Clinical radiology
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Comparative Study
SPAMM, cine phase contrast imaging and fast spin-echo T2-weighted imaging in the study of intracranial cerebrospinal fluid (CSF) flow.
To compare the qualitative assessment of cerebrospinal fluid (CSF) flow using a SPAMM (spatial modulation of magnetization) technique with cine phase contrast images (cine PC) and fast spin echo (FSE) T2-weighted images. ⋯ SPAMM provides a comparable assessment of intracranial CSF flow to that of cine phase contrast imaging at all CSF sites except the cerebral aqueduct.
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To assess routine image subtraction in 3D gadopentate dimeglumine (Gd-DTPA)-enhanced magnetic resonance (MR) angiography of the thoracic aorta. ⋯ Image subtraction significantly improved both the SNR and CNR, but did not alter the final diagnosis, and does not appear warranted in routine practice.
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Comparative Study
In-vitro visualization of biopsy needles with ultrasound: a comparative study of standard and echogenic needles using an ultrasound phantom.
To demonstrate the circumstances where echogenically enhanced biopsy needles confer an increase in visualization during ultrasound-guided biopsy using an in-vitro experiment. ⋯ Optimisation of the conditions prior to ultrasound-guided needle biopsy will increase the visualization of the chosen device thus aiding the interventionalist. Needle gauge, bevel position, movement of the needle and the probe to needle angle all affect conspicuity. Needle coating or roughening does not improve tip visualization if the angle between the needle and probe can be optimized (60 degrees ). In unfavourable situations when the angle is suboptimal (20 degrees ), we have shown that echogenic enhancement of the needle tip can make it more visible.
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To describe the optimum conditions for successful free-hand ultrasound guided intervention using an in-vitro experiment. ⋯ Understanding how to optimize the free-hand conditions will help the interventionalist to obtain greater performance using a variety of puncture devices. This concept is likely to be particularly important to the novice interventionalist as well as to those teaching the free-hand technique.
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The aim of this study was to compare the performance of three fluid attenuated inversion recovery (FLAIR) pulse sequences for control of cerebrospinal fluid (CSF) and blood flow artifacts in imaging of the brain. The first of these sequences had an initial sinc inversion pulse which was followed by conventional k-space mapping. The second had an initial sinc inversion pulse followed by k-space re-ordered by inversion time at each slice position (KRISP) and the third had an adiabatic initial inversion pulse followed by KRISP. ⋯ The KRISP FLAIR sequence controls high signal artifacts from CSF flow and blood flow and the adiabatic pulse controls high signal artifacts due to inadequate inversion of the CSF magnetization at the periphery of the head transmitter coil. The KRISP FLAIR sequence also improves cortical and meningeal definition as a result of an edge enhancement effect. The effects are synergistic and can be usefully combined in a single pulse sequence. Curati, W. L.et al. (2001)Clinical Radiology56, 375-384