Abstract:
RATIONALE AND OBJECTIVES:Tissue contrast phenomenology was investigated analytically and clinically for a class of magnetic resonance (MR) pulse sequences we call large-tip-angle (LTA) spin-echo (SE) imaging. In comparison to traditional SE sequences (denoted 90 degrees-180 degrees-echo), the LTA sequence is of the form alpha degrees-180 degrees-echo, where 90 degrees < alpha < 180 degrees. Theoretical analysis shows that appropriately designed LTA sequences can selectively boost the MR signal by 10%-150% in substances whose spin lattice (T1) relaxation values equal or exceed the sequence repetition time (TR). This unique contrast behavior potentially allows one to reduce TR (and hence imaging time) by 30% to 50% while maintaining constant T2-weighted contrast or contrast-to-noise within an image. METHODS:Preliminary clinical testing of LTA sequences was performed in 60 patients with a wide range of cranial, spinal, musculoskeletal, and abdominal pathologies. Large-tip-angle images (1,500/80/130 degrees) were blindly and prospectively compared to conventional (2,600/80/90 degrees) SE images. RESULTS:Principal diagnoses were concordant between the readers in all cases, although minor variances in detail features were noted in 6 (10%) of 60 cases. Large-tip-angle sequences revealed small cystic areas in two cerebral neoplasms and in a herniated disk which were not apparent on the standard SE images. However, the LTA images were rated to be "noisier" by visual assessment in 43 of 60 cases, the exception being for abdominal examinations, where respiratory and peristaltic artifacts were judged more severe on the standard SE sequences. CONCLUSIONS:Large-tip-angle SE imaging is an interesting technique capable of improving image contrast and signal from lesions with long T1 values when the sequence repetition time (TR) is short.
journal_name
Invest Radioljournal_title
Investigative radiologyauthors
Elster AD,Provost TJdoi
10.1097/00004424-199310000-00017subject
Has Abstractpub_date
1993-10-01 00:00:00pages
944-53issue
10eissn
0020-9996issn
1536-0210journal_volume
28pub_type
杂志文章abstract:OBJECTIVE:The objective of this study was to validate quantitation of R2* and DeltaR2* measurements obtained with a 3-dimensional (3-D) multiple gradient-recalled echo (mGRE) sequence for evaluating intrarenal oxygenation in humans. MATERIALS AND METHODS:Validation was accomplished (1) by comparing R2* values with pre...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/01.rli.0000187166.43871.fb
更新日期:2006-02-01 00:00:00
abstract::The purpose of our investigation was to determine whether iopanoyl glucuronide, the major metabolite of iopanoic acid (Telepaque), undergoes hydrolysis by bacterial beta-glucuronidase in dogs. The conjugated compound was identified and quantitated by elemental analysis, fluorescent excitation analysis, thin-layer chro...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-197805000-00011
更新日期:1978-05-01 00:00:00
abstract:OBJECTIVE:The objective of this study was to determine the gadolinium (Gd) concentration remaining in human bone tissue after administration of standard clinical doses of 2 Gd-based contrast agents: ProHance and Omniscan. MATERIALS AND METHODS:After administration of 0.1 mmol/kg of Gd chelate to patients undergoing hi...
journal_title:Investigative radiology
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doi:10.1097/01.rli.0000186569.32408.95
更新日期:2006-03-01 00:00:00
abstract:OBJECTIVES:The aim of this study was to explore the impact of dynamic contrast-enhanced (DCE) computer tomography (CT) as a biomarker in metastatic renal cell carcinoma (mRCC). MATERIALS AND METHODS:Twelve patients with favorable or intermediate Memorial Sloan Kettering Cancer Center risk group and clear cell mRCC par...
journal_title:Investigative radiology
pub_type: 杂志文章,随机对照试验
doi:10.1097/RLI.0000000000000058
更新日期:2014-09-01 00:00:00
abstract::Three facets of dual-energy quantitative computed tomography are studied: (1) the algorithm for postprocessing data (the methods of Cann, Laval-Jeantet et al, Goodsitt et al [two methods], and Nickoloff et al); (2) the influence of choice of tissue-equivalent materials for calibration; and (3) the difference between c...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199008000-00003
更新日期:1990-08-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:To evaluate the effect of the transverse ligament on translation of the menisci. METHODS:Six cadaveric knees were examined by MR imaging inside a positioning device before and after transecting the transverse ligament. The knees were examined at various positions: extension, 30 degrees of flex...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199909000-00002
更新日期:1999-09-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:To assess the abilities of dynamic diffusion-weighted MRI to demonstrate the effects in vivo of a high-viscosity iodinated contrast agent on medullary and cortical blood flow in the rat kidney. METHODS:Dynamic diffusion-weighted, echoplanar MR images obtained from five b-value single-shot acqu...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-200011000-00001
更新日期:2000-11-01 00:00:00
abstract::Compounds containing mobile protons can act as contrast agents by increasing the value of the term (1/12 - 1/11). The efficiency of this method is markedly pH- and field-dependent. There are many such compounds allowing a choice to be made based on the characteristics of the tissue or organ, magnetic field strength, a...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198809001-00058
更新日期:1988-09-01 00:00:00
abstract::A method is presented for selective catheterization and filming of the small internal spermatic and proper hepatic arteries in rabbits. The angiograms thus obtained afford clear delineation of the vessels and their branches and can enhance radiographic investigation of a variety of experimental disease models. ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-197705000-00009
更新日期:1977-05-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:
更新日期:2005-01-01 00:00:00
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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::We investigated the feasibility of using intravascular ultrasound imaging to analyze vascular physiology in various arterial beds. Canine superficial femoral, external iliac, and common carotid arteries were harvested and suspended and perfused in a bath of oxygenated, heated, physiologic salt solution. A 6-Fr, 20-MHz...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199103000-00010
更新日期:1991-03-01 00:00:00
abstract::Breast calcification diagnosis was studied by using clinical findings and computerized image processing of a mammogram in a network of trained expert learning systems (Outcome Advisor [OA]). The system was tested with records not used for training and performance was compared with radiologist. The network was 72% accu...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199106000-00004
更新日期:1991-06-01 00:00:00
abstract::We measured the amounts of three types of radiographic contrast media (RCM) that could be entrapped in liposomes prepared by the dehydration-rehydration vesicle (DRV) technique. To make DRVs, one initially makes water-containing, small unilamellar vesicles, adds contrast media and lyophilizes the mixture. Upon rehydra...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198802000-00009
更新日期:1988-02-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:To determine whether vascular endothelial growth factor (VEGF) is a histopathological factor influencing contrast enhancement of hepatocellular carcinoma (HCC) on computed tomography (CT). METHODS:Twenty-two nodular HCCs underwent multiphase helical CT and surgery. Tumor size, histological gra...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-200108000-00008
更新日期:2001-08-01 00:00:00
abstract::A new nonionic contrast medium (CM), ioxilan, was compared with iohexol and iopamidol. Following incubation of whole heparinized blood with CM, the morphology and osmotic fragility of erythrocytes were studied, the former by transmission electron microscopy. Effects on platelets and hemocoagulation were determined by ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198809001-00032
更新日期:1988-09-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-200211000-00001
更新日期:2002-11-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199912000-00003
更新日期:1999-12-01 00:00:00
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journal_title:Investigative radiology
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doi:10.1097/RLI.0000000000000306
更新日期:2017-01-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000227
更新日期:2015-12-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-200206000-00005
更新日期:2002-06-01 00:00:00
abstract::A patient, suffering a severe anaphylactoid reaction to contrast material injected for an intravenous pyelogram, developed a consumption coagulopathy and evidence of complement activation. Precontrast complement values suggested that the patient had been processing complement via the classical pathway, perhaps as a co...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198011001-00004
更新日期:1980-11-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e318032a9fe
更新日期:2007-07-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000343
更新日期:2017-02-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198808000-00013
更新日期:1988-08-01 00:00:00
abstract:OBJECTIVES:The aim of this pilot study was to assess post-treatment apparent diffusion coefficient (ADC) changes of diffuse large B-cell lymphoma lesions on respiratory-gated whole-body diffusion-weighted imaging (DWI), with integrated (18)F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (PET/CT...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e3182087b03
更新日期:2011-05-01 00:00:00
abstract::Capacity-limited elimination of sodium iopanoate and a reproducible apparent transport maximum (Tm) were demonstrated in nonoperated dogs having an intact enterohepatic circulation and normal endogenous bile salt pool. Using a multiple infusion technique, estimation of apparent Tm of iopanoate in the liver was possibl...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-197601000-00007
更新日期:1976-01-01 00:00:00
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journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199711000-00010
更新日期:1997-11-01 00:00:00
abstract::Magnetic resonance (MR) methods have been used to study the metabolic and vascular response of model tumors to tumor necrosis factor (TNF). Magnetic resonance measurements demonstrated acute reductions in tumor blood flow, measured from tumor uptake of D2O, and in tumor adenosine triphosphate (ATP), measured by 31P ma...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198912000-00022
更新日期:1989-12-01 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:2006-10-01 00:00:00