BackgroundComputed tomography (CT) scans are routinely performed in positron emission tomography (PET) and single photon emission computed tomography (SPECT) examinations globally, yet few surveys have been conducted to gather national diagnostic reference level (NDRL) data for CT radiation doses in positron emission tomography/computed tomography (PET/CT) and single photon emission computed tomography/computed tomography (SPECT/CT). In this first Nordic-wide study of CT doses in hybrid imaging, Nordic NDRL CT doses are suggested for PET/CT and SPECT/CT examinations specific to the clinical purpose of CT, and the scope for optimisation is evaluated. Data on hybrid imaging CT exposures and clinical purpose of CT were gathered for 5 PET/CT and 8 SPECT/CT examinations via designed booklet. For each included dataset for a given facility and scanner type, the computed tomography dose index by volume (CTDIvol) and dose length product (DLP) was interpolated for a 75-kg person (referred to as CTDIvol,75kg and DLP75kg). Suggested NDRL (75th percentile) and achievable doses (50th percentile) were determined for CTDIvol,75kg and DLP75kg according to clinical purpose of CT. Differences in maximum and minimum doses (derived for a 75-kg patient) between facilities were also calculated for each examination and clinical purpose.ResultsData were processed from 83 scanners from 43 facilities. Data were sufficient to suggest Nordic NDRL CT doses for the following: PET/CT oncology (localisation/characterisation, 15 systems); infection/inflammation (localisation/characterisation, 13 systems); brain (attenuation correction (AC) only, 11 systems); cardiac PET/CT and SPECT/CT (AC only, 30 systems); SPECT/CT lung (localisation/characterisation, 12 systems); bone (localisation/characterisation, 30 systems); and parathyroid (localisation/characterisation, 13 systems). Great variations in dose were seen for all aforementioned examinations. Greatest differences in DLP75kg for each examination, specific to clinical purpose, were as follows: SPECT/CT lung AC only (27.4); PET/CT and SPECT/CT cardiac AC only (19.6); infection/inflammation AC only (18.1); PET/CT brain localisation/characterisation (16.8); SPECT/CT bone localisation/characterisation (10.0); PET/CT oncology AC only (9.0); and SPECT/CT parathyroid localisation/characterisation (7.8).ConclusionsSuggested Nordic NDRL CT doses are presented according to clinical purpose of CT for PET/CT oncology, infection/inflammation, brain, PET/CT and SPECT/CT cardiac, and SPECT/CT lung, bone, and parathyroid. The large variation in doses suggests great scope for optimisation in all 8 examinations.

Test staff working in modern software consultancy companies often have to work in multiple customer projects that differ not only technically, but also regarding organisational, management and social aspects. The ease and speed with which the staff can adapt to new projects and environments is crucial for the success and profitability of the consultancy company. This paper presents the results of a study on how management in a Swedish software company can facilitate test staff relocation. Interviews with consultants in the testing department were conducted to elicit the differences between testing projects they have and are involved in and their views on the challenges of and learning needed when relocating between projects. Based on this we present an approach to better support such staff relocations in the future. The approach is based on a knowledge sharing structure and process and the introduction of specific templates to capture and document testing experience. An initial, static validation in the test consultancy show that the approach has merit and should be further evaluated. Keywords: Project staff relocation, test consultancy, test experience template ii ACKNOWLEDGEMENTSI would like to thank Dr. Robert Feldt most sincerely for the many constructive ideas given during this work. I am also grateful to Cybercom, more specifically to my advisor and to TestCenter management for believing in this work and for providing the best imaginable work environment.Finally my special gratitude is given to my beloved parents for their inexhaustible moral support, which has contributed more than they think. literature .................................................................................................... 67 D.1.3.2 Semi-static .................................................................................................................. 67 D.1.3.3 Dynamic ................................................................................................................ ..... 67 D.1.3.4 Best practices ............................................................................................................. Another was that the institute strived to promote the possibility to publish material from student thesis projects. Therefore the HMT format was outlined to contain two main parts; Part 1 is a paper written in IEEE/ACM format and covers the crucial thesis project contents and is also adapted towards publication. Part 2 is a series of appendixes which present and separate detailed methodology from specific results and other parts.This Master Thesis project is presented as a prototype version of the HMT format, and thus follows the previously described structure. The paper has been written in IEEE format since it was targeted for submission to the ICST 2008 conference ( http://www.cs.colostate.edu/icst2008/index.html). The function of this paper has been to summarize and connect the different parts of the thesis project work. It also contains an additional discussion about validity thr...