Abstract:
OBJECTIVES:The aim of this study was to investigate the feasibility of nonenhanced magnetic resonance angiography (MRA) of the lower extremities at 7 tesla (T). MATERIALS AND METHODS:Eight healthy volunteers were examined on a 7-T whole-body magnetic resonance system. For image acquisition, a custom-built 16-channel transmit/receive coil and a manually positionable AngioSURF table for multistation imaging were used. A nonenhanced T1-weighted 2-dimensional fast low-angle shot (2D FLASH) sequence was acquired with and without venous saturation radiofrequency pulses in axial orientation, covering the vasculature from the pelvis to the feet. Acquisition time of 1 table position amounted to 2 minutes and 19 seconds (with venous saturation pulse) and 1 minute and 9 seconds (without venous saturation pulse), covering a field of view of approximately 10 cm in the z-axis. Time-interleaved acquisition of modes was integrated to obtain homogeneous image quality of the vasculature. A qualitative image analysis was performed in the iliac, femoral, popliteal, and tibiofibular vessel segments regarding vessel delineation using a 5-point scale (5 to 1, excellent vessel delineation to nondiagnostic). For the quantitative image evaluation, the signal was measured in the specified segments and in the surrounding musculature of both legs to obtain contrast ratios (CR). RESULTS:T1-weighted 2D FLASH imaging enabled homogeneous, hyperintense delineation of the arteries with saturation of surrounding tissue in almost all analyzed vessel segments. The qualitative image evaluation demonstrated a moderate to good delineation and assessment of the vessel lumen (mean score: iliac, 3.17; femoral, 3.71; popliteal, 4.00; and tibiofibular, 3.31 for 2D FLASH). The quantitative analysis showed similar CRs in all vessel segments, with the best contrast to surrounding tissue achieved in the femoral segments (CRiliac, 0.59; CRfemoral, 0.69; CRpopliteal, 0.74; and CRtibiofibular, 0.57), although a medial signal drop-off in the thigh region could be found in some volunteers. Transformation of the axial images into coronal maximum intensity projection images revealed an artifact characterized by recurrent short declines of vessel signal, most probably because of an interference between the alternating pressure and flow effects during systole and diastole and the image acquisition frequency. Nevertheless, the use of time-interleaved acquisition of modes enabled a homogenous image quality with successful reduction of B1 field inhomogeneities. CONCLUSIONS:The results of our study demonstrate the feasibility of non-contrast-agent-enhanced MRA of the lower extremity vessels at 7 T. Nonenhanced MRA of the lower extremities at this very high magnetic field can be considered to be in an early but promising stage. Further sequence optimization and the examination of a larger number of participants as well as comparison with contrast-enhanced MRA and nonenhanced techniques at lower field strengths should be pursued in future trials.
journal_name
Invest Radioljournal_title
Investigative radiologyauthors
Fischer A,Maderwald S,Orzada S,Johst S,Schäfer LC,Ladd ME,Nassenstein K,Umutlu L,Lauenstein TCdoi
10.1097/RLI.0b013e3182839c2bsubject
Has Abstractpub_date
2013-07-01 00:00:00pages
525-34issue
7eissn
0020-9996issn
1536-0210journal_volume
48pub_type
杂志文章abstract:OBJECTIVE:To determine the prevalence of nephrogenic systemic fibrosis (NSF) in patients with chronic kidney disease (CKD) who have received gadopentetate dimeglumine. MATERIALS AND METHODS:We retrospectively studied all patients who underwent contrast-enhanced magnetic resonance imagings (CE-MRIs) between January 1, ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e31819343ba
更新日期:2009-03-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Very small dextran-coated magnetite particles were developed. These particles can be used either as immunospecific contrast agents for MRI by coupling to antibodies or as an interstitial contrast agent. METHODS:The particles were synthesized from iron chloride/dextran solutions. Size was evalu...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-200009000-00006
更新日期:2000-09-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Our purpose was to validate contrast-enhanced computed tomography (CECT)-derived quantitative measures of perfusion and permeability against gold standard techniques of fluorescent microspheres and Evan's Blue dye, respectively. MATERIALS AND METHODS:Normal and tumor-bearing (R3230AC) Fischer ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/01rli.0000124456.82985.35
更新日期:2004-06-01 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
abstract:RATIONALE AND OBJECTIVES:To evaluate the safety and pharmacokinetics of a newly developed MR contrast medium consisting of very small superparamagnetic iron oxide particles (VSOP) coated with citrate (VSOP-C184) in a clinical phase I trial. METHODS:A total of 18 healthy subjects received either VSOP-C184 (core diamete...
journal_title:Investigative radiology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1097/01.rli.0000129472.45832.b0
更新日期:2004-07-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Time-of-flight magnetic resonance angiography (TOF/MRA) is increasingly used to assess the nature and severity of stenotic blood vessels. Flow artifacts associated with high flows and/or narrow constrictions may confuse the interpretation of these studies. Accurate TOF/MRA evaluations demand an...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199307000-00011
更新日期:1993-07-01 00:00:00
abstract::Perfluoroctylbromide (PFOB), a radiopaque reticuloendothelial system contrast media for computed tomography, has been shown to accumulate in macrophages. In the current study PFOB was tested in rabbits as an abscess imaging agent. Two abscesses were induced in each of 24 rabbits, one in the liver and the other in the ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198409000-00017
更新日期:1984-09-01 00:00:00
abstract::The authors present a numerical deconvolution technique to compensate for image degrading effects caused by scattered photons in radiographic chest images. Fourier transform techniques are used to deconvolve a shift invariant model of the two dimensional point spread response functions of the scattered radiation. This...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198901000-00008
更新日期:1989-01-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:The authors differentiate acute tubular necrosis from transplant rejection in patients with delayed kidney graft function using gadolinium (Gd)-DTPA enhanced magnetic resonance (MR) imaging. METHODS:Twenty-four patients after renal transplantation (10 with normal graft function, 14 with delaye...
journal_title:Investigative radiology
pub_type: 临床试验,杂志文章
doi:10.1097/00004424-199606000-00009
更新日期:1996-06-01 00:00:00
abstract::This article reviews the computer system hardware and software, applications programs, and computer network services that are available on microcomputers for use by the radiologist. The American College of Radiology Institute computer network is described, which is specifically designed to help the practicing radiolog...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198602000-00015
更新日期:1986-02-01 00:00:00
abstract:OBJECTIVES:The aim of this study was to perform phantom measurements to prove the feasibility of single-source dual-energy computed tomography (DECT) of the extremities using a volume scan mode. In addition, we, for the first time, wanted to determine which concentrations of monosodium urate (MSU) in gout and calcium p...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000099
更新日期:2015-04-01 00:00:00
abstract:OBJECTIVES:The purpose of this study was to develop and validate a computer-aided diagnosis (CAD) tool for automatic classification of pulmonary nodules seen on low-dose computed tomography into solid, part-solid, and non-solid. MATERIALS AND METHODS:Study lesions were randomly selected from 2 sites participating in t...
journal_title:Investigative radiology
pub_type: 临床试验,杂志文章,多中心研究,随机对照试验
doi:10.1097/RLI.0000000000000121
更新日期:2015-03-01 00:00:00
abstract::An isotopic radiation source 125I was investigated for use in soft tissue radiaography, with particular attention to possible use in mammography for mass screening. Film sensitivities, exposure rates, absorbed doeses, contrast and resolution were determined, and compared to conventional x-ray units. It was found that ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-197509000-00007
更新日期:1975-09-01 00:00:00
abstract:OBJECTIVES AND RATIONALE:Negative enhancement of implanted liver tumors has been achieved in preclinical studies on manganese dipyridoxal-diphosphate (Mn-DPDP), a new hepatobiliary specific contrast agent for magnetic resonance imaging (MRI). The authors investigated the effects of Mn-DPDP on primary liver cancer and i...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199306000-00011
更新日期:1993-06-01 00:00:00
abstract:OBJECTIVES:The authors assessed the relative efficacy of conventional and digital storage-phosphor radiographs for the detection of skull fractures. METHODS:Fifty conventional film-screen radiographs (FSR) and 50 digital storage-phosphor radiographs (DR) with 66 fractures were compared. Five radiologists evaluated ima...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199308000-00005
更新日期:1993-08-01 00:00:00
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 for...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199310000-00017
更新日期:1993-10-01 00:00:00
abstract::The absorbed levels of ethanol or tetracycline, used as gallbladder sclerosing agents, were measured in the systemic blood circulation of 16 rabbits. The maximal systemic level of ethanol was 46 mg/dl and of tetracycline was 4.6 micrograms/ml after 30 minutes of gallbladder exposure. Comparable serum levels would be c...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198605000-00005
更新日期:1986-05-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:The relative stability and selectivity of magnetic resonance (MR) imaging contrast agents were compared with in vitro transmetallation and ligand competition reactions. MATERIALS AND METHODS:A gadolinium (Gd)-DTPA-BIGA, Gd-DTPA-BMA, Gd-DTPA, or Gd-HP-DO3A solution was mixed with an equimolar s...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199610000-00003
更新日期:1996-10-01 00:00:00
abstract::We examined the acute systemic and renal hemodynamic effects of intravenous meglumine/sodium diatrizoate-76% and iopamidol in euvolemic and dehydrated dogs. The physiologic responses were compared with acute changes in the level of an endogenous heparin-like material (EHM). One of eight dehydrated dogs receiving diatr...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198610000-00005
更新日期:1986-10-01 00:00:00
abstract::The large intestines of eight boxer dogs with canine histiocytic ulcerative colitis (CHUC) and 10 normal dogs were studied by in vivo angiography and postmortem microangiography. The vascular abnormalities were correlated with the gross and histologic pathology found at necropsy. The angiographic abnormalities were ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-197505000-00005
更新日期:1975-05-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:To investigate postmortem metabolic and morphologic alterations in the dog brain thalamus and to contribute diagnostic aids in medicolegal science. METHODS:A homogeneous group of 17 dogs was used for in vivo 1H magnetic resonance (MR) spectroscopy and electron microscopic studies, which were p...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199505000-00001
更新日期:1995-05-01 00:00:00
abstract::The potential risk of a radiologic procedure often is compared with the potential benefit of the procedure. While risk vs. benefit analysis has been useful as a step toward increased communication and understanding among radiologists, referring physicians, and the general public, it has the disadvantage that risk and ...
journal_title:Investigative radiology
pub_type: 杂志文章,评审
doi:10.1097/00004424-198901000-00005
更新日期:1989-01-01 00:00:00
abstract:RATIONALE AND OBJECTIVE:The purpose of this study was to investigate the feasibility, efficacy, and safety of ultrasound-guided percutaneous cryotherapy of stage T1 breast cancers. MATERIALS AND METHODS:Thirty patients with biopsy-confirmed breast cancers with tumor diameters of 15 mm or smaller (range, 5-15 mm; media...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/01.rli.0000166935.56971.ff
更新日期:2005-07-01 00:00:00
abstract::A method is presented by whichcomputed tomography scans carried out at a number of energies may be utilized to obtain cross-sectional images of density and atomic number in addition to the conventional array of linear attenuation coefficients. This type of analysis has been carried out for various substances of biolog...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-197703000-00016
更新日期:1977-03-01 00:00:00
abstract::The magnitude and time course of contrast enhancement in spontaneous canine brain tumors was determined for two contrast agents: meglumine iothalamate and sodium meglumine ioxaglate. Tumor enhancement during contrast infusion and at 5, 10, 15, 30 and 45 minutes was measured using quantitative computed tomography. Bloo...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198411001-00007
更新日期:1984-11-01 00:00:00
abstract:OBJECTIVE:: The final event leading to myocardial infarction is adhesion and activation of platelets after rupture of an atherosclerotic plaque, ending in thrombotic occlusion of the coronary artery. Imaging of imminent vessel occlusion may improve patient care. The feasibility of molecular magnetic resonance imaging (...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e31821e62fb
更新日期:2011-10-01 00:00:00
abstract:PURPOSE:The aim of this study was to identify the signal intensity (SI) changes in the dentate nucleus (DN) and the globus pallidus (GP) on unenhanced T1-weighted magnetic resonance (MR) images after multiple administration of gadolinium-based contrast agents (GBCAs) in children and compare those changes between linear...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000436
更新日期:2018-04-01 00:00:00
abstract::An allergic, immunologic mechanism for certain adverse reactions to radiocontrast agents has been postulated on the basis of clinical and theoretical considerations. One obstacle to the acceptance of this allergic theory has been the inability to demonstrate significant antibodies with specificity for these agents. In...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-197609000-00002
更新日期:1976-09-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:To evaluate the imaging characteristics of various iliac artery stents and stent-grafts in a multislice, computed tomography angiography (MSCTA) phantom study. METHODS:Twelve types of stents and three stent-grafts made of different materials (steel, nitinol, tantalum, cobalt-based alloy) were ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-200112000-00004
更新日期:2001-12-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:The basic characteristics of BR1, a novel echo contrast agent based on stabilized sulfur hexafluoride (SF6) microbubbles have been evaluated. METHODS:The authors determined the physicochemical properties (bubble concentration, bubble size distribution, resistance to pressure, and stability) an...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199508000-00001
更新日期:1995-08-01 00:00:00