A MODEL FOR EVALUATING THE USE OF IMAGING IN IMAGE-GUIDED INTERVENTIONAL PROCEDURES-POSSIBLE IMPLICATIONS ON OPTIMISATION OF RADIATION PROTECTION.

The present study focuses on introducing the concept of optimisation and proposing a model, including evaluation of image quality, to be used in the clinical routines where image-guided intervention is being performed. The overall aim of the study was to develop a model for evaluating the use of imaging in X-ray-guided interventional procedures and its possible implications on optimisation of radiation protection. In the search for an adequate evaluation model, data from endovascular interventions of the aorta (EVAR procedures) were used. The procedure was schematically described in steps. Every imaging event was connected to the steps in the medical procedure and was also described with the purpose of the imaging event. Available technical, as well as procedural parameters, were studied and analysed. Data were collected from the X-ray equipment for 70 EVAR procedures and, out of these, 12 procedures were randomly selected to be recorded on video to understand the procedure better. It was possible to describe the EVAR procedures in a general way with explanations of the clinical purpose connected to each imaging event. Possible quality parameters of the procedure were identified for the imaging events (radiation dose, image quality). The model method still needs to be refined and will then be applied to clinical data and to other clinical procedures to test the validity.

Effectiveness of internet-based cognitive behaviour therapy for panic disorder in routine psychiatric care.

OBJECTIVE: Guided Internet-based cognitive behaviour therapy (ICBT) for panic disorder has been shown to be efficacious in several randomized controlled trials. However, the effectiveness of the treatment when delivered within routine psychiatric care has not been studied. The aim of this study was to investigate the effectiveness of ICBT for panic disorder within the context of routine psychiatric care. METHOD: We conducted a cohort study investigating all patients (n = 570) who had received guided ICBT for panic disorder between 2007 and 2012 in a routine care setting at an out-patient psychiatric clinic providing Internet-based treatment. The primary outcome measure was the Panic Disorder Severity Scale-Self-report (PDSS-SR). RESULTS: Participants made large improvements from screening and pretreatment assessments to posttreatment (Cohen's d range on the PDSS-SR = 1.07-1.55). Improvements were sustained at 6-month follow-up. CONCLUSION: This study suggests that ICBT for panic disorder is as effective when delivered in a routine care context as in the previously published randomized controlled trials.

Head kinematics in mini-sled tests of foam padding: relevance of linear responses from free motion headform (FMH) testing to head angular responses.

The revised Federal Motor Vehicle Safety Standard (FMVSS) No. 201 specifies that the safety performance of vehicle upper interiors is determined from the resultant linear acceleration response of a free motion headform (FMH) impacting the interior at 6.7 m/s. This study addresses whether linear output data from the FMH test can be used to select an upper interior padding that decreases the likelihood of rotationally induced brain injuries. Using an experimental setup consisting of a Hybrid III head-neck structure mounted on a mini-sled platform, sagittal plane linear and angular head accelerations were measured in frontal head impacts into foam samples of various stiffness and density with a constant thickness (51 mm) at low (approximately 5.0 m/s), intermediate (approximately 7.0 m/s), and high (approximately 9.6 m/s) impact speeds. Provided that the foam samples did not bottom out, recorded peak values of angular acceleration and change in angular velocity increased approximately linearly with increasing peak resultant linear acceleration and value of the Head Injury Criterion (HIC36). The results indicate that the padding that produces the lowest possible peak angular acceleration and peak change in angular velocity without causing high peak forces is the one that produces the lowest possible HIC36 without bottoming out in the FMH test.

Influence of the lateral ventricles and irregular skull base on brain kinematics due to sagittal plane head rotation.

Two-dimensional physical models of the human head were used to investigate how the lateral ventricles and irregular skull base influence kinematics in the medial brain during sagittal angular head dynamics. Silicone gel simulated the brain and was separatedfrom the surrounding skull vessel by paraffin that provided a slip interface between the gel and vessel. A humanlike skull base model (HSB) included a surrogate skull base mimicking the irregular geometry of the human. An HSBV model added an elliptical inclusion filled with liquid paraffin simulating the lateral ventricles to the HSB model. A simplified skull base model (SSBV) included ventricle substitute but approximated the anterior and middle cranial fossae by a flat and slightly angled surface. The models were exposed to 7600 rad/s2 peak angular acceleration with 6 ms pulse duration and 5 deg forced rotation. After 90 deg free rotation, the models were decelerated during 30 ms. Rigid body displacement, shear strain and principal strains were determined from high-speed video recorded trajectories of grid markers in the surrogate brains. Peak values of inferior brain surface displacement and strains were up to 10.9X (times) and 3.3X higher in SSBV than in HSBV. Peak strain was up to 2.7X higher in HSB than in HSBV. The results indicate that the irregular skull base protects nerves and vessels passing through the cranial floor by reducing brain displacement and that the intraventricular cerebrospinal fluid relieves strain in regions inferior and superior to the ventricles. The ventricles and irregular skull base are necessary in modeling head impact and understanding brain injury mechanisms.

Simulation of acute subdural hematoma and diffuse axonal injury in coronal head impact.

Coronal head impacts were simulated in a physical model, based on the hypothesis that acute subdural hematoma (ASDH) is related to cerebral vertex displacement and diffuse axonal injury (DAI) to local Green-Lagrange strain. The geometry of the 2D model was based on anatomical measurements taken from the MRI scans of 10 adult males. Silicone gel modelled the cerebrum, paraffin the CSF and elastic membranes the trabeculae of the sulci. Pendulum impacts gave peak angular acceleration of 7800 rad s(-2) in models with and without sulci. The motion of the gel and Green-Lagrange strain were calculated from tracked coordinates of Patrick markers. Worst-case bridging vein strains are produced on the contrecoup side and are approximately doubled by adding sulci. Given that axons in the corpus callosum are highly oriented, Green-Lagrange strain was resolved in the fibre direction. It is found to be close to the minimum principal strain, indicating a degree of natural, teleological protection for the axons. The data support the use of delta0peak as a suitable descriptor for the risk of DAI but not for ASDH.

Strain relief from the cerebral ventricles during head impact: experimental studies on natural protection of the brain.

Physical models of the parasagittal human skull/brain have been tested to investigate whether the cerebral ventricles provide natural protection of the brain by relieving strain during head rotation. A sophisticated model included anatomical structures, and a semicircular model consisted of a cylinder divided into two semicircles. Silicone gel simulated the brain and was detached from the vessel by a layer of liquid paraffin simulating the cerebrospinal fluid. Both models were run with and without an elliptical inclusion filled with liquid paraffin simulating a cerebral ventricle. The 2D models were exposed to angular acceleration by a pendulum impact causing 7600 rad/s2 peak rotational acceleration with 6 ms pulse duration. After rotating 100 degrees, the models were decelerated during 30 ms. The trajectory of grid markers was analyzed from high-speed video (1000 frames/s). Rigid-body displacement, shear strain and principal strain were determined from the displacement of three-point sets inferior and superior to the ventricle. For the subventricular (inferior) region in the sophisticated model, approximately 40% lower peak strain values were obtained in the model with ventricle than in the one without. Subcortical displacement was reduced by 12%. Corresponding strain reduction in the subcortical (superior) region was approximately 40% following the acceleration and 25% following the deceleration. Similar but less pronounced effects were found for the semicircular model. The lateral ventricles play an important role as strain relievers and provide natural protection against brain injury.

Health problems and care in young families--load of illness and patterns of illness behaviour.

During a winter month 185 young suburban families reported in a diary on perceived health problems and measures taken in response to these problems. Information on socio-economical factors, medical experience and structure of the social network was obtained from a mailed questionnaire. As a mean every fourth individual-day a health problem was recorded. The majority (61%) of symptoms were infections and only 14% of illness days were classified as severe. On every sixth of all reported individual days measures were taken to handle health problems. Seven per cent of measures taken in response to a perceived health problem were taken in collaboration with the social network and in less than 1/10 of reported symptom days and 1/5 of reported illness episodes the professional medical system was contacted. For health problems in children 1/3 of the contacts were taken by telephone and often with the child welfare nurse. The demands for professional help was dependent on type and severity of symptoms, duration of illness episodes as well as on the category of family member. Within the family the health problems were preferentially handled by the mother and the dominating type of treatment was medication (73% of total activity). It is concluded that young families perceive and handle a huge amount of health problems without communication with the professional health care system.

Health problems and care in young families--an evaluation of survey procedures.

This report compares the value of a diary, and telephone interviews covering either the previous 24 hours or the previous week as methods of collecting data from young families on perceived health problems and the measures taken to deal with them. The population of 310 families was randomly divided into three groups. The study design allowed the evaluation of both qualitative and quantitative aspects of the different methods. For each individual a health problem was perceived every four days and care for health problems was reported every six days. The frequency of participation was highest in the 24-hour recall group. In the diary group a weekly telephone call elicited a higher compliance than a weekly letter of reminder. In spite of a higher reporting of symptoms in the diaries the relative number of measures taken was greater in the two recall groups. When comparing the information obtained by one-week recalls with that of 24-hour recalls it was found that the risk of forgetting a perceived symptom or measure taken was low but the risk of overreporting symptom days may increase with time. The distribution of symptoms in eight main categories was equal as reported by the different methods. The cost for the investigator per individual day covered was more expensive when using the 24-hour recall method compared to the diary method.