524,607 research outputs found

    Magnetic Resonance Imaging with Diffuse Weighted Imaging and Computed Tomography with Intravenous Contrast in Staging of Disseminated Ovarian, Stomach, Colorectal Cancer

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    The aim of the research. Development and implementation of new methods for pre-operative staging of advanced ovarian, gastric and colorectal cancer to improve patient selection for cytoreductive surgery and increase its radicality.Materials and methods. Data from 120 patients with advanced ovarian cancer, 28 with advanced gastric cancer and 119 with advanced colorectal cancer were analyzed. Preoperative detection of the incidence of peritoneal carcinoma and the possibility of surgery in radical or cytoreductive volume performed by CT with intravenous contrast (72 patients with ovarian cancer, 17 patients with gastric cancer, and 69 patients with colorectal cancer), and MR T1 and T2, contrast-enhanced T1, and diffuse-weighted sequences (48 patients with ovarian cancer, 11 patients with gastric cancer, and 50 patients with colorectal cancer). Subsequently, preoperative and intraoperative assessment of the prevalence of the tumour process with peritoneal carcinoma index (PCI) by Sugarbaker was performed.Results. A statistically significant increase in the informativeness of the preoperative assessment of the incidence of tumour process in peritoneum and the presence of distant metastases using DWI / MRI compared with CT with intravenous contrast was determined. Patients from all groups were categorized according to the completeness index of cytoreduction achieved by preoperative staging and patient selection using DWI / MRI and CT. The use of DWI / MRI allowed to significantly reduce the number of suboptimal and non-optimal cytoreductive interventions.Conclusions. DWI / MRI has made it possible to significantly improve the preoperative incidence of advanced ovarian, gastric, and colorectal cancer compared to CT, predict the radicality of future surgery, and detect inoperable cases

    Nuclear Magnetic Resonance Imaging of Li-ion Battery

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    Nuclear magnetic resonance (NMR) imaging has high sensitivity to proton (1H) and lithium (7Li). It is a useful measurement for electrolyte in Li-ion battery. 1H NMR images of lithium ion battery which is composed of LiMn2O4 / LiClO4 + propylene carbonate (PC) / Li-metal have been studied. 1H NMR images of electrolyte near cathode material (LiMn2O4) showed anomalous intensity distribution, which was quite inhomogeneous. From NMR images as a function of repetition time (TR), it was concluded that the anomalous intensity distribution was not due to change of relaxation time but an indirect (spatial) para-magnetization effect from cathode material. The paramagnetization induced by high magnetic field distorts linearity of magnetic gradient field, leading to apparent intensity variance. This functional image is an easy diagnostic measurement for magnetization of cathode material, which allows the possibility to check uniformity of cathode material and change of magnetization under electrochemical process. Received: 7 October 2010; Revised: 1 December 2010; Accepted: 17 December 201

    Linear magnetic resonance imaging measurements of the hippocampal formation differ in young versus old dogs

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    Age-related hippocampal formation (HF) atrophy has been documented on MRI studies using volumetric analysis and visual rating scales.This retrospective cross-sectional study aimed to compare linear MRI measurements of the HF between young (1–3 years) and old (>10 years) non-brachycephalic dogs, with normal brain anatomy and cerebrospinal fluid (CSF) analysis. Right and left hippocampal formation height (HFH), height of the brain (HB) and mean HFH/HB ratio were measured by two observers on a transverse T2 fluid-attenuated inversion recovery sequence containing rostral colliculi and mesencephalic aqueduct.119 MRI studies were enrolled: 75 young and 44 old dogs. Left and right HFH were greater (p<0.0001) in young, while HB was greater in old dogs (p=0.024). Mean HFH/HB ratio was 15.66 per cent and 18.30 per cent in old and young dogs (p<0.0001). No differences were found comparing measurements between epileptic and non-epileptic dogs.Old dogs have a greater HB; this may represent the different study populations or a statistical phenomenon. Ageing affects HF linear measurements. A reduction of mean HFH/HB ratio between 18.30 per cent and 15.66 per cent should be considered a physiological age-related process of the canine lifespan. The use of mean HFH/HB ratio could be considered for quantifying brain atrophy in elderly dogs

    170 Nanometer Nuclear Magnetic Resonance Imaging using Magnetic Resonance Force Microscopy

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    We demonstrate one-dimensional nuclear magnetic resonance imaging of the semiconductor GaAs with 170 nanometer slice separation and resolve two regions of reduced nuclear spin polarization density separated by only 500 nanometers. This is achieved by force detection of the magnetic resonance, Magnetic Resonance Force Microscopy (MRFM), in combination with optical pumping to increase the nuclear spin polarization. Optical pumping of the GaAs creates spin polarization up to 12 times larger than the thermal nuclear spin polarization at 5 K and 4 T. The experiment is sensitive to sample volumes containing 4×1011\sim 4 \times 10^{11} 71^{71}Ga/Hz/\sqrt{Hz}. These results demonstrate the ability of force-detected magnetic resonance to apply magnetic resonance imaging to semiconductor devices and other nanostructures.Comment: Submitted to J of Magnetic Resonanc

    Transperineal magnetic resonance image targeted prostate biopsy versus transperineal template prostate biopsy in the detection of clinically significant prostate cancer.

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    PURPOSE: Multiparametric magnetic resonance imaging can be used to guide prostate biopsy by targeting biopsies to areas in the prostate at high risk for cancer. We compared the detection of clinically significant and insignificant cancer by transperineal magnetic resonance imaging targeted biopsy and transperineal template guided prostate biopsy. MATERIALS AND METHODS: A total of 182 men with a lesion suspicious for cancer on multiparametric magnetic resonance imaging underwent transperineal magnetic resonance imaging targeted biopsy using a cognitive registration technique, followed by systematic transperineal template guided prostate biopsy. The primary outcome was the detection rate of clinically significant prostate cancer. Clinical significance was defined using maximum cancer core length 4 mm or greater and/or Gleason grade 3 + 4 or greater (University College London definition 2). We secondarily evaluated other commonly used thresholds of clinically significant disease, including maximum cancer core length 6 mm or greater and/or Gleason grade 4 + 3 or greater, maximum cancer core length 3 mm or greater and/or Gleason grade 3 + 4 or greater, and maximum cancer core length 2 or greater mm and/or Gleason grade 3 + 4 or greater. Strategies were statistically compared with the McNemar test. RESULTS: Mean ± SD patient age was 63.3 ± 7.2 years. Median prostate specific antigen was 6.7 ng/ml (IQR 4.7-10.0). Clinically significant cancer was detected by magnetic resonance imaging targeted biopsy and template guided prostate biopsy in 103 (57%) and 113 of the 182 men (62%) (p = 0.174), and clinically insignificant cancer was detected in 17 (9.3%) and 31 (17.0%), respectively (p = 0.024). CONCLUSIONS: Prostate biopsy targeted to suspicious lesions on multiparametric magnetic resonance imaging has encouraging rates of detection of clinically significant cancer while also decreasing the detection rate of clinically insignificant cancer. This is achieved with fewer biopsy cores than for systematic template guided biopsy. Further prospective, multicenter, comparative trials of the performance of targeting strategies are needed to consider magnetic resonance imaging targeted biopsy an alternative to conventional systematic biopsy

    Trigeminal nerve and pathologies in magnetic resonance imaging : a pictorial review

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    A variety of conditions may affect the trigeminal nerve. Magnetic resonance imaging is the modality of choice when trigeminal nerve pathology is suspected, and this modality plays an essential role in detecting causes. This review illustrates some of the pathological conditions relevant to the trigeminal nerve in magnetic resonance imaging

    Speckle filtering techniques for different quality level of healthy kidney ultrasound images

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    The increasing reliance of modern medicine on diagnostic techniques such as computerized tomography, histopathology, magnetic resonance imaging, radiology and ultrasound imaging shows the importance of medical images [1]. Ultrasound (US) imaging is an imaging technique that is far the least expensive and most portable comparing to other standard medical imaging modalities. US imaging is a safe technique, easy to use, noninvasive nature and provides real time imaging, hence it is used extensively. But on the downside, ultrasound imaging has a poor resolution of image compared with other medical imaging instrument like Magnetic Resonance Imaging (MRI). US has wide spread application as a primary diagnostic aid of obstetrics and gynecology, due to the lack of ionizing radiation or strong magnetic fields. General US imaging applications include soft tissue organ and carotid arter

    Embroidered Coils for Magnetic Resonance Sensors

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    Magnetic resonance imaging is a widely used technique for medical and materials imaging. Even though the objects being imaged are often irregularly shaped, suitable coils permitting the measurement of the radio-frequency signal in these systems are usually made of solid copper. One problem often encountered is how to ensure the coils are both in close proximity and conformal to the object being imaged. Whilst embroidered conductive threads have previously been used as antennae in mobile telecommunications applications, they have not previously been reported for use within magnetic resonance. In this paper we show that an embroidered single loop coil can be used in a commercial unilateral nuclear magnetic resonance system as an alternative to a solid copper. Data is presented showing the determination of both longitudinal (T1) and effective transverse (T2eff) relaxation times for a flat fabric coil and the same coil conformed to an 8 cm diameter cylinder. We thereby demonstrate the principles required for the wider use of fabric based conformal coils within nuclear magnetic resonance and magnetic resonance imaging
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