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5. A proposal of removal method for T2 decay effects in RARE sequence

Author

Takahashi, H., Ogawa, K., Oshio, K., and Momoshima, H.

Subjects
CT imaging -- Methods, Image processing -- Digital techniques, Business, Electronics, Electronics and electrical industries
Abstract

This paper proposes a new method which removes artifacts due to T2 relaxation in Rapid Acquisition with Relaxation Enhancement (RARE) images. The method removes the artifacts by dividing the average of two Hermitian symmetric data points in k-space by a hyperbolic cosine function prior to inverse Fourier transformation. In order to evaluate the effectiveness of the method, computer simulations were done in which T2 distribution was spatially variant. The results showed that the proposed method worked well for spatially variant T2 decay and was less sensitive to noise than the conventional method using the geometric mean of two symmetric points and that using an exponential filter. In addition, the method yielded good results for a wide range of T2 values.

Published
1995

9. A preliminary comparative study of the guided tissue regeneration and free gingival graft procedures for adjacent facial root coverage.

Author

Ito K, Oshio K, Shiomi N, and Murai S

Abstract

OBJECTIVE: The purpose of this study was to compare the clinical efficacy of guided tissue regeneration with expanded polytetrafluoroethylene membranes to that of free gingival graft for treatment of adjacent facial gingival recession. METHOD AND MATERIALS: Eight adjacent gingival recession sites with Miller class I or II defects containing at least a maxillary or mandibular canine were selected in 6 patients. Four recession sites in 3 patients were treated with guided tissue regeneration, and the other 4 sites in the remaining 3 patients were treated with free gingival graft. Probing depth, gingival recession, attachment level, width of keratinized gingiva, and root coverage were recorded before surgery (baseline) and 6 months and 1 year postoperatively. RESULTS: Statistically significant improvements were found for gingival recession, attachment level, and root coverage from baseline to 6 months and 1 year postoperatively in both groups. Both procedures produced the same average reduction in gingival recession, gain in attachment level, and amount of root coverage after 1 year. Probing depths did not differ between groups throughout the study. The width of keratinized gingiva was significantly greater in the grafted group than in the guided tissue regeneration group. CONCLUSION: Both procedures produced the same average amount of root coverage, reduction in gingival recession, and gain in clinical attachment. The guided tissue regeneration procedure provided a better esthetic appearance without any difference in gingival color or architecture in cases of adjacent facial gingival recession. [ABSTRACT FROM AUTHOR]

Published
2000

11. Fast spin-echo imaging in the evaluation of intradural disease of the spine

Author

Sze, G, Merriam, M, Oshio, K, and Jolesz, F A

Subjects
Adult, Male, Evaluation Studies as Topic, Humans, Comparative Study, Female, Dura Mater, Middle Aged, Magnetic Resonance Imaging, Spinal Cord Diseases, Aged
Abstract

PURPOSE: Fast spin echo (FSE) images were compared with conventional images in 46 patients with intradural spinal disease to determine their accuracy in the detection and delineation of lesions. MATERIALS AND METHODS: The images were interpreted by two neuroradiologists, who read individually. A total of 720 blinded readings formed the basis for this evaluation. A gold standard for each patient was selected, based on the blinded readings of the conventional studies. RESULTS: In the sagittal plane, the FSE sequences were found to have an accuracy of 93% and 93% for the first reader and 93% and 85% for the second reader. For the axial plane, the corresponding figures were 86% and 82% for the first reader and 64% and 77% for the second reader. These figures compared favorably with conventional sequences. Similar delineation of lesions was noted in 78% of cases. In the remaining cases, there were no significant trends. CONCLUSION: Because of these findings, FSE sequences appear as accurate as conventional sequences. In this study, they were capable of supplanting conventional sequences in the evaluation of intradural pathology of the spine in the sagittal plane, although conventional sequences were still preferred in the axial plane.

Published
1992

45. Human brain glucose metabolism mapping using multislice 2D <SUP>1</SUP>H-<SUP>13</SUP>C correlation HSQC spectroscopy<FNR HREF="fn1"></FNR><FN ID="fn1">Presented in part at the 5th and 6th Annual Meetings of the International Society for Magnetic Resonance, Vancouver, April 1997 and Sydney, April 1998.</FN>

Author

Watanabe, H., Umeda, M., Ishihara, Y., Okamoto, K., Oshio, K., Kanamatsu, T., and Tsukada, Y.

Abstract

A method for multivolume 2D 1H-13C correlation spectroscopy, multislice heteronuclear single quantum coherence (HSQC), is proposed. This permits human brain metabolism from glucose to amino acids to be followed using a 2-T whole-body scanner. The modifications from the conventional HSQC are that the 180°(13C) and 180°(1H) pulses are separated in time in the preparation period and that the 180°(13C) pulse is applied at 1/(4JCH) before the 90°(1H) polarization transfer (PT) pulse. The preparation (echo) time can be set longer than 1/(2JCH) so that, even in a whole-body system, slice-selective pulses and gradients can be applied. Another modification is that the 90°(1H) reverse PT pulses after the creation of 2IzSz are used as multislice pulses. The time-course of glutamate C4 could be followed with 15-min temporal resolution from the HSQC spectra obtained from the brains of volunteers after the oral administration of glucose C1, and the maximum S/N was 3. Magn Reson Med 43:525–533, 2000. © 2000 Wiley-Liss, Inc.

Published
2000
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46. Human brain glucose metabolism mapping using multislice 2D 1H‐13C correlation HSQC spectroscopy

Author

Watanabe, H., Umeda, M., Ishihara, Y., Okamoto, K., Oshio, K., Kanamatsu, T., and Tsukada, Y.

Abstract

A method for multivolume 2D 1H‐13C correlation spectroscopy, multislice heteronuclear single quantum coherence (HSQC), is proposed. This permits human brain metabolism from glucose to amino acids to be followed using a 2‐T whole‐body scanner. The modifications from the conventional HSQC are that the 180°(13C) and 180°(1H) pulses are separated in time in the preparation period and that the 180°(13C) pulse is applied at 1/(4JCH) before the 90°(1H) polarization transfer (PT) pulse. The preparation (echo) time can be set longer than 1/(2JCH) so that, even in a whole‐body system, slice‐selective pulses and gradients can be applied. Another modification is that the 90°(1H) reverse PT pulses after the creation of 2IzSzare used as multislice pulses. The time‐course of glutamate C4 could be followed with 15‐min temporal resolution from the HSQC spectra obtained from the brains of volunteers after the oral administration of glucose C1, and the maximum S/N was 3. Magn Reson Med 43:525–533, 2000. © 2000 Wiley‐Liss, Inc.

Published
2000
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47. 3D localized <SUP>1</SUP>H-<SUP>13</SUP>C heteronuclear single-quantum coherence correlation spectroscopy in vivo<FNR HREF="fn1"></FNR><FN ID="fn1">This work was presented in part at the 4th Annual Meeting of the International Society for Magnetic Resonance, New York, May, 1996 </FN>

Author

Watanabe, H., Ishihara, Y., Okamoto, K., Oshio, K., Kanamatsu, T., and Tsukada, Y.

Abstract

A method for spatially three-dimensional (3D) localized two-dimensional (2D) 1H-13C correlation spectroscopy, localized HSQC, is proposed. This method has the following special feature in the preparation period. The 180°(13C) and 180°(1H) pulses are separated in time, and the 180°(13C) pulse is applied at 1/(4 1JCH) before the 90°(1H) polarization transfer pulse. The preparation (echo) period 2τ can then be set substantially longer than 1/(2 1JCH), so that even in a whole-body system, slice-selective 90°(1H) pulses and gradient pulses can be applied in that period. The localization capabilities of this method were confirmed in a phantom experiment. The 3D localized 2D 1H-13C correlation spectra from a monkey brain in vivo were obtained after [1-13C]glucose injection, and amino acid metabolism was detected; that is, [4-13C]glutamate appeared immediately after the injection, followed by the appearance of [2-13C]glutamate, [3-13C]glutamate, and [4-13C]glutamine. Magn Reson Med 43:200–210, 2000. © 2000 Wiley-Liss, Inc.

Published
2000
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48. 3D localized 1H‐13C heteronuclear single‐quantum coherence correlation spectroscopy in vivo

Author

Watanabe, H., Ishihara, Y., Okamoto, K., Oshio, K., Kanamatsu, T., and Tsukada, Y.

Abstract

A method for spatially three‐dimensional (3D) localized two‐dimensional (2D) 1H‐13C correlation spectroscopy, localized HSQC, is proposed. This method has the following special feature in the preparation period. The 180°(13C) and 180°(1H) pulses are separated in time, and the 180°(13C) pulse is applied at 1/(4 1JCH) before the 90°(1H) polarization transfer pulse. The preparation (echo) period 2τ can then be set substantially longer than 1/(2 1JCH), so that even in a whole‐body system, slice‐selective 90°(1H) pulses and gradient pulses can be applied in that period. The localization capabilities of this method were confirmed in a phantom experiment. The 3D localized 2D 1H‐13C correlation spectra from a monkey brain in vivo were obtained after [1‐13C]glucose injection, and amino acid metabolism was detected; that is, [4‐13C]glutamate appeared immediately after the injection, followed by the appearance of [2‐13C]glutamate, [3‐13C]glutamate, and [4‐13C]glutamine. Magn Reson Med 43:200–210, 2000. © 2000 Wiley‐Liss, Inc.

Published
2000
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49. Common clonal origin of lymphocytes and plasma cells in splenic lymphoma with villous lymphocytes

Author

ATAYAMA, Y OSHIO K, OJIMA, K ENSUKE K, OSHINO, T ADASHI Y, ATSUO, Y OSHINOBU M, SOKAWA, M ASAFUMI I, ANO, T OMOFUMI Y, KA, H IDEYUKI O, AMAGUCHI, M IKA Y, EGUCHI, S EIGO D, SUCHIYAMA, J UNJIRO T, AYASHI, K YOICHI H, ESHIMA, T AKANORI T, HINAGAWA, K ATSUJI S, SHIMARU, F UMIHIKO I, MOTO, E IJIRO O, and ARADA, M INE H

Abstract

In two-thirds of patients with splenic lymphoma with villous lymphocytes (SLVL) a small amount of M-protein can be detected in association with the presence of plasma cells in the peripheral blood (PB) and/or bone marrow (BM). However, it is not known whether lymphoma cells and plasma cells originate from the same clone. In this report we describe a case of SLVL which was characterized by the presence of marked monoclonal gammopathy (IgG-κ 90 g/l) and increased plasma cells in the BM. In an attempt to elucidate the origin of lymphoma cells and plasma cells, we performed morphological, cytogenetic and molecular studies on PB mononuclear cells (PBMNC) without plasma cells and BMMNC containing 10% plasma cells from this patient.

Published
1997

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