A new approach to autocalibrated dynamic parallel imaging based on the Karhunen-Loeve transform: KL-TSENSE and KL-TGRAPPA.

abstract：PURPOSE:High-resolution intravascular (IV) MRI is susceptible to degradation from physiological motion and requires high frame-rates for true endoscopy. Traditional cardiac-gating techniques compromise efficiency by reducing the effective scan rate. Here we test whether compressed sensing (CS) reconstruction and ungate...

journal_title：Magnetic resonance in medicine

authors： Hegde SS,Zhang Y,Bottomley PA

更新日期：2015-08-01 00:00:00

abstract：:Echo-planar imaging (EPI) is the standard technique for dynamic susceptibility-contrast (DSC) perfusion MRI. However, EPI suffers from well-known geometric distortions, which can be reduced by increasing the k-space phase velocity. Moreover, the long echo times (TEs) used in DSC lead to signal saturation of the arteri...

journal_title：Magnetic resonance in medicine

authors： Newbould RD,Skare ST,Jochimsen TH,Alley MT,Moseley ME,Albers GW,Bammer R

更新日期：2007-07-01 00:00:00

abstract：:Spin-echo images of 10 myocardial infarcts in nine mini-pigs were obtained at 30 h, 3 days, and approximately 10 days postinfarction. Infarcts were not detected at all at 30 h in five out of five cases examined. At 3 days postembolization (six cases) one infarct was certainly detected, whilst at 10 days (nine cases) a...

journal_title：Magnetic resonance in medicine

authors： Checkley D,Loveday BE,Waterton JC,Zhu XP,Isherwood I

更新日期：1987-09-01 00:00:00

abstract：PURPOSE:To compare fitting methods and sampling strategies, including the implementation of an optimized b-value selection for improved estimation of intravoxel incoherent motion (IVIM) parameters in breast cancer. METHODS:Fourteen patients (age, 48.4 ± 14.27 years) with cancerous lesions underwent 3 Tesla breast MRI ...

journal_title：Magnetic resonance in medicine

authors： Cho GY,Moy L,Zhang JL,Baete S,Lattanzi R,Moccaldi M,Babb JS,Kim S,Sodickson DK,Sigmund EE

更新日期：2015-10-01 00:00:00

abstract：:Nitroprusside, a vasodilatory nitric oxide donor, is clinically used during vascular surgery and to lower blood pressure in acute hypertension. This article reports a novel application of blood flow (BF) and blood oxygenation level dependent (BOLD) MRI on an 11.7T scanner to image the rat chorioretinal BF and BOLD cha...

journal_title：Magnetic resonance in medicine

authors： Shih YY,Li G,Muir ER,De La Garza BH,Kiel JW,Duong TQ

更新日期：2012-10-01 00:00:00

abstract：:Stejskal and Tanner's ingenious pulsed field gradient design from 1965 has made diffusion NMR and MRI the mainstay of most studies seeking to resolve microstructural information in porous systems in general and biological systems in particular. Methods extending beyond Stejskal and Tanner's design, such as double diff...

journal_title：Magnetic resonance in medicine

authors： Shemesh N,Jespersen SN,Alexander DC,Cohen Y,Drobnjak I,Dyrby TB,Finsterbusch J,Koch MA,Kuder T,Laun F,Lawrenz M,Lundell H,Mitra PP,Nilsson M,Özarslan E,Topgaard D,Westin CF

更新日期：2016-01-01 00:00:00

abstract：:In this high resolution magnetic resonance spectroscopic study of experimental allergic encephalomyelitis (EAE) and Semliki Forest virus (SFV) infection of the Biozzi AB/H mouse, marked increases in the initially low levels of N-trimethyl compounds in the spinal cord were observed during probable demyelinating episode...

journal_title：Magnetic resonance in medicine

authors： Preece NE,Amor S,Baker D,Gadian DG,O'Neill JK,Urenjak J

更新日期：1994-12-01 00:00:00

abstract：:The success in utilizing in vivo NMR to identify and/or monitor metabolic abnormalities will be determined in large part on the reliability with which the spectral parameters of the metabolites present can be measured. For these reasons it is clear that there is a need for the development of algorithms with which to o...

journal_title：Magnetic resonance in medicine

authors： Lenkinski RE,Allman T,Scheiner JD,Deming SN

更新日期：1989-06-01 00:00:00

abstract：:Simulations of dynamic susceptibility contrast (DSC) MRI are frequently performed by assuming a certain shape for the input function and the microvascular response function. However, to investigate the influence of parameters that will affect the shape of the input function, a more complex model of the human vasculatu...

journal_title：Magnetic resonance in medicine

authors： van Osch MJ,Vonken EJ,Wu O,Viergever MA,van der Grond J,Bakker CJ

更新日期：2003-09-01 00:00:00

abstract：:Functional MR imaging (fMRI) of activation in the brain is one of the more demanding applications required of an NMR imaging instrument. Since the signal changes in activation imaging are quite small, any instrumental variations can easily compromise the fMRI contrast. The authors describe a simple method for measurin...

journal_title：Magnetic resonance in medicine

authors： Weisskoff RM

更新日期：1996-10-01 00:00:00

abstract：PURPOSE:To develop a fast and accurate method for 3D T2 mapping of prostate cancer using undersampled acquisition and dictionary-based fitting. METHODS:3D high-resolution T2 -weighted images (0.9 × 0.9 × 3 mm3 ) were obtained with a multishot T2 -prepared balanced steady-state free precession (T2 -prep-bSSFP) acquisit...

journal_title：Magnetic resonance in medicine

authors： Roccia E,Vidya Shankar R,Neji R,Cruz G,Munoz C,Botnar R,Goh V,Prieto C,Dregely I

更新日期：2019-03-01 00:00:00

abstract：:This paper describes a method for correcting the chemical-shift artifacts in 19F NMR imaging of perfluoroctylbromide emulsion (PFOB) by utilizing the two spectral peaks of PFOB which have a long T2 value in conjunction with the Dixon method. Corrected images are obtained from the magnitude of the measured images using...

journal_title：Magnetic resonance in medicine

authors： Lee HK,Nalcioglu O,Buxton RB

更新日期：1992-02-01 00:00:00

abstract：:Localized 1H NMR homonuclear J editing spectroscopy was used to measure the concentration of 2-pyrrolidinone (PRDN) in the human occipital lobe of five normal and six epileptic subjects taking vigabatrin. PRDN is a lactam cyclization product of gamma-aminobutyric acid (GABA). From a localized volume of 13.5 cm3 in the...

journal_title：Magnetic resonance in medicine

authors： Hyder F,Petroff OA,Mattson RH,Rothman DL

更新日期：1999-05-01 00:00:00

abstract：PURPOSE:Diffusion-weighted magnetic resonance imaging suffers from physiological noise, such as artifacts caused by motion or system instabilities. Therefore, there is a need for robust diffusion parameter estimation techniques. In the past, several techniques have been proposed, including RESTORE and iRESTORE (Chang e...

journal_title：Magnetic resonance in medicine

authors： Collier Q,Veraart J,Jeurissen B,den Dekker AJ,Sijbers J

更新日期：2015-06-01 00:00:00

abstract：:T2 measurements of 31P NMR signals of ATP using the Hahn 90 degrees-180 degrees spin-echo sequence imply difficulties whenever the 180 degrees pulse angle is not completely perfect. The reason for this finding is the crucial influence of the J-couplings of the ATP signals which result in intensity modulations and cons...

journal_title：Magnetic resonance in medicine

authors： Jung WI,Straubinger K,Bunse M,Widmaier S,Schick F,Küper K,Dietze G,Lutz O

更新日期：1993-07-01 00:00:00

abstract：:T2 relaxation time is a promising MRI parameter for the detection of cartilage degeneration in osteoarthritis. However, the accuracy and precision of the measured T2 may be substantially impaired by the low signal-to-noise ratio of images available from clinical examinations. The purpose of this work was to assess the...

journal_title：Magnetic resonance in medicine

authors： Raya JG,Dietrich O,Horng A,Weber J,Reiser MF,Glaser C

更新日期：2010-01-01 00:00:00

abstract：:Chemical shift-based multipoint water-fat separation methods have been applied in balanced steady-state free precession (bSSFP) sequences because of the high signal-to-noise-ratio (SNR) attainable. In this approach the echo formation is approximated to occur concurrently for both water and fat at an echo time (TE) equ...

journal_title：Magnetic resonance in medicine

authors： Kim H,Pinus AB,Wang J,Murphy PS,Constable RT

更新日期：2007-08-01 00:00:00

abstract：PURPOSE:Cross-relaxation of protons with (14) N nuclei in proteins enhances relaxivity in the quadrupolar dip range of typically 2-3 MHz Larmor frequency. The magnitude of these dips was suggested as a means of assessing the degeneracy of articular cartilage during osteoarthritis (OA). However, so far only proteoglycan...

journal_title：Magnetic resonance in medicine

authors： Rössler E,Mattea C,Stapf S

更新日期：2015-05-01 00:00:00

abstract：:In order to obtain proton magnetic resonance spectra from the normal human kidney in vivo, we employed a STEAM sequence with delay times TE = 10 ms and TM = 30 ms. Signals are attenuated during STEAM sequences by J-coupling effects and by macroscopic movement of the sample. The combination of short echo times and resp...

journal_title：Magnetic resonance in medicine

authors： Dixon RM,Frahm J

更新日期：1994-05-01 00:00:00

abstract：PURPOSE:To develop a modular magnetization preparation sequence for combined T2 -preparation and multidimensional outer volume suppression (OVS) for coronary artery imaging. METHODS:A combined T2 -prepared 1D OVS sequence with fat saturation was defined to contain a 90°-60 180°60 composite nonselective tip-down pulse,...

journal_title：Magnetic resonance in medicine

authors： Zeng DY,Baron CA,Malavé MO,Kerr AB,Yang PC,Hu BS,Nishimura DG

更新日期：2020-06-01 00:00:00

abstract：:Proton spin relaxation rate constants in normal and hyponatremic rat brain were measured to determine the sensitivity of metabolite relaxation properties to cytotoxic edema and to quantify metabolite concentration in normal and edematous brain. Relaxation rate constants for protons of water and spectral regions with d...

journal_title：Magnetic resonance in medicine

authors： Rooney WD,Ebisu T,Mancuso A,Graham S,Weiner MW,Maudsley AA

更新日期：1996-05-01 00:00:00

abstract：:To enhance contrast between flow and static tissue, NMR projective angiographic methods usually require data subtraction, or alternatively the application of special data processing routines such as the "maximum intensity projection" algorithm. We have successfully developed a direct projection method which yields suf...

journal_title：Magnetic resonance in medicine

authors： Matsuda T,Doyle M,Pohost GM

更新日期：1991-04-01 00:00:00

abstract：:An in vitro study was performed to investigate the effects of B(o) inhomogeneity on magnetic resonance images of flow. Controlled inhomogeneity gradients (Gi) were applied and the magnitude of the artifacts produced was quantified for different echo delay times (TE). Both steady and pulsatile flows were examined. In t...

journal_title：Magnetic resonance in medicine

authors： Drangova M,Pelc NJ

更新日期：1996-01-01 00:00:00

abstract：PURPOSE:To develop a method for retrospective artifact elimination of MRS data. This retrospective method was based on an approach that combines jackknife analyses with the correlation of spectral windows, and therefore termed "JKC." METHODS:Twelve healthy volunteers performed 3 separate measurement protocols using a ...

journal_title：Magnetic resonance in medicine

authors： Tapper S,Tisell A,Helms G,Lundberg P

更新日期：2019-04-01 00:00:00

abstract：:Two different types of (co-registered) images of the same slice of tissue will generally have different spatial resolutions. The judicious pixel-by-pixel combination of their data can be accomplished to yield a single image exhibiting properties of both. Here, axial (18)FDG PET and (1)H(2)O MR images of the human brai...

journal_title：Magnetic resonance in medicine

authors： Sammi MK,Felder CA,Fowler JS,Lee JH,Levy AV,Li X,Logan J,Pályka I,Rooney WD,Volkow ND,Wang GJ,Springer CS Jr

更新日期：1999-08-01 00:00:00

abstract：:Choline-containing compounds (CCCs) are elevated in breast cancer, and detected in vivo by the (1)H MRS total choline (tCho) resonance (3.25 ppm) and the (31)P MRS phosphomonoester (PME) resonance (3.8 ppm). Both the tCho and PME resonances decrease early after initiation of successful therapy. The single major compon...

journal_title：Magnetic resonance in medicine

authors： Morse DL,Raghunand N,Sadarangani P,Murthi S,Job C,Day S,Howison C,Gillies RJ

更新日期：2007-08-01 00:00:00

abstract：PURPOSE:To accelerate dynamic MR applications using infimal convolution of total generalized variation functionals (ICTGV) as spatio-temporal regularization for image reconstruction. THEORY AND METHODS:ICTGV comprises a new image prior tailored to dynamic data that achieves regularization via optimal local balancing b...

journal_title：Magnetic resonance in medicine

authors： Schloegl M,Holler M,Schwarzl A,Bredies K,Stollberger R

更新日期：2017-07-01 00:00:00

abstract：:For sodium imaging of the human brain, Gibbs' ringing can degrade image appearance and confound image analysis; k-space filtering is generally required. In this work, the signal to noise ratio (SNR) advantage of sampling density weighted apodization (SDWA) over uniform k-space sampling with postacquisition filtering a...

journal_title：Magnetic resonance in medicine

authors： Stobbe R,Beaulieu C

更新日期：2008-10-01 00:00:00

abstract：:It is demonstrated that the stability of the Carr-Purcell-Meiboom-Gill (CPMG) sequence reflects the existence of a steady state solution to the Bloch equations in the absence of T2 and T1 decay. The steady state theory is then used to evaluate the performance of low flip angle RARE imaging sequences with both constant...

journal_title：Magnetic resonance in medicine

authors： Alsop DC

更新日期：1997-02-01 00:00:00

abstract：:SENSitivity Encoding (SENSE) greatly enhances the quality of diffusion-weighted echo-planar imaging (EPI) by reducing blurring and off-resonance artifacts. Such improvement would also be desirable for diffusion tensor imaging (DTI), but measures derived from the diffusion tensor can be extremely sensitive to any kind ...

journal_title：Magnetic resonance in medicine

authors： Bammer R,Auer M,Keeling SL,Augustin M,Stables LA,Prokesch RW,Stollberger R,Moseley ME,Fazekas F

更新日期：2002-07-01 00:00:00