Abstract:
PURPOSE:To implement and evaluate the accuracy of non-invasive temperature mapping using MRI methods based on the chemical shift (CS) and T1 relaxation in media of various heterogeneity during focal (laser) and external thermal energy deposition. MATERIALS AND METHODS:All measurements were performed on a 1.5 T superconducting clinical scanner using the temperature dependence of the water proton chemical shift and the T1 relaxation time. Homogeneous gel and heterogeneous muscle phantoms were heated focally with a fiberoptic laser probe and externally of varying degree ex vivo by water circulating in a temperature range of 20-50 degrees C. Magnetic resonance imaging data were compared to simultaneously recorded fiberoptic temperature readings. RESULTS:Both methods provided accurate results in homogeneous media (turkey) with better accuracy for the chemical shift method (CS:+/-1.5 degrees C, T1:+/-2.0 degrees C). In gel, the accuracy with the CS method was +/-0.6 degrees C. The accuracy decreased in heterogeneous media containing fat (T1:+/-3.5 degrees C, CS: +5 degrees C). In focal heating of turkey muscle, the accuracy was within 1.5 degrees C with the T1 method. CONCLUSION:Temperature monitoring with the chemical shift provides better results in homogeneous media containing no fat. In fat tissue, the temperature calculation proved to be difficult.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Bertsch F,Mattner J,Stehling MK,Müller-Lisse U,Peller M,Loeffler R,Weber J,Messmer K,Wilmanns W,Issels R,Reiser Mdoi
10.1016/s0730-725x(97)00311-1subject
Has Abstractpub_date
1998-05-01 00:00:00pages
393-404issue
4eissn
0730-725Xissn
1873-5894pii
S0730725X97003111journal_volume
16pub_type
杂志文章abstract::A formulation has been developed for the determination of self and mutual inductances in unloaded, eight-column symmetric birdcage coils using their expected resonant mode current patterns and well-known inductance formulas. The average frequency differences between theory and experiment for mode one resonances for ni...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(92)90511-w
更新日期:1992-01-01 00:00:00
abstract::In this study, in order to differentiate cavernous hemangioma and hepatic metastases, rapid acquisition relaxation enhanced (RARE) sequence was used. First, in vivo measurements of T1, T2 relaxation times and proton density were obtained using T1, T2 calculation protocol (TOMIKON S50, 0.5T) and multipoint techniques. ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(99)00008-9
更新日期:1999-06-01 00:00:00
abstract::The present trend in dynamic contrast-enhanced MRI is to increase the number of estimated perfusion parameters using complex pharmacokinetic models. However, less attention is given to the precision analysis of the parameter estimates. In this paper, the distributed capillary adiabatic tissue homogeneity pharmacokinet...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.02.003
更新日期:2014-06-01 00:00:00
abstract::Magnetic resonance spectroscopy (MRS) is ideally suited for physiology-neurochemistry experiments with the living brain and particularly for studies on the primary visual cortex (striate cortex or area V1). Yet, the highly convoluted form of the human V1 has thus far prevented the performance of MRS investigations tha...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2007.03.008
更新日期:2007-07-01 00:00:00
abstract:AIM:Matrix metalloproteases (MMPs) expression and their inhibitors (TIMPs) play an important role in tumor physiopathology, so we investigated the relationship between the magnetic resonance (MR) and MMPs/TIMPs expression by breast carcinomas. MATERIALS AND METHODS:MRI parameters of 64 breast carcinomas were investiga...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2016.04.005
更新日期:2016-10-01 00:00:00
abstract::Postero-anterior radiographs and magnetic resonance imaging (MRI) of the chest were performed in nine biopsy proven cases of sarcoidosis. MRI was more sensitive than a postero-anterior chest roentgenogram in detecting hilar and mediastinal adenopathy but less informative in detecting pleural and parenchymal disease. ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(88)90131-2
更新日期:1988-09-01 00:00:00
abstract::Conditions for generation of polarized RF fields in cylindrical symmetry by high order coils are presented. Whole body NMR transmitters utilizing this principle would require a current control on a certain number of loops. In the present design this is obtained by feeding each loop by an appropriate linear combination...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(88)90398-0
更新日期:1988-05-01 00:00:00
abstract::Pelvic MR (41 patients) and CT (36 patients) examinations were performed on 14 females with a primary pelvic complaint, and on 28 females with a suspicion of local recurrent disease of gynecologic malignant tumor. Benign cystic tumors were found in eight patients, five patients had endometriomas, one had a lymphoma, a...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(93)90409-7
更新日期:1993-01-01 00:00:00
abstract::Although there is ample evidence in the literature for structural, functional and physiological asymmetries in the two hemispheres of human brain, direct evidence of a similar asymmetry in the in vivo distribution of brain metabolites has been lacking. In this study, the existence of chemical asymmetries in six differ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(96)00342-6
更新日期:1997-01-01 00:00:00
abstract::A technique for obtaining quantitative longitudinal saturation/porosity profiles of rock cores which are longer than the NMR coil has been developed. The slice-selected experiment uses a prefocused pulse in conjunction with a magnetic field gradient for the localization and a CPMG sequence to sample the data. A variet...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(94)91547-4
更新日期:1994-01-01 00:00:00
abstract::The performance evaluation of a semi-supervised fuzzy c-means (SFCM) clustering method for monitoring brain tumor volume changes during the course of routine clinical radiation-therapeutic and chemo-therapeutic regimens is presented. The tumor volume determined using the SFCM method was compared with the volume estima...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(96)00386-4
更新日期:1997-01-01 00:00:00
abstract::Twenty-seven patients with soft-tissue tumors were examined with a Picker 0.15-tesla resistive magnet and by computed tomography (CT). In all but one patient, MRI was better than or equal to CT in defining the anatomic extent of the tumor. We could determine whether major vascular structures were engulfed by the tumor...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(85)90398-4
更新日期:1985-01-01 00:00:00
abstract::A new pulse sequence for estimating cerebral blood flow called UNFAIR, which uses a combination of sequential hyperbolic secant preparatory pulses, is introduced. This sequence is based on the same generalized conditions as previously introduced inversion recovery techniques except that the spins in the image slice of...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(96)00353-0
更新日期:1997-01-01 00:00:00
abstract::Thirty patients with Chiari I malformation were examined by MRI over 2-year period. All patients underwent MRI scan before and after surgical decompression of the posterior fossa. Images of the craniocervical junction confirmed tonsillar herniation in all cases and allowed the definition of two anatomically distinct t...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(96)00383-9
更新日期:1997-01-01 00:00:00
abstract::Functional magnetic resonance imaging favors the use of multi-slice gradient-recalled echo-planar imaging due to its short image acquisition times, whole brain coverage and sensitivity to BOLD contrast. However, despite its advantages, gradient-recalled echo-planar imaging also is sensitive to static magnetic field gr...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(00)00199-5
更新日期:2000-11-01 00:00:00
abstract::Eighty-nine cases after anterior cruciate ligaments (ACL) reconstruction were followed prospectively with magnetic resonance imaging (MRI). The patients were examined using axial and sagittal MRI at least twice during the postoperative evaluation of reconstructed ACL. Two cases of pretibial cyst formation were observe...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(00)00207-1
更新日期:2000-10-01 00:00:00
abstract::Magnetic resonance imaging (MRI) has played an important role in the diagnosis and management of cancer since it was first developed, but other modalities also continue to advance and provide complementary information on the status of tumors. In the future, there will be a major continuing role for noninvasive imaging...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章,评审
doi:10.1016/j.mri.2011.02.003
更新日期:2011-06-01 00:00:00
abstract::We report on experiments to characterize internal magnetic field gradients that are caused by magnetic susceptibility differences between the solid phase and the fluids filling the pore space. Our measurements focus on low-field relaxometry of brine and oil in sandstones from various reservoirs around the world. Our r...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(01)00287-9
更新日期:2001-04-01 00:00:00
abstract::Complete dissection is the current reference method to quantify muscle and fat tissue on pig carcasses. Magnetic resonance imaging (MRI) is an appropriate nondestructive alternative method that can provide reliable and quantitative information on pig carcass composition without losing the spatial information. We have ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2005.05.001
更新日期:2005-07-01 00:00:00
abstract::Diffusion in the extracellular and intracellular spaces (ECS and ICS, respectively) was evaluated in excised spinal cords, before and after cell swelling induced by glutamate, by high b-value q-space diffusion MR of specific markers and water. The signal decays of deuterated tetramethylammonium (TMA-d(12)) chloride, a...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2004.01.029
更新日期:2004-06-01 00:00:00
abstract::Fricke-agarose gels have been irradiated with a proton beam. Then samples have been extracted at different depths with respect to the beam penetration distance, corresponding to different irradiation doses. Relaxation times T1 and T2, measured at 17 MHz, appear sensitive to this kind of radiation. In particular, T2 ex...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(96)00380-3
更新日期:1997-01-01 00:00:00
abstract::The medical specialty radiology has experienced a number of extremely important and influential technical developments in the past that have affected how medical imaging is deployed. Artificial intelligence (AI) is potentially another such development that will introduce fundamental changes into the practice of radiol...
journal_title:Magnetic resonance imaging
pub_type: 社论
doi:10.1016/j.mri.2019.12.006
更新日期:2020-05-01 00:00:00
abstract::A series of direct shear and nuclear magnetic resonance (NMR) tests were performed on a compacted weakly expansive clay saturated by sodium chloride (NaCl) solutions with different concentrations to study the effect of NaCl solution on the shear strength and its mechanism. Results from the direct shear tests show that...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2019.01.002
更新日期:2019-05-01 00:00:00
abstract::Magnetic resonance imaging (MRI) has been used to characterize tissues in morphological studies. Here, 23Na NMR imaging was used to study the distribution in muscle of brine (5 M NaCl), injected before onset of rigor mortis. First, the distribution of brine was monitored in excised muscle from rabbits for 6 hr followi...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(94)92360-4
更新日期:1994-01-01 00:00:00
abstract::Quantification of magnetic resonance (MR)-based relaxation parameters of tendons and ligaments is challenging due to their very short transverse relaxation times, requiring application of ultra-short echo-time (UTE) imaging sequences. We quantify both T1 and T2* in the quadriceps and patellar tendons of healthy volunt...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2019.07.015
更新日期:2019-11-01 00:00:00
abstract::Two parallel imaging methods used for first-pass myocardial perfusion imaging were compared in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image artifacts. One used adaptive Time-adaptive SENSitivity Encoding (TSENSE) and the other used GeneRalized Autocalibrating Partially Parallel Acquisi...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.10.012
更新日期:2007-06-01 00:00:00
abstract::Despite intense research on the blood oxygenation level-dependent (BOLD) signal underlying functional magnetic resonance imaging, our understanding of its physiological basis is far from complete. In this study, it was investigated whether the so-called poststimulus BOLD signal undershoot is solely a passive vascular ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2009.04.003
更新日期:2009-10-01 00:00:00
abstract:INTRODUCTION:Pharmacokinetic parameters derived from dynamic contrast-enhanced MRI (DCE-MRI) data are sensitive to acquisition and post-processing techniques, which makes it difficult to compare results obtained using different methods. In particular, one of the most important factors affecting estimation of model para...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2018.05.007
更新日期:2018-10-01 00:00:00
abstract::We describe a lesion with the magnetic resonance imaging (MRI) characteristics of a glioblastoma mutiforme and demonstrate how perfusion MRI and proton MR spectroscopic imaging can be used to differentiate necrotizing cerebritis from what appeared to be a high-grade glioma. A 43-year-old woman presented to her physici...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.09.028
更新日期:2007-02-01 00:00:00
abstract:PURPOSE:To evaluate the utility of fat fraction (FF) for the differentiation of different breast tissues and in various breast tumor subtypes using in vivo proton (1H) magnetic resonance spectroscopy (MRS). METHODS:1H MRS was performed on 68 malignant, 35 benign, and 30 healthy volunteers at 1.5 T. Malignant breast ti...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2018.02.004
更新日期:2018-06-01 00:00:00