3.0 T magnetic resonance in neuroradiology

Scarabino, Tommaso; Nemore, F.; Giannatempo, G.M.; Bertolino, Alessandro; Salle, Francesco Di; Salvolini, U.

doi:10.1016/j.ejrad.2003.08.008

Cited by 48 publications

(47 citation statements)

References 17 publications

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“…Furthermore, one of these three studies found a mild extracellular cerebral edema with increased B0 values and a trend for decreased ADCs (Kallenberg et al, 2007). The higher resolution and signal-to-noise ratio of 3 T MRI used in the present study makes it more sensitive for detecting cerebral abnormalities (Scarabino et al, 2003) than The values for the relative change of the apparent diffusion coefficient measured in the cerebrospinal fluid after 6 h of isobaric hypoxia were zero, because they were corrected to achieve the same values as at baseline (for details see text). c The apparent diffusion coefficient values obtained before exposure to isobaric hypoxia were defined as 100%.…”

Section: Discussionmentioning

confidence: 86%

Hypoxia-Induced Acute Mountain Sickness is Associated with Intracellular Cerebral Edema: A 3 T Magnetic Resonance Imaging Study

Schoonman

Sándor

Nirkko

et al. 2007

J Cereb Blood Flow Metab

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Acute mountain sickness is common among not acclimatized persons ascending to high altitude; the underlying mechanism is unknown, but may be related to cerebral edema. Nine healthy male students were studied before and after 6-h exposure to isobaric hypoxia. Subjects inhaled room air enriched with N 2 to obtain arterial O 2 saturation values of 75 to 80%. Acute mountain sickness was assessed with the environmental symptom questionnaire, and cerebral edema with 3 T magnetic resonance imaging in 18 regions of interest in the cerebral white matter. The main outcome measures were development of intra-and extracellular cerebral white matter edema assessed by visual inspection and quantitative analysis of apparent diffusion coefficients derived from diffusionweighted imaging, and B0 signal intensities derived from T2-weighted imaging. Seven of nine subjects developed acute mountain sickness. Mean apparent diffusion coefficient increased 2.12% (baseline, 0.8060.09; 6 h hypoxia, 0.8160.09; P = 0.034), and mean B0 signal intensity increased 4.56% (baseline, 432.1698.2; 6 h hypoxia, 450.76102.5; P < 0.001). Visual inspection of magnetic resonance images failed to reveal cerebral edema. Cerebral acute mountain sickness scores showed a negative correlation with relative changes of apparent diffusion coefficients (r = À0.83, P = 0.006); there was no correlation with relative changes of B0 signal intensities. In conclusion, isobaric hypoxia is associated with mild extracellular (vasogenic) cerebral edema irrespective of the presence of acute mountain sickness in most subjects, and severe acute mountain sickness with additional mild intracellular (cytotoxic) cerebral edema.

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Section: Discussionmentioning

confidence: 86%

Hypoxia-Induced Acute Mountain Sickness is Associated with Intracellular Cerebral Edema: A 3 T Magnetic Resonance Imaging Study

Schoonman

Sándor

Nirkko

et al. 2007

J Cereb Blood Flow Metab

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“…Recently, high field MR imaging at 3.0T has become available for clinical application [14,15,[17][18][19]. Bernstein et al were the first to describe CE MRA of the carotid arteries at 3.0T.…”

Section: Discussionmentioning

confidence: 99%

High spatial resolution contrast-enhanced MR angiography of the supraaortic arteries using the quadrature body coil at 3.0T: A feasibility study

et al. 2006

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To examine whether the the increased signal-to-noise (S/N) available at 3.0T would permit the use of the quadrature body coil for high spatial resolution contrast-enhanced (CE) MR angiography (MRA), and whether the large FOV that was used in our routine 1.5T protocol would also be feasible at 3.0T. In a prospective study, 43 patients and five volunteers were examined on a clinical whole-body 3.0T MR unit (Intera, Philips Medical Systems, Best, The Netherlands) after institutional review board approval and informed consent. Three-dimensional CE MRA (T1 gradient echo-sequence with TR/TE = 5.7/1.93 msec.; acquisition time, 1:54 min.) using randomly segmented central k-space ordering (CENTRA) was acquired with the quadrature body coil, using over a FOV of 350 mm. A high-image matrix of 432x432 yielded a non-zero filled voxel size of 0.81 mm x 0.81 mm x 1.0 mm (0.66 mm(3)). For quantitative analysis, contrast ratios (CR) between vessels (S) and signal in surrounding tissue (ST) were calculated [(S-ST)/(S+ST)]. For qualitative analysis, image quality and presence of artifacts were rated by two radiologists in consensus on a five-point scale (1=excellent to 5=nondiagnostic). Digital subtraction angiography (DSA) served as the standard of reference in patients with vascular disease. In the five volunteers, 1.5T CE MRA using a phased array neurovascular coil was available for intraindividual comparison. 3.0T CE MRA was successfully performed in 48/48 subjects (100%). Mean CR+/- SD were 0.76 (139.30/182.42) and 0.87 (235.18/270.14) at 3.0T and 1.5T respectively . Mean image quality was 3.82+/-0.86. Intraindividual comparison between 1.5T and 3.0T CE MRA in the volunteers revealed no significant difference in image quality (4.2+/-0.74 vs 4.6+/-0.80; p>0.05). Vascular disease was correctly identified in 13/13 patients with DSA correlation. CE MRA of the supraaortic arteries is feasible at 3.0T using a large FOV of 350 mm. The signal gain at 3.0T enables high spatial resolution contrast-enhanced MR angiography by using the built-in quadrature body coil only.

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“…3,4 Some studies have reported lower contrast of T 1 -SE images at 3T than 1.5T. [2][3][4]25 Scarabino and associates 4 attributed Fig. 7.…”

Section: Discussionmentioning

confidence: 99%

“…1 Early studies of the 3T MR system showed that adequate T 1 contrast images could not be obtained with the 3T system as with 1.5T systems. [2][3][4] In contrast, better contrast of T 1 -weighted images (T 1 WI) obtained by fast spinecho (FSE) has been reported at 3T than 1.5T after adjustment of various scan parameters. [5][6][7] T 1 WI is important for clinical applications and essential for evaluating brain anatomy and morphology.…”

Section: Introductionmentioning

confidence: 96%

Optimization of Scan Parameters for T1-FLAIR Imaging at 1.5 and 3T using Computer Simulation

et al. 2013

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Purpose: We attempted to optimize scan parameters for T 1 -weighted ‰uid-attenuated inversion recovery (T 1 -FLAIR) sequence at 3 and 1.5 tesla (T) using computer simulation.Methods: We measured the T 1 and T 2 relaxation time values (T 1 v and T 2 v) of gray (GM) and white matter (WM) at 3 and 1.5T, generated computer-simulated T 1 -FLAIR (CS-T 1 -FLAIR) images using those values, and compared the simulated and actual T 1 -FLAIR images to verify the contrast reliability of our computer simulation. We mathematically and visually evaluated CS-T 1 -FLAIR images at various repetition times (TR) and echo times (TE).Results: At 3T, the measured relaxation values for GM were T 1 v, 1524 ms, and T 2 v, 85 ms, and for WM, T 1 v, 750 ms, and T 2 v, 65 ms. At 1.5T, the measured relaxation values for GM were T 1 v, 1251 ms, and T 2 v, 99 ms, and for WM, T 1 v, 623 ms, and T 2 v, 75 ms. Contrast of CS-T 1 -FLAIR and actual T 1 -FLAIR images was identical. An optimal TR of 3140 ms was determined for T 1 -FLAIR at 3T and 2440 ms at 1.5T based on mathematical evaluation. The optimal TR ranges were 2400 to 3900 ms at 3T and 1800 to 3200 ms at 1.5T based on visual assessment of CS-T 1 -FLAIR. A shorter TE provided better T 1 contrast.Conclusion: We optimized T 1 -FLAIR by focusing on its most important scan parameters using computer simulations and determined that a longer TR was suitable at 3T than at 1.5T. Our computer simulation was useful for determining the optimal scan parameters.

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3.0 T magnetic resonance in neuroradiology

Cited by 48 publications

References 17 publications

Hypoxia-Induced Acute Mountain Sickness is Associated with Intracellular Cerebral Edema: A 3 T Magnetic Resonance Imaging Study

Hypoxia-Induced Acute Mountain Sickness is Associated with Intracellular Cerebral Edema: A 3 T Magnetic Resonance Imaging Study

High spatial resolution contrast-enhanced MR angiography of the supraaortic arteries using the quadrature body coil at 3.0T: A feasibility study

Optimization of Scan Parameters for T1-FLAIR Imaging at 1.5 and 3T using Computer Simulation

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