. Early-stage features

Utilisation du jus d’ananas en tant qu’agent de contraste négatif en cholangiopancréatographie par résonance magnétique

Resume Objectifs La qualite des examens de cholangiopancreatographie par resonance magnetique (CPRM) est frequemment degradee par le signal eleve du contenu digestif sur les sequences fortement ponderees en T2. L’objectif de cette etude est d’evaluer les resultats obtenus par l’ingestion de jus d’ananas en tant qu’agent de contraste negatif en CPRM. Materiels et methodes Nous avons compare les resultats de la CPRM de 50 patients ayant ingere du jus d’ananas et de 50 patients ayant ingere un produit de contraste paramagnetique (ferumoxsil-Lumirem ® ). Les observateurs ne connaissaient pas la nature du produit de contraste ingere. La qualite des examens a ete analysee en terme de suppression du signal au sein de l’estomac, du cadre duodenal et du grele proximal et en terme de visualisation du canal pancreatique, des voies biliaires intrahepatiques et de la voie biliaire principale. In vitro, nous avons analyse l’intensite du signal de differents jus d’ananas disponibles sur le marche, en se servant de sequences ponderees en T1, de sequences ponderees en T2 et de sequences de CPRM. L’intensite du signal a ete correlee avec la concentration de manganese mesuree par spectrometrie d’emission atomique. Finalement, les observateurs ont compare les gouts respectifs du jus d’ananas et du ferumoxsil. Resultats Sur les sequences de CPRM, les resultats etaient equivalents en terme de suppression de signal de l’estomac, du cadre duodenal et du grele proximal apres ingestion de jus d’ananas ou de ferumoxsil. La visualisation du canal de Wirsung, des voies biliaires intrahepatiques et de la voie biliaire principale etait equivalente apres ingestion d’ananas ou de ferumoxsil. L’intensite du signal des differents jus d’ananas sur les sequences ponderees en T2 et sur les sequences de CPRM etait bien correlee avec la concentration de manganese mesuree pour chacun des jus par spectrometrie. D’importantes variations de la concentration de manganese ont ete observees entre les differents jus d’ananas testes. La concentration de manganese variait entre 3,65 et 27,24 mg/L. Les observateurs ont considere que le jus d’ananas avait un « bon » ou un « tres bon » gout alors que le ferumoxsil avait un « mauvais » ou « tres mauvais » gout. Conclusion L’ingestion de jus d’ananas permet d’obtenir une diminution efficace du signal du tractus digestif en CPRM d’une facon comparable a celle qui est obtenue avec les produits de contraste paramagnetiques. Comme la concentration de manganese est largement variable dans les differents jus d’ananas disponibles dans le commerce, un jus d’ananas a haute concentration de manganese doit etre selectionne.

MRI of Rectal Disorders

OBJECTIVE The objective of this pictorial essay is to provide a review of the diseases involving the rectal wall with an emphasis on the key clinical and radiologic differentiating features. CONCLUSION A wide spectrum of disease processes can involve the rectum in adults. MRI is the technique of choice in the definitive diagnosis of these disease conditions, mainly because of its superior tissue contrast differentiation.

MR Imaging of sclerosing cholangitis

MRCP is a non-invasive cholangiographic technique used in detection and characterization of bile ducts abnormalities. MRCP features of primary sclerosing cholangitis are randomly distributed annular strictures alternating with slightly dilated bile ducts. Secondary sclerosing processes including ascending, ischemic, caustic, AIDS-related, eosinophilic and autoimmune cholangitis can mimic PSC at MRCP.

Imagerie par résonance magnétique de diffusion (IRMD) en pathologie hépatique: principe et applications cliniques.

Diffusion-weighted MR imaging of liver pathology: principles and clinical applications Due to ongoing technological advances, the range of clinical applications for diffusion-weighted MR imaging has expanded to now include abdominal pathology. Current applications for liver pathology include two main directions. First, oncologic imaging with detection, characterization and follow-up of lesions. Second, evaluation of diffuse liver diseases, including hepatic fibrosis. The diagnostic impact and role of diffusion-weighted MR imaging remain under investigation, but appear promising. Because of its short acquisition time, sensitivity, and additional information it provides, diffusion-weighted MR imaging should be included in routine liver imaging protocols.

Magnetic resonance imaging of the ischiorectal fossa : Spectrum of disease

Objective: Pelvic magnetic resonance imaging (MRI) studies are widely used to assess the rectum, anal canal, and their environment. The purpose of this article is to review the current role of MRI in the evaluation of diseases involving the ischiorectal fossa and their imaging features. Conclusions: The radiologist plays an essential role in the evaluation of some conditions typically located in this space and of other conditions that occasionally involve this area or invade the ischioanal space. The accurate assessment of these diseases that MRI provides further cements its role as the primary technique for the evaluation of pelvic pathology.

Non-contrast 3D MR lymphography of retroperitoneal lymphatic aneurysmal dilatation: a continuous spectrum of change from normal variants to cystic lymphangioma

ObjectiveOur objective was to demonstrate the characteristic features of retroperitoneal lymphatic aneurysmal dilatation with three-dimensional (3D) magnetic resonance (MR) lymphography.ConclusionThree-dimensional MR lymphography demonstrates that retroperitoneal lymphatic aneurysmal dilatation exhibits a continuous spectrum of change from normal variants to lymphatic aneurysmal dilatation and so-called cystic lymphangioma.Main MessageNon-contrast MR lymphography with very heavily T2-weighted fast spin echo sequences is a useful non-invasive technique without the need of contrast medium injection to obtain a unique evaluation of the lymphatic systemTo prove the lymphatic origin of a cystic formation, it is essential to demonstrate the communication with retroperitoneal lymphatic vessels3D MR lymphography demonstrates that retroperitoneal lymphatic aneurysmal dilatation exhibits a continuous spectrum of change from normal variants to lymphatic aneurysmal dilatation and so-called cystic lymphangioma

Computed Tomography Features of Acute Thrombosis of Central Veins With Perivenous Inflammatory Changes

Objective: Our purpose was to examine the computed tomographic findings in 13 patients with acute deep venous thrombosis (DVT) of central veins of the neck, chest, and abdomen in whom major perivenous inflammatory changes were noted. Methods: During a 10-year period, 13 patients with acute DVT of 21 central veins and marked perivenous inflammatory changes on computed tomography were identified. Computed tomography images were assessed for location of DVT and pattern of perivenous changes. Results: The perivenous changes took the form of a rounded or lobulated perivenous bulky mass (massive pattern or tumorlike) in 5 patients and of infiltrative changes in the other 8 patients. Direct visualization of the thrombotic vein was possible in 8 patients. Follow-up examinations (range, 6-36 months; mean, 15 months) demonstrated resolution of perivenous inflammatory changes with anticoagulation therapy in all cases. Conclusion: Perivenous inflammatory changes around the thrombotic vein presented as a rounded or lobulated perivenous bulky mass that may mimic a tumor or as infiltrative perivenous changes.