Significance of hyperattenuating and contrast-enhancing hepatic nodules detected in the cirrhotic liver during arterial phase helical CT in pre-liver transplant patients: radiologic-histopathologic correlation of explanted livers.

BACKGROUND: Hyperattenuating nodules detected by arterial phase helical computed tomography (HCT) in patients with cirrhosis usually are believed to represent hepatocellular carcinomas (HCCs). We correlated HCT morphology of hyperattenuating hepatic nodules detected during arterial phase scans with the histopathology of explanted livers of patients with hepatic cirrhosis undergoing liver transplantation. METHODS: Three hundred fifty-four patients had arterial and portal phase HCT performed before subsequent hepatic transplantation. Each patient received 180 mL of contrast by power injection at 5 mL/s. All hyperattenuating nodules detected on arterial phase HCT were assessed for morphology and evidence for contrast enhancement. Explanted livers in all patients were then sectioned at 10-mm intervals, and the histology of the nodules was correlated with the HCT findings. RESULTS: Sixty-one hyperattenuating nodules were detected on the arterial phase HCT in 43 patients: 41 nodules were benign regenerating nodules (RN), three were dysplastic nodules (DP), and 17 were HCCs. Most RN/DP nodules were 5-20 mm in diameter, had distinct margins, were homogeneous, and were isoattenuating on precontrast, portal, and delayed scans. Thirty-six showed positive contrast enhancement and displayed a wide range of attenuation profiles. HCC nodules were 6-50 mm. All showed positive contrast enhancement and displayed a wide range of attenuation profiles. CONCLUSION: Hyperattenuating nodules seen on arterial phase HCT are likely to be RN/DP nodules. In many cases, it is not possible to distinguish between RN/DP and HCC. Thus, clinical decisions regarding inclusion criteria for transplantation based on CT morphology of liver lesions may be tenuous.

Choledocholithiasis and bile duct stenosis: diagnostic accuracy of MR cholangiopancreatography.

PURPOSE: To evaluate the accuracy of magnetic resonance (MR) cholangiopancreatography for detecting bile duct calculi and stenosis. MATERIALS AND METHODS: At MR cholangiopancreatography, 108 patients suspected of having bile duct calculi or stenosis were examined with two-dimensional fast spin-echo MR sequences and respiratory gating. On the basis of findings at surgery and/or intraoperative, endoscopic retrograde, and/or percutaneous cholangiography, final diagnoses were normal bile ducts (n = 38), choledocholithiasis (n = 23), Mirizzi syndrome (n = 3), benign or malignant bile duct stenosis (n = 40), choledochal cyst (n = 1), and bile duct dilatation without calculi or stenosis (n = 3). MR cholangiopancreatographic images were analyzed retrospectively by three reviewers who were unaware of final diagnoses. RESULTS: Choledocholithiasis was diagnosed with a sensitivity of 88%-92% and a specificity of 91%-98%. False-negative readings occurred because small or impacted calculi at the distal common bile duct or ampulla were difficult to detect or distinguish from stenosis. Bile duct stenosis was diagnosed with a sensitivity of 93%-100% and a specificity of 98%. Presence or absence of bile duct abnormality was assessed with a sensitivity of 97%-99% and a specificity of 95%-97%. Interobserver agreement was very good (kappa = 0.86-0.96). CONCLUSION: With MR cholangiopancreatography, bile duct calculi and stenoses can be diagnosed with high accuracy and good interobserver agreement.

Ablation of hepatocellular carcinoma by percutaneous ethanol injection: imaging findings.

Since PEI is a treatment based on imaging techniques, the radiologist should be familiar with the various findings that may be observed after PEI on US, CT, and MR images immediately after treatment and during later follow-up. Although US is well suited for performing PEI, contrast-enhanced CT currently is the most commonly used imaging method to evaluate the effect of PEI. Residual, nodular areas of contrast enhancement correlate well with residual tumor and warrant additional treatment. Although the findings on MR images obtained after PEI are more complex, MR imaging may be used as an alternative to CT.

Computed tomography in acute left colonic diverticulitis.

BACKGROUND: The use of computed tomography (CT) in acute left colonic diverticulitis remains controversial. The purpose of this study was to define the value of CT both during the acute phase of inflammation and, later, to indicate secondary complications after successful medical treatment. METHODS: Some 423 patients with radiologically or histologically proven diverticulitis were studied prospectively from 1986 to 1995. Diverticulitis was considered moderate when CT showed localized thickening of the colonic wall (5 mm or more) and inflammation of pericolic fat; it was considered severe when abscess and/or extraluminal air and/or extraluminal contrast were observed. RESULTS: The sensitivity of CT was 97 per cent. Of 42 patients who failed conservative treatment, 32 had severe diverticulitis on CT, compared with 74 (24 per cent) of 303 who had successful conservative treatment (P < 0.0001). After a median follow-up of 46 months, 60 (20 per cent) of 300 patients had secondary complications despite initially successful conservative treatment: 28 (47 per cent) of these had initial severe diverticulitis on CT compared with 44 (19 per cent) of 236 patients who had no complications (P < 0.0001). CONCLUSION: Abscess formation and extracolonic contrast or gas are findings that may be used to predict failure of medical treatment during the first admission and a high risk of secondary complications after initially successful medical management of acute diverticulitis.

MR cholangiopancreatography: technique, potential indications, and diagnostic features of benign, postoperative, and malignant conditions.

The objective of this article is to review technical aspects, discuss potential clinical indications for MR cholangiopancreatography (MRCP) and demonstrate the spectrum of diagnostic findings in benign, postoperative, and malignant conditions. We describe our current imaging protocol in comparison with other available techniques. Using a non-breath-hold, heavily T2-weighted fast-spin-echo (FSE) sequence with or without respiratory gating we obtained coronal and axial source images and maximum intensity projections (MIPs) in 102 patients with suspected abnormalities of the biliary or pancreatic ducts. Based on this series we demonstrate the diagnostic appearance of a variety of benign, postoperative, and malignant conditions of the biliary and pancreatic ducts and discuss potential clinical indications for MRCP. The non-breath-hold FSE technique enables a consistent image quality even in patients who cannot cooperate well. Respiratory gating increased the rate of diagnostic examinations from 79 to 95 %. Acquisition of coronal and axial source images enables detection of bile duct stones as small as 2 mm, although calculi that are impacted and not surrounded by hyperintense bile may sometimes be difficult to detect. The MIP reconstructions help to determine the level of obstruction in malignant jaundice, delineate anatomical variants and malformations, and to diagnose inflammatory conditions, e. g., sclerosing cholangitis, the Mirizzi syndrome and inflammatory changes in the main pancreatic duct. The MRCP technique also correctly demonstrates the morphology of bilio-enteric or bilio-biliary anastomoses. Because MRCP provides sufficient diagnostic information in a wide range of benign and malignant biliary and pancreatic disorders, it could obviate diagnostic endoscopic retrograde cholangiopancreatography (ERCP) in many clinical settings. The ERCP technique may be increasingly reserved for patients in whom nonsurgical interventional procedures are anticipated.

[Treatment of post-coronarography femoral false aneurysm by compression, guided by Doppler echography]. / Traitement des faux-anévrismes fémoraux post-coronarographie par compression guidée par échographie-doppler.

MATERIAL AND METHODS: We evaluated the role of color Doppler US-guided compression in the non-invasive treatment of femoral artery pseudoaneurysms after cardiac catheterization, including 22 PTCA procedures. The diagnosis of 32 pseudoaneurysms in 32 patients was accomplished by detection of the typical US-Doppler pattern consisting of the swirling color Doppler flow and the "to and fro" pulsed Doppler waveform at a mean 3.6 days (1 to 14) after the cardiac catheterization. Thirteen patients had multiple cavity pseudoaneurysms (2 to 4). All the patients immediately underwent compression therapy. RESULTS: Treatment was successful in 42/49 cavities (86%) and 25/32 patients (78%), usually after 1 to 3 compression cycles of 6 to 8 minutes duration. Only one recurrence was noted at the 24 hour US-Doppler follow-up. In all cases, pain relief during compression was an excellent clinical sign of hemostatic plug formation and conversion from pseudoaneurysm to simple hematoma. Failures occurred among patients under high dose anticoagulants in spite of 4 to 10 compression cycles. COMMENTARY: In conclusion, color Doppler US-guided compression of post-cardiac catheterization pseudoaneurysms should be the first line therapeutic modality, even in cases of multiple cavities and among patients under effective anticoagulation therapy.

[Follow-up and results of liver transplantation for primary biliary cirrhosis]. / Suivi et rresultats de la transplantation hépatique pour cirrhose biliaire primitive.

Primary biliary cirrhosis is regarded as one of the optimal indications for orthotopic liver transplantation in adults. With the decrease in the operative mortality, the analysis of the potential long-term complications including disease recurrence is becoming increasingly relevant. The purpose of this study was to evaluate the long-term results of liver transplantation for primary biliary cirrhosis in our center. From 1988, 14 patients were transplanted for this indication and all of them were alive with a mean follow-up of 43 months by the end of June 1995. At that time, all complications related to chronic liver disease were reversed by the transplant except for osteopenia. Lumbar column fractures and overweight were the major inconveniences encountered. Hypertension and diabetes related to antirejection therapy disappeared during the first year of follow-up in all but one patient. Recurrence of the disease was not encountered in this series where a triple association of immunosuppressive therapy was maintained in each patient. At long-term, the frequency of disease recurrence in the liver allograft seems quite low and even in this situation immunosuppressive agents may alter the evolution of the disease. All patients (n - 12) who had at least 1 year of follow-up had a normal level of bilirubin and their quality of life was good to excellent. These results, confirmed by the international experience, support the notion that patients suffering from primary biliary cirrhosis should be transplanted as early as complications from this chronic liver disease occur.

Relationship between intrahepatic vessels and computer-generated hepatic scissurae: an in vitro assay.

Liver segmentation is a matter of increasing importance for radiologists, in particular with respect to accurate preoperative localisation of focal hepatic lesions. Procedures for delineating the segmental anatomy from CT or MR images are therefore much in demand. In this context, a convenient technique for generating the intersegmental scissurae by computer has recently been proposed [9]. The procedure, however, seemed questionable from an anatomical point of view. We therefore checked its relevance using anatomical vascular casts of post mortem livers and comparing the computer-generated scissurae with the actual course of the intrahepatic vessels. The results presented in this paper confirm that a rigid application of flat scissural planes is not able to render the real intrahepatic compartmentation. Only techniques considering the effective individual vascular anatomy can provide a correct determination of the hepatic segments.

[Ectopic varices, a rare cause of digestive hemorrhage]. / Varices ectopiques, une cause rare d'hémorragie digestive.

From January 1986 to September 1995, 4 patients were hospitalized in our ward for gastrointestinal bleeding from ectopic varices. The patients were all female, aged 30 to 65 years. The etiology of portal hypertension in these patients was alcoholic cirrhosis, cirrhosis in Wilson's disease and previous alveolar echinococcosis treated by right hepatectomy, complicated by post-operative portal thrombosis. Clinical presentation in all 4 cases was lower gastrointestinal bleeding. Diagnosis was by emergency arteriography in 3 cases; no source was found in one case with recurrent hemorrhage. The 4 patients had a history of abdominal surgery. The location of the ectopic varices was small bowel and cecum. 3 patients were treated surgically: right colectomy, partial small bowel resection and porto-caval shunt with complete lysis of adhesions. One patient was treated conservatively with emergency placement of a TIPS (transjugular intrahepatic porto-systemic shunt), with simultaneous embolization of cecal varices. Upon laparotomy, all 3 surgical cases presented ectopic varices in post-operative adhesions. In conclusion, in a patient with portal hypertension presenting with lower gastrointestinal bleeding, hemorrhage from ectopic varices should be kept in mind and investigated by arteriography. A history of abdominal surgery seems to be a predisposing factor in development of ectopic varices by adhesion formation.

[Results of surgical treatment of hepatic metastasis of colorectal origin]. / Résultats du traitement chirurgical des métastases hépatiques d'origine colorectale.

Surgery is the only treatment which can achieve long-term survival of patients with colorectal liver secondaries. This study reports the results in 71 patients with liver metastases who underwent hepatic resection from January 1980 to December 1994. The mean age was 60 years (range 37 and 80 years). Operations included 33 right hepatectomies, 5 extended right hepatectomies, 6 left hepatectomies, 11 left lobectomies,. Surgery was macroscopically and microscopically curative in 61 patients. Information was not available in 2 patients. Significant morbidity was observed in 37% of patients. Actuarial survival at 1, 3 and 5 years was 83%, 27% and 20% respectively. At the end of the follow-up, 50 patients had died and 6 were lost to follow-up. Techniques of hepatic resection for secondaries are well established and postoperative mortality is low. Pending advances in chemotherapy, we recommend surgery as being the only way of improving long-term survival in patients with colorectal hepatic metastases.

[Risk in major hepatectomy. A consecutive series of 113 extensive hepatectomies]. / Le risque des hépatectomies majeures. Une série consécutive de 113 hépatectomies larges.

Up to now, liver resections have been the initial treatment of almost all cancers and benign tumors limited to a liver lobe. This retrospective review assesses the results of a consecutive series of 113 major elective hepatic resections during a ten-year period. Major hepatectomy was defined by the resection of at least 3 Couinaud segments. Mean age was 52 years (20 to 79 years). There were 62 women and 51 men. 35 resections were performed for colorectal metastases, 22 for a benign tumor, 20 for non-colorectal metastases, 11 for hydatid disease, 10 for hepatocarcinoma, 7 for cholangiocarcinoma and 8 for other indications. The resections performed were 86 right hepatectomies with 18 extended right hepatectomies, 24 left hepatectomies with 4 extended left hepatectomies and 3 trisegmentectomies. Total vascular exclusion was used in 22 patients (19%). Mortality rate was zero. Significant morbidity was encountered in 24 patients (21%). These results suggest that the mortality rate may be independent of the extent of liver resection, provided that hepatic function is normal and preoperative selection adequate. With improving surgical management and techniques, and the use of intra-operative sonography, extensive liver surgery can now be performed with a very low mortality rate.

MRI findings in Caroli's disease and intrahepatic pigmented calculi.

This paper reports a case of Caroli's disease confined to the left lobe of the liver that mimicked left portal vein thrombosis on MRI studies because of the very high signal intensity on T1-weighted images of intrahepatic pigmented calculi. The preoperative diagnosis was a cholangiocarcinoma infiltrating the left hepatic bile duct and portal branch. The final macroscopic and histological diagnosis was Caroli's disease of the left liver lobe with wide enlarged left bile duct containing multiple pigmented calculi.

Magnetic resonance imaging with superparamagnetic iron oxide particles to evaluate hepatic macrophage-monocytic phagocytosis after arterial devascularization in minipigs.

RATIONALE AND OBJECTIVES: We examined the effects of arterial ischemia on the phagocytic activity of the hepatic macrophage-monocytic phagocytic system (MMPS). METHODS: Six minipigs were studied before and 24 hr after complete arterial devascularization of the liver. Magnetic resonance (MR) imaging was performed at 1.5 T using superparamagnetic iron oxide (SPIO) particles (18 mumol Fe/kg body weight) as an MMPS-specific contrast agent. Hepatobiliary scintigraphy, measurements of serum liver enzymes, and histology also were obtained. RESULTS: On MR imaging, the postcontrast-to-precontrast ratios of the arterially devascularized livers were significantly higher than the corresponding baseline values (p < .01). The greatest difference (52%) between the baseline and the postoperative values was observed on gradient-echo (GE) images. Scintigraphy, laboratory analyses, and histology results indicate that the MR imaging findings were probably predominantly attributable to a reduction in phagocytic activity of the hepatic MMPS. CONCLUSION: SPIO particles have already proved useful for improving detection of liver neoplasms on MR imaging, but they also may provide a novel way of evaluating the function of the hepatic MMPS in liver diseases.

Enhancement of liver hemangiomas on T1-weighted MR SE images by superparamagnetic iron oxide particles.

OBJECTIVE: Superparamagnetic iron oxide (SPIO) particles are phagocytosed by cells of the macrophage-monocytic phagocytic system. They are usually used in MRI as a negative contrast agent, because of their strong T2* effect, to improve detection of tumors in the liver and spleen. However, they also have a potent T1 relaxivity. In the current study, we describe this T1 effect in liver hemangiomas. MATERIALS AND METHODS: Twelve patients (nine women and three men, aged from 38 to 76 years) with liver hemangiomas were examined by means of MRI at 1.5 T before and after intravenous administration of SPIO particles at a dose of 15 mumol Fe/kg body wt. Signal intensity was measured from regions of interest. RESULTS: Whereas on postcontrast T2-weighted SE images the hemangiomas showed on average a signal drop of 20% (p = 0.011) and 49% (p = 0.001) (first and second echo, respectively), their signal increased by 106% (p = 0.001) on postcontrast T1-weighted SE images. CONCLUSION: The T1 effect (signal enhancement) we observed in liver hemangiomas after infusion of SPIO particles could prove to be a useful new diagnostic feature that would help characterize these common lesions and differentiate them from other liver tumors.

Collagen application versus manual compression: a prospective randomized trial for arterial puncture site closure after coronary angioplasty.

OBJECTIVES: This study evaluated the safety and efficacy of a newly developed puncture-sealing device consisting of subcutaneous bovine collagen application designed to facilitate local hemostasis after coronary angioplasty. BACKGROUND: The most common local hemostatic procedure after coronary angioplasty consists of heparin discontinuation and delayed sheath removal followed by mechanical compression at the puncture site. METHODS: Between December 1991 and February 1993, 124 patients undergoing coronary angioplasty with either a 6F guiding catheter followed by a heparin infusion for > 12 h or a 7F or 8F guiding catheter with optional heparin infusion were prospectively randomized to either delayed sheath removal followed by manual compression (n = 62) or sheath removal immediately after angioplasty combined with bovine collagen application for puncture site closure (n = 62). Half of the collagen plugs were delivered using measured and half using estimated skin-artery distance. Clinical and duplex sonographic evaluations of the puncture site were performed 24 h later. RESULTS: No significant difference in the incidence of local hematomas was observed. Major complications were false aneurysm, venous thrombosis and arterial occlusion. The incidence of false aneurysm was the same in both groups (4 [7%] of 62). Venous thrombosis (2%) and arterial occlusion (2%) were each recorded in one patient, both in the collagen application group. CONCLUSIONS: Sheath removal and collagen application with this new vascular hemostasis device used directly after coronary angioplasty are not superior to delayed sheath removal after heparin discontinuation followed by mechanical compression. Arterial collagen sealing with this device in its current form is associated with a small but worrisome risk of arterial occlusion.

[Imaging of the pericardium using magnetic resonance]. / Darstellung des Perikards mit Magnetresonanz.

Evaluation of the pericardium has been rediscovered with the advent of sectional imaging modalities such as magnetic resonance. Owing to the improved image quality, faster imaging and cine display, MRI has proved to have a useful role in assessment of the pericardium. This article illustrates the authors' wide experience with MRI of normal and abnormal pericardium in numerous patients. The anatomy of the normal pericardium is reviewed, as are the different MR imaging techniques used Advantages of MRI in specific situations are discussed. Congenital anomalies are covered but particular attention is paid to acquired diseases, such as pericardial effusions, with emphasis on the characterization of the different pericardiac fluid collections. Pericardial thickening and constrictive pericarditis, which are easily differentiated from restrictive cardiomyopathy, are also discussed. Finally, primary and metastatic tumors are described.

[The supinator fat pad in fractures of the elbow joint]. / Der Supinatorfettkörper bei Frakturen des Ellbogengelenkes.

The position of the supinator fat pad is regarded as a valuable sign in fractures of the elbow. In our patients the pad was visible in 277 out of 337 cases (82%). The sign was positive in only 27 out of 55 proximal fractures of the radius (sensitivity 0.49). There was no correlation between the severity of the fracture and the sign. There was marked variation in the distance between the pad and the radius, depending on age, build and projection. Our results indicate that the sign is not suitable for the diagnosis of fracture of the elbow.