Relation reversals in ontological systems refer to such patterns as a path from concept A to concept B in one version becoming a path with the position of A and B switched in another version. We present a scalable approach, using cloud computing, to systematically extract all hierarchical relation reversals among 8 SNOMED CT versions from 2009 to 2014. Taking advantage of our MapReduce algorith...

This case report presents three-dimensional computed tomography (3D-CT) findings in the diagnosis of Eagle's syndrome that is characterized with an elongated styloid process or a calcified stylohyoid ligament causing craniofacial or cervical pain. We have performed 3D-CT in three patients suspected to have this condition. Coronal images were taken in two patients and axial images in one patient...

OBJECTIVES Cranial computed tomography (CT) is replacing skull radiography in head trauma. Rapid radiological opinions on these images may not always be available. We assessed the ability of our permanent emergency department staff to interpret the images. METHODS A retrospective series of 100 consecutive cases was reviewed and interpreted by five permanent emergency department medical staff,...

BACKGROUND PET-CT is becoming more and more important in various aspects of oncology. Until recently it was used mainly as part of diagnostic procedures and for evaluation of treatment results. With development of personalized radiotherapy, volumetric and radiobiological characteristics of individual tumour have become integrated in the multistep radiotherapy (RT) planning process. Standard ana...

We evaluated the dosimetric effect of a respiration motion, and sought an effective planning strategy to compensate the motion using four-dimensional computed tomography (4D CT) dataset of seven selected liver patients. For each patient, we constructed four different proton plans based on: (1) average (AVG) CT, (2) maximum-intensity projection (MIP) CT, (3) AVG CT with density override of tumor...

PURPOSE To quantify the intra- and interfractional variations between lung tumours and implanted markers. MATERIALS AND METHODS Gold markers were implanted transbronchially around a lung tumour in fifteen patients. They underwent four-dimensional computed tomography scans twice, and the centroids of the tumour and markers were determined. Intrafractional variations were defined as the residua...

PURPOSE To prospectively determine management strategies used by international thoracic radiologists in evaluation of small (3-5-mm) pulmonary nodules at chest computed tomography (CT). MATERIALS AND METHODS Institutional review board exemption was granted for this study, which included consenting participants. An electronic survey was sent to members of major thoracic radiology societies in ...

Fig. 1 : CT thorax showing asymmetrical fissural and perivascular nodules and linear opacities in both lungs Fig. 2 : FDG PET showing tracer uptake in bilateral pulmonary parenchyma corresponding to the HRCT findings. Fig. 3: Post treatment HRCT thorax showing regression in fissural and perivascular nodules but persistence in the linear opacities Fig. 4: Post treatment FDG PET showing significa...

Four-dimensional computed tomography (4D CT) is used to account for respiratory motion in radiation treatment planning, but artifacts resulting from the acquisition and postprocessing limit its accuracy. We investigated the efficacy of three experimental 4D CT acquisition methods to reduce artifacts in a prospective institutional review board approved study. Eighteen thoracic patients scheduled...

The aim of our work is to present, test and validate an automated registration method used for matching brain SPECT scans with corresponding MR scans. The method was applied on a data set consisting of ten brain IDEX SPECT scans and ten T1- and T2-weighted MR scans of the same subjects. Of two subjects a CT scan was also made. (Semi-) automated algorithms were used to extract the brain from the...