Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · May 2006
Accelerating MR elastography: a multiecho phase-contrast gradient-echo sequence.
To demonstrate the feasibility of using a multiecho phase-contrast (PC) gradient-echo sequence with motion-sensitizing gradient (MSG) to accelerate MR elastography (MRE) acquisitions in comparison to single-echo PC sequences. ⋯ The results demonstrate that a multiecho sequence is suitable for accelerating MRE in nearly homogeneous tissue, such as muscle. It provides equivalent elasticity values in a significantly reduced scan time compared to a single-echo sequence. The maximum achievable ETL factor must be individually determined for the target tissue.
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J Magn Reson Imaging · May 2006
Comparative Study Controlled Clinical TrialMulticontrast black-blood MRI of carotid arteries: comparison between 1.5 and 3 tesla magnetic field strengths.
To compare black-blood multicontrast carotid imaging at 3T and 1.5T and assess compatibility between morphological measurements of carotid arteries at 1.5T and 3T. ⋯ This study demonstrated significant improvement in SNR, CNR, and image quality for high- resolution black-blood imaging of carotid arteries at 3T. Morphologic measurements are compatible between 1.5T and 3T.
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J Magn Reson Imaging · May 2006
Comparative StudyAccurate quantification of visceral adipose tissue (VAT) using water-saturation MRI and computer segmentation: preliminary results.
To describe and evaluate the accuracy of water-saturation MRI and a computer segmentation program for quantification of visceral adipose tissue (VAT). ⋯ The results obtained demonstrate that the proposed method may be able to provide accurate quantification of VAT in a highly reproducible and efficient manner.
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J Magn Reson Imaging · Apr 2006
Comparative StudyT1rho relaxation mapping in human osteoarthritis (OA) cartilage: comparison of T1rho with T2.
To quantify the spin-lattice relaxation time in the rotating frame (T1rho) in various clinical grades of human osteoarthritis (OA) cartilage specimens obtained from total knee replacement surgery, and to correlate the T1rho with OA disease progression and compare it with the transverse relaxation time (T2). ⋯ Preliminary results from a limited number of knee specimens (N = 8) suggest that T1rho relaxation mapping is a sensitive noninvasive marker for quantitatively predicting and monitoring the status of macromolecules in early OA. Furthermore, T1rho has a higher dynamic range (>100%) for detecting early pathology compared to T2. This higher dynamic range can be exploited to measure even small macromolecular changes with greater accuracy compared to T2. Because of these advantages, T1rho relaxation mapping may be useful for evaluating early OA therapy.
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J Magn Reson Imaging · Apr 2006
In vivo porcine liver radiofrequency ablation with simultaneous MR temperature imaging.
To demonstrate in vivo MR-guided temperature mapping during radiofrequency (RF) ablation of the liver with a commercially available RF generator modified to allow simultaneous RF treatment and MRI. ⋯ The feasibility of performing RF ablation with a modified commercial RF generator simultaneously with MRI was demonstrated. Interference-free MR temperature maps were produced with both variable respiratory motion and mechanical ventilation, and showed the extent of heating as the ablation progressed.