[Acute mesenteric ischemia: Value of cross-sectional imaging]. / Ischémie aiguë du mésentère : apports de l'imagerie en coupes.

Acute mesenteric ischemia (AMI) is a life-threatening emergency with prognosis directly correlated with the delay in diagnosis and treatment. Clinical and laboratory findings are nonspecific and it is imperative to look for findings of AMI on CT and ultrasound examinations performed in patients with acute abdomen. Arterial and venous ischemia are different entities with different clinical and imaging features, treatment and prognosis. The main causes of AMI are arterial thromboembolic disease and low-flow state. Venous ischemia is less frequent. Due to its high reported sensitivity (90%), CT should be performed as a firstline imaging modality when AMI is suspected. CT and ultrasound imaging features of AMI include: bowel wall thickness and enhancement abnormalities, pneumatosis, portal venous gas, demonstration of intravascular thrombus, bowel dilatation and ascitis.

[Value of MRCP for diagnosis of biliary complications after liver transplantation]. / Evaluation de la cholangiographie par résonance magnétique dans le diagnostic des complications biliaires après transplantation hépatique.

PURPOSE: To assess the value of MRCP in the detection of biliary complications after orthotopic liver transplantation. MATERIALS AND METHODS: 27 transplanted patients with suspected biliary complication underwent a total of 34 MR and direct cholangiography procedures. MRCP were reviewed by 2 independent reviewers blinded to clinical and laboratory findings. The biliary tract was divided into 7 segments, and all lesions were evaluated using this segmental anatomy. Each segment was evaluated for the presence of dilatation, stenosis and intra-ductal debris. MRCP results were compared to results frpm direct cholangiography. RESULTS: 216 (98%) of 221 biliary segments could be evaluated on MRCP, with good to excellent visualization in 179 (80%) cases. Segmental analysis showed sensitivity, specificity and accuracy values of 85%, 81% and 83% for the detection of biliary stenosis, 82%, 81% and 81% for the detection of biliary dilatation, and 60%, 88% and 80% for the detection of inyraductal debris. CONCLUSION: MRCP is accurate for the detection of biliary stenosis and dilatation in patients after liver transplantation and provides an alternative to direct cholangiography.

[Acute cholangitis: imaging diagnosis and management]. / Une angiocholite: comment la reconnaître? Quelles conduites à tenir?

Cholangitis is an infection of the biliary ductal system that results from biliary obstruction. Choledocholithiasis has been the leading cause of acute cholangitis. Acute cholangitis remains a life-threatening complication of biliary obstruction that needs emergency diagnosis and treatment. Ultrasound (US) is the primary imaging modality for assessment of patients with suspected acute cholangitis. US is both sensitive and specific in demonstrating biliary dilatation. However, biliary dilatation is not always present at the early stage of bile duct obstruction and the performance of US in demonstrating choledocholithiasis is poor. Computed tomography (CT) without contrast injection is more sensitive than US in demonstrating choledocholithiasis. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic sonography (EUS) are the most sensitive techniques to correctly determine the underlying cause and level of biliary obstruction in patients with acute cholangitis. In patients without previous cholecystectomy, clinical, biological, and US results allow to determine patients with high probability of having choledocholithiasis even if the stone is not directly visible on US. Patients undergoing cholecystectomy require laparoscopic common bile duct exploration, especially if the common bile duct clearance is not checked before surgery by MRCP or EUS.

[Laparoscopic adjustable gastric banding for morbid obesity: clinical and radiographic follow-up]. / Traitement de l'obésité morbide par anneau gastrique ajustable: un suivi clinique et radiologique.

PURPOSE: To evaluate the role of imaging for follow-up after treatment of morbid obesity by laparoscopic adjustable gastric banding (LAGB). PATIENTS AND METHODS: Since 1996, more than 1,000 patients underwent gastric banding using 5 different types of devices. Our experience is based on a retrospective study (from September 1996 to September 2002) concerning 663 consecutive patients who underwent LAGB: 114 Lapband system (LB) and 549 Swedish adjustable gastric banding (SAGB). Upper gastrointestinal series were performed within 24-48 hours after surgery in all patients. Radiological examination was also used to detect complications and to adjust gastric band. RESULTS: The five types of gastric band are easily identified on plain films. Early and late complications are illustrated: pouch dilatation, slippage, band migration, rotation of the port, and system disconnection. Radiological criteria for adjustment of gastric band are explained on the basis of barium studies performed before and after any modification of the stoma size. CONCLUSION: In patients treated with LAGB for morbid obesity, radiology plays an important role in evaluating early and late complications.

Multidetector CT of bowel obstruction: value of post-processing.

The value of imaging in patients with suspicion of bowel obstruction is dependent on the ability to answer questions relevant to the clinical management of patients. Is there mechanical obstruction? Is it a small bowel obstruction (SBO) or a large bowel obstruction (LBO)? What is the transition point? What is the cause of the obstruction? What is the severity of the obstruction? The results of studies published more than 10 years ago using axial and single-slice helical CT gave rise to findings based on axial slices that enables CT to answer these different questions. With the recent advent of multislice CT, large numbers of thin sections can be generated with short image intervals, which is well suited to postprocessing. Postprocessing techniques include standard reformatting methods such as sagittal, coronal and oblique reformatting, curved reformatting, maximum and minimum-intensity projection, variable thickness viewing, and volume and surface rendering. This pictorial review illustrates the added value of postprocessing for answering different questions concerning patients with suspicion of bowel obstruction.

[Disorders of the peritoneum]. / Le péritoine acteur de la pathologie abdominale.

The peritoneum is an important actor in diseases of the abdomen: defects of the peritoneum or mesos may lead to internal hernias; developmental anomalies of the peritoneum may lead to volvulus and bowel obstruction; diffuse or localized primary or secondary tumors of the peritoneum may develop; infectious, inflammatory or ischemic primary diseases of the peritoneum may cause abdominal pain, sepsis or result in the formation of fluid collections. The purpose of this presentation is to illustrate the role of imaging in the diagnosis of these different diseases and to provide some guidelines allowing their detection and characterization.

[Spontaneous regression of a focal nodular hyperplasia]. / Involution spontanée d'une hyperplasie nodulaire focale.

The authors report a case of near complete regression of a focal nodular hyperplasia of the liver over a course of 10 years in a 39 year old woman. This presentation is atypical because of its imaging features (initially typically hypervascular, to eventually become a fibrous scar after undergoing a pseudo-angiomatous phase) and because of its near complete spontaneous regression.

[Multidetector CT and MRI in diseases of the gastrointestinal tract]. / Scanner multidétecteur face à l'IRM dans la pathologie du tube digestif.

UNLABELLED: With the introduction of spiral scanning then multidetector technologies, the accuracy for diagnosing digestive tract diseases with CT has been highly improved, and CT is used more and more in the evaluation of patients with suspected gastrointestinal disorders. CT is able to demonstrate both the intramural and the extramural components of the disease, and has a major role in the preoperative staging and the follow-up. Improvements of CT protocols, such as CT-enteroclysis, or multiplanar 2D and 3D post-processing, including now techniques for "virtual endoscopy", lead to discuss new indications in which CT could now compete with conventional X-rays series and videoendoscopy. This precise study of the digestive wall, the peridigestive fat, the digestive tract blood supply, may be performed by MRI, under the condition of access to high level machines and standardized protocols. MR-enteroclysis and MR-virtual colonoscopy could be performed with much lower risk for the patient, in terms of radiation dose or contrast adverse effects. Endoluminal coils should give to MR an ultra-high resolution for analysing the different layers of the gastrointestinal wall. LEARNING OBJECTIVES: to review how to perform CT and MRI protocols for digestive tract imaging, to recognize the CT and MR patterns of the main digestive tract diseases, to discuss the value, limits and role of CT and MR in digestive tract diseases, to discuss the potential role of CT and MR new technological developments for digestive tract imaging in the upcoming future. CONCLUSION: CT is nowadays a modality of choice for digestive imaging. Improvements in technologies and indications, the necessary discussion of the risks and benefits for the patient should let the radiologists consider MRI in gastrointestinal disorders as an important part of the routine activity in clinical MRI.

High resolution unenhanced computed tomography in patients with swollen legs.

PURPOSE: To evaluate the accuracy of computed tomography (CT) scan imaging in distinguishing lymphedema from deep venous thrombosis (DVT) and lipodystrophy (lipedema) in patients with swollen legs. MATERIAL AND METHODS: CT scans of the lower limbs were performed in 55 patients with 76 swollen legs (44 lymphedemas, 12 DVT and 20 lipedemas). Thirty-four normal contralateral legs were also similarly evaluated. Primary lymphedema was verified by lymphography or lymphoscintigraphy, whereas secondary lymphedema was documented by a typical clinical history. DVT was established by ultrasound Doppler imaging. The diagnosis of lipedema was made with bilateral swollen legs where lymphoscintigraphy and Doppler examination were both unremarkable. Qualitative CT analysis was based on skin thickening, subcutaneous edema accumulation with a honeycombed pattern, and muscle compartment enlargement. RESULTS: Sensitivity and specificity of CT scan for the diagnosis of lymphedema was 93 and 100%, respectively; for lipedema it was 95 and 100%, respectively; andfor DVT it was 91 and 99%, respectively. Skin thickening was found in 42 lymphedemas (95%), in 9 DVT (75%), and in 2 lipedemas (16%). Subcutaneous edema accumulation was demonstrated in 42 legs (95%) with lymphedema and in 5 (42%) with DVT but in none with lipedema. A honeycombed pattern was present only in lymphedema (18 legs or 41%); muscle enlargement was present in all patients with DVT, in no patient with lipedema, and in 4 (9%) with lymphedema. CONCLUSION: Edema accumulation is readily demonstrated with plain CT scan and is not present in lipedema. Specific CT features of the subcutaneous fat and muscle compartments allow accurate differentiation between lymphedema and DVT.

Non-traumatic abdominal emergencies: imaging of acute intestinal obstruction.

The purpose of this paper is to give an overview of the main clinical questions in bowel obstruction, to discuss the value of various imaging modalities, including conventional radiography, ultrasound, and CT, to underline the impact of imaging in the management of patients with suspect bowel obstruction, and then to suggest a diagnostic triage in such patients.

Metastatic pudendal nerve compression presenting as atypical sciatica.

A rare case of Alcock's syndrome caused by tumoral compression of the pudendal nerve is reported. Spine surgeons must be aware of the possibility of Alcock's syndrome in patients presenting with atypical sciatica.

[Acute appendicitis: to image or not to image?]. / Imagerie de l'appendicite: échographie, scanner ou rien du tout?

Acute appendicitis is frequently clinically suspected. However, about 50% of emergency room patients with such a diagnosis do not have acute appendicitis and between 20-25% of patients undergoing appendectomy based on clinical diagnosis have a normal appendix. On the other hand, if left untreated acute appendicitis may result in peritonitis. The purpose of this article is to review the indications for imaging patients with clinical suspicion of acute appendicitis, to describe the US and CT features of acute appendicitis, to review the advantages and limitations of US and CT, and to present the differential diagnosis to be considered in patients with right lower quadrant pain.

Changes in renal artery resistance after meal-induced splanchnic vasodilatation in cirrhotic patients.

PURPOSE: A relationship between vasomotor tone changes in mesenteric and renal vessels in cirrhotic patients has been suspected but remains controversial. The aim of this study was to assess by duplex Doppler sonography the changes in the circulatory resistance of the renal arteries and superior mesenteric artery (SMA) following meal-induced splanchnic vasodilatation. METHODS: Twenty-seven cirrhotic patients and 15 healthy volunteers with no hepatic or renal dysfunction were prospectively included in the study. The resistance index (RI) of the SMA and of the right and left renal arteries was measured by duplex Doppler sonography before and 30 minutes after ingestion of a standard 400-kcal balanced liquid meal. Values in controls and patients and values before and after the meal were compared, and correlations between RIs, Child-Pugh class (liver function), and creatinine clearance were assessed in cirrhotic patients. RESULTS: The fasting renal artery RI was greater in cirrhotic patients than in controls (p < 0.0001), but there was no difference in fasting SMA RIs. After the meal, there was a significant decrease in the SMA RI in controls (0.85 +/- 0.04 before versus 0.74 +/- 0.03 after meal, p = 0.0001) and in cirrhotic patients (0.85 +/- 0.04 before versus 0.77 +/- 0.04 after, p = 0.0001) and a significant increase in the renal artery RI (0.57 +/- 0.06 before versus 0.62 +/- 0.05 after in controls, p = 0.001; 0.68 +/- 0.07 before versus 0.70 +/- 0.07 after in cirrhotic patients, p = 0.001). No correlation was found in cirrhotic patients between the changes in renal artery RI and the postprandial SMA RI decrease, the Child-Pugh class, or the creatinine clearance. CONCLUSIONS: Meal-induced SMA vasodilatation (RI decrease) is associated with a marked increase in the renal artery RI, worsening the renal vasoconstriction in cirrhotic patients.