J. Lebigot

Acoustic radiation force impulse: a new ultrasonographic technology for the widespread noninvasive diagnosis of liver fibrosis.

Background/aims As a module of a standard ultrasound imaging device, acoustic radiation force impulse (ARFI) is a new technology for liver stiffness evaluation (LSE). We aimed to evaluate accuracy, feasibility, reproducibility, and training effect of ARFI for liver fibrosis evaluation. Methods One hundred and one patients with chronic liver disease had LSE by Fibroscan and ARFI. LSE by ARFI was performed in the two liver lobes by two operators: an expert and a novice. Correlation and agreement were evaluated by the Pearson (Rp) and intraclass (Ric) correlation coefficients. The independent reference for liver fibrosis was fibrosis blood tests. Results ARFI results, ranging from 0.7 to 4.6 m/s, were well correlated with Fibroscan results (Rp=0.76). Fibroscan had a significantly higher area under the receiver operating characteristic curve (AUROC) than ARFI for the perprotocol diagnosis of significant fibrosis: 0.890±0.034 versus 0.795±0.047 (P=0.04). However, LSE failure occurred in zero patients using ARFI versus six patients using Fibroscan (P=0.03). Thus, on an intention-to-diagnose basis, Fibroscan and ARFI AUROCs for the diagnosis of significant fibrosis were not different: 0.791±0.049 versus 0.793±0.046 (P=0.98). Interobserver agreement was very good (Ric=0.84) and excellent for ARFI interquartile range (IQR)≤0.30 (Ric=0.91). Indeed, agreement was independently predicted only by ARFI IQR, but not by LSE result as earlier observed for Fibroscan. ARFI AUROC was 0.876±0.057 in patients with ARFI IQR ratio≤0.30, and Fibroscan AUROC was 0.912±0.034 in patients with Fibroscan IQR ratio less than 0.21 (P=0.59). Intersite ARFI agreement between the two liver lobes was fair (Ric=0.60). There was no training effect for LSE by ARFI. Conclusion ARFI is highly feasible and reproducible, and provides diagnostic accuracy similar to Fibroscan. This new device seems noteworthy for the widespread noninvasive diagnosis of liver fibrosis.

Diagnostic et quantification de la fibrose hépatique par IRM de diffusion : résultats préliminaires

Resume Objectif Le diagnostic et la quantification de la fibrose hepatique sont des sujets particulierement importants en hepatologie clinique. La biopsie hepatique en demeure la cle, mais souffre de nombreuses limitations. Le but de cette etude est de definir les possibilites de l’IRM de diffusion pour le diagnostic et la quantification de la cirrhose et de definir les meilleurs parametres de sequences pour ce faire. Materiel et methode Une IRM de diffusion a ete realisee chez 13 patients cirrhotiques et 14 volontaires presumes sains. Une sequence en apnee de 8 coupes a ete realisee avec 4 facteurs b (200, 400, 600, et 800 sec/mm 2 ) et 2 TR differents (3 500 et 5 000 ms. Le coefficient de diffusion a ete calcule (ADCs) pour chaque sequence et correle au score de Child Pugh et au taux d’acide hyaluronique sanguin. Resultats L’ADCs est statistiquement significativement plus bas chez les patients cirrhotiques (2,055 10 -3 ) que chez les patients controles (2,915 10 -3 ) (p 2 et un TR de 5000 ms. Il existait une correlation significative entre l’ADCs et le score de Child Pugh (p 2 et le TR 5 000 ms. Conclusion Notre etude preliminaire montre que l’IRM de diffusion pourrait etre capable de diagnostiquer et eventuellement de quantifier la fibrose hepatique, particulierement en utilisant des valeurs de facteur b egales a 200 sec/mm 2 et a 400 sec/mm 2 .

Liver stiffness in nonalcoholic fatty liver disease: A comparison of supersonic shear imaging, FibroScan, and ARFI with liver biopsy

Nonalcoholic fatty liver disease (NAFLD) has become a major public health issue. The goal of this study was to assess the clinical use of liver stiffness measurement (LSM) evaluated by supersonic shear imaging (SSI), FibroScan, and acoustic radiation force impulse (ARFI) in a cohort of NAFLD patients who underwent liver biopsy. A total of 291 NAFLD patients were prospectively enrolled from November 2011 to February 2015 at 2 French university hospitals. LSM was assessed by SSI, FibroScan (M probe), and ARFI within two weeks prior to liver biopsy. Calculations of the area under the receiver operating curve (AUROC) were performed and compared for the staging of liver fibrosis. AUROC for SSI, FibroScan, and ARFI were 0.86, 0.82, and 0.77 for diagnoses of ≥F2; 0.89, 0.86, and 0.84 for ≥F3; and 0.88, 0.87, and 0.84 for F4, respectively. SSI had a higher accuracy than ARFI for diagnoses of significant fibrosis (≥F2) (P = 0.004). Clinical factors related to obesity such as body mass index ≥ 30 kg/m2, waist circumference ≥102 cm or increased parietal wall thickness were associated with LSM failures when using SSI or FibroScan and with unreliable results when using ARFI. In univariate analysis, FibroScan values were slightly correlated with NAFLD activity score and steatosis (R = 0.28 and 0.22, respectively), whereas SSI and ARFI were not; however, these components of NAFLD did not affect LSM results in multivariate analysis. The cutoff values for SSI and FibroScan for staging fibrosis with a sensitivity ≥90% were very close: 6.3/6.2 kPa for ≥F2, 8.3/8.2 kPa for ≥F3, and 10.5/9.5 kPa for F4. Conclusion: Although obesity is associated with an increase in LSM failure, the studied techniques and especially SSI provide high value for the diagnosis of liver fibrosis in NAFLD patients. (Hepatology 2016;63:1817‐1827)

Radiologic versus endoscopic placement of percutaneous gastrostomy in amyotrophic lateral sclerosis: multivariate analysis of tolerance, efficacy, and survival.

PURPOSE To compare percutaneous radiologic gastrostomy (PRG) and percutaneous endoscopic gastrostomy (PEG) in terms of tolerance, efficacy, and survival in patients with amyotrophic lateral sclerosis (ALS). MATERIALS AND METHODS Forty patients with ALS (17 men; mean age, 66.1 years; range, 39-83 y) underwent 21 PEG and 22 PRG attempts (including three unsuccessful PEG attempts) from 1999 to 2005. To assess tolerance and efficacy, a successful and well tolerated placement was defined as any successful placement with no major or minor local complications or pain requiring opioid analgesic agents. Univariate analysis was performed for all recorded parameters, followed by multivariate analysis for successful and well tolerated placement, 6-month mortality rate, and survival. RESULTS General success rates were 85.7% for PEG and 100% for PRG. Pain was more frequent in PRGs (81.8% vs 52.4%; P = .05). Successful and well tolerated placement was seen in 81.8% of PRGs and 57.1% of PEGs (P = 0.1). Advanced age (P = .02) and PRG (P = .07) were predictive of successful and well tolerated placement. The interval from diagnosis to placement (P = .001) and ability to perform spirometry (P = .002) were predictive of survival. Oximetry measurements (P = .007) and interval from diagnosis to placement (P = .02) were predictive of mortality at 6 months. CONCLUSIONS PRG is more efficacious and better tolerated than PEG, essentially because it avoids the respiratory decompensation that may occur in PEG. Therefore, PRG should be preferred in cases of ALS. Survival is linked to ALS evolution and not to the choice of PRG or PEG placement.

Factors Limiting Complete Tumor Ablation by Radiofrequency Ablation

The purpose of this study was to determine radiological or physical factors to predict the risk of residual mass or local recurrence of primary and secondary hepatic tumors treated by radiofrequency ablation (RFA). Eighty-two patients, with 146 lesions (80 hepatocellular carcinomas, 66 metastases), were treated by RFA. Morphological parameters of the lesions included size, location, number, ultrasound echogenicity, computed tomography density, and magnetic resonance signal intensity were obtained before and after treatment. Parameters of the generator were recorded during radiofrequency application. The recurrence-free group was statistically compared to the recurrence and residual mass groups on all these parameters. Twenty residual masses were detected. Twenty-nine lesions recurred after a mean follow-up of 18 months. Size was a predictive parameter. Patients’ sex and age and the echogenicity and density of lesions were significantly different for the recurrence and residual mass groups compared to the recurrence-free group (p < 0.05). The presence of an enhanced ring on the magnetic resonance control was more frequent in the recurrence and residual mass groups. In the group of patients with residual lesions, analysis of physical parameters showed a significant increase (p < 0.05) in the time necessary for the temperature to rise. In conclusion, this study confirms risk factors of recurrence such as the size of the tumor and emphasizes other factors such as a posttreatment enhanced ring and an increase in the time necessary for the rise in temperature. These factors should be taken into consideration when performing RFA and during follow-up.

Permeability and functionality of pancreaticogastrostomy after pancreaticoduodenectomy with dynamic magnetic resonance pancreatography after secretin stimulation

BACKGROUND The aim of this study was to evaluate pancreatogastrostomy (PG) permeability after duodenopancreatectomy (PD) and to determine a correlation with pancreatic endocrine and exocrine functions. STUDY DESIGN This prospective study included 19 patients who underwent PD with PG between 1992 and 1999. There were 12 men and 7 women, with a mean age of 58 years (range 35 to 76 years). The mean interval between operation and evaluation was 40.3 months (range 3 to 104 months). Indications for pancreatectomy were benign lesions (n = 13) or adenocarcinoma (n = 6). Histology of the pancreatic resection margin was normal in all patients with malignancy, and the pancreatic remnant was macroscopically normal without evidence of obstructive pancreatitis. Pancreatic exocrine and endocrine functions were respectively evaluated by fecal-1 elastase and fasting blood glucose concentrations. PG permeability was determined by secretin magnetic resonance cholangiopancreatography (Secretin-MRCP). RESULTS Anastomotic permeability was considered good in seven patients (group 1, 36.8%), moderately stenosed in six patients (group 2, 31.6%), significantly stenosed in four patients (group 3, 21.1%), and obstructed in two patients (group 4, 10.5%). Fecal-1 elastase concentration was decreased in 18 patients, with a mean concentration of 80 microg/g in group 1, 98 microg/g in group 2, 67 microg/g in group 3, and 0 microg/g in group 4. There was a statistically significant correlation between Secretin-MRCP group and fecal-1 elastase concentration. Results of fasting glucose estimation were normal for 14 of 19 patients. There was no correlation between pancreatic endocrine function and Secretin-MRCP group. CONCLUSIONS Exocrine pancreatic insufficiency was presented in 95% of the patients despite a PG permeability in 68.4%. These results may be explained in part by neutralization of pancreatic enzymatic secretions by gastric acid.

Portosystemic collateral vessels in liver cirrhosis: a three-dimensional MDCT pictorial review

PurposePortosystemic collateral vessels (PSCV) are a consequence of the portal hypertension that occurs in chronic liver diseases. Their prognosis is strongly marked by the risk of digestive hemorrhage and hepatic encephalopathy.Materials and methodsCT was performed with a 16-MDCT scanner. Maximum intensity projection and volume rendering were systematically performed on a workstation to analyze PSCV.ResultsWe describe the PSCV according to their drainage into either the superior or the inferior vena cava. In the superior vena cave group, we found gastric veins, gastric varices, esophageal, and para-esophageal varices. In the inferior vena cava group, the possible PSCV are numerous, with different sub groups: gastro and spleno renal shunts, paraumbilical and abdominal wall veins, retroperitoneal shunts, mesenteric varices, gallbladder varices, and omental collateral vessels. Regarding clinical consequences esophageal and gastric varices are most frequently involved in digestive bleeding; splenorenal shunts often lead to hepatic encephalopathy; the paraumbilical vein is an acceptable derivation pathway for natural decompression of the portal system.ConclusionKnowledge of precise cartography of PSCV is essential to therapeutic decisions. MDCT is the best way to understand and describe the different types of PSCV.

Noninvasive liver steatosis quantification using Mri techniques combined with blood markers

Aims To evaluate the accuracy of different techniques of MRI steatosis quantification, based on histological grading and quantification of liver steatosis. Patients and methods Twenty-three patients (21 with nonalcoholic fatty liver disease and two controls) were included. Steatosis was evaluated in liver specimens using histological grading (five grades) and steatosis area (% of liver surface) was computed using an inhouse automated image analysis. The following five MRI quantification techniques were performed: two-point Dixon, three-point Dixon, DUAL, spin echo method and a new technique called multi-echo gradient-echo (MFGRE). Interobserver (two observers) and intersite (three different liver sites) agreements were evaluated for the two best-performing methods. Results Steatosis area was correlated with steatosis grade: Rs (Spearman coefficient)=0.82, P value of less than 0.001. The steatosis area was significantly different between S0–S2 and S3–S4 grades: 4.2±2.4 versus 16.4±8.9% (P<0.001). Correlations between the MRI techniques and steatosis area (or grading) were: MFGRE, Rs=0.72 (0.78); spin echo method, Rs=0.72 (0.76); DUAL, Rs=0.71 (0.76); two-point Dixon, Rs=0.71 (0.75); three-point Dixon, Rs=0.67 (0.77). Interobserver (Ric=0.99) and intersite (Ric=0.97) agreements were excellent for the liver steatosis measurement by MFGRE. The noninvasive diagnosis of the steatosis area was improved by adding blood markers like ALT and triglycerides to MFGRE (aR2: 0.805). Conclusion MRI, and in particular the MFGRE method, provides accurate and automatic quantification for the noninvasive evaluation of liver steatosis, either as a single measurement or in combination with blood variables.

Technique and indications of percutaneous cholecystostomy in the management of cholecystitis in 2014.

The gold standard in treatment of acute cholecystitis is cholecystectomy associated with antibiotics. In certain circumstances, percutaneous cholecystostomy is an interventional alternative. Percutaneous cholecystostomy is usually performed under local anesthesia by the radiologist using ultrasonographic or CT guidance. A drain can be inserted either through a trans-hepatic or a trans-peritoneal approach. Complications occur in nearly 10% of cases including hemorrhage, hemobilia, pneumothorax or bile leaks, depending on whether the approach was trans-hepatic or trans-peritoneal. The main indications for percutaneous cholecystostomy are resistance to medical treatment or severely-ill patients in intensive care. Drains should be maintained 3 to 6 weeks before removal. In patients with good general condition (ASA score I-II), secondary cholecystectomy can be recommended to avoid recurrence.

Radiofrequency ablation of hepatocellular carcinoma: Mono or multipolar?

Thermo‐ablation by radiofrequency is recognized as a curative treatment for early‐stage hepatocellular carcinoma. However, local recurrence may occur because of incomplete peripheral tumor destruction. Multipolar radiofrequency has been developed to increase the size of the maximal ablation zone. We aimed to compare the efficacy of monopolar and multipolar radiofrequency for the treatment of hepatocellular carcinoma and determine factors predicting failure.