Determination of cardiac output with dynamic contrast-enhanced computed tomography.

Cardiac output (CO) is an important diagnostic and prognostic factor in the haemodynamic evaluation of patients. The gold standard for CO measurement, thermodilution, requires an invasive right-heart catheterisation (RHC). In this pilot study we aimed to determine the accuracy of non-invasive CO determination from dynamic contrast-enhanced computed tomography (CT) compared to thermodilution.

A case of tracheobronchial amyloidosis treated with endoscopic debulking and external beam radiation therapy.

We report on a 55-year-old patient who was admitted to hospital because of recurrent pneumonia. CT imaging provided airway narrowing and mural thickening of the distal trachea and mainstem bronchi, compatible with endobronchial polypoid, toric-shaped changes of the distal tracheal wall spreading into both the left and right bronchial system. Bronchoscopy was performed and biopsies revealed the diagnosis of tracheobronchial amyloidosis.

Measuring quality in cancer care: overview of initiatives in selected countries.

To inform the Austrian National Cancer Plan on possible generic quality indicators that might be derived from routine data a systematic literature search in three databases, followed by extensive hand-searching to locate initiatives and their publications was carried out in spring 2011. Twenty-one initiatives that developed indicators for measuring quality of cancer care were identified: longer standing and decentralised initiatives are characteristics of the USA. The Canadian province of Ontario publishes the Cancer System Quality Index, centralised audit and peer review programmes are undertaken in the National Health Service in the UK.

Conversion of Stratus optical coherence tomography (OCT) retinal thickness to Cirrus OCT values in age-related macular degeneration.

Aim: Spectral domain optical coherence tomography (SD OCT) is of increasing importance and is gradually replacing time domain OCT (TD OCT). Our aim was to determine a formula to convert Stratus OCT (TD OCT) to Cirrus OCT (SD OCT) retinal thickness.

Methods: Central retinal thickness (CRT) and retinal volume (RV) were obtained by the macular thickness program of Stratus OCT and the cube 512 × 128 program of Cirrus OCT in patients with exudative age-related macular degeneration (AMD).

Decision support in vaccination policies.

Background: Looking across boarders reveals that the national immunization programs of various countries differ in their vaccination schedules and decisions regarding the implementation and funding of new vaccines. The aim of this review is to identify decision aids and crucial criteria for a rational decision-making process on vaccine introduction and to develop a theoretical framework for decision-making based on available literature.

Methods: Systematic literature search supplemented by hand-search.

Lessons learned from the analysis of 200 laparoscopic sigmoid resections for diverticulitis.

Introduction: Since the beginning of laparoscopic surgery indications for laparoscopic colon resections are still discussed controversively. In the latest studies benefit for laparoscopic approach is reported. The aim of this study was to evaluate the feasibility of laparoscopic sigmoid resections for diverticulitis regarding conversion rate, operation time and intraoperative and postoperative complications, and defining strategies to prevent complications.

Diffuse skull base/cervical fusion syndromes in two siblings with spondylocostal dysostosis syndrome: analysis via three dimensional computed tomography scanning.

Study Design: A study on a pair of male sibs to reach for the etiological understanding of unusual skull base/spine maldevelopment.

Objective: Previously, radiographs alone were used to formulate this diagnosis. Here, three-dimensional computed tomography (3D CT) studies further clarified the typical diagnostic findings associated with spondylocostal dysostosis (SCD).

[Cohort studies].

This article about cohort studies is part of a methods series about study designs and their critical evaluation by the Ludwig Boltzmann Institute for Health Technology assessment. This article aims to describe the theoretical concept of cohort studies and their typical characteristics. Furthermore, it strives to highlight advantages and disadvantages of this study type and to make suggestions for the critical evaluation of the significance and validity of cohort studies.

Biologics for the treatment of juvenile idiopathic arthritis: a systematic review and critical analysis of the evidence.

Biologics are an important therapeutic option for treating patients with juvenile idiopathic arthritis (JIA). In adults, they are associated with rare but severe adverse events such as serious infections and malignancies. We reviewed systematically the evidence on the efficacy and safety of biologics for the treatment of JIA.

Knowledge-based computer-aided decision support in prenatal toxoplasmosis screening (TempToxopert).

The development of TempToxopert aimed at assisting clinicians in analysing the results of prenatal toxoplasmosis screening tests. Expert knowledge about diagnostics, screening strategies, and treatment of toxoplasmosis during pregnancy was collected and represented as a rule-based decision graph. Based on actual and past individual findings, the system generates case-specific interpretative reports consisting of a diagnostic hypothesis, recommendations for further treatment, and interpretations of specific test results.

Evaluation of a new electromagnetic tracking system using a standardized assessment protocol.

This note uses a published protocol to evaluate a newly released 6 degrees of freedom electromagnetic tracking system (Aurora, Northern Digital Inc.). A practice for performance monitoring over time is also proposed.

Direct detector radiography versus dual reading computed radiography: feasibility of dose reduction in chest radiography.

The image quality of dual-reading computed radiography and dose-reduced direct radiography of the chest was compared in a clinical setting. The study group consisted of 50 patients that underwent three posteroanterior chest radiographs within minutes, one image obtained with a dual read-out computed radiography system (CR; Fuji 5501) at regular dose and two images with a flat panel direct detector unit (DR; Diagnost, Philips). The DR images were obtained with the same and with 50% of the dose used for the CR images.

Imagery of motor actions: differential effects of kinesthetic and visual-motor mode of imagery in single-trial EEG.

Single-trial motor imagery classification is an integral part of a number of brain-computer interface (BCI) systems. The possible significance of the kind of imagery, involving rather kinesthetic or visual representations of actions, was addressed using the following experimental conditions: kinesthetic motor imagery (MIK), visual-motor imagery (MIV), motor execution (ME) and observation of movement (OOM). Based on multi-channel EEG recordings in 14 right-handed participants, we applied a learning classifier, the distinction sensitive learning vector quantization (DSLVQ) to identify relevant features (i.

Brain-computer communication based on the dynamics of brain oscillations.

This chapter presents a review of brain-computer communication based on motor imagery and the dynamics of brain oscillations. The concept of motor imagery as experimental strategy and the two different modes of operation a brain-computer interface can have are explained. An EEG based brain switch that can control a FES-induced hand grasp of a tetraplegic and an approach towards an ECoG based brain switch are presented.

Phase relationships between different subdural electrode recordings in man.

Almost all brain-computer interfaces (BCIs) ignore information related to the phase coupling between electroencephalogram (EEG) or electrocorticogram (ECoG) recordings from different electrodes. This paper investigates whether additional information can be found when calculating the amount of synchronization between two electrode channels by using a phase locking measurement called the phase locking value (PLV). Special emphasis is put on the beta band (around 20 Hz) as well as the gamma band (high frequencies up to 95 Hz), which can only be used when subdural electrode recordings are available.

"Virtual keyboard" controlled by spontaneous EEG activity.

A "virtual keyboard" (VK) is a letter spelling device operated for example by spontaneous electroencephalogram (EEG), whereby the EEG is modulated by mental hand and leg motor imagery. We report on three able-bodied subjects, operating the VK. The ability in the use of the VK varies between 0.

Induced oscillations in the alpha band: functional meaning.

The phenomena of event-related desynchronization (ERD) and synchronization (ERS) reflect the dynamics of neural networks and can be observed on different scalp locations at the same moment of time. Whereas on one cortical area a focal 10-Hz ERD can be found, other areas can display a 10-Hz ERS. This phenomenon is called focal ERD/surround ERS and is interpreted as a correlate of an activated cortical area (ERD) and simultaneously deactivated or inhibited other areas.

Clinical application of an EEG-based brain-computer interface: a case study in a patient with severe motor impairment.

Objective: This case study describes how a completely paralyzed patient, diagnosed with severe cerebral palsy, was trained over a period of several months to use an electroencephalography (EEG)-based brain-computer interface (BCI) for verbal communication.

Methods: EEG feedback training was performed in the patient's home (clinic), supervised from a distant laboratory with the help of a 'telemonitoring system'. Online feedback computation was based on single-trial analysis and classification of specific band power features of the spontaneous EEG.

Event-related dynamics of cortical rhythms: frequency-specific features and functional correlates.

Oscillations in the alpha and beta band (<35 Hz) display a dynamic behavior and show characteristic spatiotemporal patterns in sensory, motor and cognitive tasks. The event-related desynchronization (ERD) of alpha band and beta rhythms can be seen as a correlate of an activated cortical area with an increased excitability level of neurons. An event-related synchronization (ERS) of frequency components between 10 and 13 Hz may represent a deactivated cortical area or inhibited cortical network, at least under certain circumstances.

Evidence for distinct beta resonance frequencies in human EEG related to specific sensorimotor cortical areas.

Objective: We studied event-related synchronization (ERS) of beta rhythms related to voluntary movement vs. stimulation of upper and lower limbs. The aim of this study was to investigate whether the frequency of the beta response is related to specific regions within the sensorimotor strip.

Information transfer rate in a five-classes brain-computer interface.

The information transfer rate, given in bits per trial, is used as an evaluation measurement in a brain-computer interface (BCI). Three subjects performed four motor-imagery (left hand, right hand, foot, and tongue) and one mental-calculation task. Classification of the electroencephalogram (EEG) patterns is based on band power estimates and hidden Markov models (HMMs).

Functional brain imaging based on ERD/ERS.

Sensory, cognitive and motor processing can result in changes of the ongoing EEG in form of an event-related desynchronization (ERD) or event-related synchronization (ERS). Both phenomena are time-locked but not phase-locked to the event and they are highly frequency-band specific. The ERD is interpreted as a correlate of an activated cortical area with increased excitability and the ERS in the alpha and lower beta bands can be interpreted, at least under certain circumstances, as a correlate of a deactivated cortical area.

Placement of endosteal implants in the zygoma after maxillectomy: a Cadaver study using surgical navigation.

Endosteal implants facilitate obturator prosthesis fixation in tumor patients after maxillectomy. Previous clinical studies have shown, however, that the survival of implants placed into available bone after maxillectomy is generally poor. Nevertheless, implants positioned optimally in residual zygomatic bone provide superior stability from a biomechanical point of view.

Frequency component selection for an EEG-based brain to computer interface.

A new communication channel for severely handicapped people could be opened with a direct brain to computer interface (BCI). Such a system classifies electrical brain signals online. In a series of training sessions, where electroencephalograph (EEG) signals are recorded on the intact scalp, a classifier is trained to discriminate a limited number of different brain states.