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Testing of beam characteristics of physiotherapy ultrasound transducers by analyzing thermal images
Abstracts / Physica Medica 32 (2016) 284–339
Conclusion. 177Lu-Octreotate PRRT can be safely performed on an outpatient basis, as long as individualised radiation protection instructions are provided and followed by the caregivers. http://dx.doi.org/10.1016/j.ejmp.2016.07.201
TESTING OF BEAM CHARACTERISTICS OF PHYSIOTHERAPY ULTRASOUND TRANSDUCERS BY ANALYZING THERMAL IMAGES Gordana Zˇauhar a,c,*, Ðeni Smilovic´-Radojcˇic´ b, Zoran Kaliman c, Tea Schnurrer Luke Vrbanic d, Slaven Jurkovic´ a,b a
University of Rijeka, Medical Faculty, Department of Medical Physics and Biophysics, Rijeka, Croatia b Clinical Hospital Rijeka, Medical Physics Department, Rijeka, Croatia c University of Rijeka, Department of Physics, Rijeka, Croatia d Clinical Hospital Rijeka, Department for Physical and Rehabilitation Medicine, Rijeka, Croatia ⇑ Corresponding author. Introduction. The clinical effects of ultrasound used for physiotherapy depend on applied intensity and time of insonation. Output intensities of 0.1–3.0 W/cm2 are typically applied for therapeutic purposes in pulsed or continuous modes. In order to accurately measure the output characteristics of ultrasonic therapy transducers, an evaluation of effective radiating area (ERA) and beam homogeneity must be made regularly in order to prevent patient damage. Purpose. Implementation of the method based on use of thermochromic tile in clinical environment for the verification of ultrasound fields produced by transducers used for physiotherapy. Materials and methods. In this work non-standardized method developed at National Physical Laboratory (NPL) was used for quality assurance of ultrasound therapy beams. The method consists of exposing thermocromic tile to the ultrasonic beam thereby forming an thermal image of the intensity profile of transducer. The image is in turn photographed and analyzed using software developed for that purpose. Results. Several physiotherapy ultrasound transducers clinically used were tested by use of thermocromic tile in the hospital environment. Thermal images were postprocesed in order to estimate effective radiating area and beam nonuniformity ratio (BNR) for tested transducers. Conclusion. Results of our measurements have shown that thermocromic tile can be used for rapid check of ultrasound transducers in the hospital environment. Furthermore, our work has also shown that it is possible postprocess thermal images in order to calculate some beam parameters such as effective radiating area (ERA) and beam nonuniformity ratio (BNR). http://dx.doi.org/10.1016/j.ejmp.2016.07.202
TOWARDS TASK-BASED ASSESSMENT OF PET PERFORMANCE: SYSTEM AND OBJECT DQE ACROSS DIFFERENT RECONSTRUCTION ALGORITHMS A. Samartzis a,*, G. Fountos b, G.A. Kastis c, E. Kounadi d, I. Datseris a, I. Kandarakis b, G. Nikiforidis e a
‘‘EVANGELISMOS” General Hospital/Nuclear Medicine Department, Ypsilantou 45-47, 10676 Athens, Greece b Technological Educational Institute (TEI) of Athens/Department of Medical Instruments Technology, Ag. Spyridonos, 12210 Athens, Greece c Research Center of Mathematics, Academy of Athens, Athens 11527, Greece d ‘‘ALEXANDRA” General Hospital/Department of Medical Physics, Vasilisis Sofias 80, 11528 Athens, Greece
319
e University of Patras/Department of Medical Physics, Medical School, Rio, 26500 Patras, Greece ⇑ Corresponding author.
Introduction. Detective quantum efficiency (DQE) of an imaging system is an indicator of the image quality metrics of the system taking into consideration detector efficiency. Purpose. To investigate a measurement method for evaluating the DQE of a PET imaging system across reconstruction algorithms. Methods and materials. A novel and highly homogeneous, high – activity flood source was prepared, placed between two semi cylindrical PMMA blocks and imaged in a PET/CT scanner. The modulation transfer function (MTF) was calculated from the line spread function (LSF) of the transverse slice of the thin flat source. The normalized noise power spectrum (NNPS) was also calculated from the coronal slice of the same source. Furthermore, the DQE was calculated from the number of photons emitted from the plane source which is a measure for the incoming SNR2. The authors adapted the DQE concept to reconstruction, in order to quantify the impact of reconstruction algorithm on image quality. Results. The effect of 2D (with septa) and 3D (without septa) scanning modes on DQE was investigated and statistical significant differences were found (p < 0.05). The reconstruction DQE was determined for conventional and fully 3D iterative reconstruction algorithms, with several combinations of iterations and subsets. Conclusion. The determination of DQE via MTF and NNPS, could be useful in characterizing different PET/CT systems in terms of image quality metrics and detector efficiency. Moreover, DQE could be a useful criterion for the evaluation of different PET reconstruction algorithms. Disclosure. The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. http://dx.doi.org/10.1016/j.ejmp.2016.07.203
FMRI STUDIES PRIOR AND POST ACUPUNCTURE TREATMENT CONCERNING SMOKING CESSATION K. Theodoratou a, F. Christidi b, P. Toulas c, D.A. Verganelakis c,* a
ICMART, SAMAG, Alimos, Greece Aiginiteion Hospital, Athens, Greece c Encephalos-Euromedica Medical Diagnostic Center, Halandri, Greece ⇑ Corresponding author. b
Introduction. Acupuncture has been widely reported to be a popular and safe intervention for smoking cessation. This study demonstrates the potential effects of acupuncture treatment for smoking cessation using the MRI technique of functional Magnetic Resonance Imaging (fMRI). Purpose. Substance dependence or addiction is nowadays uderstood in a multifactorial etiological model, which includes psychological, neurobiological, genetic, social and environmental factors. This study illustrates patterns of fMRI activation in various specific brain anatomies, such as frontal, temporal parietal, occipital and cerebellum that correlate with smoking. Materials and methods. Participants of both genders were volunteers willing to quit smoking. The inclusion criteria were age (28–42 y) and rate of smoking >15 cigarrettes per day and had no previous experience of acupuncture treatment. Group A received real acupuncture, Group B sham acupuncture and Group C was the control group with no smokers. Acupuncture points used: Du-20, LI-20, LI-4,TB-5, ST-36, LIV-3 and treatments lasted for 20 min. fMRI was applied prior and post acupuncture treatment during the first 24 hours of smoking cessation. During the fMRI experiment
Conclusion. 177Lu-Octreotate PRRT can be safely performed on an outpatient basis, as long as individualised radiation protection instructions are provided and followed by the caregivers. http://dx.doi.org/10.1016/j.ejmp.2016.07.201
TESTING OF BEAM CHARACTERISTICS OF PHYSIOTHERAPY ULTRASOUND TRANSDUCERS BY ANALYZING THERMAL IMAGES Gordana Zˇauhar a,c,*, Ðeni Smilovic´-Radojcˇic´ b, Zoran Kaliman c, Tea Schnurrer Luke Vrbanic d, Slaven Jurkovic´ a,b a
University of Rijeka, Medical Faculty, Department of Medical Physics and Biophysics, Rijeka, Croatia b Clinical Hospital Rijeka, Medical Physics Department, Rijeka, Croatia c University of Rijeka, Department of Physics, Rijeka, Croatia d Clinical Hospital Rijeka, Department for Physical and Rehabilitation Medicine, Rijeka, Croatia ⇑ Corresponding author. Introduction. The clinical effects of ultrasound used for physiotherapy depend on applied intensity and time of insonation. Output intensities of 0.1–3.0 W/cm2 are typically applied for therapeutic purposes in pulsed or continuous modes. In order to accurately measure the output characteristics of ultrasonic therapy transducers, an evaluation of effective radiating area (ERA) and beam homogeneity must be made regularly in order to prevent patient damage. Purpose. Implementation of the method based on use of thermochromic tile in clinical environment for the verification of ultrasound fields produced by transducers used for physiotherapy. Materials and methods. In this work non-standardized method developed at National Physical Laboratory (NPL) was used for quality assurance of ultrasound therapy beams. The method consists of exposing thermocromic tile to the ultrasonic beam thereby forming an thermal image of the intensity profile of transducer. The image is in turn photographed and analyzed using software developed for that purpose. Results. Several physiotherapy ultrasound transducers clinically used were tested by use of thermocromic tile in the hospital environment. Thermal images were postprocesed in order to estimate effective radiating area and beam nonuniformity ratio (BNR) for tested transducers. Conclusion. Results of our measurements have shown that thermocromic tile can be used for rapid check of ultrasound transducers in the hospital environment. Furthermore, our work has also shown that it is possible postprocess thermal images in order to calculate some beam parameters such as effective radiating area (ERA) and beam nonuniformity ratio (BNR). http://dx.doi.org/10.1016/j.ejmp.2016.07.202
TOWARDS TASK-BASED ASSESSMENT OF PET PERFORMANCE: SYSTEM AND OBJECT DQE ACROSS DIFFERENT RECONSTRUCTION ALGORITHMS A. Samartzis a,*, G. Fountos b, G.A. Kastis c, E. Kounadi d, I. Datseris a, I. Kandarakis b, G. Nikiforidis e a
‘‘EVANGELISMOS” General Hospital/Nuclear Medicine Department, Ypsilantou 45-47, 10676 Athens, Greece b Technological Educational Institute (TEI) of Athens/Department of Medical Instruments Technology, Ag. Spyridonos, 12210 Athens, Greece c Research Center of Mathematics, Academy of Athens, Athens 11527, Greece d ‘‘ALEXANDRA” General Hospital/Department of Medical Physics, Vasilisis Sofias 80, 11528 Athens, Greece
319
e University of Patras/Department of Medical Physics, Medical School, Rio, 26500 Patras, Greece ⇑ Corresponding author.
Introduction. Detective quantum efficiency (DQE) of an imaging system is an indicator of the image quality metrics of the system taking into consideration detector efficiency. Purpose. To investigate a measurement method for evaluating the DQE of a PET imaging system across reconstruction algorithms. Methods and materials. A novel and highly homogeneous, high – activity flood source was prepared, placed between two semi cylindrical PMMA blocks and imaged in a PET/CT scanner. The modulation transfer function (MTF) was calculated from the line spread function (LSF) of the transverse slice of the thin flat source. The normalized noise power spectrum (NNPS) was also calculated from the coronal slice of the same source. Furthermore, the DQE was calculated from the number of photons emitted from the plane source which is a measure for the incoming SNR2. The authors adapted the DQE concept to reconstruction, in order to quantify the impact of reconstruction algorithm on image quality. Results. The effect of 2D (with septa) and 3D (without septa) scanning modes on DQE was investigated and statistical significant differences were found (p < 0.05). The reconstruction DQE was determined for conventional and fully 3D iterative reconstruction algorithms, with several combinations of iterations and subsets. Conclusion. The determination of DQE via MTF and NNPS, could be useful in characterizing different PET/CT systems in terms of image quality metrics and detector efficiency. Moreover, DQE could be a useful criterion for the evaluation of different PET reconstruction algorithms. Disclosure. The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. http://dx.doi.org/10.1016/j.ejmp.2016.07.203
FMRI STUDIES PRIOR AND POST ACUPUNCTURE TREATMENT CONCERNING SMOKING CESSATION K. Theodoratou a, F. Christidi b, P. Toulas c, D.A. Verganelakis c,* a
ICMART, SAMAG, Alimos, Greece Aiginiteion Hospital, Athens, Greece c Encephalos-Euromedica Medical Diagnostic Center, Halandri, Greece ⇑ Corresponding author. b
Introduction. Acupuncture has been widely reported to be a popular and safe intervention for smoking cessation. This study demonstrates the potential effects of acupuncture treatment for smoking cessation using the MRI technique of functional Magnetic Resonance Imaging (fMRI). Purpose. Substance dependence or addiction is nowadays uderstood in a multifactorial etiological model, which includes psychological, neurobiological, genetic, social and environmental factors. This study illustrates patterns of fMRI activation in various specific brain anatomies, such as frontal, temporal parietal, occipital and cerebellum that correlate with smoking. Materials and methods. Participants of both genders were volunteers willing to quit smoking. The inclusion criteria were age (28–42 y) and rate of smoking >15 cigarrettes per day and had no previous experience of acupuncture treatment. Group A received real acupuncture, Group B sham acupuncture and Group C was the control group with no smokers. Acupuncture points used: Du-20, LI-20, LI-4,TB-5, ST-36, LIV-3 and treatments lasted for 20 min. fMRI was applied prior and post acupuncture treatment during the first 24 hours of smoking cessation. During the fMRI experiment