J.M. Tubiana

Diffusion-weighted magnetic resonance imaging for the assessment of fibrosis in chronic hepatitis C†

Liver biopsy is the gold standard for assessing fibrosis but has several limitations. We evaluated a noninvasive method, so‐called diffusion‐weighted magnetic resonance imaging (DWMRI), which measures the apparent diffusion coefficient (ADC) of water, for the diagnosis of liver fibrosis in patients with chronic hepatitis C virus (HCV). We analyzed 20 healthy volunteers and 54 patients with chronic HCV (METAVIR: F0, n = 1; F1, n = 30; F2, n = 8; F3, n = 5; and F4, n = 10) prospectively included. Patients with moderate‐to‐severe fibrosis (F2‐F3‐F4) had hepatic ADC values lower than those without or with mild fibrosis (F0‐F1; mean: 1.10 ± 0.11 versus 1.30 ± 0.12 × 10−3 mm2/s) and healthy volunteers (mean: 1.44 ± 0.02 × 10−3 mm2/s). In discriminating patients staged F3‐F4, the areas under the receiving operating characteristic curves (AUCs) were 0.92 (±0.04) for magnetic resonance imaging (MRI), 0.92 (±0.05) for elastography, 0.79 (±0.08) for FibroTest, 0.87 (±0.06) for the aspartate aminotransferase to platelets ratio index (APRI), 0.86 (±0.06) for the Forns index, and 0.87 (±0.06) for hyaluronate. In these patients, the sensitivity, specificity, positive predictive value, and negative predictive value were 87%, 87%, 72%, and 94%, respectively, with an ADC cutoff level of 1.21 × 10−3 mm2/s. In discriminating patients staged F2‐F3‐F4, the AUC values were 0.79 (±0.07) for MRI, 0.87 (±0.05) for elastography, 0.68 (±0.09) for FibroTest, 0.81 (±0.06) for APRI, 0.72 (±0.08) for the Forns index, and 0.77 (±0.06) for hyaluronate. Conclusion: This preliminary study suggests that DWMRI compares favorably with other noninvasive tests for the presence of significant liver fibrosis. (HEPATOLOGY 2007.)

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.

Idiopathic granulomatous hypophysitis: clinical and imaging features

Idiopathic pituitary granuloma is a rare disorder similar to lymphocytic adenohypophysitis. Few cases have been reported. We report a new histologically case proven with MRI. The patterns of clinical and radiological presentation and the management of this disorder are discussed. MRI findings suggestive of this condition include an intensely enhancing pituitary mass, associated with dural enhancement. Steroid therapy may be suggested avoiding unnecessary surgery.

Long-term follow-up after neoplastic seeding complicating percutaneous ethanol injection for treatment of hepatocellular carcinoma.

We describe a case of subcutaneous metastasis along the needle track after percutaneous ethanol injection (PEI) for treatment of hepatocellular carcinoma. After surgical resection and extrabeam radiation therapy the patient is alive without evidence of recurrence five years after PEI. One should pay attention to the abdominal wall around the needle track in interpreting CT or MR images of patients with previous PEI.

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.

Adenosarcoma arising in hepatic endometriosis

Abstract. We report a case of adenosarcoma arising in hepatic endometriosis. Both CT and MR scans demontrated a huge heterogeneous mass containing septated, thick-walled cystic lesions. After enlarged right hepatectomy, the patient was asymptomatic with no abnormalities at liver and abdominal CT scan at 2-year follow-up.

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.

Diffuse cavernous hemangioma of the rectosigmoid colon : Imaging findings

Diffuse cavernous hemangioma of the rectosigmoid colon (DCHR) is an uncommon disease that affects mainly young adults. As the main symptom is non-specific chronic rectal bleeding, the clinical diagnosis is difficult and often delayed. In this essay, we illustrate the imaging features of DCHR, including plain radiograph, barium enema, CT and MR study, and echoendoscopy. Pitfalls in diagnosis and the role of imaging study in the diagnosis, in the preoperative staging, and in the follow-up of the patients are defined.

Rhinoscleroma with orbital extension: CT and MRI

We describe the MRI features of a rhinoscleroma with orbital extension. This benign bacterial and granulomatous lesion of the paranasal sinuses gave homogeneous low intensity on T2-weighted images and enhanced with gadolinium. It could simulate a malignant sinonasal tumour or a fungal sinusitis; the diagnosis must be considered in patients from endemic areas.