Abstract:
PURPOSE:To determine the diagnostic performance of diffusion-weighted MRI and MR volumetry for the assessment of tumor response after preoperative chemoradiotherapy (CRT) in patients with locally advanced rectal cancer. MATERIALS AND METHODS:Forty-three patients with rectal cancer who underwent preoperative CRT were prospectively examined for the study. This prospective study was approved by our institutional review board. DW- and high resolution T2-weighted imaging were performed before and after therapy. Two different diffusion gradients (b = 0 and b = 600, then separately b = 0 and b = 1000) were applied. The mean tumor volume and mean ADC values were measured before and after therapy. To evaluate the responders and nonresponders to neoadjuvant CRT, two criteria, ypT stage determined in the pathologic examination after treatment and histopathologic tumor regression grade (Ryan), were used as reference standards. The patients with a lower ypT stage than T stage in the first MRI before neoadjuvant CRT were evaluated as the responder group, while the patients with a higher or the same ypT stage relative to the first MRI T stage were evaluated as the nonresponder group. According to Ryan tumor regression grade, grade 1 was evaluated as the responders, whereas grades 2 and 3 were evaluated as the nonresponder group. The percentage ADC increase and percentage tumor volume regression were compared between the responders and nonresponders using two reference standards: T downstaging and tumor regression grade (TRG). RESULTS:Before CRT, the mean tumor ADC in the responder group was significantly lower than that in the nonresponder group (p < 0.001). At the end of CRT, the mean percentage of tumor ADC change in the responder group was significantly higher than that in the nonresponder group. The percentage tumor volume regression of the responders was significantly higher than that of the nonresponders (p = 0.001). The cut-off ADC value for discriminating between the responders and nonresponders after treatment was determined to be (b = 600) 1.03 × 10(-3)mm(2)/s and the sensitivity, 71%; specificity, 79%; accuracy, 74%; positive predictive value, 81%; negative predictive value, 68% respectively. The cut-off value for discriminating between the responders and the nonresponders after treatment was determined for b = 1000 as 1.20 × 10(-3)mm(2)/s and the sensitivity, 42%; specificity, 84%; accuracy, 60%; positive predictive value, 77%; negative predictive value, 53%. CONCLUSION:The increase in the mean tumor ADC and percentage tumor volume regression in patients with rectal cancer treated with preoperative CRT was correlated with good response. DW MR imaging is a promising non-invasive technique that can help predict and monitor early therapeutic response in patients with rectal cancer who undergo CRT.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Birlik B,Obuz F,Elibol FD,Celik AO,Sokmen S,Terzi C,Sagol O,Sarioglu S,Gorken I,Oztop Idoi
10.1016/j.mri.2014.08.041subject
Has Abstractpub_date
2015-02-01 00:00:00pages
201-12issue
2eissn
0730-725Xissn
1873-5894pii
S0730-725X(14)00337-3journal_volume
33pub_type
杂志文章abstract::In vivo temporal EPR imaging was conducted on the brain of rats that received one of two kinds of blood-brain barrier-permeable nitroxide radicals via the tail vein-one is a water-soluble 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (hydroxymethyl-PROXYL); and the other is a non-water-soluble 3-methoxycarbony...
journal_title:Magnetic resonance imaging
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abstract::Renal transplant patients often require imaging to ensure appropriate graft placement, to assess integrity of transplant vessel anastomosis and to evaluate for stenosis that can be a cause of graft failure. Because there is risk for nephrogenic systemic fibrosis in the setting of renal insufficiency, the use of non-co...
journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2013.10.004
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abstract::Etched particle tracks produced after heavy ion irradiation of polymer foils are used as model systems to test the performance of NMR in a newly developed ultrahigh magnetic field gradient system. The stimulated NMR echo decay of molecules diffusing in the channels, formulated in terms of the self part of the intermed...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(94)91527-x
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abstract::The functional value of TurboFLASH MR imaging in the assessment of dynamic contrast enhancement and renal perfusion anomalies was evaluated in seven patients, who also underwent renal scintigraphy in baseline conditions. The basal renograms obtained from MAG-3 scintigraphy (mercapto acetyl triglycine, MAG3-S) and from...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(94)92534-8
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abstract::In this contribution, we explore the potential of proton electron double resonance imaging (PEDRI) in environmental science (hydrogeological) applications. After a discussion of the hydrogeological motivation for studies of free radical transport in environmental matrices, we present results from first experiments tha...
journal_title:Magnetic resonance imaging
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abstract:OBJECTIVE:Equivalent cross-relaxation rate imaging (ECRI) is an MRI technique used to evaluate qualitative changes in protein-water interactions. We aimed to prospectively evaluate the utility of ECRI for classification of adipocytic tumors. MATERIALS AND METHODS:Institutional Review Board approval was obtained and al...
journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2013.12.004
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abstract:PURPOSE:To assess the sensitivity and specificity of intra-plaque hemorrhage (IPH), large lipid-rich necrotic core (LR-NC) and ulceration or cap rupture (UCR) for symptomatic carotid plaque characterization and to evaluate a new imaging score [Hemorrhage, Ulceration or cap rupture, Lipid-rich necrotic Core (HULC) score...
journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2012.04.024
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abstract::The aim of this study was to establish a rapid method for in vivo quantification of a large range of flow velocities using phase information. A basic gradient-echo sequence was constructed, in which flow was encoded along the slice selection direction by variation of the amplitude of a bipolar gradient without changes...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
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abstract:BACKGROUND:Doppler based mitral annular velocities are an integral part of echocardiographic left ventricular diastolic function assessment. Although these measurements can be obtained by phase contrast cardiac magnetic resonance imaging (PC-CMR), this approach has limitations. The aims of this study were to assess the...
journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2018.08.018
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abstract::The biodistribution and relative molar effectiveness of the ionic (GdCl3) and chelated (Gd-DTPA) forms of gadolinium (Gd) to enhance proton relaxation rates in rat kidney, liver and spleen were evaluated. Rats were given intravenous injections of either GdCl3 (100 mumol/kg) or Gd-DTPA (178 mumol/kg). Gd-DTPA was prima...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
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journal_title:Magnetic resonance imaging
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abstract::In ultrashort TE (UTE) imaging, the short T2 values of the tissues of interest are comparable to the k-space readout duration, which result in significant T2 decay during k-space readout. This decay consequently causes significant effects on signal and contrast in UTE sequences, which we evaluate in this paper using m...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2013.11.002
更新日期:2014-04-01 00:00:00
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journal_title:Magnetic resonance imaging
pub_type: 杂志文章,评审
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更新日期:2011-06-01 00:00:00
abstract::Gadolinium DTPA was evaluated as an intravenous contrast agent for magnetic resonance imaging in 15 patients with primary or secondary intracranial neoplastic disease. T1 and T2 weighted images were obtained prior to contrast administration. T1 weighted spin echo 35/800 (TE/TR) images were utilized to detect enhanceme...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(85)90006-2
更新日期:1985-01-01 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
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journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2012.05.001
更新日期:2012-11-01 00:00:00
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journal_title:Magnetic resonance imaging
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doi:10.1016/0730-725x(93)90214-x
更新日期:1993-01-01 00:00:00
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journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(91)90007-9
更新日期:1991-01-01 00:00:00
abstract:PURPOSE:Rapid regional fluctuations in GABA may result in inhomogeneous concentrations throughout the brain parenchyma. The goal of this study is to provide further insight into the natural distribution of GABA throughout the brain and thus determine if a surrogate site may be used for spectroscopy when evaluating moto...
journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2015.02.015
更新日期:2015-06-01 00:00:00
abstract::Perfusion magnetic resonance imaging (MRI) is a promising non-invasive technique providing insights regarding the brain's microvascular architecture in vivo. The scalar perfusion metrics can be used for quantitative diagnostics of various brain abnormalities, in particular, in the stroke cases and tumours. However, co...
journal_title:Magnetic resonance imaging
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journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2015.10.025
更新日期:2016-02-01 00:00:00
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journal_title:Magnetic resonance imaging
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journal_title:Magnetic resonance imaging
pub_type: 杂志文章
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journal_title:Magnetic resonance imaging
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journal_title:Magnetic resonance imaging
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更新日期:1990-01-01 00:00:00
abstract::Multiparametric MRI is a remarkable imaging method for the assessment of patho-physiological processes. In particular, brain tumor characterization has taken advantage of the development of advanced techniques such as Diffusion- (DWI) and Perfusion- (PWI) Weighted Imaging, but a thorough analysis of meningiomas is sti...
journal_title:Magnetic resonance imaging
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更新日期:2020-04-01 00:00:00
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journal_title:Magnetic resonance imaging
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doi:10.1016/j.mri.2018.10.002
更新日期:2019-02-01 00:00:00
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journal_title:Magnetic resonance imaging
pub_type: 杂志文章
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更新日期:1996-01-01 00:00:00
abstract::Automatic segmentation of different types of tissue from magnetic resonance images is of great importance for clinical and research applications, particularly large-scale and longitudinal studies of brain pathology. We developed a fully automated algorithm for the segmentation of lateral ventricles from cranial magnet...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.08.013
更新日期:2006-12-01 00:00:00
abstract::The purpose of this study was to assess the benefits of a 3 T scanner and an eight-channel phased-array head coil for acquiring three-dimensional PRESS (Point REsolved Spectral Selection) proton (H-1) magnetic resonance spectroscopic imaging (MRSI) data from the brains of volunteers and patients with brain tumors rela...
journal_title:Magnetic resonance imaging
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更新日期:2006-12-01 00:00:00