Cardiac hybrid imaging: novel tracers for novel targets

Non-invasive cardiac imaging has explored enormous advances in the last few decades.In particular,hybrid imaging represents the fusion of information from multiple imaging modalities,allowing to provide a more comprehensive dataset compared to traditional imaging techniques in patients with cardiovascular diseases.The complementary anatomical,functional and molecular information provided by hybrid systems are able to simplify the evaluation procedure of various pathologies in a routine clinical setting.The diagnostic capability of hybrid imaging modalities can be further enhanced by introducing novel and specific imaging biomarkers.The aim of this review is to cover the most recent advancements in radiotracers development for SPECT/CT,PET/CT,and PET/MRI for cardiovascular diseases.

Strategies to Improve CT Dose Optimization for Hybrid PET/CT Imaging

Background: To evaluate whether current dose reduction strategies for the CT component of hybrid Positron Emission Tomography—Computed Tomography (PET/CT) systems could reduce patient dose with maintaining adequate image quality for PET/CT studies. Materials and Methods: Literature survey was initially based on the selection of keywords and years of publication to identify potentially relevant articles, then the further search was conducted on the authors and references from these articles. The abstract of each article was first appraised to decide whether the content was relevant to this research question. The articles were classified into five groups: studies on dosimetry, studies on radiation-induced diseases, studies on dose reduction methods for CT-based attenuation correction (CTAC), studies on dose reduction methods for CT localization, and studies on reducing the need for a full-dose diagnostic CT in PET/CT imaging. 58 peer-reviewed articles were selected and appraised and 29 articles were used to compose this literature review. Results: The published nuclear medicine and medical physics literature were reviewed. CT dose contributed 47% - 81% of the total effective dose of a standard PET/CT study and was associated with radiation-induced diseases. The dose reduction techniques were extracted and divided into three categories: reducing the CT dose for attenuation correction (AC) and localization, selectively localizing CT use, and reducing the need for a full-dose diagnostic CT. Conclusion: Three strategies have been demonstrated, with high potential for reducing patient dose while maintaining an adequate CT image quality, used for CTCA localization and diagnosis, respectively.

HYDRO:Optimizing interactive hybrid images for digital signage content

Background In modern society,the digital signage installed in many large-scale facilities supports daily life.However,owing to their limited screen size,it is difficult to simultaneously provide different types of information to many viewers at varying distances from the screen.Therefore,in this study,we extend the existing research on the use of hybrid images for tiled displays.Methods To facilitate smoother information selection,a new interactive display method is proposed that incorporates touch-activated widgets as high-frequency parts of hybrid images.These widgets are novel because they are more visible to viewers near the display.We developed an authoring tool called the hybrid image display resolution optimizer(HYDRO),which features two types of control functions to optimize the visibility of touch-activated widgets in terms of placement and resolution.Conclusion The effectiveness of the proposed method is demonstrated empirically through a quantitative user study and an eyetracking-based qualitative evaluation.

Diagnosis Performance of 99mTc-MIBI and Multimodality Imaging for Hyperparathyroidism

This study aimed to examine the diagnosis performance of^（99m）Tc-methoxyisobutylisonitrisonitrile （^（99m）Tc-MIBI） and multimodality imaging [ultrasound, single-photon emission computed tomography/computed tomography（SPECT/CT）] for hyperparathyroidism（HPT）. From Nov. 2009 to Dec. 2015, clinical data of a total of 43 HPT patients（16 males and 27 females; 26–70 years old, average age： 51.60±10.66 years old） were retrospectively analyzed. Among them, 19 patients with primary hyperparathyroidism（PHPT） underwent ^（99m）Tc-MIBI planar imaging, 24 [15 with PHPT and 9 with secondary hyperparathyroidism（SHPT）] underwent SPECT/CT hybrid imaging, and 41（33 with PHPT and 8 with SHPT） had neck ultrasound imaging. Final diagnosis was determined by pathological examination after surgery. The positive rate was compared between different imaging modalities, and the correlation analysis was conducted between imaging results and lesion size or serum parathyroid hormone（PTH） level. The results showed that the total positive rates of^（99m）Tc-MIBI imaging, ultrasound, and the two combined imaging in the 43 HPT cases were 90.70%（39/43）, 58.54%（24/41）, and 100%（41/41）, respectively. According to lesion numbers, the positive rates were 79.10%（53/67）, 53.23%（33/62）, and 88.71%（55/62）, respectively. SPECT/CT hybrid images were positive in all the 24 patients who underwent this examination. The mean maximum diameters of the lesions in ^（99m）Tc-MIBI positive and negative patients were 1.96±0.95 cm and 1.36±0.67 cm respectively, with statistically significant difference noted（P=0.03）. The T/NT of ^（99m）Tc-MIBI imaging at the early phase was correlated positively with serum PTH level（r=0.40, P=0.01）. The T/NT of ^（99m）Tc-MIBI imaging at both the early phase and the delay phase was correlated positively with lesion size（r=0.51, and r=0.45, respectively; P〈0.01 for both）. It was concluded that ^（99m）Tc-MIBI imaging presents significant value for location diagnosis of HPT, especially when combined with SPECT/CT hybrid imaging or ultrasound. The ^（99m）Tc-MIBI uptake correlates positively with serum PTH level and lesion size.

Hybrid image of three contents

A hybrid image allows multiple image interpretations to be modulated by the viewing distance.Originally,it can be constructed by combining the low and high spatial frequencies of two different images.The original hybrid image synthesis was limited to similar shapes of source images that were aligned in the edges,e.g.,faces with a different expression,to produce an effective double image interpretation.In our previous work,we proposed a noiseinserted method for synthesizing a hybrid image from dissimilar shape images or unaligned images.In this work,we propose a novel method for adding an image to be seen from a middle viewing distance.The middlefrequency(MF)image is extracted by a special bandpass filter,which generates ringing while extracting only specified frequency bands.With this method,the middle frequency should be perceived as a meaningless pattern when viewed from a far distance and close up.A parameter tuning experiment was performed to determine the suitable cutoff frequencies for designing the filter for the MF image.We found that ringings of a suitable size could be used to make the middle frequency less noticeable when seen from far away.

A polynomial hybrid reflection model and measurement of its parameters based on images of sample

Reflectance model is a basic concept in computer vision. Some existing models combining the classical diffuse reflectance model and those for surfaces containing specular components can approximately describe real reflectance. But the ratio of diffuse and specular reflection decided manually has no clear meaning. We propose a new polynomial hybrid reflectance model. The reflectance map equation with a known shape （for example cylinder） as a sample is used to estimate parameters of the proposed reflectance model by least square regression algorithm. Then the reflectance parameters for surfaces of the same class of materials can be determined. Experiments are performed for a metal surface. The synthesis images produced by the proposed method and existing ones are compared with the real acquired image, and the results show that the proposed reflectance model is suitable for describing real reflectance.

A hybrid rendering algorithm for textile objects

Although realistic textile rendering has been widely used in virtual garment and try-on systems, a robust method to simulate textile with a realistic appearance and high fidelity is yet to be established. We propose to use a novel hybrid geometric- and image-based rendering （GIBR） method to achieve photo realistic representation of textile products. The image-based technique, with its radiance synthesis algorithm, enables us to recover the reflectance properties of textile in an environment photo, and thus can render the appearance of textile material. The geometry-based technique, with its traditional illumination model of assigning illumination parameters extracted from the original scene （such as radiance and chroma dispatch）, makes it possible to interactively manipulate 3D virtual objects in the ＂real＂ environment. Our realistic textile rendering method has advantages over the traditional ones in its easiness to implement and its wide range of applications.

Adapting Nanotech Research as Nano-Micro Hybrids Approach Biological Complexity,A Review

Today＇s emergence of nano-micro hybrid structures with almost biological complexity is of fundamental interest. Our ability to adapt intelligently to the challenges has ramifications all the way from fundamentally changing research itself, over applications critical to future survival, to posing globally existential dangers. Touching on specific issues such as how complexity relates to the catalytic prowess of multi-metal compounds, we discuss the increasingly urgent issues in nanotechnology also very generally and guided by the motto ＇Bio Is Nature＇s Nanotech＇. Technology belongs to macro-evolution; for example integration with artificial intelligence （AI） is inevitable. Darwinian adaptation manifests as integration of complexity, and awareness of this helps in developing adaptable research methods that can find use across a wide range of research. The second half of this work reviews a diverse range of projects which all benefited from ＇playful＇ programming aimed at dealing with complexity. The main purpose of reviewing them is to show how such projects benefit from and fit in with the general, philosophical approach, proving the relevance of the ＇big picture＇ where it is usually disregarded.