Investigative radiology
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Investigative radiology · Jun 2007
High-resolution magnetic resonance imaging (MRI) at 3.0 Tesla in the short-term follow-up of patients with proven cervical artery dissection.
For the imaging evaluation of patients with suspected cervical artery dissection (CAD) in the last decade, magnetic resonance imaging (MRI) has become the first line imaging modality. However, CAD is a highly dynamic process with rapid changes over time. Aim of this study was to assess the short-term morphologic changes in patients with proven CAD by MRI within 2 weeks after the initial diagnosis using a multicontrast high-resolution noninvasive vessel wall imaging approach at 3.0 T. ⋯ High-resolution MRI of acute CAD at 3.0 T permits a refined cross-sectional and longitudinal analysis of the morphologic features of CAD. The increased signal-to-noise ratio at 3.0 T allows for a high spatial resolution permitting detailed analysis of the diseased vessel segment. An unequivocal distinction between intramural hematoma and thrombus was possible. Information could be gained with regard to recanalization, degree of stenosis, formation of pseudoaneurysm, and appearance of new dissections making short-term follow-up in pts with acute CAD recommendable. Further studies are needed to assess the relationship between short-term results and definite outcome.
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Investigative radiology · Jun 2007
Hyperpolarized 3He ventilation defects and apparent diffusion coefficients in chronic obstructive pulmonary disease: preliminary results at 3.0 Tesla.
Hyperpolarized 3He magnetic resonance imaging (3He MRI) at 3.0 Tesla of healthy volunteers and chronic obstructive pulmonary disease (COPD) patients was performed for quantitative evaluation of ventilation defects and apparent diffusion coefficients (ADC) and for comparison to published results acquired at 1.5 Tesla. The reproducibility of 3He ADC and ventilation defects was also assessed in subjects scanned 3 times, twice within 10 minutes, and again within 7 +/- 2 days of the first MRI visit. ⋯ ADC values for emphysematous lungs were significantly increased compared with healthy lungs in age-matched subjects, and all values were comparable to those reported previously at 1.5 Tesla. Ventilation defect score and ventilation defect volume results were also comparable to results previously reported in COPD subjects Reproducibility of ADC for same-day scan-rescan and 7-day rescan was high and similar to previously reported results.
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Investigative radiology · Jun 2007
Contrast-enhanced first-pass myocardial perfusion magnetic resonance imaging with parallel acquisition at 3.0 Tesla.
Magnetic resonance imaging (MRI) at 3 T is significantly different than 1.5 T and needs to be optimized due to increased signal-to-noise ratio (SNR) and specific absorption ratio (SAR). This study tests the hypothesis that first-pass myocardial perfusion MRI using saturation recovery (SR)-TrueFISP with parallel imaging is superior to SR-TurboFLASH and a more achievable technique for clinical application at 3 T. ⋯ Optimized SR-TrueFISP first-pass myocardial perfusion MRI at 3 T has superior image quality compared with SR-TurboFLASH, independent of the myocardial segment analyzed. However, coil sensitivity nonuniformities and dielectric resonance effects cause signal intensity differences between myocardial segments that must be accounted for when interpreting 3 T perfusion studies.
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Investigative radiology · Jun 2007
Reproducibility of quantitative cerebral T2 relaxometry, diffusion tensor imaging, and 1H magnetic resonance spectroscopy at 3.0 Tesla.
The reproducibility of quantitative cerebral T2 relaxometry, diffusion tensor imaging, and H magnetic resonance (MR) spectroscopic imaging was assessed on a clinical 3.0 T MR system. ⋯ The reproducibility of quantitative brain MRI at 3.0 T is better than or at least comparable to the reproducibility at 1.5 T.
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Investigative radiology · Jun 2007
Inversion recovery single-shot TurboFLASH for assessment of myocardial infarction at 3 Tesla.
The aim of the study was to assess the diagnostic accuracy of imaging myocardial infarction with a single-shot inversion recovery turbofast low-angle shot (SS IR turboFLASH) sequence at 3.0 Tesla in comparison with an established segmented inversion recovery turboFLASH sequence at 1.5 Tesla. ⋯ The loss of CNR, which is caused by replacement of the segmented technique by the single-shot technique, is completely compensated by the approximately 2-fold CNR increase at the higher field strength. The IR turboFLASH technique at 3.0 Tesla IR can be used as a single-shot technique with acquisition of 9 slices during a single breath-hold without loss of diagnostic accuracy compared with the segmented technique at 1.5 Tesla.