ABSTRACT
Patients with biliary strictures often represent a diagnostic and therapeutic challenge, due to the site and complexity of biliary obstruction and wide differential diagnosis. Multidisciplinary decision making is required to reach an accurate and timely diagnosis and to plan optimal care. Developments in endoscopic ultrasound and peroral cholangioscopy have advanced the diagnostic yield of biliary endoscopy, and novel optical imaging techniques are emerging. Endoscopic approaches to biliary drainage are preferred in most scenarios, and recent advances in therapeutic endoscopic ultrasound allow drainage where the previous alternatives were only percutaneous or surgical. Here we review recent advances in endoscopic practice for the diagnosis and management of biliary strictures. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni and Peter Jansen.
Subject(s)
Bile Duct Neoplasms/diagnosis , Bile Ducts/diagnostic imaging , Cholangiocarcinoma/diagnosis , Cholestasis/diagnosis , Bile Duct Neoplasms/pathology , Bile Ducts/pathology , Bile Ducts/surgery , Biopsy , Cholangiocarcinoma/pathology , Cholangiocarcinoma/surgery , Cholangiopancreatography, Endoscopic Retrograde/methods , Cholestasis/etiology , Cholestasis/pathology , Cholestasis/surgery , Constriction, Pathologic/diagnosis , Constriction, Pathologic/etiology , Constriction, Pathologic/pathology , Constriction, Pathologic/surgery , Diagnosis, Differential , Drainage/methods , Endosonography/methods , HumansABSTRACT
BACKGROUND: Universal infant free school meals (UIFSM) were introduced in September 2014 and are available to all key stage 1 (4-7 years) children attending state-maintained infant and primary schools in England. The present study aimed to investigate the school-based factors, child and family socio-demographic characteristics, and parental beliefs associated with UIFSM take up in an urban community. METHODS: A cross-sectional questionnaire survey was completed in October to November 2015, amongst parents whose children attended eligible schools in Leicester, England. A questionnaire about school meals was also completed by each school. RESULTS: Parents reported their child did not take (non-UIFSM, n = 159) or took (UIFSM, n = 517) a UIFSM on most days. The non-UIFSM group were more likely to be White-British, have a higher socio-economic status, have English as a first language, and involve their child in the decision over whether or not to take UIFSM, compared to the UIFSM group. Cluster analysis revealed that non-UIFSM parents were either concerned over quality of meals and what/how much their child ate, concerned only by what/how much their child ate or whether their child did not like the food provided. Two subsets of parents in the UIFSM group were either very positive about UIFSM or appeared to take meals because they were free. Schools used a variety of measures to increase and maintain UIFSM take up. CONCLUSIONS: Parents like to have control over what their child eats at school and children need to enjoy their school meals. Using a range of interventions to target subsets of parents may help local authorities, schools and caterers to increase UIFSM take up.
Subject(s)
Culture , Food Services , Meals , Schools , Urban Population , Child , Child, Preschool , Cluster Analysis , Cross-Sectional Studies , England , Female , Humans , Male , Parents , Socioeconomic Factors , Surveys and QuestionnairesABSTRACT
A new technique of patient positioning for radiotherapy/radiosurgery of extracranial tumours using three-dimensional (3D) ultrasound images has been developed. The ultrasound probe position is tracked within the treatment room via infrared light emitting diodes (IRLEDs) attached to the probe. In order to retrieve the corresponding room position of the ultrasound image, we developed an initial ultrasound probe calibration technique for both 2D and 3D ultrasound systems. This technique is based on knowledge of points in both room and image coordinates. We first tested the performance of three algorithms in retrieving geometrical transformations using synthetic data with different noise levels. Closed form solution algorithms (singular value decomposition and Horn's quaternion algorithms) were shown to outperform the Hooke and Jeeves iterative algorithm in both speed and accuracy. Furthermore, these simulations show that for a random noise level of 2.5, 5, 7.5 and 10 mm, the number of points required for a transformation accuracy better than 1 mm is 25, 100, 200 and 500 points respectively. Finally, we verified the tracking accuracy of this system using a specially designed ultrasound phantom. Since ultrasound images have a high noise level, we designed an ultrasound phantom that provides a large number of points for the calibration. This tissue equivalent phantom is made of nylon wires, and its room position is optically tracked using IRLEDs. By obtaining multiple images through the nylon wires, the calibration technique uses an average of 300 points for 3D ultrasound volumes and 200 for 2D ultrasound images, and its stability is very good for both rotation (standard deviation: 0.4 degrees) and translation (standard deviation: 0.3 mm) transformations. After this initial calibration procedure, the position of any voxel in the ultrasound image volume can be determined in world space, thereby allowing real-time image guidance of therapeutic procedures. Finally, the overall tracking accuracy of our 3D ultrasound image-guided positioning system was measured to be on average 0.2 mm, 0.9 mm and 0.6 mm for the AP, lateral and axial directions respectively.
