Zoekresultaten

Lesion detection performance

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.

OPTIMAX 2018: a focus on education in Radiology

OPTIMAX

This year, OPTIMAX was warmly welcomed by University College Dublin. For the sixth time students and teachers from Europe, South Africa, South America and Canada have come together enthusiastically to do research in the Radiography domain. As in previous years, there were several research groups consisting of PhD-, MSc- and BSc students and tutors from the OPTIMAX partner Universities or on invitation by partner Universities. OPTIMAX 2018 was partly funded by the partner Universities and partly by the participants.

Treating phantom limb pain following amputation

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.

Factors associated with phantom limb pain

OBJECTIVE: To analyse the prevalence of phantom (limb) pain over time and to analyse factors associated with phantom (limb) pain in a prospective cohort of amputees.DESIGN: A multicentre longitudinal study.PATIENTS: One hundred and thirty-four patients scheduled for amputation were included.METHODS: Patients filled in questionnaires before amputation, and postal questionnaires six months, 1(1/2) years and 2(1/2) years to a maximum of 3(1/2) years after amputation. Preoperative assessment included patients' characteristics, date, side and level of, and reason for amputation. The follow-up questionnaires assessed the frequencies of the experienced phantom pain, prosthetic use and walking distance. The occurrence of phantom pain was defined as phantom pain a few times a day or more frequently.RESULTS: Pre- and postoperative questionnaires were available filled in by 85 amputees (33 females and 52 males). The percentage of lower limb amputees with phantom pain was the highest at six months after amputation, and of upper limb amputees at 1(1/2) years. In general, more women than men experienced phantom pain. One and a half years and 2(1/2) years after amputation the highest percentages of the lower limb amputees used their prosthesis more than 4 hours a day (66%), after that time this percentage decreased to 60%. The results of the two-level logistic regression analysis to predict phantom pain show that phantom pain was less frequently present in men (odds ratio (OR) = 0.12), in lower limb amputees (OR = 0.14) and that it decreased in due course (OR = 0.53 for 1 year).CONCLUSION: Protective factors for phantom pain are: being male, having a lower limb amputation and the time elapsed since amputation.

Comparative analysis of radiation dose and low contrast detail detectability using routine paediatric chest radiography protocols

OBJECTIVES: To compare low contrast detail (LCD) detectability and radiation dose for routine paediatric chest X-ray (CXR) imaging protocols among various hospitals.METHODS: CDRAD 2.0 phantom and medical grade polymethyl methacrylate (PMMA) slabs were used to simulate the chest region of four different paediatric age groups. Radiographic acquisitions were undertaken on 17 X-ray machines located in eight hospitals using their existing CXR protocols. LCD detectability represented by image quality figure inverse (IQF inv) was measured physically using the CDRAD analyser software. Incident air kerma (IAK) measurements were obtained using a solid-state dosimeter. RESULTS: The range of IQF inv, between and within the hospitals, was 1.40-4.44 and 1.52-2.18, respectively for neonates; 0.96-4.73 and 2.33-4.73 for a 1-year old; 0.87-1.81 and 0.98-1.46 for a 5-year old and 0.90-2.39 and 1.27-2.39 for a 10-year old. The range of IAK, between and within the hospitals, was 8.56-52.62 μGy and 21.79-52.62 μGy, respectively for neonates; 5.44-82.82 μGy and 36.78-82.82 μGy for a 1-year old; 10.97-59.22 μGy and 11.75-52.94 μGy for a 5-year old and 13.97-100.77 μGy and 35.72-100.77 μGy for a 10-year old. CONCLUSIONS: Results show considerable variation, between and within hospitals, in the LCD detectability and IAK. Further radiation dose optimisation for the four paediatric age groups, especially in hospitals /X-ray rooms with low LCD detectability and high IAK, are required.