Acute pancreatitis: interobserver agreement and correlation of CT and MR cholangiopancreatography with outcome.

PURPOSE: To assess the correlation between and the interobserver agreement of contrast medium-enhanced computed tomography (CT) and nonenhanced and contrast-enhanced magnetic resonance (MR) imaging findings in patients with acute pancreatitis and to correlate these findings with outcome. MATERIALS AND METHODS: Two blinded reviewers separately assessed contrast-enhanced CT and nonenhanced and contrast-enhanced MR images in 30 patients with acute pancreatitis and established a severity index based on the presence of peripancreatic fluid collections and pancreatic necrosis. The Spearman rank correlation coefficient and weighted kappa statistic were used to assess the correlation between each imaging technique and the interobserver agreement, respectively. Correlation between hospitalization days, morbidity, and severity indexes were assessed by using linear correlation. RESULTS: A strong correlation existed for both reviewers when comparing contrast-enhanced CT with nonenhanced (r = 0.82, 0.79) or contrast-enhanced (r = 0.82, 0.79) MR cholangiopancreatography or when comparing nonenhanced and contrast-enhanced MR cholangiopancreatography (r = 0.99, 1.00). The interobserver agreement in staging was stronger with nonenhanced (kappa = 0.76) and contrast-enhanced (kappa = 0.78) MR cholangiopancreatography than with contrast-enhanced CT (kappa = 0.70). There was no linear correlation between the severity index for contrast-enhanced CT and outcome, while there was a linear correlation between nonenhanced or contrast-enhanced MR cholangiopancreatographic staging and the patient morbidity rate. CONCLUSION: MR cholangiopancreatography could be an alternative to contrast-enhanced CT for the initial staging of acute pancreatitis.

Segmented 5 versus nonsegmented flow quantitation: comparison of portal vein flow measurements.

RATIONALE AND OBJECTIVES: Times of acquisition, mean velocities, mean flows, and their respective standard deviations provided by segmented and nonsegmented flow quantifications (FQ) were compared in the main portal veins of ten healthy adults. METHODS: The segmented FQ performed five phase-encoding lines per segment. The authors successively applied the two electrocardiogram-triggered techniques in the same slice perpendicular to the portal flow direction. Their measurements were compared in particular by means of the statistical analysis proposed by Bland and Altman. RESULTS: The segmented 5 FQ reduced the acquisition time by two compared with the nonsegmented FQ. The mean velocity and mean flow values of the two techniques were not significantly different. The standard deviations were similar. CONCLUSIONS: The segmented 5 FQ showed its major advantage in the portal vein: the acquisition time was reduced without any loss of accuracy or any uncertainty enhancement.

Diagnosis of choledocholithiasis: EUS or magnetic resonance cholangiography? A prospective controlled study.

BACKGROUND: Endoscopic ultrasonography (EUS) appears to be the best imaging method for the diagnosis of choledocholithiasis. The aim of this preliminary, prospective, controlled study was to assess the accuracy of EUS and magnetic resonance cholangiopancreatography (MRCP) in the diagnosis of common bile duct stones. METHODS: From December 1995 through April 1997, all patients referred because of suspicion of the presence of common bile duct stones were included in the study. EUS and MRCP were performed. Each examination was performed by a different operator unaware of the result of the other procedure. The definitive diagnosis was established by means of endoscopic retrograde cholangiography with sphincterotomy or a surgical procedure. RESULTS: Forty-three patients (18 men, 25 women) with a mean age of 60.9 +/- 14.5 years (range 25 to 81 years) were included in the study. Eleven patients were excluded because of unavailability of magnetic resonance imaging(n = 5) or EUS (n = 6). Ten patients (31.2%) had choledocholithiasis. For this diagnosis, the sensitivity of EUS was 100%, the specificity was 95.4%, the positive predictive value was 90.9%, and the negative predictive value was 100%. The corresponding values for MRCP were 100%, 72.7%, 62.5%, and 100%, not significantly different from EUS results. The accuracy of EUS was 96.9%, and that of MRCP was 82.2%. CONCLUSION: This preliminary study confirmed EUS as an accurate and noninvasive procedure for the diagnosis of common bile duct stones. MRCP, which had a high sensitivity and high negative predictive value, might be an accurate technique for patients with a contraindication to EUS.

[Contribution of Abdoscan in MRI cholangio-pancreatography and MRI urography]. / Apport de l'Abdoscan en cholangio-pancréatographie par IRM et en urographie par IRM.

MR Cholangiopancreatography (MRCP) and MR Urography (MRU) are promising recent imaging modalities. Oral magnetic particles (Abdoscan, Nycomed SA, Oslo, Norway) is an oral negative contrast agent eliminating signal intensity of the gastro-intestinal tract thus improving image quality at MRCP and MRU.

Mediastinal masses: diagnostic approach.

In most clinical situations the modern radiological approach to a mediastinal mass consists of performing a CT scan following the chest radiograph. Magnetic resonance imaging is indicated when CT findings are equivocal and as the first-line method in particular situations such as suspected involvement of the posterior mediastinum. In both techniques, tissular components of the mass assessed by density or signal intensity analysis, together with the precise location, are the leading edge of the radiological diagnosis. This review deals mainly with the differential diagnosis of primary neoplasms according to CT and MRI findings.

Localized fibrous tumor of the liver: imaging findings.

We report the imaging of a localized fibrous tumor of the liver, focusing on color Doppler US, CT, MR imaging, and angiographic findings. We discuss the differential diagnosis of such a rare, benign lesion of the liver. Detailed imaging of this tumor has not been reported in the literature previously.

[MRI cholangiopancreatography in the pathology of the bile ducts and pancreas]. / Apport de la cholangiopancréatographie IRM dans la pathologie des voies biliaires et pancréatiques.

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.

[Techniques of MRI cholangiopancreatography. History, current status and future prospects]. / Techniques de cholangiopancréatographie par IRM. Historique, état actuel et perspectives.

Magnetic resonance cholangiopancreatography (MRCP) is a recent, non invasive, diagnostic modality capable of producing high quality images of biliary and pancreatic ducts. On the basis of the literature and our experience, we report the history and the current status of this new technology, including 2D, 3D and single shot fast spin echo sequences. As perspectives echo-planar imaging and functional imaging are discussed.

Tolerability and utility of mangafodipir trisodium injection (MnDPDP) at the dose of 5 mumol/kg body weight in detecting focal liver tumors: results of a phase III trial using an infusion technique.

PURPOSE: To evaluate the tolerability of mangafodipir trisodium (MnDPDP) and its utility for enhancing the ability of magnetic resonance (MR) imaging to detect focal hepatic lesions compared with non-enhanced MR and contrast-enhanced computed tomography (CT). MATERIALS AND METHODS: 119 patients with focal hepatic lesions were examined by MR and by contrast-enhanced CT. MR was performed before and after the infusion of 5 mumol/kg MnDPDP, at a concentration of 10 mumol/ml. Histologic confirmation was obtained in 79 patients. RESULTS: There were no severe adverse events. Five patients reported mild adverse events related to the infusion. MnDPDP-enhanced SE T1 and GE T1 sequences revealed more focal lesions than the same sequences before contrast infusion in, respectively 22.6 and 36.1% of the cases, and fewer focal lesions in, respectively 5.9 and 1.7% of the cases. Contrast-enhanced MR demonstrated more focal lesions than the SE T2 sequence in 29.4% of cases and fewer lesions in 5.9% of cases. MnDPDP-enhanced MR revealed more nodules than CT in 31.1% of cases and fewer nodules in 13.4% of cases. The additional information provided by MnDPDP enhancement led to modification of management for 12 patients (10.1%). CONCLUSION: MnDPDP is a well-tolerated contrast agent allowing better MR detection of focal hepatic lesions than non-enhanced MR or contrast-enhanced CT.

[Hypoplasia of the inferior vena cava with intrahepatic continuation. Color Doppler ultrasonography and MRI]. / Hypoplasie de la veine cave inférieure avec continuation intrahépatique. Echo-Doppler couleur et IRM.

We report a rare case of inferior vena cava hypoplasia discovered fortuitously, with intra-hepatic venous shunts, explored only by color-doppler ultrasound and MRI. These noninvasive imaging tests demonstrated that the intra hepatic collateral pathway arose from an inferior (accessory) right hepatic vein and flowed into the right and middle hepatic veins. Due to these findings a cavography was avoided in this asymptomatic patient.

CT of small-bowel neoplasms.

The diagnosis of neoplasms of the small intestine remains a difficult challenge owing to their nonspecific clinical presentation. CT is an efficient and contributive tool in their diagnosis and preoperative staging. Enabled by CT, the evaluation of the intramural and extramural portions of such tumors complements the mucosal analysis allowed by barium examination. Strict technical rules should be applied to minimize pitfalls mainly resulting from insufficient bowel opacification. Although characteristic appearances are rare, typical CT findings may suggest a specific diagnosis where lipomas and carcinoid tumors are concerned.

[MRI of the heart: morphological and functional aspects]. / IRM du coeur: aspects morphologiques et fonctionnels.

The performances of cardiac magnetic resonance imaging have been recently improved by the possibility of obtaining functional information by means of gradient echo sequences. Cavity volumetry and wall thickness and mass measurements are now possible. Ultrarapid sequences are useful for the analysis of myocardial perfusion and methods for measuring blood flow and temporal labelling of the ventricular wall open up new prospects for functional evaluation of the heart. In clinical practice, MRI can be useful for the exploration of cardiac parietal and intracavitary masses, constrictive pericarditis, hypertrophic and restrictive cardiomyopathy and cardiac malformations. Assessment of valvular and coronary heart disease is based on new techniques and is currently under evaluation.

[How can intrathoracic lymphatic involvement be assessed: does tomography have a role? What is the contribution of computed tomography and MRI?]. / Comment évaluer l'extension ganglionnaire intrathoracique: les tomographies ont-elles un rôle? Quel est l'apport de la TDM, et l'IRM?

The authors report their analysis of the literature on the evaluation of intrathoracic extension of non-small-cell bronchial cancers to lymph nodes, using tomography, computed tomography and magnetic resonance imaging. The criteria used to assess the metastatic character of a lymph node, the characteristics of the populations studied and the methods of comparison with the clinicopathological "truth" account for the variations of the results published. Tomographs are useless today. The performances of CT and MRI are equivalent, and it is not necessary to associate both techniques. Although its performances are mediocre, CT allows mapping the mediastinal lymph nodes, which is useful to continue the assessment of extension and to make decisions.