Fourier Transformation Magnetic Resonance Imaging Research Articles

A comparison of magnetic resonance angiography and constructive interference in steady state-three-dimensional Fourier transformation magnetic resonance imaging in patients with hemifacial spasm

Although the decision to perform a microvascular decompression of the facial nerve is based on clinical history and assessment, preoperative imaging of the neurovascular relationships at the REZ is important to exclude a non-vascular cause or identify dolichoectatic vessels that might influence the surgical approach. We designed the current study to compare the specificity and sensitivity of gadolinium-enhanced 3D fast inflow with steady state precession (FISP) MRA with CISS. The imaging findings of 47 patients that had microvascular decompression for hemifacial spasm were retrospectively reviewed in a single blind fashion. The 47 non-symptomatic sides served as controls. Neurovascular contact could be seen in 13/47 (27.6%) in routine T2 axial scans, in 22/35 (62.8%) in high resolution T2W, in 18/34 (52.9%) in the case of MRA, and in all cases (13) when the CISS sequence was used. This study demonstrated 56.2% sensitivity and 50% specificity for MRA with gadolinium enhancement, whereas the CISS sequence can achieve a sensitivity of 100% in correctly demonstrating neurovascular compression in HFS. Overall accuracy of the two methods was 55.8 and 100% for MRA and CISS, respectively. The CISS sequence is superior in identifying neurovascular compression when compared with MRA. Preoperative knowledge of the compressing vessel has counselling implications and the higher risk of complications should be communicated to the patient. Due to cost and time implications we suggest that MR-CISS imaging replace the enhanced MRA sequence in the detailed preoperative MR assessment of hemifacial spasm

Value of Constructive Interference in Steady-state, Three-dimensional, Fourier Transformation Magnetic Resonance Imaging for the Neuroendoscopic Treatment of Hydrocephalus and Intracranial Cysts

Value of Constructive Interference in Steady-state, Three-dimensional, Fourier Transformation Magnetic Resonance Imaging for the Neuroendoscopic Treatment of Hydrocephalus and Intracranial Cysts

Value of Constructive Interference in Steady-state, Three-dimensional, Fourier Transformation Magnetic Resonance Imaging for the Neuroendoscopic Treatment of Hydrocephalus and Intracranial Cysts

Value of Constructive Interference in Steady-state, Three-dimensional, Fourier Transformation Magnetic Resonance Imaging for the Neuroendoscopic Treatment of Hydrocephalus and Intracranial Cysts

Geometric Analysis and Symbol Calculus: Fourier Transform Magnetic Resonance Imaging and Wavelets

Due to its unequalled advantages, the magnetic resonance imaging (MRI) modality has truly revolutionized the diagnosis and evaluation of pathology. Because many morphological anatomic details that may not be visualized by other high tech imaging methods can now be readily shown by diagnostic MRI, it has already become the standard modality by which all other clinical imaging techniques are measured. The unique quantum physical basis of the MRI modality combined with the imaging capabilities of current computer technology has made this imaging modality a target of interdisciplinary interest for clinicians, physicists, biologists, engineers, and mathematicians. Due to the fact that MRI scanners perform corticomorphic processing, this modality is by far more complex than all the other high tech clinical imaging techniques. The purpose of this paper is to outline a phase coherent wavelet approach to Fourier transform MRI. It is based on distributional harmonic analysis on the Heisenberg nilpotent Lie group G and the associated symplectically invariant symbol calculus of pseudodifferential operators. The contour and contrast resolution of MRI scans which is controlled by symplectic filter bank processing gives the noninvasive MRI modality superiority over X-ray computed tomography (CT) in soft tissue differentiation.

Non-Commutative Affine Geometry and Symbol Calculus: Fourier Transform Magnetic Resonance Imaging and Wavelets

Abstract. Magnetic Resonance Imaging (MRI) is one of the most significant advances in medical imaging in this century. The multiplanar capability and high-resolution imaging are unmatched by any other current clinical imaging technique. The physical and mathematical principles on which this non-invasive imaging technology is based are as complex as the computer-controlled synergy of the MRI scanner organization. The MRI scanner is a quantum electrodynamical (QED) device, the components of which implement and detect the wavelet interference and resonance phenomena which underly the symplectic MRI filter-bank processing. Notice the fact that QED has approved the semi-classical approach to quantum holography. In this paper, a semi-classical QED treatment of the basic MRI system organization is presented, with deep roots in the Keppler phase triangulation procedure of physical astronomy and in the symplectically invariant symbol calculus of pseudodifferential operators. It is based on non-commutative geometry of affine transvections and non-commutative Fourier analysis. This allows for modeling the interference patterns of phase coherent wavelets by distributional harmonic analysis on the Heisenberg nilpotent Lie group G of quantum mechanics. Geometric quantization yields the tomographic slices by the planar coadjoint orbit stratification O v,v ≠ 0, of the unitary dual Ĝ of the Heisenberg group G. The resonance of affine wavelets is treated by harmonic analysis on the affine solvable Lie group GA(ℝ), which is intrinsically operating on non-trivial blocks of G. It allows the acquisition of the coordinates of high-resolution tomographic scans within the tomographic slices by the Lauterbur spatial encoding technique of quantum holography.

Signal-to-noise ratio and section thickness in two-dimensional versus three-dimensional Fourier transform MR imaging.

The efficiency and quality of three-dimensional Fourier transform (3DFT) magnetic resonance imaging were evaluated and compared with those of 2DFT imaging. For a fixed imaging time and number of sections, 3DFT imaging with conventional spin echoes always had a worse signal-to-noise ratio (S/N) than did 2DFT imaging, when both were optimized with respect to choice of repetition time (TR). With partial-flip magnetic resonance (MR) imaging, S/N was nearly equal for 2DFT and 3DFT imaging when both were optimized with respect to TR and flip angle. 3DFT imaging can have cross-section artifacts that exceed those of 2DFT imaging. For very thin sections these artifacts may be lessened, and 3DFT imaging can achieve this with smaller gradient pulses. Over-all, 3DFT imaging was found to be advantageous only for the very-thin-section imaging and in combination with partial-flip MR imaging.