In vivo method for correcting transmit/receive nonuniformities with phased array coils. 2005

Jinghua Wang, and Maolin Qiu, and R Todd Constable
Department of Diagnostic Radiology, Yale University School Medical Center, The Anlyan Center, 300 Cedar Street, New Haven, CT 06510, USA. Jinghua.wang@yale.edu

Phased array coils are finding widespread applications in both the research and the clinical setting. However, intensity nonuniformities with such coils can reduce the potential benefits of these coils, particularly for applications such as tissue segmentation. In this work, a method is described for correcting the nonuniform signal response based on in vivo measures of both the transmission field of body coil and the reception sensitivity of phased array coils, separately. For a uniform phantom, the reception sensitivity can be calculated using both Bloch equations and transmission field maps. For a heterogeneous object such as a brain, a minimal contrast acquisition must be obtained to map the receiver nonuniformities. This transmit field/receiver sensitivity (TFRS) approach is compared with the standard methods of using the body coil to obtain a reference scan and low-pass filtering. The quantitative comparison results shows that the TFRS approach provides superior results in correcting intensity nonuniformities for a uniform phantom. This approach reduces the ratio between signal intensity SD of an image and its mean intensity from approximately 21% before correction to 13% after correction. Results are also shown demonstrating the utility of this approach in vivo with human brain images. The method is general and can be applied with most pulse sequences, any coil combination for transmission and reception, and in any anatomic region.

UI MeSH Term Description Entries
D007089 Image Enhancement Improvement of the quality of a picture by various techniques, including computer processing, digital filtering, echocardiographic techniques, light and ultrastructural MICROSCOPY, fluorescence spectrometry and microscopy, scintigraphy, and in vitro image processing at the molecular level. Image Quality Enhancement,Enhancement, Image,Enhancement, Image Quality,Enhancements, Image,Enhancements, Image Quality,Image Enhancements,Image Quality Enhancements,Quality Enhancement, Image,Quality Enhancements, Image
D007090 Image Interpretation, Computer-Assisted Methods developed to aid in the interpretation of ultrasound, radiographic images, etc., for diagnosis of disease. Image Interpretation, Computer Assisted,Computer-Assisted Image Interpretation,Computer-Assisted Image Interpretations,Image Interpretations, Computer-Assisted,Interpretation, Computer-Assisted Image,Interpretations, Computer-Assisted Image
D008279 Magnetic Resonance Imaging Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques. Chemical Shift Imaging,MR Tomography,MRI Scans,MRI, Functional,Magnetic Resonance Image,Magnetic Resonance Imaging, Functional,Magnetization Transfer Contrast Imaging,NMR Imaging,NMR Tomography,Tomography, NMR,Tomography, Proton Spin,fMRI,Functional Magnetic Resonance Imaging,Imaging, Chemical Shift,Proton Spin Tomography,Spin Echo Imaging,Steady-State Free Precession MRI,Tomography, MR,Zeugmatography,Chemical Shift Imagings,Echo Imaging, Spin,Echo Imagings, Spin,Functional MRI,Functional MRIs,Image, Magnetic Resonance,Imaging, Magnetic Resonance,Imaging, NMR,Imaging, Spin Echo,Imagings, Chemical Shift,Imagings, Spin Echo,MRI Scan,MRIs, Functional,Magnetic Resonance Images,Resonance Image, Magnetic,Scan, MRI,Scans, MRI,Shift Imaging, Chemical,Shift Imagings, Chemical,Spin Echo Imagings,Steady State Free Precession MRI
D001921 Brain The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM. Encephalon
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000465 Algorithms A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task. Algorithm
D012680 Sensitivity and Specificity Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed) Specificity,Sensitivity,Specificity and Sensitivity
D015203 Reproducibility of Results The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results. Reliability and Validity,Reliability of Result,Reproducibility Of Result,Reproducibility of Finding,Validity of Result,Validity of Results,Face Validity,Reliability (Epidemiology),Reliability of Results,Reproducibility of Findings,Test-Retest Reliability,Validity (Epidemiology),Finding Reproducibilities,Finding Reproducibility,Of Result, Reproducibility,Of Results, Reproducibility,Reliabilities, Test-Retest,Reliability, Test-Retest,Result Reliabilities,Result Reliability,Result Validities,Result Validity,Result, Reproducibility Of,Results, Reproducibility Of,Test Retest Reliability,Validity and Reliability,Validity, Face
D016477 Artifacts Any visible result of a procedure which is caused by the procedure itself and not by the entity being analyzed. Common examples include histological structures introduced by tissue processing, radiographic images of structures that are not naturally present in living tissue, and products of chemical reactions that occur during analysis. Artefacts,Artefact,Artifact
D019047 Phantoms, Imaging Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990) Phantoms, Radiographic,Phantoms, Radiologic,Radiographic Phantoms,Radiologic Phantoms,Phantom, Radiographic,Phantom, Radiologic,Radiographic Phantom,Radiologic Phantom,Imaging Phantom,Imaging Phantoms,Phantom, Imaging

Related Publications

Jinghua Wang, and Maolin Qiu, and R Todd Constable
November 1991, Applied optics,
Jinghua Wang, and Maolin Qiu, and R Todd Constable
December 2021, Sensors (Basel, Switzerland),
Jinghua Wang, and Maolin Qiu, and R Todd Constable
October 2018, IEEE transactions on ultrasonics, ferroelectrics, and frequency control,
Jinghua Wang, and Maolin Qiu, and R Todd Constable
February 1986, Magnetic resonance in medicine,
Jinghua Wang, and Maolin Qiu, and R Todd Constable
August 2013, Magnetic resonance in medicine,
Jinghua Wang, and Maolin Qiu, and R Todd Constable
June 2021, IEEE transactions on ultrasonics, ferroelectrics, and frequency control,
Jinghua Wang, and Maolin Qiu, and R Todd Constable
February 2004, Journal of magnetic resonance imaging : JMRI,
Jinghua Wang, and Maolin Qiu, and R Todd Constable
February 1995, Magnetic resonance in medicine,
Jinghua Wang, and Maolin Qiu, and R Todd Constable
September 2004, Journal of magnetic resonance (San Diego, Calif. : 1997),
Jinghua Wang, and Maolin Qiu, and R Todd Constable
August 2018, Sensors (Basel, Switzerland),
Copied contents to your clipboard!