Influence of clinical suspicion on CT accuracy of acute mesenteric ischemia: Retrospective study of 362 patients.

PURPOSE: Acute mesenteric ischemia (AMI) may be underdiagnosed when not clinically suspected before CT is performed. We assessed the influence of a clinical suspicion of AMI on the CT accuracy. METHOD: This retrospective single-centre study included patients who underwent CT in 2014-2019 and had clinically suspected AMI and/or confirmed AMI. CT protocols were adapted based on each patient's presentation and on findings from unenhanced images. The CT protocol was considered optimal for AMI when it included arterial and portal venous phases. CT protocols, accuracy of reports, and outcomes were compared between the groups with and without suspected AMI before CT. RESULTS: Of the 375 events, 337 (90 %) were suspected AMI and 66 (18 %) were AMI, including 28 (42 %) with and 38 without suspected AMI. These two groups did not differ significantly regarding the medical history, clinical presentation, or laboratory tests. The CT protocol was more often optimal for AMI in the group with suspected AMI (26/28 [93 %] vs. 28/38 [74 %], p = 0.046). Diagnostic accuracy was not different between groups with and without suspected AMI (26/28 [93 %] vs. 34/38 [90 %], p = 1.00). However, it was lower in the group without suspicion of AMI when the CT protocol was not optimal for AMI (27/28 [96 %] vs 7/10 [70 %], p = 0.048). CONCLUSIONS: The negative influence of not clinically suspecting AMI can be mitigated by using a tailored CT protocol.

Adult appendicitis: Clinical practice guidelines from the French Society of Digestive Surgery and the Society of Abdominal and Digestive Imaging.

INTRODUCTION: The French Society of Digestive Surgery (SFCD) and the Society of Abdominal and Digestive Imaging (SIAD) have collaborated to propose recommendations for clinical practice in the management of adult appendicitis. METHODS: An analysis of the literature was carried out according to the methodology of the French National Authority for Health (HAS). A selection was performed from collected references and then a manual review of the references listed in the selected articles was made in search of additional relevant articles. The research was limited to articles whose language of publication was English or French. Articles focusing on the pediatric population were excluded. Based on the literature review, the working group proposed recommendations whenever possible. These recommendations were reviewed and approved by a committee of experts. RESULTS: Recommendations about appendicitis in adult patients were proposed with regard to clinical, laboratory and radiological diagnostic modalities, treatment strategy for uncomplicated and complicated appendicitis, surgical technique, and specificities in the case of macroscopically healthy appendix, terminal ileitis and appendicitis in the elderly and in pregnant women. CONCLUSION: These recommendations for clinical practice may be useful to the surgeon in optimizing the management of acute appendicitis in adults.

Hepatospecific MR contrast agent uptake on hepatobiliary phase can be used as a biomarker of marked ß-catenin activation in hepatocellular adenoma.

OBJECTIVES: To assess the value of hepatospecific MR contrast agent uptake on hepatobiliary phase (HBP) images to detect marked activation of the ß-catenin pathway in hepatocellular adenomas (HCAs). METHODS: This multicentric retrospective IRB-approved study included all patients with a pathologically proven HCA who underwent gadobenate dimeglumine-enhanced liver MRI with HBP. Tumor signal intensity on HBP was first assessed visually, and lesions were classified into three distinct groups-hypointense, isointense, or hyperintense-according to the relative signal intensity to liver. Uptake was then quantified using the lesion-to-liver contrast enhancement ratio (LLCER). Finally, the accuracy of HBP analysis in depicting marked ß-catenin activation in HCA was evaluated. RESULTS: A total of 124 HCAs were analyzed including 12 with marked ß-catenin activation (HCA B+). Visual analysis classified 94/124 (76%), 12/124 (10%), and 18/124 (14%) HCAs as being hypointense, isointense, and hyperintense on HBP, respectively. Of these, 1/94 (1%), 3/12 (25%), and 8/18 (44%) were HCA B+, respectively (p < 0.001). The LLCER of HCA B+ was higher than that of HCA without marked ß-catenin activation in the entire cohort (means 4.9 ± 11.8% vs. - 19.8 ± 11.4%, respectively, p < 0.001). A positive LLCER, i.e., LLCER ≥ 0%, had 75% (95% CI 43-95%) sensitivity and 97% (95% CI 92-99%) specificity, with a LR+ of 28 (95% CI 8.8-89.6) for the diagnosis of HCA B+. CONCLUSIONS: Hepatospecific contrast uptake on hepatobiliary phase is strongly associated with marked activation of the ß-catenin pathway in hepatocellular adenoma, and its use might improve hepatocellular adenoma subtyping on MRI. KEY POINTS: • Tumor uptake on hepatobiliary phase in both the visual and quantitative analyses had a specificity higher than 90% for the detection of marked ß-catenin activation in hepatocellular adenoma. • However, the sensitivity of visual analysis alone is inferior to that of LLCER quantification on HBP due to the high number of HCAs with signal hyperintensity on HBP, especially those developed on underlying liver steatosis.

Non-invasive diagnosis of severe alcoholic hepatitis: Usefulness of cross-sectional imaging.

PURPOSE: To describe the computed tomography (CT) and magnetic resonance imaging (MRI) features of severe acute alcoholic hepatitis (SAAH) and estimate the capabilities of CT and MRI in differentiating SAAH from alcoholic cirrhosis and non-alcoholic steato-hepatitis (NASH) cirrhosis. MATERIALS AND METHODS: Fifty patients with pathologically proven SAAH (SAAH group) who underwent CT or MRI examinations up to 30 days before or 15 days after liver biopsy between January 2008 and June 2018 were retrospectively included. There were 31 men and 29 women with a mean age of 52±9 (SD) years (range: 33-67 years). Imaging features of the SAAH group were compared to those obtained in two control groups including 62 patients with alcoholic cirrhosis without acute alcoholic hepatitis (control group 1) and 19 patients with NASH cirrhosis (control group 2) by two independent radiologists blinded to the final diagnosis. Univariate analyses were performed to compare imaging characteristics between the three groups, followed by diagnostic performance analysis for the diagnosis of SAAH of the main CT features. RESULTS: Heterogeneous steatosis was significantly more frequent in SAAH group than in the control groups (41/50; 82% vs. 7/62; 10% and 1/19; 5% in control groups 1 and 2, respectively for reader 1 and 34/50; 68% vs. 8/62; 13% and 1/19; 5% in control groups 1 and 2, respectively for reader 2; both P=0.01). Transient perfusion disorders were more frequent in SAAH group than in the control groups (35/50; 70% vs. 12/62; 21% and 5/19; 26% in control groups 1 and 2, respectively for reader 1 and 39/50; 78% vs. 14/62; 23% and 13/19; 6% in control groups 1 and 2, respectively for reader 2; both P=0.01). The combination of these two findings yielded 100% specificity (45/45; 95% CI: 92-100) for readers 1 and 2 for the diagnosis of SAAH vs. alcoholic cirrhosis and NASH cirrhosis. CONCLUSION: The imaging features of SAAH are specific and mainly associate transient heterogeneous steatosis and liver perfusion disorders. CT/MRI may be useful to differentiate SAAH from alcoholic cirrhosis and NASH cirrhosis.

Morphological imaging and CT histogram analysis to differentiate pancreatic neuroendocrine tumor grade 3 from neuroendocrine carcinoma.

PURPOSE: To compare morphological imaging features and CT texture histogram parameters between grade 3 pancreatic neuroendocrine tumors (G3-NET) and neuroendocrine carcinomas (NEC). MATERIALS AND METHODS: Patients with pathologically proven G3-NET and NEC, according to the 2017 World Health Organization classification who had CT and MRI examinations between 2006-2017 were retrospectively included. CT and MRI examinations were reviewed by two radiologists in consensus and analyzed with respect to tumor size, enhancement patterns, hemorrhagic content, liver metastases and lymphadenopathies. Texture histogram analysis of tumors was performed on arterial and portal phase CT images. images. Morphological imaging features and CT texture histogram parameters of G3-NETs and NECs were compared. RESULTS: Thirty-seven patients (21 men, 16 women; mean age, 56±13 [SD] years [range: 28-82 years]) with 37 tumors (mean diameter, 60±46 [SD] mm) were included (CT available for all, MRI for 16/37, 43%). Twenty-three patients (23/37; 62%) had NEC and 14 patients (14/37; 38%) had G3-NET. NECs were larger than G3-NETs (mean, 70±51 [SD] mm [range: 18 - 196mm] vs. 42±24 [SD] mm [range: 8 - 94mm], respectively; P=0.039), with more tumor necrosis (75% vs. 33%, respectively; P=0.030) and lower attenuation on precontrast (30±4 [SD] HU [range: 25-39 HU] vs. 37±6 [SD] [range: 25-45 HU], respectively; P=0.002) and on portal venous phase CT images (75±18 [SD] HU [range: 43 - 108 HU] vs. 92±19 [SD] HU [range: 46 - 117 HU], respectively; P=0.014). Hemorrhagic content on MRI was only observed in NEC (P=0.007). The mean ADC value was lower in NEC ([1.1±0.1 (SD)]×10-3 mm2/s [range: (0.91 - 1.3)×10-3 mm2/s] vs. [1.4±0.2 (SD)]×10-3 mm2/s [range: (1.1 - 1.6)×10-3 mm2/s]; P=0.005). CT histogram analysis showed that NEC were more heterogeneous on portal venous phase images (Entropy-0: 4.7±0.2 [SD] [range: 4.2-5.1] vs. 4.5±0.4 [SD] [range: 3.7-4.9]; P=0.023). CONCLUSION: Pancreatic NECs are larger, more frequently hypoattenuating and more heterogeneous with hemorrhagic content than G3-NET on CT and MRI.

Relevance of liver surface nodularity for preoperative risk assessment in patients with resectable hepatocellular carcinoma.

BACKGROUND: Quantification of liver surface nodularity (LSN) on routine preoperative CT images allows detection of cirrhosis and clinically significant portal hypertension. This study aimed to assess the relevance of LSN in preoperative assessment of operative risks for patients with resectable hepatocellular carcinoma (HCC). METHODS: All patients undergoing hepatectomy for HCC between 2012 and 2017 were analysed retrospectively. LSN was assessed at the liver-fat interface on the left liver lobe on preoperative CT images. The feasibility of LSN quantification was assessed. The association between LSN and outcomes (severe complications and posthepatectomy liver failure (PHLF)) was evaluated by multivariable analysis and after propensity score matching. RESULTS: Among 210 patients, LSN measurement was successful in 187 (89·0 per cent). Among these, the median LSN score was 2·42 (i.q.r. 2·21-2·66) and 52·9 per cent had severe fibrosis, including 33·7 per cent with cirrhosis. LSN score increased with hepatic venous pressure gradient (P = 0·048), severity of steatosis (P = 0·011) and fibrosis grade (P = 0·001). LSN score was independently associated with severe complications (odds ratio (OR) 5·25; P = 0·006) and PHLF (OR 6·78; P = 0·003). After matching with respect to model for end-stage liver disease, aspartate aminotransferase-to-platelet ratio index and fibrosis-4 score, patients with a LSN score of 2·63 or higher retained an increased risk of PHLF (OR 5·81; P = 0·018). In the subgroup of patients without severe fibrosis, LSN was accurate in predicting severe complications (P = 0·005). Patients with (P = 0·039) or without (P = 0·018) severe fibrosis with increased LSN score had a higher comprehensive complication index score. Among patients with cirrhosis who had clinically significant portal hypertension, a LSN value below 2·63 ruled out the risk of PHLF. CONCLUSION: LSN measurement represents a practical tool that may allow improvement in the preoperative evaluation and management of patients with HCC.

ANTECEDENTES: La cuantificación de la nodularidad de la superficie hepática (liver surface nodularity, LSN) en las imágenes de la tomografía computarizada (TC) de rutina preoperatoria permite detectar la cirrosis y la hipertensión portal clínicamente significativa (clinically significant portal hypertension, CSPH). Este estudio tuvo como objetivo evaluar la relevancia de la LSN en la evaluación preoperatoria del riesgo quirúrgico en pacientes con carcinoma hepatocelular resecable (hepatocellular carcinoma, HCC). MÉTODOS: Todos los pacientes sometidos a hepatectomía por HCC entre 2012 y 2017 fueron analizados de forma retrospectiva. La LSN se evaluó en la interfase hígado-grasa en el lóbulo hepático izquierdo en la TC preoperatoria. Se evaluó la viabilidad de la cuantificación de la LSN. La asociación entre la LSN y los resultados (complicaciones graves e insuficiencia hepática poshepatectomía (post-hepatectomy liver failure, PHLF) se analizó en un análisis multivariable y después del método de emparejamiento por puntaje de propensión. RESULTADOS: Del total de 210 pacientes, la medición de la LSN fue exitosa en 187 (89,0%). En estos pacientes, la mediana de LSN fue de 2,42 (rango intercuartílico 2,21-2,66) y el 53,0% tenía fibrosis severa, incluyendo un 33,7% con cirrosis. La LSN aumentó con el gradiente de presión venosa hepática (P = 0,048), la gravedad de la esteatosis (P = 0,011) y el grado de fibrosis (P = 0,001). La LSN se asoció de forma independiente con complicaciones graves (razón de oportunidades, odds ratio, OR = 5,25; P = 0,006) y PHLF (OR = 6,78; P = 0,003). Después de emparejar para el modelo de enfermedad hepática terminal, el índice de relación aspartato amino transferase-plaquetas y el grado de fibrosis-4, los pacientes con LSN ≥ 2,63 mantuvieron un mayor riesgo de PHLF (OR = 5,81; P = 0,018). Dentro del subgrupo de pacientes sin fibrosis severa, la LSN fue precisa en predecir complicaciones graves (P = 0,005). Los pacientes con (P = 0,039) y sin (P = 0,018) fibrosis severa con aumento de la LSN tuvieron un índice de complicación global más alto. De los pacientes cirróticos con CSPH, un valor de LSN de 2,63 descartó el riesgo de PHLF. CONCLUSIÓN: La LSN representa una herramienta práctica, que puede permitir mejorar la evaluación preoperatoria y el manejo de pacientes con HCC.

Metabolic syndrome and hepatic surgery.

In Europe, the prevalence of metabolic syndrome (MS) has reached the endemic rate of 25%. Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of MS. Its definition is histological, bringing together the different lesions associated with hepatic steatosis (fat deposits on more than 5% of hepatocytes) without alcohol consumption and following exclusion of other causes. MS and NAFLD are implicated in the carcinogenesis of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). At present, HCC and ICC involving MS represent 15-20% and 20-30% respectively of indications for hepatic resection in HCC and ICC. Moreover, in the industrialized nations NAFLD is tending to become the most frequent indication for liver transplantation. MS patients combine the operative risk associated with their general condition and comorbidities and the risk associated with the presence and/or severity of NAFLD. Following hepatic resection in cases of HCC and ICC complicating MS, the morbidity rate ranges from 20 to 30%, and due to cardiovascular and infectious complications, post-transplantation mortality is heightened. The operative risk incurred by MS patients necessitates appropriate management including: (i) precise characterization of the subjacent liver; (ii) an accurately targeted approach privileging detection and optimization of treatment taking into account the relevant cardiovascular risk factors; (iii) a surgical strategy adapted to the histology of the underlying liver, with optimization of the volume of the remaining (postoperative) liver.

Unenhanced CT for clinical triage of elderly patients presenting to the emergency department with acute abdominal pain.

PURPOSE: The purpose of this study was to compare the diagnostic accuracy and inter-reader agreement of unenhanced computed tomography (CT) to those of contrast-enhanced CT for triage of patients older than 75years admitted to emergency department (ED) with acute abdominal pain (AAP). PATIENTS AND METHODS: Two hundred and eight consecutive patients presenting with AAP to the ED who underwent CT with unenhanced and contrast-enhanced images were retrospectively included. There were 90 men and 118 women with a mean age of 85.4±4.9 (SD) (range: 75-101.4years). Three readers reviewed unenhanced CT images first, and then unenhanced and contrast-enhanced CT images as a single set. Diagnostic accuracy was compared to the standard of reference defined as the final diagnosis obtained after complete clinico-biological and radiological evaluation. Correctness of the working diagnosis proposed by the ED physician was evaluated. Intra- and inter-reader agreements were calculated using the kappa test and interclass correlation. Subgroup analyses were performed for patients requiring only conservative management and for those requiring intervention. RESULTS: Diagnostic accuracy ranged from 64% (95% CI: 62-66%) to 68% (95% CI: 66-70%) for unenhanced CT, and from 68% (95% CI: 66-70%) to 71% (95% CI: 69-73%) for both unenhanced and contrast-enhanced CT. Contrast-enhanced CT did not significantly improve the diagnostic accuracy (P=0.973-0.979). CT corrected the working diagnosis proposed by the ED physician in 59.1% (range: 58.1-60.0%) and 61.2% (range: 57.6-65.5%) of patients before and after contrast injection (P>0.05). Intra-observer agreement was moderate to substantial (k=0.513-0.711). Inter-reader agreement was substantial for unenhanced (kappa=0.745-0.789) and combined unenhanced and contrast-enhanced CT (kappa=0.745-0.799). Results were similar in subgroup analyses. CONCLUSION: Unenhanced CT alone is accurate and associated with high degrees of inter-reader agreement for clinical triage of patients older than 75years with AAP in the emergency setting.

Can we refine the management of blunt liver trauma?

AIM: To describe the management of blunt liver injury and to study the potential relation between delayed complications, type of trauma mechanisms and liver lesions. PATIENTS AND METHODS: This is a retrospective single center study including 116 consecutive patients admitted with blunt liver injury between 2007 and 2015. RESULTS: Initial CT-scan identified an active bleeding in 33 (28%) patients. AAST (American Association for the Surgery of Trauma) grade was 1 to 3 in 82 (71%) patients and equal to 5 in 15 (13%) patients. Eighty (69%) patients had NOM, with a success rate of 96%. Other abdominal organ lesions were associated to invasive initial management. A follow-up CT-scan was useful to detect hepatic and extra-hepatic complications (46 complications in 80 patients), even without clinical or biological abnormalities. Subsequent hepatic complications such as bleeding, pseudo aneurysms, biloma and biliary peritonitis developed in 15 patients and were associated with the severity of blunt liver injury according to AAST classification (3.7±1.0 vs. 3.0±1.1, P=0.010). Total biliary complications occurred in 13 patients and were significantly more frequently observed in patients with injury of central segments 1, 4 and 9 (69% vs. 36%, P=0.033). CONCLUSIONS: Non-operative management is possible in most blunt liver injury with a success rate of 96%. A systematic CT-scan should be advocated during follow-up, especially when AAST grade is equal or superior to 3. Biliary complications should be suspected when lesions involve segments 1, 4 and 9.

Femoral arterial and central venous catheters in the trauma resuscitation room.

BACKGROUND: Arterial and central venous femoral catheters (fAC-CVC) use during the initial management of severe trauma patients is not a standard technique in most trauma centers. Arguments in favor of their use are: continuous monitoring of blood pressure, safe drug administration, easy blood sampling and potentially large bore venous access. The lack of evidence makes the practice heterogeneous. The aim of the present study was to describe the use and complications of fAC-CVC in the trauma bay in two centers where they are routinely used. METHODS: This was a retrospective analysis of routine fAC-CVC use from two French trauma centers. All patients admitted directly to the trauma resuscitation room were included. Demographic, clinical and biological data were collected from the scene to discharge to describe the use of catheters during initial trauma management including infectious, mechanical and thrombotic complications. RESULTS: 243 pairs of femoral catheters were inserted among 692 patients admitted in both trauma centers. Femoral AC-CVC use was more frequent in critically ill patients with higher ISS 26 [17; 41] vs 13 [8; 24], p < 0.001(median [quartile 1-3]), severe traumatic brain injury (AIS head 1[0-4] vs 0[0-3], p < 0.001), lower systolic blood pressure, 92 (37) vs 113 (28) mmHg, p < 0.001 mean (standard deviation), lower haemoglobin on arrival, 10.9 (3) vs 13.3 (2.1) g/dL (p < 0.001), and higher blood lactate concentration, 4.0 (3.9) vs 2.1 (1.8) mmol/L (p < 0.001). In patients with fAC-CVC use time in the trauma room was longer, 46 [40;60] vs 30 [20;40] minutes (p < 0.05). In total 52 colonizations and 3 bloodstream infections were noted in 1000 catheter days. An incidence of 12% of mechanical complications and of 42% deep venous thromboses were observed. Of the latter none was associated with confirmed pulmonary embolism. CONCLUSION: Femoral AC-CVC appeared to be deployed more often in critically ill patients, presenting with shock and/or traumatic brain injury in particular. The observed rate of complications in this sample seems to be low compared to reported rates.

Acute mesenteric ischemia: A critical role for the radiologist.

Acute mesenteric ischemia is defined as an inadequate blood supply to the gastrointestinal tract resulting in ischemic and inflammatory injury that may progress to necrosis of the bowel wall. Prognosis is poor with a mortality rate greater than 95% without treatment, dropping to around 70% when surgical treatment is performed. Contrast-enhanced computed tomography (CT) has become the cornerstone of the diagnosis by showing features of vascular disorders (occlusion and/or insufficient blood supply) and features of intestinal ischemic injury. CT should be performed as rapidly as possible. Imaging-based patient management is required, and multimodal and multidisciplinary management should be introduced. The treatment involves multidisciplinary management by gastroenterologists, vascular and digestive surgeons, cardiologists, intensivists, and diagnostic and interventional radiologists. Based on our experience at a dedicated mesenteric stroke center, this article gives an overview of the diagnosis of acute mesenteric ischemia. The goal of this review is to improve the understanding of the imaging-based diagnosis to further improve the management of this life-threatening condition.

Non-invasive evaluation of portal hypertension using shear-wave elastography: analysis of two algorithms combining liver and spleen stiffness in 191 patients with cirrhosis.

BACKGROUND: Two algorithms based on sequential measurements of liver and spleen stiffness using two-dimensional shearwave elastography (2D-SWE) have been recently proposed to estimate clinically significant portal hypertension (hepatic venous pressure gradient [HVPG] ≥10 mm Hg) in patients with cirrhosis, with excellent diagnostic accuracy. AIM: To validate externally these algorithms in a large cohort of patients with cirrhosis. METHODS: One hundred and ninety-one patients with stable cirrhosis (Child-Pugh class A 39%, B 29% and C 31%) who underwent liver and spleen stiffness measurements using 2D-SWE at the time of HVPG measurement were included. Diagnostic accuracy of the 2 algorithms was assessed by calculating sensitivity, specificity, positive and negative predictive values. RESULTS: The first algorithm, using liver stiffness <16.0 kilopascals (kPa) and then spleen stiffness <26.6 kPa, was used to rule-out HVPG ≥10 mm Hg. In our population, its sensitivity and negative predictive value were 95% and 63% respectively. The second algorithm, using liver stiffness >38.0 kPa, or liver stiffness ≤38.0 kPa but spleen stiffness >27.9 kPa, was used to rule-in HVPG ≥10 mm Hg. In our population, its specificity and positive predictive value were 52% and 83% respectively. Restricting the analyses to the 74 patients without any history of decompensation of cirrhosis or to the 65 patients with highly reliable liver stiffness measurement did not improve the results. CONCLUSION: In our population, diagnostic accuracies of non-invasive algorithms based on sequential measurements of liver and spleen stiffness using 2D-SWE were acceptable, but not good enough to replace HVPG measurement or to base clinical decisions.

Volumetric measurement of hepatic tumors: Accuracy of manual contouring using CT with volumetric pathology as the reference method.

PURPOSE: The purpose of this study was to assess the accuracy of liver tumor volumetry by manual contouring on computed tomography (CT) compared to pathological tumor volume determined from surgical specimen that served as a reference method. PATIENTS AND METHOD: Thirty-eight patients with planned liver surgery and a total of 41 liver tumors were included. There were 24 men and 14 women (mean age: 57 years; range: 32-85 years). Two readers calculated tumor volume by manual contouring on axial CT images. The reference tumor volume was calculated by manual contouring with dedicated software applied to the liver specimen slice. CT and pathology volumes were compared and the percentage of error (PE%) was calculated. Intraobserver and interobserver variabilities were calculated using Bland and Altman plots, and intraclass correlation coefficients (ICC). RESULTS: A strong correlation was found between CT tumor volumes and pathology tumor volumes (r=0.994; P<0.001 for both readers). The mean (±SD) and median (range) PE% were 19%±12% and 16% (1%, +42%) and 19%±15% and 17% (0%, +55%) for readers 1 and 2, respectively. Readers 1 and 2 significantly overestimated tumor volume (i.e., PE%>40%) in 3 (7%) and 2 (5%) tumors on CT, respectively. Tumor volume was not significantly underestimated in any of the patients (i.e. PE%>33%). Tumor size, CT attenuation, time between imaging and surgery, contours and margin definition did not influence the results of PE% values (all P values>0.05 for both readers). The bias and limits of agreement between the two readers were +4.6% and (-24%, +33%) with an ICC of 0.997. CONCLUSION: There was a strong correlation between tumor volume measured on CT and that assessed with surgical specimen. Tumor size, visibility of contours and tumor margins and the time between CT and surgery did not influence the results.

Simultaneous MR quantification of hepatic fat content, fatty acid composition, transverse relaxation time and magnetic susceptibility for the diagnosis of non-alcoholic steatohepatitis.

Non-alcoholic steatohepatitis (NASH) is characterized at histology by steatosis, hepatocyte ballooning and inflammatory infiltrates, with or without fibrosis. Although diamagnetic material in fibrosis and inflammation can be detected with quantitative susceptibility imaging, fatty acid composition changes in NASH relative to simple steatosis have also been reported. Therefore, our aim was to develop a single magnetic resonance (MR) acquisition and post-processing scheme for the diagnosis of steatohepatitis by the simultaneous quantification of hepatic fat content, fatty acid composition, T2 * transverse relaxation time and magnetic susceptibility in patients with non-alcoholic fatty liver disease. MR acquisition was performed at 3.0 T using a three-dimensional, multi-echo, spoiled gradient echo sequence. Phase images were unwrapped to compute the B0 field inhomogeneity (ΔB0 ) map. The ΔB0 -demodulated real part images were used for fat-water separation, T2 * and fatty acid composition quantification. The external and internal fields were separated with the projection onto dipole field method. Susceptibility maps were obtained after dipole inversion from the internal field map with single-orientation Bayesian regularization including spatial priors. Method validation was performed in 32 patients with biopsy-proven, non-alcoholic fatty liver disease from which 12 had simple steatosis and 20 NASH. Liver fat fraction and T2 * did not change significantly between patients with simple steatosis and NASH. In contrast, the saturated fatty acid fraction increased in patients with NASH relative to patients with simple steatosis (48 ± 2% versus 44 ± 4%; p < 0.05) and the magnetic susceptibility decreased (-0.30 ± 0.27 ppm versus 0.10 ± 0.14 ppm; p < 0.001). The area under the receiver operating characteristic curve for magnetic susceptibility as NASH marker was 0.91 (95% CI: 0.79-1.0). Simultaneous MR quantification of fat content, fatty acid composition, T2 * and magnetic susceptibility is feasible in the liver. Our preliminary results suggest that quantitative susceptibility imaging has a high diagnostic performance for the diagnosis of NASH.

[Liver abscess]. / Abcès hépatiques.

Liver abscess is a rare and severe infection. Incidence increases because of aging of population, advances in liver and biliary surgery including liver transplantation, and immunodeficiency factors. Diagnosis depends mainly on imaging and needle aspiration for microbiological identification. Treatment is based on antibiotics, percutaneous or surgical drainage, and control of the primary source.

Academic productivity of French radiology residents: Where do we stand?

RATIONALE AND OBJECTIVES: Although medical research by French radiology residents is encouraged, their publication productivity remains unknown. Thus, we aimed to assess and analyze the publication rate of medical theses and the overall academic productivity of radiology residents who graduated in 2009 and 2010. MATERIALS AND METHODS: The list of radiology residents and imaging theses were obtained from the French internet database of university theses. The main characteristics of the theses were recorded and correlated with associated publications identified by scanning the PubMed database. All other publications by French radiology residents not related to the theses were also obtained, described and compared to published theses. RESULTS: Seventy-nine out of 224 (35.3%) medical theses written by French radiology residents in 2009 and 2010 were transformed into articles published in Medline-indexed journals. Residents were first authors in 69% (60/87) of these articles. The factors associated with publication of the thesis were a prospective design (P=0.01) and the publication as a first author of an original study not related to the thesis (P=0.01). Seventy-one percent of the residents had published at least one other article, including 36.6% as first authors. CONCLUSION: Academic productivity of French radiology residents is high thanks to published theses and other articles.