Evaluating the effectiveness of different perceptual training methods in a difficult visual discrimination task with ultrasound images.

Recent work has shown that perceptual training can be used to improve the performance of novices in real-world visual classification tasks with medical images, but it is unclear which perceptual training methods are the most effective, especially for difficult medical image discrimination tasks. We investigated several different perceptual training methods with medically naïve participants in a difficult radiology task: identifying the degree of hepatic steatosis (fatty infiltration of the liver) in liver ultrasound images. In Experiment 1a (N = 90), participants completed four sessions of standard perceptual training, and participants in Experiment 1b (N = 71) completed four sessions of comparison training. There was a significant post-training improvement for both types of training, although performance was better when the trained task aligned with the task participants were tested on. In both experiments, performance initially improves rapidly, with learning becoming more gradual after the first training session. In Experiment 2 (N = 200), we explored the hypothesis that performance could be improved by combining perceptual training with explicit annotated feedback presented in a stepwise fashion. Although participants improved in all training conditions, performance was similar regardless of whether participants were given annotations, or underwent training in a stepwise fashion, both, or neither. Overall, we found that perceptual training can rapidly improve performance on a difficult radiology task, albeit not to a comparable level as expert performance, and that similar levels of performance were achieved across the perceptual training paradigms we compared.

Infliximab Trough Levels Are Associated With Transmural Sonographic Healing in Inflammatory Bowel Disease.

BACKGROUND: Mucosal healing improves clinical outcomes in patients with inflammatory bowel disease (IBD) and is associated with higher infliximab trough levels (ITLs). Transmural healing, assessed by intestinal ultrasound (IUS), is emerging as an objective target in Crohn's disease (CD) and ulcerative colitis (UC). This study explores the correlation between maintenance ITLs and sonographic transmural healing. METHODS: Patients on maintenance infliximab therapy were prospectively enrolled to undergo paired IUS examination and serum ITL. Infliximab trough levels were compared between patients with and without sonographic markers of inflammation using the Mann-Whitney U test. RESULTS: A prospective cohort of 103 patients (51% male; 79 CD; 24 UC; median duration of disease 8 years) underwent IUS and serum ITL testing. Forty-one percent of CD and 66% of UC patients demonstrated sonographic healing (bowel wall thickening ≤3 mm with no increase in color Doppler signal). Crohn's disease patients with sonographic healing had higher median ITL compared with those with sonographic inflammation (4.8 µg/mL vs 3.1 µg/mL; P = .049). Additionally, the presence of hyperemia on Doppler was independently associated with lower ITL compared with those without hyperemia (2.1 µg/mL vs 4.2 µg/mL, respectively; P = .003). There was no significant association between ITL and other sonographic markers of inflammation. In UC, lower ITL was associated with hyperemia on Doppler imaging (P = .04). There was no association between ITL and sonographic healing or any other individual sonographic parameter of inflammation. CONCLUSIONS: Lower maintenance infliximab levels are associated with sonographic parameters of inflammation in UC and CD. Further studies are needed to determine whether targeting higher infliximab levels can increase sonographic healing.

Transmural healing assessed by intestinal ultrasound allows for objective assessment of disease activity. Lower maintenance infliximab levels were associated with sonographic parameters of inflammation in IBD. Further studies are needed to determine whether targeting higher infliximab levels can increase sonographic healing.

Systematic Review: Clinical Utility of Gastrointestinal Ultrasound in the Diagnosis, Assessment and Management of Patients With Ulcerative Colitis.

BACKGROUND AND AIMS: Gastrointestinal ultrasound is useful in the assessment of patients with Crohn's disease, but its application in ulcerative colitis [UC] is less well established. Here we systematically review the role of gastrointestinal ultrasound in patients with UC. METHODS: Searches of the PUBMED and EMBASE databases were performed with the following search strategy: [ultrasound OR sonography] AND [intestinal OR bowel] AND [ulcerative colitis OR inflammatory bowel disease]. The final search was performed in August 2019. RESULTS: Of 6769 studies identified in the search with a further two studies found from other sources, 50 studies met the inclusion criteria. Increased bowel wall thickness and detection of increased blood flow by colour Doppler were the most often applied criteria for defining disease activity and distribution. When compared with other reference investigations, gastrointestinal ultrasound accurately determined disease extent, severity and response to medical therapy. While further information can be obtained from haemodynamic measurements of the abdominal vessels and contrast-enhanced ultrasound, their clinical value was uncertain. Likewise, hydrocolonic sonography has few advantages over standard gastrointestinal ultrasound examination. Of several scoring systems proposed, there is disparity between the measures and a general lack of validation. There has been limited application of gastrointestinal ultrasound in acute severe ulcerative colitis with toxic megacolon, and, while performing well in children, normal limits differ from those in adults. CONCLUSION: Current evidence indicates that gastrointestinal ultrasound has utility in the non-invasive assessment of patients with UC. Continued advances in technology with better image resolution, validation of scoring systems and application at the point of care by gastroenterologists are likely to contribute to increased use of gastrointestinal ultrasound in routine clinical practice.

Fontan-associated liver disease: pathophysiology, investigations, predictors of severity and management.

Cardiac hepatopathy is the liver injury resulting from congestion and ischaemia associated with acute or chronic heart failure. The improved longevity of adults with operated congenital heart disease who develop heart failure as an increasingly late event makes this form of liver injury increasingly clinically relevant. Patients with congenital heart disease with a single ventricle anomaly, who require creation of a Fontan circulation, are particularly vulnerable as they have elevated venous filling pressures with chronic liver congestion. Progression to liver fibrosis and eventually cirrhosis may occur, with its associated risks of liver failure and hepatocellular carcinoma. This risk likely increases over the patient's lifetime, related to the duration post-surgical repair and reflects the chronicity of congestion. Liver biopsy is rarely performed due to a higher risk of complications in the setting of elevated venous pressures, and the frequent use of anticoagulation. Non-invasive methods of liver assessment are poorly validated and different factors require consideration compared to other chronic liver diseases. This review discusses the current understanding of cardiac hepatopathy in congenital heart disease patients with a Fontan circulation. This entity has recently been called Fontan Associated Liver Disease in the literature, with the term useful in recognising that the pathophysiology is incompletely understood, and that long-standing venous pressure elevation and hypoxaemia are presumed to play an additional significant role in the pathogenesis of the liver injury.

Variability of Liver Shear Wave Measurements Using a New Ultrasound Elastographic Technique.

OBJECTIVES: A new 2-dimensional (2D) shear wave elastographic (SWE) device has been developed for the noninvasive assessment of liver fibrosis. Guidelines on measurement acquisition parameters are not yet well established for this technique. Our study aimed to assess 2D SWE measurement variability and to determine the number of measurements required per patient to reliably assess liver stiffness. METHODS: Two-dimensional SWE was assessed in 55 patients with mixed-etiology chronic liver disease on an Aplio 500 ultrasound system (Toshiba Medical Systems Corporation, Tochigi, Japan). Ten measurements were obtained per patient by an operator blinded to all preceding readings. Results were analyzed with clinical information obtained from medical records. RESULTS: The median interquartile range/median ratio for 2D SWE was 0.131 (quartiles 1-3, 0.089-0.174). Five readings provided an approximation within 0.11 m/s, or 4.2% of the median velocity of 10 measurements. Factors associated with increased measurement variability included body mass index (ρ = 0.388; P = .01), increased skin-to-liver capsule distance (ρ = 0.426; P = .002), and measurements taken within 1.5 cm of the liver capsule (P < .001). Measurements with heterogeneous shear wave profiles (indicated by a region of interest [ROI] SD/speed ratio > 0.15) showed greater deviation from the set's median velocity than those with an ROI SD/speed ratio of 0.15 or lower (0.42 versus 0.22 m/s; P = .001). CONCLUSIONS: Two-dimensional SWE showed low overall measurement variability, with a minimum of 5 readings providing equivalent precision to the existing method using 10 samples. Obesity, increasing abdominal wall thickness, subcapsular measurements and an ROI SD/speed ratio of greater than 0.15 were all associated with increased measurement variability. The ROI SD/speed ratio warrants further evaluation as a quality assessment metric, to allow objective operator assessment of individual 2D SWE measurement reliability in real time.

Targeted ultrasound of the liver: Impact on scanning time of a new approach in chronic liver disease.

INTRODUCTION: Targeted ultrasound of the liver (TUSL) has been proposed as a new approach in chronic liver disease to meet the increasing demands on ultrasound services in this patient population. This study analyses the impact of TUSL on examination time. METHODS: Retrospective cohort analysis of time taken to perform liver ultrasound on consecutive chronic liver disease patients pre- (n = 230) and post- (n = 147) introduction of TUSL. Within each cohort, patients were subdivided into three categories based on the clinical indication: Group 1. hepatocellular carcinoma (HCC) surveillance; Group 2. detection of cirrhosis, fibrosis or fatty liver; Group 3. detection of portal hypertension. The primary outcome was difference in examination time in the pre- and post-intervention groups. RESULTS: Introduction of TUSL led to 49% reduction in examination time (median (Q1-Q3) 23.7 (16.7-36.2) min in pre-TUSL period vs 12.1 (6.4-19.5) min in post, P < 0.001) and it was consistent across all three clinical indication groups (gr1: median 23.1 minutes vs 8.1 minutes (P < 0.001), gr2: 23.0 minutes vs 14.3 minutes (P < 0.001), gr3: 32.2 minutes vs 15.3 minutes (P = 0.006)). After the adjustment for clinical indication and sonographer's experience, impact of TUSL on time reduction remained significant with a 66.6% time reduction (95% CI 53.6 to 79.5). CONCLUSION: Targeted ultrasound of the liver improves efficiency of chronic liver disease ultrasound with halving of examination times and consequently has the potential to greatly improve resource utilization.

Fortuitously discovered liver lesions.

The fortuitously discovered liver lesion is a common problem. Consensus might be expected in terms of its work-up, and yet there is none. This stems in part from the fact that there is no preventive campaign involving the early detection of liver tumors other than for patients with known liver cirrhosis and oncological patients. The work-up (detection and differential diagnosis) of liver tumors comprises theoretical considerations, history, physical examination, laboratory tests, standard ultrasound, Doppler ultrasound techniques, contrast-enhanced ultrasound (CEUS), computed tomography and magnetic resonance imaging, as well as image-guided biopsy. CEUS techniques have proved to be the most pertinent method; these techniques became part of the clinical routine about 10 years ago in Europe and Asia and are used for a variety of indications in daily clinical practice. CEUS is in many cases the first and also decisive technical intervention for detecting and characterizing liver tumors. This development is reflected in many CEUS guidelines, e.g., in the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) guidelines 2004, 2008 and 2012 as well as the recently published World Federation for Ultrasound in Medicine and Biology-EFSUMB guidelines 2012. This article sets out considerations for making a structured work-up of incidental liver tumors feasible.

Guidelines and good clinical practice recommendations for Contrast Enhanced Ultrasound (CEUS) in the liver - update 2012: A WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS.

Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.

Targeted liver ultrasound for chronic liver disease: time to focus?

Increasing prevalence of chronic liver disease has led to dramatically increased demands on ultrasound for diagnosis, monitoring and surveillance of complications. Targeted ultrasound of the liver provides an efficient and possibly more accurate means of meeting this demand. It uses a matrix to guide the ultrasound examination to address the specific clinical questions commonly asked in this population. It is easy to implement and can be modified to meet local preferences and emerging technologies.

Two decades of percutaneous transjejunal biliary intervention for benign biliary disease: a review of the intervention nature and complications.

OBJECTIVE: To assess outcomes of percutaneous transjejunal biliary intervention (PTJBI) in terms of success and effectiveness in patients with a Roux-en-Y hepaticojejunostomy for benign biliary strictures and stones. METHODS: Clinical and radiographic records of 63 patients with a Roux-en-Y choledochojejunostomy or hepaticojejunostomy for benign disease who underwent at least one PTJBI between 1986 and 2007 were reviewed. Effectiveness was determined by successful access rate, rates of stricture dilatation and/or stone extraction, morbidity, complications and hospitalisation. RESULTS: PTJBI was attempted 494 times. Successful access to the Roux-en-Y was accomplished in 93% of interventions. After access to the Roux-en-Y was granted, all strictures were effectively dilated. Ninety-seven percent of extraction attempts of intrahepatic calculi were successful. The median number of interventions per patient was five. The median interval between interventions was 51.5 weeks (range 2.7-1,279.6 weeks). The early complication rate was 3%. Morbidity, measured in terms of cholangitis episodes was 14%, in 25 out of 63 patients. Mean hospitalisation was 4.1 nights per year. CONCLUSION: PTJBI is safe and effective in treating benign biliary strictures and/or calculi. High success rates and short hospitalisation periods, together with few complications make it a well-accepted and integral part of managing complex biliary problems.

Lobar and segmental liver atrophy associated with hilar cholangiocarcinoma and the impact of hilar biliary anatomical variants: a pictorial essay.

The radiological features of lobar and segmental liver atrophy and compensatory hypertrophy associated with biliary obstruction are important to recognise for diagnostic and therapeutic reasons. Atrophied lobes/segments reduce in volume and usually contain crowded dilated bile ducts extending close to the liver surface. There is often a "step" in the liver contour between the atrophied and non-atrophied parts. Hypertrophied right lobe or segments enlarge and show a prominently convex or "bulbous" visceral surface. The atrophied liver parenchyma may show lower attenuation on pre-contrast computed tomography (CT) and CT intravenous cholangiography (CT-IVC) and lower signal intensity on T1-weighted magnetic resonance imaging (MRI). Hilar biliary anatomical variants can have an impact on the patterns of lobar/segmental atrophy, as the cause of obstruction (e.g. cholangiocarcinoma) often commences in one branch, leading to atrophy in that drainage region before progressing to complete biliary obstruction and jaundice. Such variants are common and can result in unusual but explainable patterns of atrophy and hypertrophy. Examples of changes seen with and without hilar variants are presented that illustrate the radiological features of atrophy/hypertrophy.

Hepatic vein morphology: a new sonographic diagnostic parameter in the investigation of cirrhosis?

OBJECTIVE: The purpose of this study was to evaluate the accuracy of a new sonographic marker for the diagnosis of cirrhosis using hepatic vein wall changes. METHODS: A prospective pilot study evaluating 88 patients, 38 with cirrhosis and 50 with no evidence of liver disease, was undertaken. Hard copy sonograms of the hepatic veins were obtained and reviewed in a blinded fashion by 2 radiologists. The hepatic vein morphology was assessed by 3 parameters: hepatic vein wall straightness, uniformity of hepatic vein wall echogenicity, and visualization of a complete 1-cm hepatic vein segment. The 3 parameters were compared to evaluate sensitivity and specificity for the diagnosis of cirrhosis. Interobserver and intraobserver errors for each parameter were also calculated with kappa statistics to assess reproducibility. RESULTS: There was a strong correlation between altered straightness and nonuniformity of hepatic vein wall echogenicity and cirrhosis. The straightness parameter had superior sensitivity of 97% (95% confidence interval [CI], 85%-100%) and specificity of 91% (95% CI, 78%-97%) for diagnosis of cirrhosis. Uniformity of hepatic vein wall echogenicity was the next most useful parameter, with sensitivity of 88% (95% CI, 73%-97%) and specificity of 86% (95% CI, 72%-95%). The continuous 1-cm segment of the hepatic vein had sensitivity of 68% (95% CI, 49%-83%) and specificity of 91% (95% CI, 78%-97%). Hepatic vein evaluation was found to show both good intraobserver and interobserver error. CONCLUSIONS: Hepatic vein morphology on sonography, in particular, changes in the straightness and uniformity of hepatic vein wall echogenicity, is a new sign of cirrhosis, which may increase the overall accuracy of sonographic diagnosis of cirrhosis and which appears to have a moderately high degree of reproducibility.

Preoperative imaging for DIEA perforator flaps: a comparative study of computed tomographic angiography and doppler ultrasound.

BACKGROUND: Abdominal donor-site flaps, including the transverse rectus abdominis musculocutaneous (TRAM) and deep inferior epigastric artery (DIEA) perforator flaps, are standard in autologous breast reconstruction. With significant variation in the vascular anatomy of the abdominal wall, preoperative imaging is essential for preoperative planning and reducing intraoperative error. Doppler and color duplex sonography have been used with varying results, and the quest continues for optimal preoperative assessment. Computed tomographic angiography has recently been proposed as a noninvasive modality for this purpose. This is the first study to formally compare preoperative Doppler ultrasound with computed tomographic angiography for imaging the DIEA. METHODS: Eight consecutive patients undergoing DIEA perforator flap surgery for breast reconstruction underwent both computed tomographic angiography and Doppler ultrasound preoperatively. All investigations and procedures were performed at the same institution with the same primary and assisting surgeons and the same radiology team. RESULTS: Computed tomographic angiography was superior to Doppler ultrasound at identifying the course of the DIEA and its branching pattern, and in visualizing its perforators. Preoperative computed tomographic angiography was highly specific (100 percent) and more sensitive in mapping and visualizing perforators (p = 0.0078). It was also proficient at identifying the superficial epigastric arterial system and for effectively displaying the results intraoperatively. It was substantially quicker and removed the interobserver error associated with Doppler ultrasonography. The study was ceased after eight patients because of the overwhelming benefit of computed tomographic angiography over Doppler ultrasonography. CONCLUSION: Computed tomographic angiography is a valuable imaging modality for the preoperative assessment of the donor-site vascular supply for TRAM and DIEA perforator flaps.

Preoperative imaging for DIEA perforator flaps: a comparative study of computed tomographic angiography and Doppler ultrasound.

BACKGROUND: Abdominal donor-site flaps, including the transverse rectus abdominis musculocutaneous (TRAM) and deep inferior epigastric artery (DIEA) perforator flaps, are standard in autologous breast reconstruction. With significant variation in the vascular anatomy of the abdominal wall, preoperative imaging is essential for preoperative planning and reducing intraoperative error. Doppler and color duplex sonography have been used with varying results, and the quest continues for optimal preoperative assessment. Computed tomographic angiography has recently been proposed as a noninvasive modality for this purpose. This is the first study to formally compare preoperative Doppler ultrasound with computed tomographic angiography for imaging the DIEA. METHODS: Eight consecutive patients undergoing DIEA perforator flap surgery for breast reconstruction underwent both computed tomographic angiography and Doppler ultrasound preoperatively. All investigations and procedures were performed at the same institution with the same primary and assisting surgeons and the same radiology team. RESULTS: Computed tomographic angiography was superior to Doppler ultrasound at identifying the course of the DIEA and its branching pattern, and in visualizing its perforators. Preoperative computed tomographic angiography was highly specific (100 percent) and more sensitive in mapping and visualizing perforators (p = 0.0078). It was also proficient at identifying the superficial epigastric arterial system and for effectively displaying the results intraoperatively. It was substantially quicker and removed the interobserver error associated with Doppler ultrasonography. The study was ceased after eight patients because of the overwhelming benefit of computed tomographic angiography over Doppler ultrasonography. CONCLUSION: Computed tomographic angiography is a valuable imaging modality for the preoperative assessment of the donor-site vascular supply for TRAM and DIEA perforator flaps.

Value of magnetic resonance cholangiopancreatography in the diagnosis of biliary abnormalities in postcholecystectomy patients: a probabilistic cost-effectiveness analysis of diagnostic strategies.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is considered the gold standard for imaging of the biliary tract but is associated with complications. Less invasive imaging techniques, such as magnetic resonance cholangiopancreatography (MRCP), have a much lower complication rate. The accuracy of MRCP is comparable to that of ERCP, and MRCP may be more effective and cost-effective, particularly in cases for which the suspected prevalence of disease is low and further intervention can be avoided. A model was constructed to compare the effectiveness and cost-effectiveness of MRCP and ERCP in patients with a previous history of cholecystectomy, presenting with abdominal pain and/or abnormal liver function tests. METHODS: Diagnostic accuracy estimates came from a systematic review of MRCP. A decision analytic model was constructed to represent the diagnostic and treatment pathway of this patient group. The model compared the following two diagnostic strategies: (i) MRCP followed with ERCP if positive, and then management based on ERCP; and (ii) ERCP only. Deterministic and probabilistic analyses were used to assess the likelihood of MRCP being cost-effective. Sensitivity analyses examined the impact of prior probabilities of common bile duct stones (CBDS) and test performance characteristics. The outcomes considered were costs, quality-adjusted life years (QALYs), and cost per additional QALY. RESULTS: The deterministic analysis indicated that MRCP was dominant over ERCP. At prior probabilities of CBDS, less than 60 percent MRCP was the less costly initial diagnostic test; above this threshold, ERCP was less costly. Similarly, at probabilities of CBDS less than 68 percent, MRCP was also the more effective strategy (generated more QALYs). Above this threshold, ERCP became the more effective strategy. Probabilistic sensitivity analyses indicated that, in this patient group for which there is a low to moderate probability of CBDS, there was a 59 percent likelihood that MRCP was cost-saving, an 83 percent chance that MRCP was more effective with a higher quality adjusted survival, and an 83 percent chance that MRCP had a cost-effectiveness ratio more favorable than dollars 50,000 per QALY gained. CONCLUSIONS: Costs and cost-effectiveness are dependent upon the prior probability of CBDS. However, probabilistic analysis indicated that, with a high degree of certainty, MRCP was the more effective and cost-effective initial test in postcholecystectomy patients with a low to moderate probability of CBDS.

Accuracy of computed tomographic intravenous cholangiography (CT-IVC) with iotroxate in the detection of choledocholithiasis.

To determine the accuracy of computed tomographic intravenous cholangiography (CT-IVC) for detection of choledocholithiasis. Sixty-five patients undergoing endoscopic retrograde cholangiography (ERC) underwent CT-IVC prior to ERC, using a single detector helical CT following intravenous infusion of 100 ml iotroxate. Patients with bilirubin levels >3 times normal were excluded. ERC was indeterminate in three patients (4.7%) and CT-IVC in four (6.3%). Twenty-three patients had ductal calculi at ERC, and CT-IVC was positive in 22, with two false positives and one false negative: sensitivity 95.6%, specificity 94.3%. Stones were multiple in nine and solitary in 14. Of the 14 solitary stones, ten were

Role of radiology in the treatment of malignant hilar biliary strictures 1: review of the literature.

Malignant strictures of the biliary tree are an uncommon cause of obstructive jaundice. There are a number of pathological subtypes, but tumours in this region tend to have similar clinical and diagnostic features and therapeutic and prognostic implications. We review the published literature on this topic discussing diagnostic modalities and treatment options with a focus on radiological intervention. Diagnosis currently is best achieved using a range of procedures. Direct cholangiography remains the gold standard in delineating anatomy, but the invasiveness of this procedure limits its use as a purely diagnostic tool. Magnetic resonance technology, in particular magnetic resonance cholangiopancreatography, has an increasing role as accessibility is improved. Treatment of these tumours is difficult. Surgical resection and palliative biliary enteric bypass are the most common methods used with endoscopic and percutaneous therapies reserved for palliating patients not fit for surgery. There is little firm evidence to suggest that any one palliative modality is superior. Interventional radiology is particularly suitable for palliative management of difficult and expansive lesions as the anatomy can preclude easy access by surgical or endoscopic techniques. Good palliative results with minimal mortality and morbidity can be achieved with percutaneous stenting.

Ultrasound diagnostic capabilities in native kidney disease.

Renal ultrasound and Doppler studies remain vital diagnostic tools in the evaluation of common renal disorders. It is a non invasive and radiation free tool, which provides anatomical and functional information not provided by other modalities used in isolation. It is a first line tool for many suspected pathologies and is a valuable complementary tool to other modalities.