T1ρ/T2 mapping and histopathology of degenerative cartilage in advanced knee osteoarthritis

AIM To investigate whether normal thickness cartilage in osteoarthritic knees demonstrate depletion of proteoglycan or collagen content compared to healthy knees.METHODS Magnetic resonance(MR) images were acquired from5 subjects scheduled for total knee arthroplasty(TKA)(mean age 70 years) and 20 young healthy control subjects without knee pain(mean age 28.9 years). MR images of T1ρ mapping, T2 mapping, and fat suppressed proton-density weighted sequences were obtained.Following TKA each condyle was divided into 4 parts(distal medial, posterior medial, distal lateral, posterior lateral) for cartilage analysis. Twenty specimens(bone and cartilage blocks) were examined. For each joint,the degree and extent of cartilage destruction was determined using the Osteoarthritis Research Society International cartilage histopathology assessment system.In magnetic resonance imaging(MRI) analysis, 2 readers performed cartilage segmentation for T1ρ/T2 values and cartilage thickness measurement.RESULTS Eleven areas in MRI including normal or near normal cartilage thickness were selected. The corresponding histopathological sections demonstrated mild to moderate osteoarthritis(OA). There was no significant difference in cartilage thickness in MRI between control and advanced OA samples [medial distal condyle, P = 0.461;medial posterior condyle(MPC), P = 0.352; lateral distal condyle, P = 0.654; lateral posterior condyle, P = 0.550],suggesting arthritic specimens were morphologically similar to normal or early staged degenerative cartilage.Cartilage T2 and T1ρ values from the MPC were significantly higher among the patients with advanced OA(P= 0.043). For remaining condylar samples there was no statistical difference in T2 and T1ρ values between cases and controls but there was a trend towards higher values in advanced OA patients. CONCLUSION Though cartilage is morphologically normal or near normal, degenerative changes exist in advanced OA patients. These changes can be detected with T2 and T1ρ MRI techniques.

New scoring system in assessment of Hoffa's fat pad synovitis: A comparative study with established scoring systems

AIM To investigate the reliability of the established and new scoring methods for Hoffa's fat pad synovitis using magnetic resonance imaging(MRI).METHODS A total of 139 knees of 115 patients who underwent MRI of the knee with and without gadolinium contrast were enrolled in this study. Proton density(PD)-weighted, PD-weighted fat-suppressed(PD-FS), and postcontrast T1-weighted fat-suppressed(T1CE) images were used for evaluation. Using contrast and noncontrast images, our grading method for synovitis was performed to measure synovial thickness and signal intensity changes of the fat pad [Synovial membrane(SM) score], which was compared with the established methods,including MRI Osteoarthritis Knee Score(MOAKS), parapatellar synovitis score,Whole-Organ Magnetic Resonance Imaging Score(WORMS), and suprapatellar effusion diameter. Intraclass correlation coefficients(ICC) for intra and interobserver reproducibility and Spearman correlation coefficients(r) were calculated for the parapatellar synovitis score and each scoring method.RESULTS All of the scores presented substantial to almost perfect intrareliability. Among three readers, effusion diameter had substantial to almost perfect interreliability(ICC = 0.68-0.81) and WORMS had substantial interreliability(ICC = 0.61-0.70).For two out of three readers, there was substantial interreliability for the thickness score in T1CE(ICC = 0.55-0.69), SM scores in T1CE(ICC = 0.56-0.78)and PD-FS(ICC = 0.51-0.79), and parapatellar synovitis score in T1CE(ICC =0.53-0.72). The parapatellar synovitis score was significantly correlated with the thickness score in T1CE(r = 0.70) and the SM score in T1CE(r = 0.81) and PD-FS(r = 0.65).CONCLUSION The newly proposed quantitative thickness score on T1CE and the semiquantitative SM score on T1CE and PD-FS can be useful for Hoffa's fat pad synovitis.

Effect of age on aortic atherosclerosis

Objective To examine the association of atherosclerosis burden in the survivors of an asymptomatic elderly cohort study and its relationship to other coronary risk factors (specifically, age) by evaluating aortic atherosclerotic wall burden by magnetic resonance imaging (MRI). Methods A total of 312 participants in an ongoing observational cohort study underwent cardiac and descending thoracic aorta imaging by MRI. Maximum wall thickness was measured and the mean wall thickness calculated.Wall/outer wall ratio was used as a normalized wall index (NWI) adjusted for artery size difference among participants. Percent wall volume (PWV) was calculated as NWI ×100.Results In this asymptomatic cohort (mean age: 76 years), the mean (SD) aortic wall area andwall thicknesswere 222 ±45 mm2 and 2.7 ±0.4 mm, respectively. Maximum wall thickness was 3.4 ±0.6 mm, and PWV was 32% ±4%. Women appeared to have smaller wall area,but after correcting for their smaller artery size, had significantly higher PWV than men (P = 0.03). Older age was associatedwith larger wall area (P = 0.04 for trend) with similar PWVs. However, there were no statistically significant associations between standard risk factors,Framingham global risk, or metabolic syndrome status, therapy for cholesterol or hypertension, coronary or aortic calcium score, and the aortic wall burden. Aortic calcificationwas associated with coronary calcification. Conclusions Asymptomatic elderly in this cohort had a greater descending thoracic aortic wall volume that correlated with age, andwomen had a significantly increased PWV compared to men. In these survivors, the atherosclerotic aortic wall burden was not significantly associated with traditional risk factors or with coronary or aortic calcium scores or coronary calcium progression. Results suggest that age, or as yet unidentified risk factor(s), may be responsible for the increase in atherosclerosis.

Macroscopic Violation of Duality Generated on a Laser Beam

It is shown theoretically and experimentally that passage of a laser beam through particular conventional Ronchi gratings prepares the beam in an altered state that violates quantum duality. The violation is characterized by a readily measured net transfer of energy between the prepared beam and an unmodified beam from a similar, independent laser. Notably, the experiment is conducted with the beams at macroscopic power levels where measurability of the duality-violating transfer is vastly improved over that of the discrete photon regime. These results are consistent with other recently reported experiments that have challenged the validity of the duality-related principle of complementarity.

动态增强磁共振成像在乳腺癌诊断及疗效监测中的应用进展(英文)

经过20余年的相关研究,MRI现已成为临床公认的用于检出和诊断乳腺疾病的影像检查手段之一。笔者简要阐述了乳腺动态增强(DCE)磁共振成像技术及其临床应用。详细介绍了动态增强中有关药代动力学的测量方法、各种相关参数的定性分析、以及Ktrans和kep等反应药代动力学特征参数的定量分析。笔者不但就当前"是否有必要对每位患者进行动脉输入函数进行测量"等有争议的话题进行了讨论,还在对当前广泛应用的各种动态增强MRI后处理软件进行了较详尽的描述之后,进一步对动态增强MRI在乳腺癌的诊断及疗效监测等方面的临床应用情况进行了详尽的回顾。作者认为:总体来讲,对于乳腺癌的诊断,关键在于关注病灶中最具侵袭性部分的MRI特征。而对于乳腺癌疗效的监测,则应该对整个病灶进行分析。最后,笔者就乳腺MRI对乳腺癌高危人群的筛查以及风险的处理等问题进行了讨论。笔者预测乳腺MRI在女性乳腺疾病尤其是乳腺癌的筛查、诊断、治疗及疗效监测等一系列问题上将继续发挥不可替代的重要作用。

巴赫曼束(心耳间横肌束)及其动脉血供的多层螺旋CT成像对心房间传导异常和心律失常的提示

目的利用64层CT成像回顾性研究健康人和病人的巴赫曼束（BB）的解剖及其血供。方法本研究依从HIPAA法案并得到了机构审查委员会的批准可免除知情同意书。回顾317例病人（对照组164例，病人组153例）的临床病史、心电图（ECG）和64层CT冠状动脉成像影像。病人组中，房颤（AF）或房间传导阻滞（IAB）68例（P波持续时间≥120ms），严重冠状动脉疾病（CAD）46例[发出窦房结（SAN）动脉的冠状动脉狭窄程度≥70％]，严重CAD同时有心电图异常39例（AF或IAB）。对BB的长度、

Primary pancreatic gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) arises from the interstitial cells of Cajal (ICC) and is the most common mesenchymal tumor of the gastrointestinal tract,accounting for approximately 1%-2%of all malignant gastrointestinal tract tumors^([1]).The most common sites of origin are stomach and small bowel.

Diversity of Gene Expression in Hepatocellular Carcinoma Cells

Understanding tumor diversity has been a long-lasting and challenging question for researchers in the field of cancer heterogeneity or tumor evolution. Studies have reported that com- pared to normal cells, there is a higher genetic diversity in tumor cells, while higher genetic diversity is associated with higher progression risks of tumor. We thus hypothesized that tumor diversity also holds true at the gene expression level. To test this hypothesis, we used t-test to compare the means of Simpson＇s diversity index for gene expression （SDIG） between tumor and non-tumor samples. We found that the mean SDIG in tumor tissues is significantly higher than that in the non-tumor or normal tissues （P 〈 0.05） for most datasets. We also combined microarrays and next-generation sequencing data for validation. This cross-platform and cross-experimental validation greatly increased the reliability of our results.

An image segmentation framework for extracting tumors from breast magnetic resonance images

Magnetic resonance imaging(MRI)has been a prevalence technique for breast cancer diagnosis.Computer-aided detection and segmentation of lesions from MRIs plays a vital role for the MRI-based disease analysis.There are two main issues of the existing breast lesion segmentation techniques:requir ing manual delineation of Regions of Interests(ROIs)as a step of initialization;and requiring a large amount of labeled images for model construction or parameter lear ning,while in real clinical or experimental settings,it is highly challenging to get suficient labeled MRIs.To resolve these issues,this work proposes a semi-supervised method for breast tumor segmentation based on super voxel strategies.After image segmentation with advanced cluster techniques,we take a supervised learning step to classify the tumor and nontumor patches in order to automatically locate the tumor regions in an MRI To obtain the opt imal performance of tumor extraction,we take extensive experiments to learn par ameters for tumor segmentation and dassification,and design 225 classifiers corresponding to diferent parameter settings.We call the proposed method as Semi supervised Tumor Segmentation(SSTS),and apply it to both mass and nonmass lesions.Experimental results show better performance of SsTS compared with five state of-the art methods.

Ring artifacts removal in X-ray-induced acoustic computed tomography

X-ray-induced acoustic computed tomography(XACT)is a hybrid imaging modality for detecting X-ray absorption distribution via ultrasound emission.It facilitates imaging from a single projection X-ray illumination,thus reducing the radiation exposure and improving imaging speed.Nonuniform detector response caused by the interference between multichannel data acquisition for ring array transducers and amplifier systems yields ring artifacts in the reconstructed XACT images,which compromises the image quality.We propose model-based algorithms for ring artifacts corrected XACT imaging and demonstrate their effcacy on numerical and experimental measurements.The corrected reconstructions indicate significantly reduced ring artifacts as compared to their conventional counterparts.

卵圆孔未闭的64层MDCT影像

目的 研究64层CT血管成像对于显示卵圆孔未闭的房间隔解剖细节，并且观察左向右分流情况的可行性，同时与经食管超声心动图检查病人的结果进行对照。材料和方法 该研究得到HIPPA机构审查委员会许可，264例病人行心电门控冠状动脉cT成像（男性159例，女性105例；平均年龄60岁）以评价卵圆孔未闭的形态学特征。

＂RADIOTRANSCRIPTOMICS＂： A synergy of imaging and transcriptomics in clinical assess- ment

Recent advances in quantitative imaging and ＂omics＂ technology have generated a wealth of mineable biological ＂big data＂. With the push towards a P4 ＂predictive, preventive, personalized, and participatory＂ approach to medicine, researchers began integrating complementary tools to further tune existing diagnostic and therapeutic models. The field of radiogenomics has long pioneered such multidisciplinary investigations in neuroscience and oncology, correlating genotypic and phenotypic signatures to study structural and functional changes in relation to altered molecular behavior. Given the innate dynamic nature of complex disorders and the role of environmental and epigenetic factors in pathogenesis, the transcriptome can further elucidate serial modifications undetected at the genome level. We therefore propose ＂radiotranscriptomics＂ as a new member of the P4 medicine initiative, combining transcriptome information, including gene expression and isoform variation, and quantitative image annotations.

Video Polyp Segmentation: A Deep Learning Perspective

We present the first comprehensive video polyp segmentation(VPS)study in the deep learning era.Over the years,developments in VPS are not moving forward with ease due to the lack of a large-scale dataset with fine-grained segmentation annotations.To address this issue,we first introduce a high-quality frame-by-frame annotated VPS dataset,named SUN-SEG,which contains 158690colonoscopy video frames from the well-known SUN-database.We provide additional annotation covering diverse types,i.e.,attribute,object mask,boundary,scribble,and polygon.Second,we design a simple but efficient baseline,named PNS+,which consists of a global encoder,a local encoder,and normalized self-attention(NS)blocks.The global and local encoders receive an anchor frame and multiple successive frames to extract long-term and short-term spatial-temporal representations,which are then progressively refined by two NS blocks.Extensive experiments show that PNS+achieves the best performance and real-time inference speed(170 fps),making it a promising solution for the VPS task.Third,we extensively evaluate 13 representative polyp/object segmentation models on our SUN-SEG dataset and provide attribute-based comparisons.Finally,we discuss several open issues and suggest possible research directions for the VPS community.Our project and dataset are publicly available at https://github.com/GewelsJI/VPS.

Mesoporous silica rods with cone shaped pores modulate inflammation and deliver BMP-2 for bone regeneration

Biomaterials with suitable osteoimmunomodulation properties and ability to deliver osteoinductive biomolecules,such as bone morphogenetic proteins,are desired for bone regeneration.Herein,we report the development of mesoporous silica rods with large cone-shaped pores(MSR-CP)to load and deliver large protein drugs.It is noted that those cone-shaped pores on the surface modulated the immune response and reduced the pro-inflammatory reaction of stimulated macrophage.Furthermore,bone morphogenetic proteins 2(BMP-2)loaded MSR-CP facilitated osteogenic differentiation and promoted osteogenesis of bone marrow stromal cells.In vivo tests confirmed BMP-2 loaded MSR-CP improved the bone regeneration performance.This study provides a potential strategy for the design of drug delivery systems for bone regeneration.