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Volume 53, Issue 11
Displaying 1-36 of 36 articles from this issue
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Article type: Cover
1997 Volume 53 Issue 11 Pages Cover6-
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
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Article type: Cover
1997 Volume 53 Issue 11 Pages Cover7-
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
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Article type: Index
1997 Volume 53 Issue 11 Pages Toc5-
Published: November 20, 1997
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Article type: Index
1997 Volume 53 Issue 11 Pages Toc6-
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
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[in Japanese]Article type: Article
1997 Volume 53 Issue 11 Pages I-
Published: November 20, 1997
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Article type: Appendix
1997 Volume 53 Issue 11 Pages II-
Published: November 20, 1997
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Article type: Appendix
1997 Volume 53 Issue 11 Pages III-
Published: November 20, 1997
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Article type: Appendix
1997 Volume 53 Issue 11 Pages IV-
Published: November 20, 1997
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Article type: Bibliography
1997 Volume 53 Issue 11 Pages V-
Published: November 20, 1997
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TOSHIO TSUCHIHASHI, TOSHIO MAKI, TAKESHI SUZUKIArticle type: Article
1997 Volume 53 Issue 11 Pages 1647-1656
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
JOURNAL FREE ACCESSThis study involved an evaluation of the increased null point resulting from increases in TE with the fast short inversion time inversion recovery(STIR)and conventional STIR imaging used for fat suppression. The null point for baby oil and subcutaneous fat increased with increases in TE. However, with a nickel chloride solution and Gd-DTPA solution, which have approximately the same T_1, no change in null point was observed as a result of increased TE. ^1H-MR spectroscopy measurements verified two different peak signals(most likely CH_2 and CH_3)for T_1 and T_2 with baby oil and subcutaneous fat. The phenomenon evaluated in this study is thought to be caused by differing components in the relaxation time within the pixel. The reason for this is most likely the creation of the same status as the out-of-phase of gradient echo by the first 180° RF pulse and 90° RF pulse, with the total transverse magnetization being influenced by TE.View full abstractDownload PDF (1033K) -
YOSHIHISA MURAMATSU, KOUZOU HANAI, SYOUICHI KATSUTA, YASUYUKI FUJITAArticle type: Article
1997 Volume 53 Issue 11 Pages 1657-1664
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
JOURNAL FREE ACCESSStandard dose evaluation methods have not yet been developed for helical scanning in x-ray computed tomography. This report describes a new concept in dose evaluation, the hilical computed tomography dose index(HTDI). The center of a cylindrical phantom, separated from the patient couch, is set as the rotational center. A pencil-type ionization chamber is inserted into the phantom, and the integral dose is evaluated for a change in the scanning range. Measurement is performed at the center of the phantom and 1 cm inward from the surface of the phantom. The integral dose is substituted into an arithmetic expression to calculate the HTDI. The obtained HTDI is directly comparable to the computed tomography dose index(CTDI)obtained using conventional dose evaluation system, and can therefore serve as a dose index specific to helical scanning.View full abstractDownload PDF (992K) -
SATORU MATSUO, MITSURU KOMIZU, TETSUO KIDA, KAZUO NOMA, KEIJI HASHIMOT ...Article type: Article
1997 Volume 53 Issue 11 Pages 1665-1672
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
JOURNAL FREE ACCESSWe examined the relation between the frequency components of x-ray images of the chest and phalanges and their read sizes for digitizing. Images of the chest and phalanges were radiographed using three types of screens and films, and the noise images in background density were digitized with a drum scanner, changing the read sizes. The frequency components for these images were evaluated by converting them to the secondary Fourier to obtain the power spectrum and signal to noise ratio(SNR). After changing the cut-off frequency on the power spectrum to process a low pass filter, we also examined the frequency components of the images in relation to the normalized mean square error(NMSE)for the image converted to reverse Fourier and the original image. Results showed that the frequency components were 2.0 cycles/mm for the chest image and 6.0 cycles/mm for the phalanges. Therefore, it is necessary to collect data applying the read sizes of 200μm and 50μm for the chest and phalangeal iamges, respectively, in order to digitize these images without loss of their frequency components.View full abstractDownload PDF (1691K) -
HIROAKI ARAIArticle type: Article
1997 Volume 53 Issue 11 Pages 1673-1682
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
JOURNAL FREE ACCESSX-ray characteristics including subject thickness(copper plate), tube voltage, tube current and irradiation time were measured at stability, with an automatic dose control x-ray generator for cineangiography. Regardless of subject thickness, it is possible that the energy input to the x-ray tube in one frame may be decreased. The automatic control response was measured after rapid fluctuation in subject thickness. Two inverter-type x-ray generators with different automatic control units were studied. The older control unit changes exposure by tube voltage and tube current, while the newer one changes exposure dose by tube voltage, tube current and irradiation time. The maximum rate of change in tube voltage is greater with the newer control unit. In addition, the actual tube current response of the newer control unit in increasing nominal value is faster than the older one. In the new control unit, for each pulse, irradiation is cut off by means of a signal that the exposure has reached the proper value. Thus given the same differential in subject thickness, the newer control unit resumed stability faster than the older one.View full abstractDownload PDF (1141K) -
MASAKATSU HATAGAWA, MAKOTO INOUE, TAKAYOSHI OGAWA, KOMYO KARIYAArticle type: Article
1997 Volume 53 Issue 11 Pages 1683-1690
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
JOURNAL FREE ACCESSThe presampling modulation transfer function(MTF)and the final MTF have been used in evaluating the resolution of digital imaging systems. These MTFs are generally measured by the slit method. On the other hand, in the analog system, the square wave response function(SWRF)method is widely used to measure MTF. In this study, we examined the use of the SWRF method with a digital imaging system. Results showed that output modulations of square waves were varied when data were sampled sparsely. However, the presampling MTF and the final MTF could be measured from the maximum and minimum values of output modulation. The measured final MTFs obtained from the slit method and the SWRF method were in good agreement with one another.View full abstractDownload PDF (1051K) -
JOJI KATO, HARUYOSHI SAITO, KENICHI TOMISATO, TOMOYUKI MARUYAMA, TSUNE ...Article type: Article
1997 Volume 53 Issue 11 Pages 1691-1696
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
JOURNAL FREE ACCESSWe investigated the removal of alimentary tract signal in T_2 echo planar imaging using an oral positive contrast agent for the alimentary tract mainly consisting of ferric ammonium citrate(FerriSeltz:Otsuka Pharmaceutical Co., Ltd.). It has been reported that the FerriSeltz preparation is useful as negative contrast agent because of its enhancing effect of reducing T_2 at high concentrations. However, it was shown to enhance susceptibility artifact in echo planar imaging(EPI). Thus, it is considered difficult to use FerriSeltz at high concentrations in EPI. In contrast, in IR EPI(TI 150 and 200 ms)high concentrations of FerriSeltz are not required, and it is possible to achieve excellent signal suppression at an ordinary concentration of 5.97 mmol/1. This might be due to the fact that the bounce point of FerriSeltz aqueous solution reached about 150 to 200 ms. At present, no effective negative contrast agent for alimentary tract MRI is available. Therefore, it is thought that IR EPI combined with FerriSeltz is a useful technique, since it can eliminate the signal of the alimentary tract at an ordinary concentration.View full abstractDownload PDF (1437K) -
TOSHINORI MARUYAMA, SACHIKO GOTO, YOSHIHARU AZUMA, YOSHITADA NAKAGIRI, ...Article type: Article
1997 Volume 53 Issue 11 Pages 1697-1704
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
JOURNAL FREE ACCESSThe effectiveness of the extended-cycle process, in which processing time is longer than the manugacturer's recommendation, was investigated using four mammographic films, Konica New CM, Fuji UM-MA HC, Kodak Min-R 2000, and Kodak Min-R M, Fuji UR-2, a double-emulsion film, was used as a control. The sensitometric strips exposed by a sensitometer were processed in different combinations of developing temperatures ranging from 28 to 36℃, processing times from 45 to 210 sec chemicals, Konica XD-90C, Fuji RD-5 and Kodak RP X-Omat. Those characteristics(average gradient, relative speed, base plus fog)obtained from characteristic curves were evaluated for the different developing temperatures, times and chemicals. Fuji UR-2 was scarcely affected, while mammographic films were greatly affected in the different combinations without an increase in base plus fog. For New CM, UM-MA HC and Min-R M, the average gradient and relative speed increased as developing temperature increased and developing time was extended, but the increases were limited with the combination of 36℃ and 210 sec for New CM and UM-MA HC. For Min-R 2000, the average gradient was almost constant, and the relative speed increased like the other three mammographic films. Changes in average gradient and relative speed due to chemical variations showed increases or decreases from 6% to 9% compared with Konica chemical. These results suggested that the extended-cycle process for the above mammographic films has the possibility to contribute to dose reduction and advancement of contrast on mammography.View full abstractDownload PDF (909K) -
HIROJI IIDA, TOMOYUKI YAMAMOTO, YASUHIRO SHIMADAArticle type: Article
1997 Volume 53 Issue 11 Pages 1705-1713
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
JOURNAL FREE ACCESSUsing a questionnaire we investigated whether radiation protection is correctly understood by medical doctors(n=140)and nurse(n=496). Although medical exposure is usually understood by medical doctors and dentists, their knowledge was found to be insufficient. Sixty-eight percent of medical doctors and 50% of dentists did not know about the system of radiation protection. Dose monitoring was not correctly carried out by approximately 20% of medical staff members, and medical personnel generally complained of anxiety about occupational exposure rather than medical exposure. They did not receive sufficient education on radiation exposure and protection in school. In conclusion, the results of this questionnaire suggested that they do not have adequate knowledge about radiation exposure and protection. The lack of knowledge about protection results in anxiety about exposure. To protect oneself from occupational exposure, individual radiation doses must be monitored, and medical practice should be reconsidered based on the results of monitoring. To eliminate unnecessary medical and occupational exposure and to justify practices such as radiological examinations, radiation protection should be well understood and appropriately carried out by medical doctors and dentists. Therefore, the education of medical students on the subject of radiation protection is required as is postgraduate education for medical doctors, dentists and nurses.View full abstractDownload PDF (1120K) -
KOUZOU HANAI, [in Japanese], [in Japanese], [in Japanese], [in Japanes ...Article type: Article
1997 Volume 53 Issue 11 Pages 1714-1732
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
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KAZUTAKA MASUDA, [in Japanese], [in Japanese], [in Japanese], [in Japa ...Article type: Article
1997 Volume 53 Issue 11 Pages 1733-1758
Published: November 20, 1997
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[in Japanese]Article type: Article
1997 Volume 53 Issue 11 Pages 1759-1761
Published: November 20, 1997
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[in Japanese], [in Japanese]Article type: Article
1997 Volume 53 Issue 11 Pages 1762-1763
Published: November 20, 1997
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Article type: Appendix
1997 Volume 53 Issue 11 Pages 1764-1765
Published: November 20, 1997
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Article type: Appendix
1997 Volume 53 Issue 11 Pages 1766-1768
Published: November 20, 1997
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Article type: Appendix
1997 Volume 53 Issue 11 Pages 1769-
Published: November 20, 1997
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Article type: Appendix
1997 Volume 53 Issue 11 Pages 1770-1771
Published: November 20, 1997
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Article type: Appendix
1997 Volume 53 Issue 11 Pages 1772-1773
Published: November 20, 1997
Released on J-STAGE: June 29, 2017
JOURNAL RESTRICTED ACCESSTo protect personal information, PDF files cannot be viewed.View full abstractDownload PDF (118K) -
Article type: Appendix
1997 Volume 53 Issue 11 Pages 1774-1777
Published: November 20, 1997
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Article type: Appendix
1997 Volume 53 Issue 11 Pages 1778-
Published: November 20, 1997
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[in Japanese]Article type: Article
1997 Volume 53 Issue 11 Pages 2-
Published: November 20, 1997
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[in Japanese]Article type: Article
1997 Volume 53 Issue 11 Pages 3-5
Published: November 20, 1997
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[in Japanese], [in Japanese]Article type: Article
1997 Volume 53 Issue 11 Pages 6-8
Published: November 20, 1997
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[in Japanese], [in Japanese]Article type: Article
1997 Volume 53 Issue 11 Pages 9-11
Published: November 20, 1997
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]Article type: Article
1997 Volume 53 Issue 11 Pages 12-14
Published: November 20, 1997
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[in Japanese], [in Japanese]Article type: Article
1997 Volume 53 Issue 11 Pages 15-16
Published: November 20, 1997
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[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...Article type: Article
1997 Volume 53 Issue 11 Pages 17-20
Published: November 20, 1997
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Article type: Cover
1997 Volume 53 Issue 11 Pages Cover8-
Published: November 20, 1997
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