Japanese Journal of Radiological Technology
Online ISSN : 1881-4883
Print ISSN : 0369-4305
ISSN-L : 0369-4305
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Volume 71, Issue 7
Displaying 1-9 of 9 articles from this issue
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Opening Article
Original
  • Development of a Knowledge-based Application Utilizing Ontologies for the Continuing Site-specific JJ1017 Master Maintenance
    Tatsuaki Kobayashi, Shintaro Tsuji, Ayako Yagahara, Takumi Tanikawa, T ...
    2015 Volume 71 Issue 7 Pages 585-594
    Published: 2015
    Released on J-STAGE: July 20, 2015
    DOIhttps://doi.org/10.6009/jjrt.2015_JSRT_71.7.585
    JOURNAL FREE ACCESS
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    The purpose of this study was to develop the JJ1017 Knowledge-based Application (JKA) to support the continuing maintenance of a site-specific JJ1017 master defined by the JJ1017 guideline as a standard radiologic procedure master for medical information systems that are beingadopted by some medical facilities in Japan. The method consisted of the following three steps: (1) construction of the JJ1017 Ontology (JJOnt) as a knowledge base using the Hozo (an environment for building/using ontologies); (2) development of modules (operation, I/O, graph modules) that are required to continue the maintenance of a site-specific JJ1017 master; and (3) unit testingof the JKA that consists of the JJOnt and the modules. As a result, the number of classes included in the JJOnt was 21,697. Within the radiologic procedure classes included in the above, the ratio of a JJ1017 master code for an external beam radiotherapy was the highest (51%). In unit testingof the JKA, we checked the main operations (e.g., keyword search of a JJ1017 master code/code meaning, editing the description of classes, etc.). The JJOnt is a knowledge base for implementingfeatures that medical technologists find necessary in medical information systems. To enable medical technologists to exchange/retrieve semantically accurate information while using medical information systems in the future, we expect the JKA to support the maintenance and improvement of the site-specific JJ1017 master.
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Note
  • Evaluation of Imaging Quality and ADC for the Tetrahedral Gradients of Diffusion Weighted Imaging
    Natsumi Yamaguchi, Akio Ogura, Norio Hayashi, Daisuke Koyama, Osakabe ...
    2015 Volume 71 Issue 7 Pages 595-604
    Published: 2015
    Released on J-STAGE: July 20, 2015
    DOIhttps://doi.org/10.6009/jjrt.2015_JSRT_71.7.595
    JOURNAL FREE ACCESS
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    The diffusion weighted images (DWIs) are used widely in clinical practice. Recently, the gradient overplus imaging was developed in addition to orthogonal technique for the duration method of motion-probing gradient pulses. The gradient overplus technique can reduce the load of a gradient strength, and enables setting of the shortest TE compared with the orthogonal gradients, and moreover it has the information on diffusion tensor. The apparent diffusion coefficient (ADC) values, signal-to-noise ratio (SNR), and geometric distortion were compared for the two duration methods of DWI using four different phantoms of coefficient of viscosity. In the gradient overplus, the time of smallest TE becamesmalle r than theorthogonal gradients according to theincre aseof theb value. As a result, SNR increased by shortening of TE, and thus the geometric distortion was improved. Moreover, the ADC value did not show any difference in the two duration methods of DWI. The gradient overplus technique is a more useful techniquein a clinical study than theorthogonal gradients becausethequality of imageis improved, and theADC valueis thesameas theorthogonal gradients.
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Clinical Technologies
  • Effects of Non-radioactive Material around Radioactive Material on PET Image Quality
    Shinya Toshimitsu, Yoshiharu Kangai, Azusa Yamane, Yutaka Hirokawa
    2015 Volume 71 Issue 7 Pages 605-611
    Published: 2015
    Released on J-STAGE: July 20, 2015
    DOIhttps://doi.org/10.6009/jjrt.2015_JSRT_71.7.605
    JOURNAL FREE ACCESS
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    Purpose: Subcutaneous fat is a non-radioactive material surrounding the radioactive material. We developed a phantom, and examined the effect of subcutaneous fat on PET image quality. Methods: We created a cylindrical nonradioactive mimic of subcutaneous fat, placed it around a cylindrical phantom in up to three layers with each layer having a thickness of 20 mm to reproduce the obesity caused by subcutaneous fat. In the cylindrical phantom, hot spheres and cold spheres were arranged. The radioactivity concentration ratio between the hot spheres and B.G. was 4:1. The radioactivity concentration of B.G. was changed as follows: 1.33, 2.65, 4.00, and 5.30 kBq/mL. 3D-PET images were collected during 10 minutes. Results: When the thickness of the mimicked subcutaneous fat increased from 0 mm to 60 mm, noise equivalent count decreased by 58.9‒60.9% at each radioactivity concentration. On the other hand, the percentage of background variability increased 2.2‒5.2 times. Mimic subcutaneous fat did not decrease the percentage contrast of the hot spheres, and did not affect the cold spheres. Conclusion: Subcutaneous fat decreases the noise equivalent count and increases the percentage of background variability, which degrades PET image quality.
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  • A New Regression Equation for 123I-IMP Non-invasive Cerebral Blood Flow Measurement Using the Graph Plot Method
    Taeko Tomimatsu, Kosuke Yamashita, Asato Ofuji, Rieko Nagaoka, Ryuichi ...
    2015 Volume 71 Issue 7 Pages 612-620
    Published: 2015
    Released on J-STAGE: July 20, 2015
    DOIhttps://doi.org/10.6009/jjrt.2015_JSRT_71.7.612
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    Purpose: A graph plot (GP) methodusing 123I-N-isopropyl-p-iodoamphetamine (123I-IMP) has been proposed as a simple andnon-invasive estimation of quantitative cerebral bloodflow (CBF). A regression equation for the GP methodwas estimatedby the data of resting state. Therefore, the accuracy of CBF values in high flow range may be an underestimated possibility in this method.The aim of this study was to formulate a new regression equation for the GP methodby the data of resting state andacetazolamide (ACZ) challenge, andto clarify the accuracy of it. Methods: The images of 26 consecutive patients who underwent both 123I-IMP chest radioisotope-angiography (RIA) andsingle photon emission computedtomography (SPECT) examinations were usedto construct the new regression equation. Examinations of the resting state andACZ challenge were performedin different days. All patients were analyzedby both the GP methodandautoradiography (ARG) methodwhich is the conventional examination with the one-point arterial bloodsampling. A linear regression equation between the index of the input function was obtainedby the GP methodandCBF value of ARG. The linear regression equation basedon the resting data was comparedwith the equation basedon the resting andACZ challenge (rest+stress) data. Results: Goodliner correlation was obtainedbetween the index of the input function obtainedby the GP methodandCBF value of the ARG methodin the rest+stress state (y=2.75x+15.1, r=0.78). In contrast, correlation results between the index of the input function obtainedby the GP methodandCBF value of the ARG methodin the resting state was expressed as y=2.28x+18.4, r=0.54 rCBF values basedon the resting data was 20% underestimated in the high flow range comparedwith values basedon the rest+stress data. Conclusion: The new linear regression equation for the GP methodis useful for clinical study. Key words: non-invasive cerebral blood flow measurement method, graph plot (GP), autoradiography (ARG), 123I-N-isopropyl-p-iodoamphetamine (123I-IMP)
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Educational Lecture-Monte Carlo Simulation for Radiological Technology
Basic Lecture-Disease of the Brain: From Diagnosis to Treatment
Report from JSRT Members
JIRA Topics
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