[Radiofrequency ablation for palliation of soft tissue tumor pain]. / La radiofréquence dans le traitement palliatif à visée antalgique des tumeurs des parties molles.

PURPOSE: To assess the efficacy of radiofrequency (RF) ablation for palliation of soft tissue tumor pain. MATERIALS AND METHODS: Retrospective study of 12 patients receiving palliative treatment for soft tissue tumors (5 primary tumors including 4 sarcomas and 1 PEComa and 7 metastatic tumors) with pain refractory to standard management. RF ablation was performed under CT or ultrasound guidance. RESULTS: The efficacy was determined by using pain scores and treatment regimen modifications after RF ablation. Response was graded as absent, partial or complete. Short term symptomatic relief was observed in 100% of cases, with complete response in 43% of cases ; Mid term and long term symptomatic relief was observed in 70% and 83% of cases respectively. We also observed dosage reduction for narcotics with corresponding reduction in related side-effects and functional improvement in some patients. A single case of complication with serosanguinous collection within a region of necrosis was observed. CONCLUSION: Radiofrequency ablation for palliation of soft tissue tumor pain may be a useful complement to standard management. It results in symptomatic improvement with few complications.

[Liver and focal liver contrast: radiologic-pathologic correlation]. / Foie et contraste des lésions focales: corrélation radio-histologique.

Knowledge of the histological features of different components of a liver lesion greatly assists radiologists because it provides understanding of the correspondingimaging features. The imaging characteristics of lesions depend on variations of the extracellular architecture, mainly surrounding stromal tissue. Until histological imaging techniques become available, cellular analysis relies on optical microscopy and immunohistochemistry. Recent advances in imaging techniques now provide additional information on lesions due to improved spatial, temporal and contrast resolution. Correct interpretation of these imaging features should improve diagnosis.

[New possibilities to study biliary tree and gallbladder: functional magnetic resonance cholangiography contrast-enhanced with mangafodipir trisodium (Mn DPDP)]. / Les nouvelles possibilités d'exploration des voies biliaires en IRM: de l'imagerie morphologique à l'imagerie fonctionnelle avec perfusion de Mangafodipir Trisodium (Mn DPDP).

Mangafodipir trisodium (Teslascan) is a hepatobiliary contrast agent that provides noninvasive opacification of the bile ducts. Using this contrast medium combined with a T1-weighted gradient echo enhanced sequence provides functional imaging of the bile ducts. Second-intention MRI was obtained after the usual morphological study of the bile ducts using heavily T2-weighted sequences (SS-FSE Te eff long and SS FSE Te eff short). This method can detect many biliary duct anomalies: biliary leakage in the postoperative context, mapping of bile ducts and the gallbladder in the search for anatomical variants, analysis of biliodigestive or biliobiliary anastomoses, or a dynamic study of bile secretion and excretion. Opacification of the bile ducts has only been possible until now with invasive tests aggravated by a certain co-morbidity rate and their functional study using biliary scintigraphy limited by mediocre spatial resolution. This new possibility provides access not only to morphological imaging, but also to functional imaging with excellent spatial resolution.

[CT enteroclysis: a pictorial essay]. / L'enteroscanner: revue iconographique.

The objective of the CT-enteroclysis is to distend the entire small intestine equally and sufficiently using a nasojejunal probe and an enteroclysis catheter for administration of a neutral opacifying agent. Today this is the best radiological method available to explore the small intestine because of its good spatial resolution and the rapidity of the exam. It is a high-performance exam when searching for transmural and extramural pathologies, in particular small tumoral lesions. It remains less effective in the exploration of anomalies of the lumen's mucosal lining, contrary to videocapsule endoscopy and the double-balloon enteroscope. It has been recognized that the CT-enteroclysis is a high-performance examination that should replace the small-bowel follow-through exam. However, there are undeniable disadvantages: higher does of radiation, patient discomfort during placement of the enteroclysis catheter, false-positive results, long interpretation time, and the impossibility of exploring the endoluminal aspect of the intestinal mucosal lining. All radiologists should therefore become familiar with the problems involved with this exam and its signs and patterns, which are illustrated in this pictorial review.

[Fibrous tissue(s): a key for lesion characterization in digestive diseases]. / Le(s) tissu(s) fibreux, clé(s) de la caractérisation lésionnelle en pathologie digestive.

Fibrosis is one of the hallmarks of inflammatory and repair processes in pathology. Various exogenous and endogenous stimuli, including tumor development, can induce inflammatory reactions. During the post-equilibrium phase after IV injection of non specific contrast media, CT and/or MR allow the study of these inflammatory answers to tumoral or infectious processes. Delayed enhancement of collagenic fibrous tissue during the late post-equilibrium phase is an essential complementary data in the characterization of many liver lesions: cirrhosis, cholangiocarcinoma, focal nodular hyperplasia, fibrous metastasis. but also for the differential diagnosis of pancreatic diseases (groove pancreatitis vs ductal adenocarcinoma) or of gastro-intestinal diseases (gastric adenocarcinoma vs lymphoma, mechanical complication vs inflammatory bouts of ileal Crohn's disease).

[MRI of portal cavernoma with biliary involvement]. / IRM des cavernomes portaux à retentissement biliaire.

PURPOSE: To assess the value of MRI in the diagnosis of portal cavernoma with biliary obstruction. MATERIAL: and methods: six patients referred for clinical suspicion of biliary obstruction and portal cavernoma were explored with MRI. all patients were explored using a signa 1.5 t GE MR unit, with high gradient field strength and torso phased array coil. Biliary ducts were explored with ss-fse sequences of MR-cholangiopancreatography (MRCP), coronal and oblique coronal 20mm thick slices. Then, coronal T2w with shorter TE eff, MR-angiography and delayed T1w sequences were performed. CT scan and sonographic examinations of the liver were performed in all patients. Two patients were operated on and 2 underwent endoscopic retrograde cholangiography. RESULTS: Three different types of biliary involvement were found: in 3 cases findings that mimic cholangiocarcinoma spreading along the common bile duct and in 3 other cases multiple smooth extrinsic impressions along the common bile duct; in one patient MRCP demonstrated an irregular narrowing of the common bile duct mimicking chronic cholangitis. In all cases, the bile duct varices appeared of low T2W signal; in three cases, fibrosis was identified on delayed sequences. CONCLUSION: MRCP and MR-angiography can be proposed as a first imaging study in patients with portal cavernoma and cholestasis or bile duct dilatation.

[Imaging of the intrahepatic biliary tree with thick slice MR cholangiography]. / Imagerie des voies biliaires intrahépatiques en cholangiographie-IRM en coupes épaisses.

PURPOSE: To assess the value of single shot fast spin echo MR sequence (SS-FSE) in the evaluation of the normal and pathologic intrahepatic biliary tree. MATERIAL AND METHODS: 418 consecutive patients (457 examinations) referred for clinical and/or biological suspicion of biliary obstruction underwent MR cholangiopancreatography (MRCP). All patients were imaged with a Signa 1.5 T GE MR unit, with High Gradient Field Strength and Torso Phased Array Coil. Biliary ducts were imaged with SS-FSE sequence, coronal and oblique coronal 20 mm thick slices on a 256 x 256 matrix. Total acquisition time was 1 second. Source images were reviewed by two radiologists blinded to clinical information. In case of disagreement, a third radiologist's opinion was requested. In all cases, MRCP results were compared with direct biliary tract evaluation, other imaging studies and clinical and biological follow-up. RESULTS: In all cases, MRCP produced high quality images. Numerous branch of division were observed although the peripheral intrahepatic ducts were well seen in more than 90% in an area 2 cm below the capsule. The number of division was statistically higher when mechanical obstruction was present. Intrahepatic calculi or peripheral cholangiocarcinoma were well detect by MRCP. For the detection of cholangitis, MRCP sensitivity was 87.5% but the positive predictive value was only 57.7% because of a high number of false positive. The diagnosis of primary sclerosing cholangitis must be made only on strict criteria and slightly dilated peripheral bile ducts unconnected to the central ducts in several hepatic segments were a characteristic MR sign of primary sclerosing cholangitis. CONCLUSION: MRCP can be proposed as a first intention imaging technique for the evaluation of intrahepatic ducts.

[Computed tomography study of the sigmoid colon: discriminating diagnostic criteria and interobserver correlations]. / Exploration tomodensitométrique du côlon sigmoïde: critères diagnostiques discriminants et corrélations interobservateurs.

PURPOSE: To assess the value of pericolonic findings at CT in the evaluation of the sigmoid colon. MATERIALS AND METHODS: A total of 210 CT examinations were retrospectively reviewed by 3 blinded radiologists. Data was analyzed to determine the interobserver correlation and the value of pericolonic and colonic wall findings in diagnosis of sigmoid colon pathology. RESULTS: The interobserver correlation for pericolonic findings was equal to or superior to that for colonic wall findings. The presence of abnormal pericolonic fat was the most sensitive (88%) and specific (93%) sign to differentiate a diseased sigmoid colon from a normal one or from sigmoid diverticulosis. Wall-thickening was less sensitive (82%) and specific (76%). Findings suggesting malignancy over diverticulitis included acute zone of transition, focal fatty infiltration, and lymph nodes. Symmetrical and circumferential wall thickening, target-like enhancement, and local fatty proliferation were findings suggesting colitis over diverticulitis. Wall thickening more than 15 mm, involvement of 15 cm or less, asymmetrical involvement, acute zone of transition, and homogeneous or heterogeneous enhancement were findings suggesting malignancy over colitis. CONCLUSION: To render a diagnosis, the evaluation of the fat infiltration must prevail on the parietal thickening appreciation.