当前位置： SCI文献检索 > ACADEMIC RADIOLOGY期刊下所有文献 > Magnetic field strength increase yields significantly greater contrast-to-noise ratio increase: Measured using BOLD contrast in the primary visual area.

Magnetic field strength increase yields significantly greater contrast-to-noise ratio increase: Measured using BOLD contrast in the primary visual area.

Abstract：

RATIONALE AND OBJECTIVE:The advantage of a higher static magnetic field for functional MRI has been advocated; however, the observed advantage varies. The aim of this study was to evaluate the effect of increasing static magnetic field strength on the task-related increase in blood oxygenation level-dependent (BOLD) signal and residual noise with visual stimuli of different frequencies, which may enable better comparisons of results of different MRI scanners. MATERIALS AND METHODS:Eight right-handed healthy volunteers were presented checkerboard stimuli flickering at 5 different frequencies up to 8 Hz. Field strengths of 3 T or 1.5 T were used to measure frequency-dependent signal changes in the primary visual area. Regression analysis was performed for the signal increase and the "noise," which was defined by the root mean of squares of the residual signal fluctuation. These values were compared and their relationship was analyzed. Imaging parameters were identical except for the use of a 25% shorter echo time using 3 T. RESULTS:The frequency-dependent increase in BOLD signal using 3 T was twice that using 1.5 T. In contrast, the ratio of noise values that reflect time-course signal fluctuation (3 T/1.5 T) was only 0.88. There was large individual variance in these values, but the slope and noise values were linearly related using either field strength. The contrast-to-noise ratio using 3 T was 2.3 times higher than that using 1.5 T. CONCLUSION:There was a greater-than-linear increase in the contrast-to-noise ratio compared with the increase of field strength, demonstrating an advantage of using higher field strengths in fMRI studies.

journal_name

Acad Radiol

journal_title

Academic radiology

authors

Okada T,Yamada H,Ito H,Yonekura Y,Sadato N

doi

10.1016/j.acra.2004.11.012

keywords:

subject

Has Abstract

pub_date

2005-02-01 00:00:00

pages

142-7

issue

2

eissn

1076-6332

issn

1878-4046

pii

S1076-6332(04)00706-8

journal_volume

12

pub_type

杂志文章

相关文献

ACADEMIC RADIOLOGY文献大全
  • A segmentation-based method for metal artifact reduction.

    abstract：RATIONALE AND OBJECTIVES:We propose a novel segmentation-based interpolation method to reduce the metal artifacts caused by surgical aneurysm clips. MATERIALS AND METHODS:Our method consists of five steps: coarse image reconstruction, metallic object segmentation, forward-projection, projection interpolation, and fina...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2006.12.015

    authors： Yu H,Zeng K,Bharkhada DK,Wang G,Madsen MT,Saba O,Policeni B,Howard MA,Smoker WR

    更新日期：2007-04-01 00:00:00

  • Lung Mass in Smokers.

    abstract：RATIONALE AND OBJECTIVE:Emphysema is characterized by airspace dilation, inflammation, and irregular deposition of elastin and collagen in the interstitium. Computed tomographic studies have reported that lung mass (LM) may be increased in smokers, a finding attributed to inflammatory and parenchymal remodeling process...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2016.10.011

    authors： Washko GR,Kinney GL,Ross JC,San José Estépar R,Han MK,Dransfield MT,Kim V,Hatabu H,Come CE,Bowler RP,Silverman EK,Crapo J,Lynch DA,Hokanson J,Diaz AA,COPDGene Investigators.

    更新日期：2017-04-01 00:00:00

  • Optimization of shaded surface display for CT angiography.

    abstract：RATIONALE AND OBJECTIVES:The authors performed this study to determine the optimum threshold for performing computed tomographic (CT) angiography with shaded surface display (SSD). MATERIALS AND METHODS:A dedicated phantom was developed with an 8-mm luminal diameter. Each of 19 vessels had stenoses ranging from 0% to ...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/S1076-6332(03)80641-4

    authors： Addis KA,Hopper KD,Iyriboz TA,Kasales CJ,Liu Y,Wise SW

    更新日期：2001-10-01 00:00:00

  • Continuous quality improvement for radiologists.

    abstract：:Continuous quality improvement methods provide a relatively new way to improve quality in healthcare by using a systems approach with key features of customer-mindedness, data collection, experimentation, and teamwork. CQI is not meant to solve simple problems but is increasingly applied in our complex healthcare orga...

    journal_title：Academic radiology

    pub_type： 杂志文章,评审

    doi：10.1016/s1076-6332(03)00670-6

    authors： Applegate KE

    更新日期：2004-02-01 00:00:00

  • Full field digital mammography and breast density: comparison of calibrated and noncalibrated measurements.

    abstract：RATIONALE AND OBJECTIVES:Mammographic breast density is an important and widely accepted risk factor for breast cancer. A statement about breast density in the mammographic report is becoming a requirement in many States. However, there is significant inter-observer variation between radiologists in their interpretatio...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2011.07.011

    authors： Heine JJ,Fowler EE,Flowers CI

    更新日期：2011-11-01 00:00:00

  • Asymmetry analysis in rodent cerebral ischemia models.

    abstract：RATIONALE AND OBJECTIVES:An automated method for identification and segmentation of acute/subacute ischemic stroke, using the inherent bi-fold symmetry in brain images, is presented. An accurate and automated method for localization of acute ischemic stroke could provide physicians with a mechanism for early detection ...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2008.03.013

    authors： Liu SX,Imielinska C,Laine A,Millar WS,Connolly ES,D'Ambrosio AL

    更新日期：2008-09-01 00:00:00

  • A preliminary report on the role of spatial frequency analysis in the perception of breast cancers missed at mammography screening.

    abstract：RATIONALE AND OBJECTIVES:Because several factors are involved in cancer detection, a malignant lesion that is visible on a mammogram will not necessarily be reported by the radiologist reading the case. Indeed, a significant fraction of screening-detected cancers are visible in retrospect, and were perceived by the rad...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2004.04.015

    authors： Mello-Thoms C,Chapman B

    更新日期：2004-08-01 00:00:00

  • Isotropic reconstruction of SPECT data using OSEM3D: correlation with CT.

    abstract：RATIONALE AND OBJECTIVES:A statistical based iterative single-photon emission-computed tomography (SPECT) reconstruction algorithm (OSEM) modeling the depth-dependent collimator response in three dimensions has recently been introduced (OSEM3D). The aim of this study was to evaluate the axial shape fidelity of OSEM3D i...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2005.12.004

    authors： Römer W,Reichel N,Vija HA,Nickel I,Hornegger J,Bautz W,Kuwert T

    更新日期：2006-04-01 00:00:00

  • Attenuation of contrast material-induced renal artery vasoconstriction by nitric oxide donors.

    abstract：RATIONALE AND OBJECTIVES:The authors studied the role of the endothelium and associated endothelial pathways in contrast material-induced renal vasoconstriction. MATERIALS AND METHODS:Isometric contractions in human and rabbit renal artery rings with intact and denuded endothelium were stimulated with phenylephrine an...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/s1076-6332(97)80254-1

    authors： Drescher P,Madsen PO

    更新日期：1997-12-01 00:00:00

  • Isolated calf vein thrombosis: comparison of MR venography and conventional venography after initial sonography in symptomatic patients.

    abstract：RATIONALE AND OBJECTIVES:The authors performed this study to compare magnetic resonance (MR) venography and conventional venography in the diagnosis of deep venous thrombosis (DVT) in the calf after sonography. MATERIALS AND METHODS:Sonography was performed in 595 patients who were suspected of having lower-extremity ...

    journal_title：Academic radiology

    pub_type： 临床试验,杂志文章

    doi：10.1016/s1076-6332(03)80764-x

    authors： Sica GT,Pugach ME,Koniaris LS,Goldhaber SZ,Polak JF,Mukerjee A,Tempany CM

    更新日期：2001-09-01 00:00:00

  • Clinical competence assessment in radiology: introduction of an objective structured clinical examination in the medical school curriculum.

    abstract：RATIONALE AND OBJECTIVES:Traditional oral and written examinations can be limited in predicting future clinical performance. Therefore Objective Structured Clinical Examinations (OSCEs) have been introduced in other specialties. The authors assessed their value in radiology. MATERIALS AND METHODS:The study includes 12...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/S1076-6332(03)80746-8

    authors： Morag E,Lieberman G,Volkan K,Shaffer K,Novelline R,Lang EV

    更新日期：2001-01-01 00:00:00

  • Results of the 1993 survey of the American Association of Academic Chief Residents in Radiology.

    abstract：RATIONALE AND OBJECTIVES:A survey of chief residents of academic radiology programs is conducted annually on behalf of the American Association of Academic Chief Residents in Radiology (A3CR2). Data are obtained to improve the training of diagnostic radiology residents and to increase the understanding of radiologists ...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/s1076-6332(05)80835-9

    authors： Oser AB,Baker SM,Wilson AJ,Evens RG

    更新日期：1994-10-01 00:00:00

  • Acoustic noise transfer function in clinical MRI a multicenter analysis.

    abstract：RATIONALE AND OBJECTIVES:Acoustic noise both in terms of its magnitude and frequency during magnetic resonance imaging (MRI) scan is influenced by imaging parameters and pulse sequences. It varies because of many different factors such as structure, materials, and magnetic field strength. The purpose of our study is to...

    journal_title：Academic radiology

    pub_type： 杂志文章,多中心研究

    doi：10.1016/j.acra.2010.09.009

    authors： Hamaguchi T,Miyati T,Ohno N,Hirano M,Hayashi N,Gabata T,Matsui O,Matsushita T,Yamamoto T,Fujiwara Y,Kimura H,Takeda H,Takehara Y

    更新日期：2011-01-01 00:00:00

  • Independent predictors of acute appendicitis on CT with pathologic correlation.

    abstract：RATIONALE AND OBJECTIVES:To assess computed tomographic (CT) signs that have been described in published studies for the diagnosis of appendicitis to identify independent findings that predict appendicitis. METHODS AND MATERIALS:A retrospective database search identified 67 patients with a CT scan of the abdomen/pelvi...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2008.02.009

    authors： Ives EP,Sung S,McCue P,Durrani H,Halpern EJ

    更新日期：2008-08-01 00:00:00

  • Effect of gravity on drug distribution after port-catheter implantation for hepatic arterial infusion chemotherapy: evaluation of the relationship between the injection posture and intrahepatic perfusion on fused images acquired with a combined SPECT/CT s

    abstract：RATIONALE AND OBJECTIVES:We evaluated the effect of gravity on intrahepatic perfusion (IHP) in patients with a port-catheter system (PCS) implanted for hepatic arterial infusion chemotherapy (HAIC). Using fused single photon-emission computed tomographic (SPECT)/computed tomographic (CT) images, we compared IHP after t...

    journal_title：Academic radiology

    pub_type： 临床试验,杂志文章

    doi：10.1016/j.acra.2008.12.004

    authors： Tamura Y,Ikeda O,Nakasone Y,Shiraishi S,Tomiguchi S,Yamashita Y,Takamori H,Baba H

    更新日期：2009-06-01 00:00:00

  • Evidence-based radiology: requirements for electronic access.

    abstract：RATIONALE AND OBJECTIVES:The purpose of this study was to determine the electronic requirements for supporting evidence-based radiology in today's medical environment. MATERIALS AND METHODS:A software engineering technique, use case modeling, was performed for several clinical settings to determine the use of imaging ...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/s1076-6332(03)80311-2

    authors： Bui AA,Taira RK,Dionisio JD,Aberle DR,El-Saden S,Kangarloo H

    更新日期：2002-06-01 00:00:00

  • Comparison between acetazolamide challenge and 10% carbon dioxide challenge perfusion CT in rat C6 glioma.

    abstract：RATIONALE AND OBJECTIVES:The aim of this study was to investigate the effect of perfusion computed tomography (PCT) with acetazolamide (ACZ) challenge and compare it to 10% carbon dioxide (CO(2)) challenge in rat C6 glioma. MATERIALS AND METHODS:PCT was performed on 32 rats, including 20 with orthotopically implanted ...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2011.09.017

    authors： Lu N,Di Y,Feng XY,Qiang JW,Zhang JW,Wang YG,Guo QY

    更新日期：2012-02-01 00:00:00

  • Social Media Utilization at an Academic Radiology Practice.

    abstract：RATIONALE AND OBJECTIVES:We report social media (SoMe) utilization trends at an academic radiology department, highlighting differences between trainees and faculty and between Baby Boomers versus Generation X and Millennials. MATERIALS AND METHODS:An anonymous online survey regarding SoMe utilization and SoMe-based e...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2017.08.012

    authors： Koontz NA,Kamer AP,Dodson SC,Capps AE,Tomblinson CM,Brown BP,Frank MS,Heitkamp DE

    更新日期：2018-01-01 00:00:00

  • Proteoglycan depletion-induced changes in transverse relaxation maps of cartilage: comparison of T2 and T1rho.

    abstract：RATIONALE AND OBJECTIVES:The authors performed this study to (a) measure changes in T2 relaxation rates, signal-to-noise ratio (SNR), and contrast with sequential depletion of proteoglycan in cartilage; (b) determine whether there is a relationship between the T2 relaxation rate and proteoglycan in cartilage; and (c) c...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/s1076-6332(03)80666-9

    authors： Regatte RR,Akella SV,Borthakur A,Kneeland JB,Reddy R

    更新日期：2002-12-01 00:00:00

  • Evaluation of Intracranial Vascular Status in Patients with Acute Ischemic Stroke by Time Maximum Intensity Projection CT Angiography: A Preliminary Study.

    abstract：RATIONALE AND OBJECTIVES:To describe the application of time maximum intensity projection CTA (t-MIP CTA) in acute ischemic stroke and compare t-MIP CTA and single-phase CTA (sCTA) in assessing collateral circulation and predicting prognosis. MATERIALS AND METHODS:Twenty-nine acute ischemic stroke patients who underwe...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2019.06.013

    authors： Cao R,Jiang Y,Lu J,Wu G,Zhang L,Chen J

    更新日期：2020-05-01 00:00:00

  • Robust, standardized quantification of pulmonary emphysema in low dose CT exams.

    abstract：RATIONALE AND OBJECTIVES:The aim of this study was to present and evaluate a fully automated system for emphysema quantification on low-dose computed tomographic images. The platform standardizes emphysema measurements against changes in the reconstruction algorithm and slice thickness. MATERIALS AND METHODS:Emphysema...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2011.06.015

    authors： Ceresa M,Bastarrika G,de Torres JP,Montuenga LM,Zulueta JJ,Ortiz-de-Solorzano C,Muñoz-Barrutia A

    更新日期：2011-11-01 00:00:00

  • Preoperative and intraoperative sonographic visibility of collagen-based breast biopsy marker clips.

    abstract：RATIONALE AND OBJECTIVES:The aim of this study was to determine the sonographic visibility of implanted collagen-based breast biopsy marker clips in the clinic and operating room. MATERIALS AND METHODS:Female patients aged > or =18 years who presented for preoperative surgical evaluation within 4 weeks of ultrasound-g...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2009.10.017

    authors： Eby PR,Calhoun KE,Kurland BF,Demartini WB,Gutierrez RL,Peacock S,Anderson BO,Byrd DR,Mann GN,Lehman CD

    更新日期：2010-03-01 00:00:00

  • Design considerations for using PET as a response measure in single site and multicenter clinical trials.

    abstract：RATIONALE AND OBJECTIVES:Positron emission tomography (PET) is used to evaluate response to therapy with increasing interest in having PET provide endpoints for clinical trials. Here we demonstrate impacts of PET measurement error and choice of quantification method on clinical trial design. MATERIALS AND METHODS:Samp...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2011.10.008

    authors： Doot RK,Kurland BF,Kinahan PE,Mankoff DA

    更新日期：2012-02-01 00:00:00

  • Is an ROC-type response truly always better than a binary response in observer performance studies?

    abstract：RATIONALE AND OBJECTIVES:The aim of this study was to assess similarities and differences between methods of performance comparisons under binary (yes or no) and receiver-operating characteristic (ROC)-type pseudocontinuous (0-100) rating data ascertained during an observer performance study of interpretation of full-f...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2009.12.012

    authors： Gur D,Bandos AI,Rockette HE,Zuley ML,Hakim CM,Chough DM,Ganott MA,Sumkin JH

    更新日期：2010-05-01 00:00:00

  • Assessment of intraaxial and extraaxial brain lesions with digitized computed tomographic images versus film: ROC analysis.

    abstract：RATIONALE AND OBJECTIVES:The authors evaluated the diagnostic accuracy of viewing computed tomographic (CT) scans as film versus soft-copy images at a workstation. METHODS:Receiver operating characteristic analysis of the interpretation of 202 CT scans (103 were normal, 99 were abnormal) by five neuroradiologists was ...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/s1076-6332(97)80004-9

    authors： el-Saden SM,Hademenos GJ,Zhu W,Sayre JW,Glenn B,Steidler J,Kode L,King B,Quinones D,Valentino DJ,Bentson JR

    更新日期：1997-02-01 00:00:00

  • Beyond Correlations, Sensitivities, and Specificities: A Roadmap for Demonstrating Utility of Advanced Imaging in Oncology Treatment and Clinical Trial Design.

    abstract：:Despite the widespread belief that advanced imaging should be very helpful in guiding oncology treatment decision and improving efficiency and success rates in treatment clinical trials, its acceptance has been slow. Part of this is likely attributable to gaps in study design and statistical methodology for these imag...

    journal_title：Academic radiology

    pub_type： 杂志文章,评审

    doi：10.1016/j.acra.2017.03.002

    authors： Huang EP,Lin FI,Shankar LK

    更新日期：2017-08-01 00:00:00

  • A robust method for estimating regional pulmonary parameters in presence of noise.

    abstract：RATIONALE AND OBJECTIVES:Estimation of regional lung function parameters from hyperpolarized gas magnetic resonance images can be very sensitive to presence of noise. Clustering pixels and averaging over the resulting groups is an effective method for reducing the effects of noise in these images, commonly performed by...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2008.03.002

    authors： Guyer RA,Hellman MD,Emami K,Kadlecek S,Cadman RV,Yu J,Vadhat V,Ishii M,Woodburn JM,Law M,Rizi RR

    更新日期：2008-06-01 00:00:00

  • Nephrogenic systemic fibrosis and management of high-risk patients.

    abstract：:The purpose of this work is to provide current information on the rapidly evolving subject of nephrogenic systemic fibrosis (NSF), to establish the radiologic approach to the management of high-risk patients for NSF, and to assess the probabilistic risk of NSF compared to contrast induced nephropathy (CIN), as encount...

    journal_title：Academic radiology

    pub_type： 杂志文章,评审

    doi：10.1016/j.acra.2009.01.001

    authors： Altun E,Semelka RC,Cakit C

    更新日期：2009-07-01 00:00:00

  • Prediction accuracy of a sample-size estimation method for ROC studies.

    abstract：RATIONALE AND OBJECTIVES:Sample-size estimation is an important consideration when planning a receiver operating characteristic (ROC) study. The aim of this work was to assess the prediction accuracy of a sample-size estimation method using the Monte Carlo simulation method. MATERIALS AND METHODS:Two ROC ratings simul...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2010.01.007

    authors： Chakraborty DP

    更新日期：2010-05-01 00:00:00

  • Hybrid segmentation and virtual bronchoscopy based on CT images.

    abstract：RATIONALE AND OBJECTIVES:Introduction of combination of the segmentation tool SegoMeTex and the virtual endoscopy system VIVENDI to perform virtual endoscopic inspections of the human lung. This virtual bronchoscopy system enables visualization of the tracheobronchial tree down to seventh generation. Furthermore, the m...

    journal_title：Academic radiology

    pub_type： 杂志文章

    doi：10.1016/j.acra.2004.01.012

    authors： Mayer D,Bartz D,Fischer J,Ley S,del Río A,Thust S,Kauczor HU,Heussel CP

    更新日期：2004-05-01 00:00:00