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Evaluation of radiographers’ and CT technologists’ knowledge regarding CT exposure parameters

Abstract

Introduction: Since the CT operators play an important role in the diagnosis and treatment of diseases and exposing the patients to radiation exposure, they must be aware of all CT parameters which affect the image quality and patient dose and update their knowledge in parallel with the progresses in CT technology. Therefore, the knowledge of radiographers and CT technologists regarding the CT parameters was assessed in this study to identify and resolve any potential deficiencies.

Material and methods: This study was conducted in 2018 among 113 radiographers and 103 CT technologists in Khuzestan province using a three-part questionnaire containing demographic characteristics, general opinion on CT scan dose and questions assessing technologists’ knowledge of CT exposure parameters. Data were analyzed using SPSS software.

Results: Total knowledge scores of radiographers and CT technologists about CT exposure parameters were 36 and 42, respectively. The highest knowledge score among technologist was the knowledge of changing parameters based on patient characteristics and the lowest was in the field of awareness of noise index and diagnostic reference levels.

Conclusion: Total knowledge scores of radiographers and CT technologists about different scan parameters affecting dose and image quality was very low. Reviewing and updating the content of academic education and holding retraining courses are suggested.

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Evaluation of phoneme perception based on the digitalized phoneme test in children with cochlear implants

Evaluation of phoneme perception based on the digitalized phoneme test in children with cochlear implants

Early diagnosis of congenital defect of hearing poses new challenges for a multidisciplinary team of pedoaudiologists, ENT (ear-nose-throat) specialists and speech therapists. This study assessed the perception of phonemes in children with a cochlear implant and the possibilities of applying acoustical solutions in the audiologic evaluation. The participants were 17 implanted children, aged 5-9 years, who received a cochlear implant when they were from 18 months to 3 years old. Detection thresholds and discrimination score were assessed. This study also aimed at verifying the possibilities of applying the digital audioprocessing algorithm in clinical practice. The test based on the phonemes aa, uu, ii, ss, sh (Ling 5 sound test) was used. The test was modified in the frequency domain - the main aim of this modification was to improve the precision of the reconstruction of the audible threshold. The results indicated significant correlations between pure tone audiometry results and thresholds of phoneme detection [dB SPL]. The identification score in this group was 95-100% for sound pressure level 65 dB SPL.

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Initial experience of using an iron-containing fiducial marker for radiotherapy of prostate cancer: Advantages in the visualization of markers in Computed Tomography and Magnetic Resonance Imaging

Abstract

Visualization of markers is critical for imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). However, the size of the marker varies according to the imaging technique. While a large-sized marker is more useful for visualization in MRI, it results in artifacts on CT and causes substantial pain on administration. In contrast, a small-sized marker reduces the artifacts on CT but hampers MRI detection. Herein, we report a new ironcontaining marker and compare its utility with that of non-iron-containing markers. Five patients underwent CT/MRI fusion-based intensity-modulated radiotherapy, and the markers were placed by urologists. A Gold Anchor™ (GA; diameter, 0.28 mm; length, 10 mm) was placed using a 22G needle on the right side of the prostate. A VISICOIL™ (VIS; diameter, 0.35 mm; length, 10 mm) was placed using a 19G needle on the left side. MRI was performed using T2*-weighted imaging. Three observers evaluated and scored the visual qualities of the acquired images. The mean score of visualization was almost identical between the GA and VIS in radiography and cone-beam CT (Novalis Tx). The artifacts in planning CT were slightly larger using the GA than using the VIS. The visualization of the marker on MRI using the GA was superior to that using the VIS. In conclusion, the visualization quality of radiography, conebeam CT, and planning CT was roughly equal between the GA and VIS. However, the GA was more strongly visualized than was the VIS on MRI due to iron containing.

Open access
Dosimetric comparison of three dimensional conformal radiotherapy and intensity modulated radiotherapy in high grade gliomas

:1-14. Paddick I. A simple scoring ratio to index the conformity of radiosurgical treatment plans. Technical note. J Neurosurg (2000) Dec;93 Suppl 3:219-22. Narayan A, Yamada J, Berry S, et al. Intensity-modulated radiotherapy in high-grade gliomas: Clinical and Dosimetric Results. Int J Radiat Oncol Biol Phys (2006) 64;3:892-97. Hermanto U, Frija EK, Lii M-FJ. Intensity- modulated radiotherapy (IMRT) and conventional three-dimensional conformal radiotherapy for high-grade gliomas: Does IMRT increase the integral dose to the

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Entropy as a quality descriptor for the dose distribution — theory and practice for the patient target volume

techniques for non-small cell lung cancer. Brit J Radiology. 1999; 72 : 279-288. Niemierko A, Goitein M. Dose-volume distributions: a new approach to dose-volume histograms in three-dimensional treatment planning. Med Phys. 1994; 21 (1): 3-11. Paddick I. A simple scoring ratio to index the conformity of radiosurgical treatment plans. J Neurosurg. 2000; 93 (S3): 219-222. Knoos T, Kristensen I, Nilsson P. Volumetric and dosimetric evaluation of radiation treatment plans: Radiation

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Comparison of three and four-field radiotherapy technique and the effect of laryngeal shield on vocal and spinal cord radiation dose in radiotherapy of non-laryngeal head and neck tumors

Oncol Biol Phys. 1991;21(1):123-135. [22] Emami B, Lyman J, Brown A, et al. Tolerance of normal tissue to therapeutic irradiation. Int J Radiat Oncol Biol Phys. 1991;21(1):109-122. [23] Jones B, Dale R. Mathematical models of tumor and normal tissue response. Acta Oncol. 1999;38(7):883-893. [24] Rancati T, Fiorino C, Sanguineti G. NTCP modeling of sub-acute/late laryngeal edema scored by fiberopitic examination. Int J Radiat Oncol Biol Phys. 2009;75(30):915-923. [25] Niemierko A. Goitein M. Modeling of normal tissue response to radiation: the

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