The aim of the study was to investigate the effectiveness of the air-gap technique as a substitute for the grid in the pelvic examination for patient radiation dose reduction while maintaining the image quality. An anthropomorphic phantom... more
The aim of the study was to investigate the effectiveness of the air-gap technique as a substitute for the grid in the pelvic examination for patient radiation dose reduction while maintaining the image quality. An anthropomorphic phantom (PBU-50) was used in this study to simulate an actual human pelvic structure. The phantom was exposed for pelvic examination using the grid and the air-gap technique to compare the exposure factors, the patient dose and the image quality produced from both methods. The patient dose was measured using a Dose Area Product (DAP) meter which was then used to estimate the gonadal dose. The images were scored by three experienced radiographers based on the Commission of European Communities (CEC) image quality criteria to determine the image quality. The result of the study indicated that the air-gap of 25 cm was the optimum air-gap distance. The gonadal dose and the effective dose were reduced from 0.130 mGy to 0.062 mGy and from 0.357 mGy to 0.172 mGy respectively when using the air-gap technique and when using the grid. The study indicated that the image quality produced by the air-gap technique was more superior to the grid. In conclusion, besides the magnification issue, the air-gap technique is suitable to be used in the pelvic radiographic examination as it reduces the patient radiation dose while improving the image quality.
Owing to recent advances in computing power, iterative reconstruction (IR) algorithms have become a clinically viable option in computed tomographic (CT) imaging. Substantial evidence is accumulating about the advantages of IR algorithms... more
Owing to recent advances in computing power, iterative reconstruction (IR) algorithms have become a clinically viable option in computed tomographic (CT) imaging. Substantial evidence is accumulating about the advantages of IR algorithms over established analytical methods, such as filtered back projection. IR improves image quality through cyclic image processing. Although all available solutions share the common mechanism of artifact reduction and/or potential for radiation dose savings, chiefly due to image noise suppression, the magnitude of these effects depends on the specific IR algorithm. In the first section of this contribution, the technical bases of IR are briefly reviewed and the currently available algorithms released by the major CT manufacturers are described. In the second part, the current status of their clinical implementation is surveyed. Regardless of the applied IR algorithm , the available evidence attests to the substantial potential of IR algorithms for overcoming traditional limitations in CT imaging.
With the technological advancements in the medical imaging field, the past decade has witnessed a dramatic evolution of multimodality imaging systems. Scientists, technologists and researchers have been able to bring systems in clinical... more
With the technological advancements in the medical imaging field, the past decade has witnessed a dramatic evolution of multimodality imaging systems. Scientists, technologists and researchers have been able to bring systems in clinical practice, in which two or more standalone diagnostic imaging modalities have been combined. Some of those multimodality imaging systems are: PET/CT, SPECT/CT, PET/MRI and PET/SPECT/CT. With this technique a patient is scanned in a single session and the desired structural and functional information of the organ of interest is achieved. Recent clinical imaging studies in the areas of cardiology, endocrinology, infection, musculoskeletal and neurology has shown, that with multimodality diagnostic imaging, a significant increase in diagnostic accuracy is achieved, as compared to single diagnostic imaging modality. In this review, emphasis is given to the technical aspects and clinical applications of the SPECT/CT hybrid imaging modality.
Background: Cardiovascular imaging using hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI) requires a radio frequency phased array resonator capable of high acceleration factors in order to achieve the... more
Background: Cardiovascular imaging using hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI) requires a radio frequency phased array resonator capable of high acceleration factors in order to achieve the shortest breath-holds while maintaining optimal MRI signal-to-noise ratio (SNR) and minimum PET photon attenuation. To our knowledge, the only two arrays used today for hybrid PET/MRI cardiovascular imaging are either incapable of achieving high acceleration or affect the PET photon count greatly.
