Quantified 123I-Thyroid Scan based classification of hyperthyroidism

The original thyroid scan (TS) was widely used to identify typical imaging patterns, suggesting the widely accepted main following clinical diagnoses: Grave's disease, Toxic adenoma, [hetero]-nodular goiters and thyroiditis. With the diffusion of sensitive TSH assays, considerable advances in the comprehension of the molecular mechanisms of hormonosynthesis, and new quantification possibilities especially using ¹²³I, the TS is a textbook of molecular imaging. The image can be finely quantified with, not only as regards the Uptake (¹²³IUp) and related parameters but also, the quantification of the spatial targeting leading to a Spatial Target Index (STI). Using this new molecular ¹²³I-TS, TSH values, and when required, correlation to Multiparametric Ultrasounds (MPUS), we generated a basic classification system of hyperthyroidism, with well-defined indexed criteria (C11-1 to C17-3), that allows reporting 24 distinct etiologies. Selected criteria involve TS and contrast patterns, precocious ¹²³IUp (p¹²³IUp), maximal TSH-dependent physiological Uptake, lobar concentration, Uptake and concentration ratios, STI, ^99mTc-MIBI TS and correlative MPUS. This approach allows to identify 4 subtypes of Graves’ disease, including hyperplastic, nodular and common GD variants entangled with Hashimoto's struma, 4 subtypes of Thyroid Functional Autonomy, including Disseminated Functional Autonomy, that cannot be diagnosed with other conventional procedures. Criteria C14-1 to C17-3 report on hyperthyroidism and iodine overload, factitia, main thyroiditis presentations and rare central or tumoral etiologies of hyperthyroidism. This classification, based on ¹²³I-TS molecular imaging, leads to unprecedented diagnostic finesse and paves the way for a personalized theranostic approach in thyroid pathology. Further development towards artificial intelligence networks is under study.     

BacStalk: A comprehensive and interactive image analysis software tool for bacterial cell biology

Prokaryotic cells display a striking subcellular organization. Studies of the underlying mechanisms in different species have greatly enhanced our understanding of the morphological and physiological adaptation of bacteria to different environmental niches. The image analysis software tool BacStalk is designed to extract comprehensive quantitative information from the images of morphologically complex bacteria with stalks, flagella, or other appendages. The resulting data can be visualized in interactive demographs, kymographs, cell lineage plots, and scatter plots to enable fast and thorough data analysis and representation. Notably, BacStalk can generate demographs and kymographs that display fluorescence signals within the two-dimensional cellular outlines, to accurately represent their subcellular location. Beyond organisms with visible appendages, BacStalk is also suitable for established, non-stalked model organisms with common or uncommon cell shapes. BacStalk, therefore, contributes to the advancement of prokaryotic cell biology and physiology, as it widens the spectrum of easily accessible model organisms and enables highly intuitive and interactive data analysis and visualization.     

网袋强化椎体成形术在骨质疏松椎体骨折治疗中的经验教训

摘要 目的：探讨和总结使用网袋强化椎体成形术在骨质疏松椎体骨折围手术期的注意事项及相关对策。方法：回顾性分析2017年6月到2020年6月3年时间内,使用网袋强化椎体成形术治疗骨质疏松性椎体骨折患者共计112例。统计和比较患者在围手术期的各项指标,分析穿刺失败的原因及相关危险因素。结果：112例患者共涉及138个椎体。其中一期穿刺失败率（骨水泥分布不佳）为47个,占34.0%。骨水泥注入3 mL以下者为19个,占13.8%。骨水泥渗漏为36个,占26.1%。所有患者在术后3天及3月复查, VAS评分和ODI评分较前均有显著改善(P<0.05)。所有患者均未出现严重并发症(P>0.05)。结论：网袋强化椎体成形术在骨质疏松性椎体骨折的治疗中是一种理想的治疗方式,但在具体过程中仍有相关的经验和教训需要整理和总结。     

冠状动脉磁共振血管成像和CT对可疑冠心病患者心脏事件的预测价值的比较研究

摘要 目的：探讨与比较冠状动脉核磁共振(MR)血管成像和CT对可疑冠心病患者心脏事件的预测价值。方法：2018年4月到2020年10月选择在本院诊治的103例可疑冠心病患者作为研究对象,所有患者都给予冠状动脉MRI血管成像与64层螺旋CT冠状动脉成像检查,记录影像学特征。随访患者的预后并进行预测价值分析。结果：103例可疑冠心病患者随访到2021年4月1日,发生心血管不良终点事件23例(不良事件组),发生率为22.3%。不良事件组的MRI血管成像显示右冠状动脉血管长度与内径都低于非不良事件组(P<0.05)。不良事件组的CT显示斑块率、斑块性质等与非不良事件组对比差异有统计学意义(P<0.05),两组斑块位置对比差异无统计学意义(P>0.05)。多因素Cox回归分析显示斑块性质、斑块率、右冠状动脉血管长度与内径都为导致心血管不良终点事件的重要因素(P<0.05)。结论：冠状动脉MRI血管成像和CT都可有效预测可疑冠心病患者心脏事件发生情况,能满足临床诊断可疑冠心病与预测预后的要求。     

ROI-Based Compression Strategy of 3D MRI Brain Datasets for Wireless Communications

ObjectivesBecause of the large amount of medical imaging data, the transmission process becomes complicated in telemedicine applications. Thus, in order to adapt the data bit streams to the constraints related to the limitation of the bandwidths a reduction of the size of the data by compression of the images is essential. Despite the improvements in the field of compression, the transmission itself can also introduce errors. For this reason, it is important to develop an adequate strategy which will help reduce this volume of data without having to introduce some distortion and resist the errors introduced by the channel noise during transmission. Thus, in this paper, we propose a ROI-based coding strategy and unequal bit stream protection to meet this dual constraint.Material and methodsThe proposed ROI-based compression strategy with unequal bit stream protection is composed of three parts: the first one allows the extraction of the ROI region, the second one consists of a ROI-based coding and the third one allows an unequal protection of the ROI bit stream.First, the Regions Of Interest (ROI) are extracted by hierarchical segmentation of these regions according to a segmentation method based on the technique of Marker-based-watershed combined with the technique of active contours by level set. The resulting regions are selectively encoded by a 3D coder based on a shape adaptive discrete wavelet transform 3D-BISK, where the compression ratio of each region depends on its relevance in diagnosis. These obtained regions of interest are protected with an error-correcting code of Reed-Solomon type with a code rate that varies according to the relevance of the region by an unequal protection strategy (UEP).ResultsThe performance of the proposed compression scheme is evaluated in several ways. First, tests are performed to study the impact of errors on the different bit streams. In the first place, these tests are carried out in order to study the effect of the variation of the compression rates on the different bit streams. Secondly, different Reed Solomon error-correcting codes of different code rates are tested at different compression rates on a BSC channel. Finally, the performances of this coding strategy are compared with those of SPIHT 3D in the case of transmission on a BSC channel.ConclusionThe obtained results show that the proposed method is quite efficient in transmission time reduction. Therefore, our proposed scheme will reduce the volume of data without having to introduce some distortion and resist the errors introduced by the channel noise in the case of telemedicine.     

Analytical validation of quantitative immunohistochemical assays of tumor infiltrating lymphocyte biomarkers

Tumor infiltrating lymphocytes (TIL), especially T-cells, have both prognostic and therapeutic applications. The presence of CD8+ effector T-cells and the ratio of CD8+ cells to FOXP3+ regulatory T-cells have been used as biomarkers of disease prognosis to predict response to various immunotherapies. Blocking the interaction between inhibitory receptors on T-cells and their ligands with therapeutic antibodies including atezolizumab, nivolumab, pembrolizumab and tremelimumab increases the immune response against cancer cells and has shown significant improvement in clinical benefits and survival in several different tumor types. The improved clinical outcome is presumed to be associated with a higher tumor infiltration; therefore, it is thought that more accurate methods for measuring the amount of TIL could assist prognosis and predict treatment response. We have developed and validated quantitative immunohistochemistry (IHC) assays for CD3, CD8 and FOXP3 for immunophenotyping T-lymphocytes in tumor tissue. Various types of formalin fixed, paraffin embedded (FFPE) tumor tissues were immunolabeled with anti-CD3, anti-CD8 and anti-FOXP3 antibodies using an IHC autostainer. The tumor area of stained tissues, including the invasive margin of the tumor, was scored by a pathologist (visual scoring) and by computer-based quantitative image analysis. Two image analysis scores were obtained for the staining of each biomarker: the percent positive cells in the tumor area and positive cells/mm² tumor area. Comparison of visual vs. image analysis scoring methods using regression analysis showed high correlation and indicated that quantitative image analysis can be used to score the number of positive cells in IHC stained slides. To demonstrate that the IHC assays produce consistent results in normal daily testing, we evaluated the specificity, sensitivity and reproducibility of the IHC assays using both visual and image analysis scoring methods. We found that CD3, CD8 and FOXP3 IHC assays met the fit-for-purpose analytical acceptance validation criteria and that they can be used to support clinical studies.     

A semi-automated method for hexahedral mesh construction of human vertebrae from CT scans

Generation of finite element (FE) meshes of vertebrae from computed tomography (CT) scans is labour intensive due to their geometric complexity. As such, techniques that simplify creation of meshes of vertebrae are needed to make FE analysis feasible for large studies and clinical applications. Techniques to obtain a geometric representation of bone contours from CT scans of vertebrae and construct a hexahedral mesh from the contours were developed. An automated edge detection technique was developed to identify surface contours of the vertebrae, followed by atlas based B-spline curve fitting to construct curves from the edge points. The method was automatic and robust to missing data, with a controllable degree of smoothing and interpolation. Parametric mapping was then used to generate nodes for each CT slice, which were connected between slices to obtain a hexahedral mesh. This method could be adapted for modelling a variety of orthopaedic structures.     

An automatic 2D–3D image matching method for reproducing spatial knee joint positions using single or dual fluoroscopic images

Fluoroscopic image technique, using either a single image or dual images, has been widely applied to measure in vivo human knee joint kinematics. However, few studies have compared the advantages of using single and dual fluoroscopic images. Furthermore, due to the size limitation of the image intensifiers, it is possible that only a portion of the knee joint could be captured by the fluoroscopy during dynamic knee joint motion. In this paper, we presented a systematic evaluation of an automatic 2D–3D image matching method in reproducing spatial knee joint positions using either single or dual fluoroscopic image techniques. The data indicated that for the femur and tibia, their spatial positions could be determined with an accuracy and precision less than 0.2 mm in translation and less than 0.4° in orientation when dual fluoroscopic images were used. Using single fluoroscopic images, the method could produce satisfactory accuracy in joint positions in the imaging plane (in average up to 0.5 mm in translation and 1.3° in rotation), but large variations along the out-plane direction (in average up to 4.0 mm in translation and 2.2° in rotation). The precision of using single fluoroscopic images to determine the actual knee positions was worse than its accuracy obtained. The data also indicated that when using dual fluoroscopic image technique, if the knee joint outlines in one image were incomplete by 80%, the algorithm could still reproduce the joint positions with high precisions.     

Results of automatic image registration are dependent on initial manual registration

Measurement of static alignment of articulating joints is of clinical benefit and can be determined using image-based registration. We propose a method that could potentially improve the outcome of image-based registration by using initial manual registration. Magnetic resonance images of two wrist specimens were acquired in the relaxed position and during simulated grasp. Transformations were determined from voxel-based image registration between the two volumes. The volumes were manually aligned to match as closely as possible before auto-registration, from which standard transformations were obtained. Then, translation/rotation perturbations were applied to the manual registration to obtain altered initial positions, from which altered auto-registration transformations were obtained. Models of the radiolunate joint were also constructed from the images to simulate joint contact mechanics. We compared the sensitivity of transformations (translations and rotations) and contact mechanics to altering the initial registration condition from the defined standard. We observed that with increasing perturbation, transformation errors appeared to increase and values for contact force and contact area appeared to decrease. Based on these preliminary findings, it appears that the final registration outcome is sensitive to the initial registration.     

In vivo measurement of surface skin strain during human gait to improve the design of rehabilitation devices

Abstract

When designing any rehabilitation, sportswear or exoskeleton device the mechanical behaviour of the body segment must be known, specifically the skin, because an excessive tissue strain may lead to ulceration and bedsores. To date, it is not known if the kinematic variability between subjects have an effect on the skin strain field, and therefore, in the design and manufacturing of rehabilitation products, such as orthoses. Several studies have analysed the skin deformation during human motion, nevertheless, the comparison between the skin strain field in different subjects during normal or pathological gait has not been reported yet. This work presents a comparison of skin strain analysis for different gait patterns to study the differences between people and, specifically, if it is possible to standardize the orthotic design between subjects with the same gait disorder. Moreover, the areas with relatively minimum strain during the ankle-foot motion are compared to improve the design of structural parts of rehabilitation devices. In this case, a validated 3D digital image correlation system has been used for this purpose combined with strain ellipse theory. The results demonstrate variations in the skin strain field between subjects with the same pathology and similarities between subjects with normal gait. However, more studies and experiments are necessaries to validate this hypothesis and also to test it between different gait pathologies.