IntroductionThe EOS stereoradiography system has shown to provide reliable varus/valgus (VV) measurements of the lower limb in 2D (VV2D) and 3D (VV3D) after total knee arthroplasty (TKA). Validity of these measurements has not been investigated yet, therefore the purpose of this study was to determine validity of EOS VV2D and VV3D.MethodsEOS images were made of a lower limb phantom containing a knee prosthesis, while varying VV angle from 15° varus to 15° valgus and flexion angle from 0° to 20°, and changing rotation from 20° internal to 20° external rotation. Differences between the actual VV position of the lower limb phantom and its position as measured on EOS 2D and 3D images were investigated.ResultsRotation, flexion or VV angle alone had no major impact on VV2D or VV3D. Combination of VV angle and rotation with full extension did not show major differences in VV2D measurements either. Combination of flexion and rotation with a neutral VV angle showed variation of up to 7.4° for VV2D; maximum variation for VV3D was only 1.5°. A combination of the three variables showed an even greater distortion of VV2D, while VV3D stayed relatively constant. Maximum measurement difference between preset VV angle and VV2D was 9.8°, while the difference with VV3D was only 1.9°. The largest differences between the preset VV angle and VV2D were found when installing the leg in extreme angles, for example 15° valgus, 20° flexion and 20° internal rotation.ConclusionsAfter TKA, EOS VV3D were more valid than VV2D, indicating that 3D measurements compensate for malpositioning during acquisition. Caution is warranted when measuring VV angle on a conventional radiograph of a knee with a flexion contracture, varus or valgus angle and/or rotation of the knee joint during acquisition.

To explore reasons that influence a resident's choice for the nuclear medicine subspecialty in the integrated nuclear medicine and radiology residency program in the Netherlands. MethodsA web questionnaire was developed and distributed among residents in the Dutch integrated nuclear medicine and radiology training. ResultsA total of 114 residents were included. The survey results revealed four categories of incentives to choose the nuclear medicine subspecialty: 1) Expertise of nuclear medicine physicians and their quality of supervision in the training hospital, 2) Opportunities to do scientific research during and after residency, 3) Diversity of pathology, radiotracers, examinations and therapies in the training hospital, and 4) The expectation that the role of hybrid imaging will increase in the future. They also revealed four groups of disincentives to choose the nuclear medicine subspecialty: 1) Lack of collaboration and integration between nuclear medicine and radiology in some training hospitals, 2) Imbalance between nuclear medicine and radiology during the first 2.5 years of basic training during residency at the expense of nuclear medicine, 3) Uncertainty regarding the international recognition of the nuclear medicine subspecialty training, and 4) Uncertain future of nuclear medicine regarding the chances of employment and the ratio of work activities of nuclear medicine to radiology. ConclusionThis study provided insight into residents' motives to pursue or refrain from nuclear medicine subspecialization in an integrated nuclear medicine and radiology residency program. Medical imaging specialists in training hospitals and developers of curricula for nuclear medicine and radiology training should take these motives into account to ensure a sufficient outflow of newly graduated nuclear medicine specialists.