نتایج جستجو برای: Misregistration artifact

تعداد نتایج: 19385  

2014
Ching‐Yi Hsieh Gregory Gladish Charles E. Willis

Misregistration due to cardiac motion causes artifacts in two-exposure dual-energy subtraction images, in both the soft-tissue-only image and the bone-only image. Two previous investigations have attempted to avoid misregistration artifacts by using cardiac gating of the first and second exposures. The severity of misregistration was affected by the heart rate, the time interval between the low...

Journal: :Applied optics 2007
Francesco Dell'Endice Jens Nieke Daniel Schläpfer Klaus I Itten

Hyperspectral imaging (HSI) sensors suffer from spatial misregistration, an artifact that prevents the accurate acquisition of the spectra. Physical considerations let us assume that the influence of the spatial misregistration on the acquired data depends both on the wavelength and on the across-track position. A scene-based method, based on edge detection, is therefore proposed. Such a proced...

Journal: :AJNR. American journal of neuroradiology 1990
T C Larson W M Kelly R L Ehman F W Wehrli

Spatial misregistration of signal recovered from flowing spins within vascular structures is a common phenomenon seen in MR imaging of the CNS. The condition is displayed as a bright line or dot offset from the true anatomic location of the lumen of the imaged vessel. Its origin is the time delay between application of the phase- and frequency-encoding gradients used to locate spins within the ...

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 2007
K Lance Gould Tinsu Pan Catalin Loghin Nils P Johnson Ashrith Guha Stefano Sdringola

UNLABELLED Cardiac PET combined with CT is rapidly expanding despite artifactual defects and false-positive results due to misregistration of PET and CT attenuation correction data-the frequency, cause, and correction of which remain undetermined. METHODS Two hundred fifty-nine consecutive patients underwent diagnostic rest-dipyridamole myocardial perfusion PET/CT using (82)Rb, a 16-slice PET...

Journal: :Journal of breast imaging 2023

Abstract Contrast-enhanced mammography (CEM) has emerged as an important new technology in breast imaging. It can demonstrate a number of imaging artifacts that have the potential to limit interpretation by either obscuring or potentially mimicking disease. Commonly encountered on CEM include patient motion (ripple and misregistration), pectoral highlighting artifact, implant halo corrugation c...

Journal: :Radiologia 2014
M Ramalho V Herédia R O P de Campos M de Toni B M Dale R C Semelka

PURPOSE To implement in-phase and out-of-phase (IP/OP) techniques with Magnetization-Prepared Gradient Recalled Echo (MP-GRE) and to evaluate the feasibility and diagnostic image quality among pre and post-optimized MP-GRE sequences, including patients unable to cooperate with breath-hold requirements. MATERIALS AND METHODS Institutional review board approval with waiver of informed consent w...

2007
L. F. Foo S. T. Jawetz K. Butts Pauly H. G. Potter

Introduction / Background: MR imaging of arthroplasty has traditionally been limited by the presence of artifact generated by the metallic components, which comparatively demonstrate higher magnetic susceptibility than the adjacent bone and soft tissue (1-3). The sources of these artifacts include induction of radiofrequency eddy currents in the metal, warping of the slice during slice selectio...

Journal: :AJNR. American journal of neuroradiology 1990
L Ketonen S Totterman J H Simon T H Foster D K Kido J Szumowski S E Joy

The value of a reduced bandwidth MR imaging technique was tested prospectively in 51 spinal MR examinations by using default (16 kHz) bandwidth, 2000/30, 90 (TR/TEs) and 600/30, and reduced (8 kHz) bandwidth, 2000/48, 92 and 600/30, techniques at 1.5 T. Bandwidth reduction was used to maintain the signal-to-noise ratio for a reduced scan time. Concerns have been raised as to the effect of bandw...

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 2007
Sibyll Goetze Tracy L Brown William C Lavely Zhe Zhang Frank M Bengel

UNLABELLED The accuracy of myocardial perfusion SPECT improves with attenuation correction. Algorithms for attenuation correction in hybrid SPECT/CT systems have the potential for misregistration of emission and transmission scans because CT and SPECT are obtained sequentially. Misregistration will influence regional tracer distribution and may reduce diagnostic accuracy. This study focused on ...

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