Influential factors on urine EV DNA methylation detection and its diagnostic potential in prostate cancer.

The value of Extracellular vesicles (EVs) diagnostic markers is widely recognized. However, current research on EV DNA remains limited. This study investigates the biological properties, preprocessing factors, and diagnostic potential of EV DNA. We found that DNA positive vesicles account for 23.3% ± 6.7% of the urine total EV, with a large amount of DNA attached to the outside. EV DNA fragments are large, there is no significant effect on uEV DNA when store urine less than 6 h at 4°C. In addition, the influence of different EV extraction methods on methylation detection is also minor. More importantly, RASSF1A methylation in urine total EV DNA can distinguish between PCa and BPH, with an AUC of 0.874. Our results suggest the potential of urine EV DNA as a novel marker for PCa diagnosis. This provides a new idea for the study of urinary tumor markers.

Correlation of Sysmex-XN9000 and CellaVision Advanced RBC software on anisocytosis.

OBJECTIVE: This study aims to evaluate the consistency of heterogeneity degree of erythrocyte volume parameters between the blood automated analyzer Sysmex-XN9000 and the advanced red blood cell software CellaVisionDI-60. METHOD: 500 blood samples of volunteers were analyzed by Sysmex-XN9000 and CellaVision-DI60. The sensitivity, specificity, positive predictive value, negative predictive value, false positive rate, and false negative rate were evaluated. The consistency of all parameters was tested. RESULT: Taking the standard RBC group as the control group, the RBC parameters of the macrocytic and the microcytic group were compared. There was a statistical difference between the groups. ROC curve analysis showed that the best cutoff value of microcytic and of macrocytic affecting MCV were 4.1% and 5.7%, respectively. The best cutoff value of anisocytosis was 15.0%. The correlation coefficient between anisocytosis and red blood cell distribution width (RDW-CV) was 0.756. The sensitivity, specificity, positive predictive value and coincidence rate of anisocytosis were high. The false negative rate was 10.0%, and the false positive rate was 7.4%. CONCLUSION: All parameters of the degree of heterogeneity have good accuracy and consistency in the two instruments. Anisocytosis is with higher coincidence rate and positive predictive value. MIC and MAC have a good prediction on the increase or decrease of MCV. Although advanced RBC software's false negative and false positive rates are high, the red blood cell image system is more intuitive and time-saving in observing cells. Consequently, CellaVision-DI60 is suggested to combine with XN-9000 for judging the anisocytosis in daily work comprehensively.

Tumor-derived extracellular vesicle nucleic acids as promising diagnostic biomarkers for prostate cancer.

Liquid biopsy as a non-invasive method has a bright future in cancer diagnosis. Tumor-related extracellular vesicles (EVs) and their components (nucleic acids, proteins, and lipids) in biofluids may exert multiple functions in tumor growth, metastasis, immune escape, and angiogenesis. Among all the components, nucleic acids have attracted the most interest due to their simplicity of extraction and detection. In this review, the biological functions of EVs in prostate cancer (PCa) genesis and progression were summarized. Moreover, the diagnostic value of EV RNA markers found in clinical body fluid samples was reviewed, including their trends, challenging isolation methods, and diagnostic efficacy. Lastly, because relatively much progress has been made in PCa, studies on EV DNA markers are also discussed.

Combination of UC-3500 and UF-5000 as a quick and effective method to exclude bacterial urinary tract infection.

BACKGROUND: Our study aims to evaluate the performance of the combination of Sysmex urine dry chemistry analyzer UC-3500 and urine particle analyzer UF-5000 in screening bacterial urinary tract infection (UTI). METHODS: We analyzed 2000 urine specimens from patients with suspected UTI by using a urine dry chemistry analyzer (UC-3500) and a fully automated sediment analyzer (UF-5000). After being tested by the instrument, all specimens were sent to our clinical microbiology laboratory for culture. In addition, 600 urine specimens were selected to evaluate the accuracy of the six screening strategies established in this study. RESULTS: The consistency of UF-5000 bacterial classification and bacterial culture was fair (Kappa = 0.339). The counts of WBC and BACT elevated with sequential group designs (P < 0.001). The cut-off value of WBC was 32.20/µL for males (AUC, 0.942, 95%CI, 0.930-0.955) and 39.15/µL for females (AUC, 0.931, 95%CI, 0.914-0.948). The sensitivity and specificity of WBC were relatively higher than those of BACT. Strategy④ and Strategy⑥ in all six strategies had a good negative predictive value (NPV) which was 98.73%. CONCLUSION: UF-5000 bacterial classification cannot be used as a practical reference. 32.20/µL (male) and 39.15/µL (female) for WBC as well as 22.35/µL (male) and 127.25/µL (female) for BACT were used as cut-off values to effectively determine whether UTI occurs. WBC, BACT and LEU joint screening programs were suitable to rapidly and effectively exclude bacterial UTI.

Loading of "cocktail siRNAs" into extracellular vesicles via TAT-DRBD peptide for the treatment of castration-resistant prostate cancer.

Extracellular vesicles (EVs) are cell-derived, membranous nanoparticles that mediate intercellular communication by transferring biomolecules between cells. As natural vehicles, EVs may exhibit higher delivery efficiency, lower immunogenicity, and better compatibility than existing RNA carriers. A major limitation of their therapeutic use is the shortage of efficient, robust, and scalable methods to load siRNA of interest. Here, we report a novel strategy using polycationic membrane-penetrating peptide TAT to encapsulate siRNAs into EVs. Three TAT peptides were co-expressed with DRBD as 3TD fusion protein. The sequence-independent binding of DRBD facilitates multiplex genes targeting of mixed siRNAs. Functional assays for siRNA-mediated gene silencing of CRPC were performed after engineered EVs treatment. EVs were isolated using differential centrifugation from WPMY-1 cell culture medium. The increase of merged yellow fluorescence in the engineered EVs showed by TIRFM and the decrease in zeta potential absolute values certified the co-localization of siRNA with EVs, which indicated that siRNA had been successfully delivered into WPMY-1 EVs. qRT-PCR analysis revealed that the mRNA level of FLOH1, NKX3, and DHRS7 was dramatically decreased when cells were treated with engineered EVs loaded with siRNAs mixtures relative to the level of untreated cells. Western and flow cytometry results indicate that delivery of siRNA mixtures by engineered EVs can effectively downregulate AR expression and induce LNCaP-AI cell apoptosis. The uptake efficiency of the EVs and the significantly downregulated expression of three genes suggested the potential of TAT as efficient siRNA carriers by keeping the function of the cargoes.

Genetic testing and clinical relevance of patients with thoracic aortic aneurysm and dissection in northwestern China.

BACKGROUND: Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening pathology that remains a challenge worldwide. Up to 40% of TAAD cases are hereditary with complex heterogeneous genetic backgrounds. The purposes of this study were to determine the diagnostic rate of patients with TAAD, investigate the molecular pathologic spectrum of TAAD by next-generation sequencing (NGS), and explore the future preclinical prospects of genetic diagnosis in patients at high -risk of study. METHODS: NGS was used to screen 15 genes associated with genetic TAAD in 212 patients from northwestern China. Clinical data of patients were gathered by electrocardiography, transthoracic echocardiography, and computed tomography. RESULTS: Of the 212 patients, 67 (31.60%) tested positive for a (likely) pathogenic variant, 42 (19.81%) had a variant of uncertain significance (VUS), and 103 (48.58%) had no variant (likely benign/benign/negative). A total of 135 reportable variants were detected in our test, among which 77 (57.04%) are first reported in this paper. A genotype-phenotype correlation of FBN1 was assessed, and the data showed that the patients with truncating and splicing mutations are more prone to developing severe aortic dissection than those with missense mutations, especially frameshift mutations (82.76% vs. 42.86%). In this study, 43 (20.28%) patients had a family history of sudden death or TAAD, whereas 132 (62.26%) did not (the remaining 37 were not available), and the positive rate of genetic testing was higher in TAAD patients with family history than in those without (76.74% vs. 18.94%). CONCLUSION: Our study concludes that genetic variation is an important consideration in the risk stratification of individualized prediction and disease diagnosis.

Circulating tumour DNA methylation in hepatocellular carcinoma diagnosis using digital droplet PCR.

OBJECTIVE: To evaluate the performance of a DNA methylation-based digital droplet polymerase chain reaction (ddPCR) assay to detect aberrant DNA methylation in cell-free DNA (cfDNA) and to determine its application in the detection of hepatocellular carcinoma (HCC). METHODS: The present study recruited patients with liver-related diseases and healthy control subjects. Blood samples were used for the extraction of cfDNA, which was then bisulfite converted and the extent of DNA methylation quantified using a ddPCR platform. RESULTS: A total of 97 patients with HCC, 80 healthy control subjects and 46 patients with chronic hepatitis B/C virus infection were enrolled in the study. The level of cfDNA in the HCC group was significantly higher than that in the healthy control group. For the detection of HCC, based on a cut-off value of 15.7% for the cfDNA methylation ratio, the sensitivity and specificity were 78.57% and 89.38%, respectively. The diagnostic accuracy was 85.27%, the positive predictive value was 81.91% and the negative predictive value was 87.20%. The positive likelihood ratio of 15.7% in HCC diagnosis was 7.40, while the negative likelihood ratio was 0.24. CONCLUSIONS: A sensitive methylation-based assay might serve as a liquid biopsy test for diagnosing HCC.

A De Novo sSMC (22) Characterized by High-Resolution Chromosome Microarray Analysis in a Chinese Boy with Cat-Eye Syndrome.

We report a 15-year-old boy with cat-eye syndrome (CES) without short stature or intellectual disorder. The boy was confirmed by cytogenetic and high-resolution chromosome microarray analysis (CMA). The G-banding karyotype confirmed the de novo of the patient. Also, the CMA result showed 1.76 Mb tetrasomy of proximal 22Q11.1 ⟶ 22Q11.21 consistent with CES {arr22q11.1q11.21 (16,888,899-18,644,241) X4}, a typical small type I CES chromosome. The patient has many of the basic characteristics of CES; however, he is taller than his peers instead of shorter. It is rarely reported in the past since short stature is a common feature of this syndrome. Furthermore, the boy has no intellectual disorder and attends a normal school since he was six-year-old. What bothered him most were recurrent respiratory infections, retromicrognathia, and heart defects.

Exosomes derived from osteogenic tumor activate osteoclast differentiation and concurrently inhibit osteogenesis by transferring COL1A1-targeting miRNA-92a-1-5p.

In patients with prostate cancer (PCa), bone lesions appear osteoblastic in radiographs; however, pathological fractures frequently occur in PCa patients, and bone resorption is observed in all metastatic lesions under histopathologic assessment. The mechanisms that balance the activities of osteoblasts and osteoclasts in PCa patients remain unclear. We unexpectedly discovered that PCa exosomes are critical mediators in the regulation of bone homeostasis that results in osteoclastic lesions and thereby promotes tumor growth in bone. We evaluated how exosomes derived from osteoblastic, osteoclastic, and mixed PCa cell lines affect osteoblast and osteoclast differentiation, revealing that all three types of PCa exosomes promoted osteoclastogenesis in vitro and induced osteolysis in vivo. Mechanistically, microRNAs (miRNAs) delivered by PCa exosomes were found to play several key roles in bone homeostasis. Among the delivered miRNAs, miR-92a-1-5p, the most abundant miRNA, downregulated type I collagen expression by directly targeting COL1A1, and thus promoting osteoclast differentiation and inhibiting osteoblastogenesis. Furthermore, PCa exosomes also markedly reduced type I collagen expression in vivo. Our findings not only offer a novel perspective on tumor bone metastasis, where-contrary to our initial hypothesis-exosomes derived from an osteoblastic tumor induce osteoclast differentiation, but also suggest potential therapeutic targets for PCa bone metastasis.

Identification of Urinary Exosomal miRNAs for the Non-Invasive Diagnosis of Prostate Cancer.

BACKGROUND: Novel and non-invasive biomarkers with higher sensitivity and specificity for the diagnosis of prostate cancer (PCa) is urgently needed. In this study, we used next-generation sequencing (NGS) to characterize the genome-wide exosomal miRNA expression profiling in urine specimens and explored the diagnostic potential of urinary exosomal miRNAs for PCa. METHODS: Urinary exosomal microRNA expression profiling was performed by next-generation sequencing (NGS) and then validated by quantitative real-time PCR. RESULTS: Significant downregulation of urinary exosomal miR-375 was observed in PCa patients compared with healthy controls, while the expression levels of urinary exosomal miR-451a, miR-486-3p and miR-486-5p were found to be significantly up-regulated in the PCa patients. Furthermore, the expression level of urinary exosomal miR-375 showed a significant correlation with the clinical T-stage and bone metastasis of patients with PCa (P<0.05). Receiver operator characteristic curve demonstrated that the urinary exosomal miR-375, miR-451a, miR-486-3p and miR-486-5p levels can be used to differentiate PCa patients from healthy controls, with area under the curves (AUCs) of 0.788, 0.757, 0.704 and 0.796, respectively. The urinary exosomal miR-375 was found to be superior in discriminating between localized and metastatic PCa with an AUC of 0.806. Moreover, PCa patients can be distinguished from patients with benign prostatic hyperplasia by using a panel combining urinary exosomal miR-375 and miR-451a with an AUC of 0.726. CONCLUSION: These findings demonstrate that the urinary exosomal miRNAs can serve as novel and non-invasive biomarkers for diagnosing and predicting the progression of PCa.

Effects of TFDP3 knock-out by CRISPR/Cas9 on biological function of prostate cancer PC3 cells / 中国肿瘤生物治疗杂志

@#目的：通过 CRISPR/Cas9 技术构建前列腺癌 PC3 细胞 TFDP3 基因敲除的稳转株，探讨抑制 TFDP3 表达对 PC3 细 胞周期、凋亡、迁移和侵袭能力的影响。方法：通过生物信息学筛选 sgRNA，通过 CRISPR/Cas9 技术、构建抑制 TFDP3 基因表达 的 sgRNA-Cas9 共转染慢病毒，感染 PC3 细胞后筛选获取稳转细胞株。通过流式细胞术对 TFDP3 基因敲除的实验组与空白对照 组进行细胞周期和凋亡检测，并进一步通过划痕实验和 Transwell 实验进行细胞迁移和侵袭能力检测。结果：通过生物信息学 筛选获得 3 条 sgRNA，其中 sgRNA2 有明显的抑制前列腺癌细胞基因表达的功能；通过 CRISPR/Cas9 技术成功构建了基于 CRISPR/Cas9 介导的 TFDP3 低表达的 PC3 细胞稳转株。抑制 TFDP3 基因表达后，相比于对照组，KO 组中 G0/G1 期细胞 百分比增加、G2/M 期细胞百分比下降（P<0.05 或 P<0.01），细胞凋亡率显著升高（P<0.05），细胞迁移率明显下降 [24 h 迁移率： (44.00±1.60)% vs (65.00±4.40)%，P<0.01]，穿过聚碳酸酯膜的侵袭细胞数明显下降 [（185.89±11.71）vs （248.33±11.95）个， P<0.01]。结论：通过 CRISPR/Cas9 技术抑制 TFDP3 基因表达后，PC3 细胞发生周期阻滞、凋亡率也有所增加、迁移和侵袭能力 显著减弱，提示 TFDP3 是一个前列腺癌促癌基因。

Functional MRI Investigation of Ultrasound Stimulation at ST 36.

BACKGROUND: Clinical and experimental data suggest that ultrasound stimulation (US) at acupoints can produce similar effective treatment compared to manual acupuncture (MA). Although the brain activation to MA at acupoints is investigated by numerous studies, the brain activation to US at acupoints remains unclear. METHODS: In the present work, we employed task state functional magnetic resonance imaging (fMRI) to explore the human brain's activation to US and MA at ST 36 (Zusanli) which is one of the most commonly used acupoints in acupuncture-related studies. 16 healthy subjects underwent US and MA procedures in an interval of more than one week. On-off block design stimulation was used for the recording of fMRI-related brain patterns. RESULTS: Both US and MA at ST 36 produced activations in somatosensory and limbic/paralimbic regions (postcentral gyrus, insula, middle prefrontal cortex, and anterior cingulate cortex). Only US at ST 36 produced a significant signal increase in the inferior parietal lobule and decrease in the posterior cingulate cortex, whereas MA at ST 36 produced a significant signal increase in the lentiform nucleus and cerebellum. CONCLUSIONS: Our results indicate that US may be a possible noninvasive alternative method to MA due to its similar activation patterns.

Prostate cancer LNCaP-AI+F cell-derived exosomes promote activation of stromal cell WPMY-1 / 中国肿瘤生物治疗杂志

@# Objective: To investigate the effects of prostate cancer exosomes on the migration and invasion ability of stromal cells (WPMY-1), and to explore its mechanism. Methods: Exosomes in LNCaP-AI+F prostate cancer cell supernatant were isolated by ultracentrifugation and the typical structure of exosome was captured by electron microscope. The particle size distribution was analyzed by Zetaview, and Wb was used to identify the marker proteins and other proteins.After co-incubation of WPMY-1 cells and prostate cancer exosomes (40 µg/ml), laser confocal microscope was used to observe the uptake of PKH67-labeled exosomes by WPMY-1 cells; Transwell assay was used to detect the migration and invasion ability of WPMY-1 cells; qPCR was performed to detect the expression of three cancer-associated fibroblast (CAF)-related molecules (IL-8, PDGFB and MMP9) at mRNA level; and the phosphorylation of EGFR and ERK1/2 was analyzed by Wb. Results: Typical cup-shaped structure of exosomes was observed under electron microscope. The Zetaview results showed that the particle size distribution was concentrated at about 100 nm. The expression of exosome marker proteins CD63 andALIX further verified that the isolated particles were exosomes. Besides, EGFR, HER2 and SRC, which were related to the progression of prostate cancer, were also enriched in exosomes. After co-incubation, confocal microscope imaging showed a number of PKH67 labeled exosomes in recipient WPMY-1 cells. Transwell experiments showed that exosomes could significantly enhance the migration and invasion ability of WPMY-1 cells (all P<0.01). Compared with the control group, increased secretion of IL-8, PDGFB and MMP9 was observed after exosome treatment (40 µg/ml) (P<0.05 or P<0.01). Wb indicated that exosomes could promote the phosphorylation of EGFR and ERK1/2 of WPMY-1 cells (P<0.01). Conclusion: Prostate cancer cell exosomes could act on the stromal cell WPMY-1 to highly express multiple CAF-related molecules, promote the phosphorylation of EGFR and ERK1/2 and enhance the migration and invasion ability of WPMY-1 cells.

Exosomal miR-141-3p regulates osteoblast activity to promote the osteoblastic metastasis of prostate cancer.

Exosomes from cancer cells, which contain microRNA and reach metastasis loci prior to cancer cells, stimulate the formation of a metastatic microenvironment. Previous studies have shown that exosomal miR-141-3p is associated with metastatic prostate cancer (PCa). However, the role and regulatory mechanism of miR-141-3p in the microenvironment of bone metastases require further study. In this study, we performed a series of experiments in vivo and in vitro to determine whether exosomal miR-141-3p from MDA PCa 2b cells regulates osteoblast activity to promote osteoblastic metastasis. We demonstrate that extracts obtained from cell culture supernatants contained exosomes and that miR-141-3p levels were significantly higher in MDA PCa 2b cell exosomes. Via confocal imaging, numerous MDA PCa 2b exosomes were observed to enter osteoblasts, and miR-141-3p was transferred to osteoblasts through MDA PCa 2b exosomes in vitro. Exosomal miR-141-3p from MDA PCa 2b promoted osteoblast activity and increased osteoprotegerin OPG expression. miR-141-3p suppressed the protein levels of the target gene DLC1, indicating its functional significance in activating the p38MAPK pathway. In animal experiments, exosomal miR-141-3p had bone-target specificity and promoted osteoblast activity. Mice injected with miR-141-3p-mimics exosomes developed apparent osteoblastic bone metastasis. Exosomal miR-141-3p from MDA PCa 2b cells promoted osteoblast activity and regulated the microenvironment of bone metastases, which plays an important role in the formation of bone metastases and osteogenesis damage in PCa. Clarifying the specific mechanism of bone metastasis will help generate new possibilities for the treatment of PCa.

A specific aptamer-cell penetrating peptides complex delivered siRNA efficiently and suppressed prostate tumor growth in vivo.

Specific and efficient delivery of siRNA into intended tumor cells remains as a challenge, even though RNAi has been exploited as a new strategy for prostate cancer therapy. This work aims to address both specificity and efficiency of SURVIVIN-siRNA delivery by constructing a therapeutic complex using combinatorial strategies. A fusion protein STD was first expressed to serve as a backbone, consisting of streptavidin, a cell-penetrating peptide called Trans-Activator of Transcription (TAT) and a double-stranded RNA binding domain. A biotinylated Prostate Specific Membrane Antigen (PSMA) specific aptamer A10 and SURVIVIN-siRNA were then linked to STD protein to form the therapeutic complex. This complex could specifically targeted PSMA(+) tumor cells. Compared to lipofectamine and A10-siRNA chimera, it demonstrated higher efficiency in delivering siRNA into target cells by 19.2% and 59.9%, and increased apoptosis by 16.8% and 26.1% respectively. Upon systemic administration, this complex also showed significant efficacy in suppressing tumor growth in athymic mice (p <0.001). We conclude that this therapeutic complex could specifically and efficiently deliver SURVIVIN-siRNA to target cells and suppressed tumor growth in vivo, which indicates its potential to be used as a new strategy in prostate cancer therapy.

Diurnal microstructural variations in healthy adult brain revealed by diffusion tensor imaging.

Biorhythm is a fundamental property of human physiology. Changes in the extracellular space induced by cell swelling in response to the neural activity enable the in vivo characterization of cerebral microstructure by measuring the water diffusivity using diffusion tensor imaging (DTI). To study the diurnal microstructural alterations of human brain, fifteen right-handed healthy adult subjects were recruited for DTI studies in two repeated sessions (8∶30 AM and 8∶30 PM) within a 24-hour interval. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial (λ//) and radial diffusivity (λ⊥) were compared pixel by pixel between the sessions for each subject. Significant increased morning measurements in FA, ADC, λ// and λ⊥ were seen in a wide range of brain areas involving frontal, parietal, temporal and occipital lobes. Prominent evening dominant λ⊥ (18.58%) was detected in the right inferior temporal and ventral fusiform gyri. AM-PM variation of λ⊥ was substantially left side hemisphere dominant (p<0.05), while no hemispheric preference was observed for the same analysis for ADC (p = 0.77), λ// (p = 0.08) or FA (p = 0.25). The percentage change of ADC, λ//, λ⊥, and FA were 1.59%, 2.15%, 1.20% and 2.84%, respectively, for brain areas without diurnal diffusivity contrast. Microstructural variations may function as the substrates of the phasic neural activities in correspondence to the environment adaptation in a light-dark cycle. This research provided a baseline for researches in neuroscience, sleep medicine, psychological and psychiatric disorders, and necessitates that diurnal effect should be taken into account in following up studies using diffusion tensor quantities.

Discerning mild cognitive impairment and Alzheimer Disease from normal aging: morphologic characterization based on univariate and multivariate models.

RATIONALE AND OBJECTIVES: Differentiating mild cognitive impairment (MCI) and Alzheimer Disease (AD) from healthy aging remains challenging. This study aimed to explore the cerebral structural alterations of subjects with MCI or AD as compared to healthy elderly based on the individual and collective effects of cerebral morphologic indices using univariate and multivariate analyses. MATERIALS AND METHODS: T1-weighted images (T1WIs) were retrieved from Alzheimer Disease Neuroimaging Initiative database for 116 subjects who were categorized into groups of healthy aging, MCI, and AD. Analysis of covariance (ANCOVA) and multivariate analysis of covariance (MANCOVA) were performed to explore the intergroup morphologic alterations indexed by surface area, curvature index, cortical thickness, and subjacent white matter volume with age and sex controlled as covariates, in 34 parcellated gyri regions of interest (ROIs) for both cerebral hemispheres based on the T1WI. Statistical parameters were mapped on the anatomic images to facilitate visual inspection. RESULTS: Global rather than region-specific structural alterations were revealed in groups of MCI and AD relative to healthy elderly using MANCOVA. ANCOVA revealed that the cortical thickness decreased more prominently in entorhinal, temporal, and cingulate cortices and was positively correlated with patients' cognitive performance in AD group but not in MCI. The temporal lobe features marked atrophy of white matter during the disease dynamics. Significant intercorrelations were observed among the morphologic indices with univariate analysis for given ROIs. CONCLUSIONS: Significant global structural alterations were identified in MCI and AD based on MANCOVA model with improved sensitivity. The intercorrelation among the morphologic indices may dampen the use of individual morphological parameter in featuring cerebral structural alterations. Decrease in cortical thickness is not reflective of the cognitive performance at the early stage of AD.

MRI evaluation of metal acupuncture needles.

OBJECTIVE: To evaluate the MR compatibility of three metal acupuncture needles (a standard stainless steel needle, a gold needle and an austenitic stainless steel needle) by comparing their imaging artefacts, radiofrequency heating effects and ease of operation. METHODS: The MRI artefacts of the three metal needles were first evaluated by placing them in an agar gel phantom and performing MRI of the phantom. The increase in temperature during MRI was recorded using an MR-compatible fibreoptic thermometer. MRI of acupuncture at SP6 was performed using the MR-compatible gold needle and the austenitic stainless steel needle. RESULTS: The standard stainless steel acupuncture needle produced large imaging artefacts on MRI. The gold needle was superior for MRI but not rigid enough for some clinical applications such as scalp acupuncture. The austenitic stainless steel needle is non-ferromagnetic and compatible with MRI. None of these acupuncture needles introduced radiofrequency heating during MRI. CONCLUSIONS: The evaluation of MR compatibility showed that gold and austenitic stainless steel needles are MR-compatible and therefore can be used for MRI of acupuncture.