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J Konishi - One of the best experts on this subject based on the ideXlab platform.

  • mr contrast of ferritin and hemosiderin in the brain comparison among gradient Echo conventional Spin Echo and fast Spin Echo sequences
    2003
    Co-Authors: Tabassum Laz Haque, Yukio Miki, Mitsunori Kanagaki, Takahiro Takahashi, Akira Yamamoto, J Konishi, Kazuhiko Nozaki, Nobuo Hashimoto
    Abstract:

    Abstract Objective: To compare the magnetic resonance image contrasts due to ferritin and hemosiderin in the brain tissue among different pulse sequences. Materials and methods: Fourteen patients with cavernous hemangioma in the brain prospectively underwent MR imaging with T2*-weighted gradient-Echo (GRE), T2-weighted conventional Spin-Echo (SE) and fast Spin-Echo (FSE) sequences. The relative contrast ratios (CRs) of the hypointense part of cavernous hemangioma, globus pallidus and putamen to the deep frontal white matter were measured on each pulse sequence and statistically analyzed using analysis of variance followed by paired t-test. Results: In the hypointense part of cavernous hemangioma, relative CRs were significantly lower on T2*-weighted GRE than on T2-weighted SE images (P=0.0001), and on T2-weighted SE than on T2-weighted FSE images (P=0.0001). In the globus pallidus, relative CRs were significantly lower on T2-weighted SE than on T2*-weighted GRE images (P=0.002), and on T2*-weighted GRE than on T2-weighted FSE images (P=0.0002). In the putamen, relative CRs were significantly lower on T2-weighted SE than on T2*-weighted GRE images (P=0.001), and there was no significant difference between CRs on T2-weighted FSE and T2*-weighted GRE images (P=0.90). Conclusion: Hemosiderin showed best image contrast on T2*-weighted GRE images but ferritin showed more prominent image contrast on T2-weighted SE than on T2*-weighted GRE images, which may help to determine an appropriate pulse sequence in neurological diseases associated with excessive ferritin accumulation.

Clare M Tempany - One of the best experts on this subject based on the ideXlab platform.

  • three dimensional fast recovery fast Spin Echo mrcp comparison with two dimensional single shot fast Spin Echo techniques
    2006
    Co-Authors: Aaron D Sodickson, Koenraad J Mortele, Matthew A Barish, Kelly H Zou, Steven Thibodeau, Clare M Tempany
    Abstract:

    Purpose: To retrospectively evaluate the technical quality of and the visibility of the biliary tree and pancreatic duct on magnetic resonance (MR) cholangiopancreatographic (MRCP) images obtained with a single-breath-hold three-dimensional (3D) fast-recovery fast Spin-Echo (FRFSE) sequence in comparison with conventional two-dimensional (2D) single-shot fast Spin-Echo (SSFSE) thin-section and thick-slab sequences. Materials and Methods: Institutional review board approval was obtained; informed consent was not required for this HIPAA-compliant study. MRCP was performed at 1.5 T in 53 consecutive patients (25 men and 28 women, aged 23–84 years). A single-breath-hold volume acquisition was performed by using the 3D FRFSE sequence and the conventional 2D SSFSE sequences. Two radiologists graded studies obtained with each sequence in a blinded fashion, and the paired Student t test was used to assess differences in technical quality, visibility of eight individual ductal segments of the biliary tree and panc...

John P. Mugler - One of the best experts on this subject based on the ideXlab platform.

  • Optimized three-dimensional fast-Spin-Echo MRI
    2014
    Co-Authors: John P. Mugler
    Abstract:

    Spin-Echo-based acquisitions are the workhorse of clinical MRI because they provide a variety of useful image contrasts and are resistant to image artifacts from radio-frequency or static field inhomogeneity. Three-dimensional (3D) acquisitions provide datasets that can be retrospectively reformatted for viewing in freely selectable orientations, and are thus advantageous for evaluating the complex anatomy associated with many clinical applications of MRI. Historically, however, 3D Spin-Echo-based acquisitions have not played a significant role in clinical MRI due to unacceptably long acquisition times or image artifacts associated with details of the acquisition method. Recently, optimized forms of 3D fast/turbo Spin-Echo imaging have become available from several MR-equipment manufacturers (for example, CUBE [GE], SPACE [Siemens], and VISTA [Philips]). Through specific design strategies and optimization, including short non-spatially selective radio-frequency pulses to significantly shorten the Echo spacing and variable flip angles for the refocusing radio-frequency pulses to suppress blurring or considerably lengthen the useable duration of the Spin-Echo train, these techniques permit single-slab 3D imaging of sizeable volumes in clinically acceptable acquisition times. These optimized fast/turbo Spin-Echo pulse sequences provide a robust and flexible approach for 3D Spin-Echo-based imaging with a broad range of clinical applications. J. Magn. Reson. Imaging 2014;39:745-767. © 2014 Wiley Periodicals, Inc.

  • optimized single slab three dimensional Spin Echo mr imaging of the brain
    2000
    Co-Authors: John P. Mugler, Robert V Mulkern, Sumi Bao, Charles R G Guttmann, Richard L Robertson, Ferenc A Jolesz, James R Brookeman
    Abstract:

    The development and optimization of Spin-Echo-based, single-slab, three-dimensional techniques for magnetic resonance imaging of the whole brain are described. T1-weighted and T2-weighted image sets with a volume resolution of 1 mm(3) and fluid-attenuated inversion-recovery image sets with a volume resolution of 3 mm(3) were obtained in acquisition times of less than 10 minutes per image set.

Yuji Murata - One of the best experts on this subject based on the ideXlab platform.

  • preoperative staging of endometrial carcinoma diagnostic effect of t2 weighted fast Spin Echo mr imaging
    1998
    Co-Authors: Satoru Takahashi, Takamichi Murakami, Y Narumi, Hirohisa Kurachi, K Tsuda, Tonsok Kim, Takayuki Enomoto, Kaname Tomoda, Akira Miyake, Yuji Murata
    Abstract:

    PURPOSE: To evaluate the usefulness of T2-weighted fast Spin-Echo magnetic resonance (MR) imaging with a 512 x 256 matrix for assessment of the preoperative stage of endometrial carcinoma. MATERIALS AND METHODS: Twenty-eight women with histopathologically proved endometrial carcinoma underwent preoperative T2-weighted fast Spin-Echo, dynamic T1-weighted fast Spin-Echo, and postcontrast T1-weighted Spin-Echo MR imaging with a phased-array surface coil. The uterine long-axis planes in each sequence were reviewed at separate sessions by three radiologists blinded to the histopathologic data. RESULTS: For the diagnosis of myometrial invasion, no statistically significant differences were found among T2-weighted imaging, dynamic imaging, and postcontrast T1-weighted imaging. For the diagnosis of deep myometrial invasion, T2-weighted and dynamic images showed higher specificity than postcontrast T1-weighted images (T2-weighted, 89%; dynamic, 88%; and postcontrast T1-weighted, 80%). For cervical invasion, T2-wei...

Aaron D Sodickson - One of the best experts on this subject based on the ideXlab platform.

  • three dimensional fast recovery fast Spin Echo mrcp comparison with two dimensional single shot fast Spin Echo techniques
    2006
    Co-Authors: Aaron D Sodickson, Koenraad J Mortele, Matthew A Barish, Kelly H Zou, Steven Thibodeau, Clare M Tempany
    Abstract:

    Purpose: To retrospectively evaluate the technical quality of and the visibility of the biliary tree and pancreatic duct on magnetic resonance (MR) cholangiopancreatographic (MRCP) images obtained with a single-breath-hold three-dimensional (3D) fast-recovery fast Spin-Echo (FRFSE) sequence in comparison with conventional two-dimensional (2D) single-shot fast Spin-Echo (SSFSE) thin-section and thick-slab sequences. Materials and Methods: Institutional review board approval was obtained; informed consent was not required for this HIPAA-compliant study. MRCP was performed at 1.5 T in 53 consecutive patients (25 men and 28 women, aged 23–84 years). A single-breath-hold volume acquisition was performed by using the 3D FRFSE sequence and the conventional 2D SSFSE sequences. Two radiologists graded studies obtained with each sequence in a blinded fashion, and the paired Student t test was used to assess differences in technical quality, visibility of eight individual ductal segments of the biliary tree and panc...