Abstract:
OBJECTIVES:The objective of this study was to evaluate the use of dielectric pads for improving high spatial resolution imaging of the inner ear at 7 T. MATERIALS AND METHODS:Two sets of dielectric pads were designed using electromagnetic simulations and implemented using a deuterated suspension of barium titanate. Their effect on transmit efficiency, contrast homogeneity, and diagnostic image quality was evaluated in vivo (N = 10). In addition, their effect on the specific absorption rate was evaluated numerically. RESULTS:Statistically significant improvements (P < 0.001) in several measures of the image quality were obtained by using dielectric pads. The dielectric pads lead to an increase in the transmit efficiency and uniformity at the location of the inner ear, which is reflected in both an increased contrast homogeneity and an increased diagnostic value. Simulations show that the dielectric pads do not increase the peak local specific absorption rate. CONCLUSIONS:Using geometrically tailored dielectric pads enables high spatial resolution magnetic resonance imaging of the human inner ear at 7 T. The high spatial resolution improves the depiction of the fine inner ear structures, showing the benefit of magnetic resonance imaging at ultrahigh fields.
journal_name
Invest Radioljournal_title
Investigative radiologyauthors
Brink WM,van der Jagt AM,Versluis MJ,Verbist BM,Webb AGdoi
10.1097/RLI.0000000000000026subject
Has Abstractpub_date
2014-05-01 00:00:00pages
271-7issue
5eissn
0020-9996issn
1536-0210journal_volume
49pub_type
杂志文章abstract::Observation of the relaxivity of MRI contrast media over a wide range of magnetic fields is not only necessary for predicting their efficiency at any field but also compulsory for understanding and improving their mechanisms of action. The best experimental approach to this problem is the field cycling method, which a...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198809001-00047
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abstract::A feasibility study is described to provide quantitative texture measures to distinguish between normal lung, alveolar infiltrates and interstitial infiltrates. Advanced computer imaging technology and decision making processes were applied to distinguish between these textural patterns. The results, based on computer...
journal_title:Investigative radiology
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doi:10.1097/00004424-197807000-00005
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abstract::Patients with intracranial arteriovenous malformations (AVM) can expect significant mortality (15% to 20%) and morbidity (20% to 30%) over a 15-year to 20-year period. Recent advances in interventional neuroradiology, neurosurgery, neuroanesthesia, and stereotactic radiotherapy provide the opportunity to obliterate ma...
journal_title:Investigative radiology
pub_type: 杂志文章,评审
doi:10.1097/00004424-199008000-00014
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abstract:RATIONALE AND OBJECTIVES:To improve the accuracy of magnetic resonance imaging (MRI) in evaluating the response of osteosarcomas to preoperative chemotherapy, the authors developed a technique of mapping tumor necrosis and viability by quantitating slope values of gadolinium-DTPA (Gd-DTPA) uptake on dynamic fast low-an...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199205000-00010
更新日期:1992-05-01 00:00:00
abstract::Groups of 5 fasting male and female patients aged 32-83 years were each given 3 gm of the cholecystographic contrast medium iosumetic acid in micronized form (particle size less than 20 mum); Group I with 150 ml tea (standard administration); Group II with 500 ml tea; Group III with 150 ml tea plus 10 mg metocloprami...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-197607000-00009
更新日期:1976-07-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000446
更新日期:2018-06-01 00:00:00
abstract::At a given radiation dosage and field of view, five variables are under meaningful control for intravenous digital subtraction angiography (IV-DSA): concentration and quantity of contrast media injected, volume of injectate, rate of injection, and site of injection. Some controversy exists regarding the selection of a...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198401000-00007
更新日期:1984-01-01 00:00:00
abstract::Because of a need to correlate pulmonary microvascular changes with physiologic data during lung injury, in vitro and in vivo pulmonary capillary microangiography was performed on normal dogs and those subjected to oleic acid injury and glass bead microembolization. During these studies, no significant differences wer...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:
更新日期:1983-01-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199308000-00005
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journal_title:Investigative radiology
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doi:10.1097/00004424-200005000-00003
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-200211000-00001
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abstract::Sixteen observers averaging 7.4 years experience in interpreting radiology images and 16 observers without radiology training were tested for their ability to detect low-contrast signals in structured noise backgrounds using a digital display system. No significant difference in true positives, false positives, time t...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198704000-00006
更新日期:1987-04-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-200208000-00005
更新日期:2002-08-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000712
更新日期:2021-02-01 00:00:00
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journal_title:Investigative radiology
pub_type: 临床试验,杂志文章
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更新日期:2001-06-01 00:00:00
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doi:10.1097/00004424-200212000-00006
更新日期:2002-12-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199212000-00011
更新日期:1992-12-01 00:00:00
abstract::The rate at which isotopes descend from the cisterna magna to the lumbar subarachnoid space is highly variable. In monkeys, with and without previous lumbar puncture, transit time was measured. In animals with a previous lumbar puncture, transit times were 10 to 120 minutes; in monkeys without a previous lumbar punctu...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198805000-00005
更新日期:1988-05-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198411000-00011
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journal_title:Investigative radiology
pub_type: 杂志文章
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pub_type: 杂志文章
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e3182718672
更新日期:2013-01-01 00:00:00
abstract::The efficacy and safety of perfluoroctylbromide as a diagnostic contrast agent for direct lymphography was studied in mongrel dogs. This radiopaque perfluorocarbon has several advantages over Ethiodol. The liquid compound has injection times one-fifth of that required for Ethiodol. When dosages were three to four tim...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-197707000-00012
更新日期:1977-07-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/01.rli.0000133816.83192.38
更新日期:2004-09-01 00:00:00
abstract::Video dilution technique (VDT) is currently performed in conjunction with routine cerebral angiography to determine carotid blood flow in humans. Preliminary results indicate that the blood flows (as a percentage of cardial output) of the common, internal, and external carotid arteries are 8.5%, 5.5%, and 3.0%, respec...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198105000-00004
更新日期:1981-05-01 00:00:00
abstract::The residency program at the University of Pennsylvania offers a 1-month fellowship for senior residents in medical student education. Instructional philosophy, methods, and content are discussed, observed, practiced, and evaluated. Close supervision and immediate feedback provide training particularly needed by futur...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199006000-00028
更新日期:1990-06-01 00:00:00
abstract:INTRODUCTION:The aim of the present study was to evaluate the potential of high-resolution MRI at 2 Tesla (T) for direct noninvasive imaging of the aortic wall in a mouse model of atherosclerosis. MATERIAL AND METHODS:A specific mouse antenna was developed and sequence parameters were adjusted. T(1)- and T2-weighted i...
journal_title:Investigative radiology
pub_type: 杂志文章
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更新日期:2003-08-01 00:00:00
abstract:MATERIALS AND METHODS:Stenotic kidney (STK) and contralateral kidney magnetization transfer ratios (MTRs; Mt/M0) were measured at 3.0-T magnetic resonance imaging, at offset frequencies of 600 and 1000 Hz, before and 1 month post-PTRA in 7 RVD pigs. Stenotic kidney MTR was correlated to renal perfusion, renal blood flo...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000711
更新日期:2021-02-01 00:00:00
abstract:PURPOSE:To determine the reproducibility, accuracy, and predictors of accuracy of computed tomography (CT) angiography to detect and characterize coronary atherosclerotic plaque as compared with intravascular ultrasound. METHODS:Ten ex vivo human coronary arteries were imaged in a moving phantom by dual-source CT (col...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e3181e0a541
更新日期:2010-11-01 00:00:00
abstract::Advances in the field of magnetic resonance (MR) as it pertains to clinical diagnostic radiology are examined in this review on the basis of publications in Investigative Radiology over the past 2 years (2005-2006). The articles published during that timeframe are discussed, organizationally wise, by anatomic region w...
journal_title:Investigative radiology
pub_type: 杂志文章,评审
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更新日期:2006-12-01 00:00:00