141 research outputs found

    The combined S velocity achieved from tricuspid annulus and pulmonary annulus with tissue Doppler imaging could predict the proximal right coronary artery occlusion in patients with inferior myocardial infarction

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    Aim: To investigate if combined S velocity (CSV) calculated from tricuspid annulus and pulmonary annulus with tissue Doppler imaging in individuals with acute inferior myocardial infarction were linked to proximal RCA lesions. Methods: The study comprised 48 patient who had been diagnosed with acute inferior myocardial infarction and had culprit lesions in the right coronary artery. The RCA occlusion in Group A was proximal to the right ventricular branch, while the RCA occlusion in Group B was distant to the RV branch. The combined S velocity was tested, as well as other echocardiographic parameters. Results: In terms of metrics indicating right ventricular function, there were substantial disparities between the groups. A favorable association was established in the univariate correlation analysis between CSV and tissue Doppler imaging derived tricuspid annulus systolic velocity (St), pulmonary annulus motion velocity evaluated by TDI (PAMVUT), RV tricuspid annular plane systolic excursion (TAPSE), and fractional area change (FAC). CSV was identified as an independent predictor of proximal RCA occlusion in a multivariate logistic regression test. In the ROC analysis, CSV<18.3 cm/s and PAMVUT<8.6 cm/s indicated proximal RCA occlusion with 83 percent sensitivity and 71 percent specificity (AUC=0.83, p<0.001), and 85 percent sensitivity and 71 percent specificity (AUC=0.81, p<0.001), respectively. Conclusion: CSV measurements were revealed to be an important predictor of proximal RCA occlusions in this investigation

    Tissue morphology and gene expression characterisation of transplantable adenocarcinoma bearing mice exposed to fluorodeoxyglucose-conjugated magnetic nanoparticles

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    Fluorodeoxyglucose-conjugated magnetic nanoparticles, designed to target cancer cells with high specificity when heated by an alternating magnetic field, could provide a low-cost, non-toxic treatment for cancer. However, it is essential that the in vivo impacts of such technologies on both tumour and healthy tissues are characterised fully. Profiling tissue gene expression by semi-quantitative reverse transcriptase real-time PCR can provide a sensitive measurement of tissue response to treatment. However, the accuracy of such analyses is dependent on the selection of stable reference genes. In this study, we determined the impact of fluorodeoxyglucose-conjugated magnetic nanoparticles on tumour and non-tumour tissue gene expression and morphology in MAC16 adenocarcinoma established male NMRI mice. Mice received an injection of 8mg / kg body weight fluorodeoxyglucose-conjugated magnetic nanoparticles either intravenously in to the tail vein, directly into the tumour or subcutaneously directly overlying the tumour. Tissues from mice were sampled between 70 minutes and 12 hours post injection. Using the bioinformatic geNorm tool, we established the stability of six candidate reference genes (Hprt, Pgk1, Ppib, Sdha, Tbp and Tuba); we observed Pgk1 and Ppib to be the most stable. We then characterised the expression profiles of several apoptosis genes of interest in our adenocarcinoma samples, observing differential expression in response to mode of administration and exposure duration. Using histological assessment and fluorescent TUNNEL staining, we observed no detrimental impact on either tumour or non-tumour tissue morphology or levels of apoptosis. These observations define the underlying efficacy of fluorodeoxyglucose-conjugated magnetic nanoparticles on tumour and non-tumour tissue morphology and gene expression, setting the basis for future studies

    The measurement of membranous urethral length using transperineal ultrasound prior to radical prostatectomy

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    Objective: To compare preoperative membranous urethral length (MUL) measurements using magnetic resonance imaging (MRI) with two-dimensional transperineal ultrasound imaging (TPUS) in two supine positions on two separate days in men prior to radical prostatectomy. Materials and methods: MUL was prospectively measured in 18 male volunteers using MRI and on two separate occasions in two different patient positions using TPUS; the patient supine with the knees extended (Supine) and supine with the knees flexed to 70 degrees (Supine KF). Agreement between TPUS and MRI measurements of MUL was assessed using Bland-Altman method comparison techniques and a two-way mixed-effects single measures intraclass correlation (ICC). Test-retest reliability was assessed using a two-way random effects single measures ICC. Results: The mean difference in MUL measurements between MRI and i) TPUS Supine was -0.8 mm (95% limits of agreement (LOA): -3.2, 1.7) and ii) TPUS Supine KF was -0.8mm (95% LOA: -3.5, 1.9). ICC indicated a point estimate of excellent agreement between MRI and TPUS Supine ICC 0.93 (95% CI: 0.76, 0.98) and TPUS Supine KF ICC 0.91 (95 0 /0CI 0.79, 0.97). There was excellent agreement between TPUS Supine and TPUS Supine KF (ICC 0.98, 95% CI: 0.96, 0.99) with a mean difference of 0.3mm (95% LOA: -1.2 to 1.3mm). Conclusions: Preoperative MUL can be reliably measured using TPUS and demonstrates excellent agreement with MRI measurements of MUL. TPUS provides clinicians with an accessible non-invasive alternative to MRI for the measurement of MUL that can be used in outpatient urological settings and for patients where MRI is contraindicated

    Evaluation of cancer outcome assessment using MRI: A review of deep-learning methods

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    Accurate evaluation of tumor response to treatment is critical to allow personalized treatment regimens according to the predicted response and to support clinical trials investigating new therapeutic agents by providing them with an accurate response indicator. Recent advances in medical imaging, computer hardware, and machine-learning algorithms have resulted in the increased use of these tools in the field of medicine as a whole and specifically in cancer imaging for detection and characterization of malignant lesions, prognosis, and assessment of treatment response. Among the currently available imaging techniques, magnetic resonance imaging (MRI) plays an important role in the evaluation of treatment assessment of many cancers, given its superior soft-tissue contrast and its ability to allow multiplanar imaging and functional evaluation. In recent years, deep learning (DL) has become an active area of research, paving the way for computer-assisted clinical and radiological decision support. DL can uncover associations between imaging features that cannot be visually identified by the naked eye and pertinent clinical outcomes. The aim of this review is to highlight the use of DL in the evaluation of tumor response assessed on MRI. In this review, we will first provide an overview of common DL architectures used in medical imaging research in general. Then, we will review the studies to date that have applied DL to magnetic resonance imaging for the task of treatment response assessment. Finally, we will discuss the challenges and opportunities of using DL within the clinical workflow

    An in-vivo pilot study into the effects of FDG-mNP in cancer in mice

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    Purpose Previously, fluorodeoxy glucose conjugated magnetite nanoparticles (FDG-mNPs) injected into cancer cells in conjunction with the application of magnetic hyperthermia have shown promise in new FDG-mNPs applications. The aim of this study was to determine potential toxic or unwanted effects involving both tumour cells and normal tissue in other organs when FDG-mNPs are administered intravenously or intratumourally in mice. Materials and methods FDG-mNPs were synthesized. A group of six prostate-tumour bearing mice were injected with 23.42 mg/ml FDG-mNPs (intravenous injection, n = 3; intratumoural injection into the prostate tumour, n = 3). Mice were euthanized and histological sampling of tissue was conducted for the prostate tumour, as well as for lungs, lymph nodes, liver, kidneys, spleen, and brain, at 1 hour (n = 2) and 7 days (n = 4) post-injection. A second group of two normal (non-cancerous) mice received the same injection intravenously into the tail vein and were euthanised at 3 and 6 months post-injection, respectively, to investigate if FDG-mNPs remained in organs at those time points. Results In prostate-tumour bearing mice, FDG-mNPs concentrated in the prostate tumour, while relatively small amounts were found in the organs of other tissues, particularly the spleen and the liver; FDG-mNP concentrations decreased over time in all tissues. In normal mice, no detrimental effects were found in either mouse at 3 or 6 months. Conclusion Intravenous or intratumoural FDG-mNPs can be safely administered for effective cancer cell destruction. Further research on the clinical utility of FDG-mNPs will be conducted by applying hyperthermia in conjunction with FDG-mNPs in mice
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