Diffuse liver disease classification from ultrasound surface characterization, clinical and laboratorial data

In this work liver contour is semi-automatically segmented and quantified in order to help the identification and diagnosis of diffuse liver disease. The features extracted from the liver contour are jointly used with clinical and laboratorial data in the staging process. The classification results of a support vector machine, a Bayesian and a k-nearest neighbor classifier are compared. A population of 88 patients at five different stages of diffuse liver disease and a leave-one-out cross-validation strategy are used in the classification process. The best results are obtained using the k-nearest neighbor classifier, with an overall accuracy of 80.68%. The good performance of the proposed method shows a reliable indicator that can improve the information in the staging of diffuse liver disease

Profiles of US and CT imaging features with a high probability of appendicitis

To identify and evaluate profiles of US and CT features associated with acute appendicitis. Consecutive patients presenting with acute abdominal pain at the emergency department were invited to participate in this study. All patients underwent US and CT. Imaging features known to be associated with appendicitis, and an imaging diagnosis were prospectively recorded by two independent radiologists. A final diagnosis was assigned after 6 months. Associations between appendiceal imaging features and a final diagnosis of appendicitis were evaluated with logistic regression analysis. Appendicitis was assigned to 284 of 942 evaluated patients (30%). All evaluated features were associated with appendicitis. Imaging profiles were created after multivariable logistic regression analysis. Of 147 patients with a thickened appendix, local transducer tenderness and peri-appendiceal fat infiltration on US, 139 (95%) had appendicitis. On CT, 119 patients in whom the appendix was completely visualised, thickened, with peri-appendiceal fat infiltration and appendiceal enhancement, 114 had a final diagnosis of appendicitis (96%). When at least two of these essential features were present on US or CT, sensitivity was 92% (95% CI 89-96%) and 96% (95% CI 93-98%), respectively. Most patients with appendicitis can be categorised within a few imaging profiles on US and CT. When two of the essential features are present the diagnosis of appendicitis can be made accuratel

Better Visualization of Vermiform Appendix with Tissue Harmonic Imaging Compared to Conventional Sonography

BACKGROUND: Surgery of appendicitis carries 7-11% negative appendectomy rates. Sonographically visualized normal appendix precludes unnecessary computed tomography (CT) examination and may reduce negative appendectomy rates. Tissue harmonic imaging (THI) has been reported to improve the overall image quality. OBJECTIVE: We aimed to assess whether THI is more successful than conventional ultrasonography (US) in detecting normal and pathologic appendices. PATIENTS AND METHODS: The study was performed on 185 patients who applied for routine US examinations in whom clinical findings of appendicitis were detected in 25. We searched for the appendix; applying both THI and conventional US to each patient, one before and the other after the routine US examinations. Patients were divided into two groups; one was evaluated first with conventional US and the other first with THI. When the appendix was found, localization, diameter and time spent for visualization were recorded. Twelve patients were operated; all of whom had appendicitis pathologically. Two methods were compared for: 1. Success rates in all patients; female, male and child groups separately; 2. Visualization of pathologic and normal appendices; 3. Time for visualization of appendix; 4. Comparison of success rates in the adult and child population. The relationship between the rate of visualization and body mass index was evaluated. RESULTS: The appendix was visualized better by THI in all patients, and in the female and male groups (P < 0.001). In children, both methods were more successful compared to adults (P < 0.001, compared to male group, P < 0.001, compared to female group), with no difference between the methods (P = 0.22). When only the normal appendices were concerned, there was significant difference between both methods (P < 0.000). Both methods detected pathologic appendices better than normal ones, with a higher ratio for THI (P = 0.022 for the THI group, and χ(2 )= 7.22, P = 0.07 for the conventional US group). THI visualized the appendix faster. Both methods were more successful in lean patients (P = 0.004 for THI, P = 0.001 for conventional US imaging). CONCLUSIONS: THI visualizes appendix better than conventional US. It is a simple and time saving method that may eliminate further diagnostic imaging, and it may decrease negative appendectomy rates and related complications