1. |
- Berntorp, Erik, et al.
(författare)
-
Centraliserad vård grundläggande i vårdprogram för blödarsjuka
- 1999
-
Ingår i: Läkartidningen. - 0023-7205. ; 96:15, s. 1849-1852
-
Tidskriftsartikel (refereegranskat)abstract
- Haemophilia is a rare and potentially life-threatening disease. In Sweden, with a population of approximately 8.5 million, about 350 people suffer from the more severe forms of haemophilia or von Willebrand disease. Meticulous management is important if the patients are to be spared chronic disability and serious treatment complications. The disease is lifelong and affects psychosocial aspects of life among patients and their families. With the help of a grant from the Swedish Board of Halth and Welfare, a care programme has been designed to guarantee Swedish haemophiliacs comparable and optimal care. The programme has been drawn up by representatives of the three haemophilia centres in Sweden (at University Hospital, Malmo, Sahlgrenska University Hospital, Gothenburg, and Karolinska Hospital, Stockholm) in co-operation with the World Federation of National Haemophilia Organisations. To ensure optimal individual application of the programme, individualised management strategies and patient information leaflets have been prepared.
|
|
2. |
- Johnsson, Stefan, et al.
(författare)
-
Off-axis primary-dose measurements using a mini-phantom
- 1997
-
Ingår i: Medical Physics. - : Wiley. - 0094-2405. ; 24:5, s. 763-767
-
Tidskriftsartikel (refereegranskat)abstract
- The characterization of the incident photon beam is usually divided into its dependence on collimator setting (head-scatter factor) and off-axis position (primary off-axis ratio). These parameters are normally measured "in air" with a build-up cap thick enough to generate full dose build-up at the depth of dose maximum. In order to prevent any influence from contaminating electrons, it has been recommended that head-scatter measurements are carried out using a mini-phantom rather than a conventional build-up cap. Due to the volume of the mini-phantom, the effects from attenuation and scatter are not negligible. In relative head-scatter measurements these effects cancel and the head scatter is thus a good representation of the variation of the incident photon beam with collimator setting. However, in off-axis measurements, attenuation and scatter conditions vary due to beam softening and do not cancel in the calculation of the primary off-axis ratio. The purpose of the present work was to estimate the effects from attenuation and phantom scatter in order to determine their influence on primary off-axis ratio measurements. We have characterized the off-axis beam-softening effect by means of narrow-beam transmission measurements to obtain the effective attenuation coefficient as a function of off-axis position. We then used a semi-analytical expression for the phantom-scatter calculation that depends solely on this attenuation coefficient. The derived formalism for relative "in air" measurements using a mini-phantom is clear and consistent, which enables the user to separately calculate the effects from scatter and attenuation. For the investigated beam qualities, 6 and 18 MV, our results indicate that the effects from attenuation and scatter in the mini-phantom nearly cancel (the combined effect is less than 1%) within 12.5 cm from the central beam axis. Thus, no correction is needed when the primary off-axis ratio is measured with a mini-phantom.
|
|
3. |
- Johnsson, Stefan, et al.
(författare)
-
Transmission measurements in air using the ESTRO mini-phantom
- 1999
-
Ingår i: Physics in Medicine and Biology. - 1361-6560. ; 44:10, s. 2445-2450
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this work is to study the possibility of using the ESTRO mini-phantom for transmission measurements of primary kerma in water at a point free in air. We discuss in-air measurements in general, with special attention given to in-air equivalent measurements using a water equivalent mini-phantom. The study includes four different photon energies (4, 6, 10 and 18 MV), where scoring of dose and primary kerma inside a mini-phantom in narrow beam geometry is performed with the Monte Carlo code EGS4. The results reveal that relative measurements (i.e. with and without a water absorber present) at 10 cm depth in a mini-phantom do not represent the variation of primary kerma in water at a point free in air (deviations as large as 7% at 4 MV are observed). Minimum deviations are obtained at depths somewhat larger than the depth of dose maximum. The observed deviations are due to a considerable beam hardening in the water absorber, which changes the amount of attenuation and scatter inside the mini-phantom.
|
|
4. |
- Tullberg, T, et al.
(författare)
-
Manipulation does not alter the position of the sacroiliac joint : a roentgen stereophotogrammetric analysis
- 1998
-
Ingår i: Spine. - 0362-2436 .- 1528-1159. ; 23:10, s. 1124-1128, discussion 1129
-
Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN A roentgen stereophotogrammetric analysis study of patients with sacroiliac joint dysfunction. OBJECTIVES To investigate whether manipulation can influence the position between the ilium and the sacrum, and whether positional tests for the sacroiliac joint are valid. SUMMARY OF BACKGROUND DATA Sacroiliac joint dysfunction is a subject of controversy. The validity of different sacroiliac joint tests is unknown. Long-standing therapeutic tradition is to manipulate supposed dysfunctions of the sacroiliac joint. Many manual therapists claim that their good clinical results are a consequence of a reduction of subluxation. METHODS Ten patients with symptoms and sacroiliac joint tests results indicating unilateral sacroiliac joint dysfunction were recruited. Twelve sacroiliac joint tests were chosen. The results of most of these tests were required to be positive before manipulation and normalized after manipulation. Roentgen stereophotogrammetric analysis was performed with the patient in the standing position, before and after treatment. RESULTS In none of the 10 patients did manipulation alter the position of the sacrum in relation to the ilium, defined by roentgen stereophotogrammetric analysis. Positional test results changed from positive before manipulation to normal after. CONCLUSIONS Manipulation of the sacroiliac joint normalized different types of clinical test results but was not accompanied by altered position of the sacroiliac joint, according to roentgen stereophotogrammetric analysis. Therefore, the positional test results were not valid. However, the current results neither disprove nor prove possible beneficial clinical effects achieved by manipulation of the sacroiliac joint. Because the supposed positive effects are not a result of a reduction of subluxation, further studies of the effects of manipulation should focus on the soft tissue response.
|
|