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The reference method for detecting and quantifying hepatic steatosis and fibrosis is the histopathological analysis of liver biopsies. Studies performed in animals and humans have shown that magnetic resonance imaging (MRI) is useful for the accurate and non-invasive quantification of these lesions. For fibrosis quantification, functional MRI methods have to be used, including perfusion MRI, diffusion MRI, and more particularly MR elastography. Modifications of the visco-elastic parameters of the liver can also be observed with MR elastography in hepatic diseases without fibrosis, such as the early stages ofnon-alcoholi steatohepatitis. Finally, accurate quantification of liver steatosis can be performed by observing the difference of resonance frequencies between the protons of fat and water at spectroscopy or chemical shift MRI. In conclusion, combined quantification of liver steatosis and fibrosis can be performed with MRI.

Introduction: Papillary necrosis results from ischemia of the renal medulla and papillae, induced by a variety of mechanisms. Papillary necrosis is a rare adverse effect of continuous protease-inhibitor therapy with indinavir., Case: We describe the case of a patient who developed bilateral papillary necrosis. It was reversible after treatment interruption and increased hydration., Conclusion: This case shows the need to monitor kidney markers in patients under continuous treatment with indinavir.

Tumor angiogenesis induces the proliferation of immature blood vessels that are both heterogeneous and leaky. These characteristics can be demonstrated by measuring the perfusion parameters with MRI. Perfusion MRI is usually performed with in T1-weighted dynamic imaging after bolus injection of an exogenous contrast agent such as gadolinium chelate. The perfusion parameters are obtained by semi-quantitative or quantitative analysis of the enhancement curves in the tumor and the arterial input. Perfusion can also be assessed without injecting a contrast agent using arterial spin labeling techniques, diffusion MRI, or BOLD (blood oxygen level dependent) MRI. However, these latter methods are limited by a low signal-to-noise ratio and problems with quantification. The main indication for perfusion MRI is the assessment of antiangiogenic and antivascular treatments. New possibilities for demonstrating angiogenic blood vessels are being opened by molecular imaging.

With multidetector helical CT, the entire liver can be imaged rapidly with thin slices. High temporal and spatial resolution is important to improve multiphase examinations of the liver. The need to perform multiphase examinations to diagnose benign liver tumors should, however, be assessed by keeping in mind the risk of radiation and contrast-induced adverse events. MRI offers several advantages relative to CT. Excellent contrast resolution is obtained. Multiphase examinations can be performed in all patients. Reticuloendothelial contrast agents may be useful to characterize benign tumors. Several benign liver tumors, particularly hemangiomas and lesions of focal nodular hyperplasia, can be characterized with CT and MRI. Histologic examination is still needed to characterize some benign liver tumors.

The sensitivity of ultrasonography (US) as the initial imaging procedure in acute diverticulitis of the left colon was retrospectively compared with that of computed tomography (CT) in 34 patients. Final diagnosis was based on clinical findings and follow-up in a first group of 20 patients with mild diverticulitis, and was proved by surgery in a second group of 14 patients with severe diverticulitis. In the first group, US showed findings consistent with diverticulitis in 19 patients, as did CT. The image of an inflamed diverticulum was shown by US in 10 patients. In the surgical group, findings consistent with diverticulitis were shown by US in 11 cases, and by CT in 13 cases. An inflamed diverticulum was not detected at US in this group of patients, presumably because the diverticulum was incorporated in the inflammatory process. These results suggest that US is a valuable technique in the initial evaluation of patients suspected of having acute diverticulitis, especially when the disease is not severe. The image of an inflamed diverticulum shown at US strongly suggests the diagnosis of mild diverticular disease. When diverticulitis is severe, CT should be performed in addition to US.

Twelve caucasian patients with intraperitoneal hemorrhage due to spontaneous rupture of hepatocellular carcinoma were treated by emergency transcatheter arterial embolization (n = 9) or chemoembolization (n = 3). Pretreatment angiography showed active bleeding (extravasation of contrast medium) in two patients only. Successful hemostasis was initially achieved in all patients. Early recurrence of hemorrhage was noted in 3 patients with large tumors; two were successfully treated by a second embolization and one died immediately after the first embolization. Of the 12 patients, two underwent subsequent chemoembolization while two had surgical resection of their tumors. The mean length of survival was 7 months from the time of rupture. No serious complications related to embolization or chemoembolization were noted. Our data suggest that emergency embolization or chemoembolization is an effective treatment in caucasian patients with intraperitoneal hemorrhage from hepatocellular carcinoma. Prognosis of ruptured hepatocellular carcinoma in those patients, however, remains poor.

A case of chronic biliary fascioliasis is reported, which was confirmed by endoscopic retrograde cholangiography. After unsuccessful attempts of treatment with classic antiparasitic drugs, cure was obtained with triclabendazole the absorption of which was studied.

Extracorporeal shock wave lithotripsy of gallstones is a safe and well-tolerated procedure. Patients are now treated without general anesthesia and, increasingly, on an outpatient basis. Skin petechiae and transient hematuria are the most common side effects. Episodes of biliary colic are common in the follow-up period, but more serious adverse side effects such as cholecystitis and pancreatitis are distinctly uncommon. It is estimated that only 15% to 20% of all patients with symptomatic cholelithiasis are suitable lithotripsy candidates. As our knowledge of the procedure grows, it seems clear that the best results are obtained in patients with solitary radiolucent stones less than or equal to 20 mm, with stone-free rates at 12 months above 80%, for this selected group of patients. Adjuvant oral bile-acid dissolution therapy should be used in conjunction with gallstone lithotripsy. Gallstone recurrence remains to be established by clinical studies. Therapy for gallstones in 1991 has to be reevaluated by an interdisciplinary approach, taking into account not only open cholecystectomy, but also other modalities such as medical dissolution, laparoscopic surgery, percutaneous cholecystolithotomy and extra-corporeal shock wave lithotripsy. The appeal of the laparoscopic approach will substantially reduce the pool of patients for lithotripsy. Nevertheless, lithotripsy will continue to be a viable treatment option for patients with a single radiolucent stone. It is an outpatient procedure and doesn't require any incision or general anesthesia.

Duplication of the gallbladder is a rare congenital anomaly. Preoperative diagnosis is sometimes difficult. We report the imaging findings of two cases of gallbladder duplication. Cholecystography and sonography are complementary for this diagnosis.

The main aspects of hepatic chemoembolization are first described: principles, drugs and their vectors, various techniques and contra-indications. In the literature as in our own experience, most encouraging results are reported in metastases from endocrine tumors and hepatocellular carcinoma. Favourable results in the latter disease have been particularly emphasized by Japanese authors whose data are reported, as well as results in a personal series and in three controlled studies. Chemoembolization is now able to induce partial or complete responses. Nevertheless, unambiguous selection of responding patients cannot be stated yet, especially for hepatocellular carcinoma where an underlying chronic liver disease probably plays an important role in prognosis. Consequently, chemoembolization of malignant hepatic tumors must still be considered as a technique under evaluation.

Liver abscess is a rare complication of Crohn's disease. The authors describe a case of liver abscess associated with inactive regional enteritis which recovered completely under antibiotic treatment alone.

Computed tomography (CT) of the esophagus, the stomach and the duodenum allows characterization of some lesions: lipomas, cysts and duplications, recent haematomas, vascular anomalies. CT is particularly used for the extramural staging of neoplasms: despite important limitations, CT may be useful as staging test to identify a subgroup of patients with definitive metastases or local invasion who therefore have unresectable tumors. CT is helpful for the staging of lymphomas. The importance of this staging classification is reflected in differences in treatment and prognosis. CT is also useful for the follow-up after treatment, the diagnosis of recurrence and postoperative complications.

As it appears from a review of the literature of the last decade, arteriography is important in the diagnosis and management of gastrointestinal haemorrhage but its role has to be evaluated by a multidisciplinary approach. In fact, the role of arteriography in upper gastrointestinal bleeding is often therapeutic, because diagnosis is often made by endoscopy. In lower gastrointestinal bleeding, arteriography is mainly diagnostic and its role in treatment remains limited. Controlled studies are necessary to compare transcatheter embolization with other treatments.

We made the diagnosis of internal jugular vein thrombosis by computed tomography in 3 cases. The CT diagnostic signs are the following: widening of the vein caliber, absence of opacification or nonhomogeneous aspect of the opacification of the lumen, and parietal contrast fixation. Classical and more recent etiology refers to cervico-facial infections and injuries, central venous catheterizations and local surgery, compression by a cervical mass, and use of oral contraceptives. The advantage of CT consists in its noninvasive contribution to defining a diagnosis that pathology, which is nonspecific (painful cervical tumefaction), often cannot reach.