99mTc-MAG3 scare are often indicated for renal function examinations in infants because of the minimum recommended age (1 month), the short physical half-life of 99mTc (6.01 h), the high extraction rate of the radiopharmaceutical (60% in the first filtration), and the high kidney uptake (97%), providing a good image quality even for infants [2].
Despite the limitations, we believe that our study provides a good image of health research publications in the WHO African Region and has added value to the knowledge of health research productivity on the African continent.
"They're only a problem if the examinations are unnecessary or if the exposures are higher than necessary to provide a good clinical image," Boice says.
On the one hand, non-surgical procedures provide a good body image and quality of life, but may be associated with increased risk of advanced-stage cancer and mortality; on the other hand, surgery ensures a very high protection from cancer but is associated with a number of disadvantages of invasiveness, non-reversibility and surgical morbidity.
The structural similarity (SSIM) [12], as a representative approach of top-down model, is based on the assumption that HVS is highly adapted to extract the structural information from the visual scene, and thus, a measurement of SSIM should provide a good approximation of image quality.
In literature, active contour model was well known to automatically recover the shape of objects from various types of images and provide a good detection of object boundaries in PolSAR images [3].
The method is derived from the hypothesis that the HVS is highly adapted for extracting the structural information from the visual scene, and therefore, a measurement of structural similarity can provide a good approximation of the perceived image quality.
The first update rule is built on the intuition that if the weighted mean reconstruction error is larger than the weighted mean standard deviation, i.e., the difference between the data and the fit cannot be explained by the expected signal variation due to noise, the polynomial model does not provide a good fit to the underlying image data.
Under the assumption that the human visual system (HVS) is highly adapted to extract structural information from the field of vision, Wang et al. [20] proposed that measuring the change of structural information can provide a good approximation of the perceived image distortion.
The estimation accuracy and computational complexity are both proportional to the maxCycle and N. So, in this paper, we select maxCycle to be 10 and N to be 7 to provide a good trade-off between the image quality and time cost.
