Magnetic Resonance Imaging (MRI) scanners produce loud acoustic noise originating from vibrational Lorentz forces induced by rapidly changing currents in the magnetic field gradient coils. Using zero echo time (ZTE) MRI pulse sequences, gradient switching can be reduced to a minimum, which enables near silent operation.Besides silent MRI, ZTE offers further interesting characteristics, including a nominal echo time of TE = 0 (thus capturing short-lived signals from MR tissues which are otherwise MR-invisible), 3D radial sampling (providing motion robustness), and ultra-short repetition times (providing fast and efficient scanning).In this work we describe the main concepts behind ZTE imaging with a focus on conceptual understanding of the imaging sequences, relevant acquisition parameters, commonly observed image artefacts, and image contrasts. We will further describe a range of methods for anatomical and functional neuroimaging, together with recommendations for successful implementation.
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http://dx.doi.org/10.1016/j.pnmrs.2021.03.002 | DOI Listing |
Magn Reson Med
December 2024
Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada.
Purpose: The purpose of this study was to investigate microstructural changes in the aging adult prostate by comparing the effects of varying diffusion times using diffusion MRI, and to provide an age-related benchmark for future prostate cancer studies.
Methods: The prostates of normal male volunteers (n = 70, 19-69 years) were scanned at 3 T with an oscillating gradient spin echo (OGSE: 6 ms), pulsed gradient spin echo (PGSE: 40 ms) and pulsed gradient stimulated echo (PGSTE: 100 ms), and anatomical T-weighted image. Volume and mean diffusivity (MD) were measured in the peripheral (PZ) and transition zones (TZ), which were assessed versus age.
Long time series of velocity profiles collected by up-looking acoustic profilers in the westernmost sill of the Strait of Gibraltar show an unexpected pattern in the deepest ∼80 m of the water column, consisting in an appreciable diurnal weakening of the measured horizontal velocity. A harmonic analysis performed on long time series reveals a surprising magnitude of S constituent (exactly 1 cpd of frequency) in the horizontal velocity and echo amplitude, which prevails over the rest of diurnal constituents within this depth range, including K, despite being around 200 times smaller than it in the tide generating potential. High resolution echograms collected by a new instrument recently installed in the mooring line, point at the diel vertical migration of living acoustic scatterers (zooplankton) as the most reasonable cause.
View Article and Find Full Text PDFCardiovasc Diabetol
December 2024
Cardiovascular Research Institute, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave, s7-119, New York, NY, USA.
Background: Long-term consumption of Western Diet (WD) is a well-established risk factor for the development of cardiovascular disease (CVD); however, there is a paucity of studies on the long-term effects of WD on the pathophysiology of CVD and sex-specific responses.
Methods: Our study aimed to investigate the sex-specific pathophysiological changes in left ventricular (LV) function using transthoracic echocardiography (ECHO) and LV tissue transcriptomics in WD-fed C57BL/6 J mice for 125 days, starting at the age of 300 through 425 days.
Results: In female mice, consumption of the WD diet showed long-term effects on LV structure and possible development of HFpEF-like phenotype with compensatory cardiac structural changes later in life.
Sci Rep
December 2024
Department of Public Health, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, 1111 Xianxia Road, Shanghai, 200335, China.
Breast ultrasound is recommended for early breast cancer detection in China, but the rapid increase in imaging data burdens sonographers. This study evaluated the agreement between artificial intelligence (AI) software and sonographers in analyzing breast nodule features. Breast ultrasound images from two hospitals in Shanghai were analyzed by both the software and the sonographers for features including echotexture, echo pattern, orientation, shape, margin, calcification, and posterior echo attenuation.
View Article and Find Full Text PDFAJNR Am J Neuroradiol
December 2024
From the Department of Radiology (H.N.M., F.B.G.), Bai Jerbai Wadia Hospital for Children, Mumbai, Maharashtra, India.
Background And Purpose: Congenital vertebral anomalies are commonly associated with underlying spinal cord anomaly which necessitates imaging both the spinal cord and the bony vertebral column to understand the extent of the deformity better. While MRI is the gold standard for spinal cord imaging, it does not provide CT-like bone details. Many MR bone imaging techniques have been tested in various adult spine conditions in the past decade but not much has been described on their reliability in pediatric spine.
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