Phantom limb pain following amputation is highly prevalent as it affects up to 80% of amputees. Many amputees suffer from phantom limb pain for many years and experience major limitations in daily routines and quality of life. Conventional pharmacological interventions often have negative side-effects and evidence regarding their long-term efficacy is low. Central malplasticity such as the invasion of areas neighbouring the cortical representation of the amputated limb contributes to the occurrence and maintenance of phantom limb pain. In this context, alternative, non-pharmacological interventions such as mirror therapy that are thought to target these central mechanisms have gained increasing attention in the treatment of phantom limb pain. However, a standardized evidence-based treatment protocol for mirror therapy in patients with phantom limb pain is lacking, and evidence for its effectiveness is still low. Furthermore, given the chronic nature of phantom limb pain and suggested central malplasticity, published studies proposed that patients should self-deliver mirror therapy over several weeks to months to achieve sustainable effects. To achieve this training intensity, patients need to perform self-delivered exercises on a regular basis, which could be facilitated though the use of information and communication technology such as telerehabilitation. However, little is known about potential benefits of using telerehabilitation in patients with phantom limb pain, and controlled clinical trials investigating effects are lacking. The present thesis presents the findings from the ‘PAtient Centered Telerehabilitation’ (PACT) project, which was conducted in three consecutive phases: 1) creating a theoretical foundation; 2) modelling the intervention; and 3) evaluating the intervention in clinical practice. The objectives formulated for the three phases of the PACT project were: 1) to conduct a systematic review of the literature regarding important clinical aspects of mirror therapy. It focused on the evidence of applying mirror therapy in patients with stroke, complex regional pain syndrome and phantom limb pain. 2) to design and develop a clinical framework and a user-centred telerehabilitation for mirror therapy in patients with phantom limb pain following lower limb amputation. 3) to evaluate the effects of the clinical framework for mirror therapy and the additional effects of the teletreatment in patients with phantom limb pain. It also investigated whether the interventions were delivered by patients and therapists as intended.
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Op verzoek van Jelle Scheurleer: Purpose: To investigate the accuracy of dose calculation on cone beam CT (CBCT) data sets after HU-RED calibration and validation in phantom studies and clinical patients. Material and methods: Calibration of HU-RED curves for kV-CBCT were generated for three clinical protocols (H&N, thorax and pelvis) by using a Gammex RMI phantom with human tissue equivalent inserts and additional perspex blocks to account for patient scatter. Two calibration curves per clinical protocol were defined, one for the Varian Truebeam 2.0 and another for the OBI systems (Varian, Palo Ato). Differences in HU values with respect to the CT-calibration curve were evaluated for all the inserts. Four radiotherapy plans (breast, prostate, H&N and lung) were produced on an anthropomorphic phantom (Alderson) to evaluate dose differences on the kV-CBCT with the new calibration curves with respect to the CT based dose calculation. Dose differences were evaluated according to the D2%, D98% and Dmean metrics extracted from the DVHs of the plans and - evaluation (2%, 1mm) on the three planes at the isocenter for all plans. Clinical evaluation was performed on 5 patients and dose differences were evaluated as in the phantom study.
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Background: Phantom limb pain is a frequent and persistent problem following amputation. Achieving sustainable favorable effects on phantom limb pain requires therapeutic interventions such as mirror therapy that target maladaptive neuroplastic changes in the central nervous system. Unfortunately, patients’ adherence to unsupervised exercises is generally poor and there is a need for effective strategies such as telerehabilitation to support long-term self-management of patients with phantom limb pain. Objective: The main aim of this study was to describe the user-centered approach that guided the design and development of a telerehabilitation platform for patients with phantom limb pain. We addressed 3 research questions: (1) Which requirements are defined by patients and therapists for the content and functions of a telerehabilitation platform and how can these requirements be prioritized to develop a first prototype of the platform? (2) How can the user interface of the telerehabilitation platform be designed so as to match the predefined critical user requirements and how can this interface be translated into a medium-fidelity prototype of the platform? (3) How do patients with phantom limb pain and their treating therapists judge the usability of the medium-fidelity prototype of the telerehabilitation platform in routine care and how can the platform be redesigned based on their feedback to achieve a high-fidelity prototype?
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Objective: To evaluate the delivery, acceptance and experiences regarding a traditional and teletreatment approach to mirror therapy as delivered in a randomized controlled trial. Design: Mixed methods, prospective study. Setting: Rehabilitation centres, hospital and private practices. Subjects: Adult patients with phantom pain following lower limb amputation and their treating physical and occupational therapists. Interventions: All patients received 4 weeks of traditional mirror therapy (n=51), followed by 6 weeks of teletreatment (n=26) or 6 weeks of self-delivered mirror therapy (n=25). Main measures: Patient files, therapist logs, log files teletreatment, acceptance questionnaire and interviews with patients and their therapists. Results: In all, 51 patients and 10 therapists participated in the process evaluation. Only 16 patients (31%) received traditional mirror therapy according to the clinical framework during the first 4 weeks. Between weeks 5 and 10, the teletreatment was used by 14 patients (56%) with sufficient dose. Teletreatment usage decreased from a median number of 31 (weeks 5–10) to 19 sessions (weeks 11–24). Satisfactory teletreatment user acceptance rates were found with patients demonstrating higher scores (e.g. regarding the usefulness to control pain) than therapists. Potential barriers for implementation of the teletreatment perceived by patients and therapists were related to insufficient training and support as well as the frequency of technical problems. Conclusion: Traditional mirror therapy and the teletreatment were not delivered as intended in the majority of patients. Implementation of the teletreatment in daily routines was challenging, and more research is needed to evaluate user characteristics that influence adherence and how technology features can be optimized to develop tailored implementation strategies.
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Aim: Optimise a set of exposure factors, with the lowest effective dose, to delineate spinal curvature with the modified Cobb method in a full spine using computed radiography (CR) for a 5-year-old paediatric anthropomorphic phantom.Methods: Images were acquired by varying a set of parameters: positions (antero-posterior (AP), posteroanterior (PA) and lateral), kilo-voltage peak (kVp) (66-90), source-to-image distance (SID) (150 to 200cm), broad focus and the use of a grid (grid in/out) to analyse the impact on E and image quality(IQ). IQ was analysed applying two approaches: objective [contrast-to-noise-ratio/(CNR] and perceptual, using 5 observers. Monte-Carlo modelling was used for dose estimation. Cohen’s Kappa coefficient was used to calculate inter-observer-variability. The angle was measured using Cobb’s method on lateralprojections under different imaging conditions.Results: PA promoted the lowest effective dose (0.013 mSv) compared to AP (0.048 mSv) and lateral (0.025 mSv). The exposure parameters that allowed lower dose were 200cm SID, 90 kVp, broad focus and grid out for paediatrics using an Agfa CR system. Thirty-seven images were assessed for IQ andthirty-two were classified adequate. Cobb angle measurements varied between 16°±2.9 and 19.9°±0.9.Conclusion: Cobb angle measurements can be performed using the lowest dose with a low contrast-tonoise ratio. The variation on measurements for this was ±2.9° and this is within the range of acceptable clinical error without impact on clinical diagnosis. Further work is recommended on improvement tothe sample size and a more robust perceptual IQ assessment protocol for observers.
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Introduction: In clinical practice AP pelvis standard protocols are suitable for average size patients. However, as the average body size has increased over the past decades, radiographers have had to improve their practice in order to ensure that adequate image quality with minimal radiation dose to the patient is achieved. Gonad shielding has been found to be an effective way to reduce the radiation dose to the ovaries. However, the effect of increased body size, or fat thickness, in combination with gonad shielding is unclear. The goal of the study was to investigate the impact of gonad shielding in a phantom of adult female stature with increasing fat thicknesses on SNR (as a measure for image quality) and dose for AP pelvis examination. Methods: An adult Alderson female pelvis phantom was imaged with a variety of fat thickness categories as a representation of increasing BMI. 72 images were acquired using both AEC and manual exposure with and without gonad shielding. The radiation dose to the ovaries was measured using a MOSFET system. The relationship between fat thickness, SNR and dose when the AP pelvis was performed with and without shielding was investigated using the Wilcoxon signed rank test. P-values < 0.05 were considered to be statistically significant. Results: Ovary dose and SNR remained constant despite the use of gonad shielding while introducing fat layers. Conclusion: The ovary dose did not increase with an increase of fat thickness and the image quality was not altered. Implications for practice: Based on this phantom study it can be suggested that obese patients can expect the same image quality as average patients while respecting ALARA principle when using adequate protocols.
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Incidental findings on low-dose CT images obtained during hybrid imaging are an increasing phenomenon as CT technology advances. Understanding the diagnostic value of incidental findings along with the technical limitations is important when reporting image results and recommending follow-up, which may result in an additional radiation dose from further diagnostic imaging and an increase in patient anxiety. This study assessed lesions incidentally detected on CT images acquired for attenuation correction on two SPECT/CT systems.METHODS: An anthropomorphic chest phantom containing simulated lesions of varying size and density was imaged on an Infinia Hawkeye 4 and a Symbia T6 using the low-dose CT settings applied for attenuation correction acquisitions in myocardial perfusion imaging. Twenty-two interpreters assessed 46 images from each SPECT/CT system (15 normal images and 31 abnormal images; 41 lesions). Data were evaluated using a jackknife alternative free-response receiver-operating-characteristic analysis (JAFROC).RESULTS: JAFROC analysis showed a significant difference (P < 0.0001) in lesion detection, with the figures of merit being 0.599 (95% confidence interval, 0.568, 0.631) and 0.810 (95% confidence interval, 0.781, 0.839) for the Infinia Hawkeye 4 and Symbia T6, respectively. Lesion detection on the Infinia Hawkeye 4 was generally limited to larger, higher-density lesions. The Symbia T6 allowed improved detection rates for midsized lesions and some lower-density lesions. However, interpreters struggled to detect small (5 mm) lesions on both image sets, irrespective of density.CONCLUSION: Lesion detection is more reliable on low-dose CT images from the Symbia T6 than from the Infinia Hawkeye 4. This phantom-based study gives an indication of potential lesion detection in the clinical context as shown by two commonly used SPECT/CT systems, which may assist the clinician in determining whether further diagnostic imaging is justified.
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Purpose: To determine whether using different combinations of kVp and mAs with additional filtration can reduce the effective dose to a paediatric phantom whilst maintaining diagnostic image quality.Methods: 27 images of a paediatric AP pelvis phantom were acquired with different kVp, mAs and additional copper filtration. Images were displayed on quality controlled monitors with dimmed lighting. Ten diagnostic radiographers (5 students and 5 experienced radiographers) had eye tests to assess visual acuity before rating the images. Each image was rated for visual image quality against a reference image using 2 alternative forced choice software using a 5-point Likert scale. Physical measures (SNR and CNR) were also taken to assess image quality.Results: Of the 27 images rated, 13 of them were of acceptable image quality and had a dose lower than the image with standard acquisition parameters. Two were produced without filtration, 6 with 0.1mm and 5 with 0.2mm copper filtration. Statistical analysis found that the inter-rater and intra-raterreliability was high.Discussion: It is possible to obtain an image of acceptable image quality with a dose that is lower than published guidelines. There are some areas of the study that could be improved. These include using a wider range of kVp and mAs to give an exact set of parameters to use.Conclusion: Additional filtration has been identified as amajor tool for reducing effective dose whilst maintaining acceptable image quality in a 5 year old phantom.
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Patients scheduled for a magnetic resonance imaging (MRI) scan sometimes require screening for ferromagnetic Intra Orbital Foreign Bodies (IOFBs). To assess this, they are required to fill out a screening protocol questionnaire before their scan. If it is established that a patient is at high risk, radiographic imaging is necessary. This review examines literature to evaluate which imaging modality should be used to screen for IOFBs, considering that the eye is highly sensitive to ionising radiation and any dose should be minimised.Method: Several websites and books were searched for information, these were as follows: PubMed, Science Direct, Web of Knowledge and Google Scholar. The terms searched related to IOFB, Ionising radiation, Magnetic Resonance Imaging Safety, Image Quality, Effective Dose, Orbits and X-ray. Thirty five articles were found, several were rejected due to age or irrelevance; twenty eight were eventually accepted. Results: There are several imaging techniques that can be used. Some articles investigated the use of ultrasound for investigation of ferromagnetic IOFBs of the eye and others discussed using ComputedTomography (CT) and X-ray. Some gaps in the literature were identified, mainly that there are no articles which discuss the lowest effective dose while having adequate image quality for orbital imaging.Conclusion: X-ray is the best method to identify IOFBs. The only problem is that there is no research which highlights exposure factors that maintain sufficient image quality for viewing IOFBs and keep the effective dose to the eye As Low As Reasonably Achievable (ALARA).
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Stereotactische radiotherapie van wervelmetastasen vereist een hoge precisie in alle stappen van de behandeling. Deze techniek werd in het VU medisch centrum in 2009 geïntroduceerd. Data met betrekking tot de behandeling van de eerste 17 klinische patiënten is geëvalueerd. Deze patiënten werden behandeld op een Novalis Tx versneller die beschikt over zowel een kilovolt (kV) cone beam CT (CBCT) scan als het ExacTrac® kV röntgensysteem. De gebruikte methode van de verschillende beeldmodaliteiten voor positionering en verificatie, de behandelingstijd en de intrafractie beweging worden in dit artikel beschreven.
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