Japanese Journal of Radiological Technology
Online ISSN : 1881-4883
Print ISSN : 0369-4305
ISSN-L : 0369-4305
Search
Advanced search
OR
Browse
Search
Volume 69, Issue 10
Displaying 1-12 of 12 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Opening Article
Original
  • Usefulness of Subtraction Computed Tomography Angiography Employing Orbital Synchronized Helical Scanning for Diagnosis of Lower Extremity Arteries with Vessel Wall Calcification
    Satoshi Inada, Takanori Masuda, Naoya Maruyama, Yoriaki Matsumoto, Tak ...
    2013 Volume 69 Issue 10 Pages 1119-1129
    Published: October 20, 2013
    Released on J-STAGE: October 21, 2013
    DOIhttps://doi.org/10.6009/jjrt.2013_JSRT_69.10.1119
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Purpose: Massive calcification complicates the diagnosis of the blood vessel lumen in computed tomography angiography (CTA) of the arteries of the lower extremities. The purpose of this study was to evaluate subtraction CTA with the use of orbital synchronized helical scanning (OS-SCTA). Method: Phantom study: We performed OS-SCTA and non-OSCTA of a calcified vessel phantom (φ2.5 mm), and compared them with a non-calcified vessel phantom as the reference by full width at half maximum (FWHM) and full width at tenth maximum (FWTM) of maximum intensity projection (MIP) images. Clinical study: 58 patients with peripheral artery disease who were referred for angiography also underwent OS-SCTA. OS-SCTA was produced using MIP images. Findings were graded according to three categories: (1) stenosis greater than 50% or occluded; (2) stenosis less than 50%; (3) not detected due to insufficient image quality. OS-SCTA findings were compared with the angiographic findings for each arterial segment. Results: In the phantom study, FWHM showed no significant difference between OS-SCTA and the reference (P=0.135), whereas FWTM showed a significant difference (P<0.001). FWHM and FWTM showed a significant difference between non-OS-SCTA and the reference (P<0.001), due to misregistration with helical artifacts. In a clinical study comparing OS-SCTA with angiography, the sensitivity and specificity were 93.3% and 95.1% in calcified segments, 91.8% and 93.9% in non-calcified segments, and 92.2% and 94.6% in all segments. There was no significant difference between calcified segments and non-calcified segments (sensitivity: P=0.568, specificity: P=0.549). Conclusion: OS-SCTA is beneficial for the diagnosis of lower extremity arteries with vessel wall calcification, since it shows detection accuracy comparable to that of angiography.
    View full abstract
    Download PDF (2798K)
Note
  • Detailed Analysis of Multi-leaf Collimator Movement during Radiation Delivery Using an In-house-developed Program
    Yumiko Adachi, Naoki Hayashi, Hideki Kato, Isao Ehara, Ryuichi Yada, T ...
    2013 Volume 69 Issue 10 Pages 1130-1139
    Published: October 20, 2013
    Released on J-STAGE: October 21, 2013
    DOIhttps://doi.org/10.6009/jjrt.2013_JSRT_69.10.1130
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Multi-leaf collimators (MLCs) are used to modulate intensity during intensity modulated radiation therapy (IMRT). Evaluation of MLC movement in IMRT is important, since the accuracy of MLC movements affects the dose distribution. This evaluation is conventionally performed using an attached Dynalog File Viewer (DFV). However, due to its being an overall evaluation, it is not possible to discover significant errors. In this study, we developed software that permits easy analysis of MLC movements that can be used to retrospectively evaluate MLC movement during irradiation. We also evaluated the usefulness of our in-house program and confirmed its potential for use in clinical scenarios. We created a program that can read MLC logfiles using Visual Basic 6.0 and visualize the temporal changes and movements of the MLC. To evaluate our in-house program’s efficacy in analyzing dynamic MLC-QA (quality assurance), we compared the numerical results yielded by our in-house program and the DFV. The results showed that our in-house program was able to reveal errors below the error root mean square (RMS) values obtained using the DFV. Using irregular surface compensator (ISC) irradiation conditions in a clinical context, we compared our in-house program with the DFV and, using RMS analysis, identified cases that showed excessive error. Our in-house program can also be used to investigate whether unacceptable errors are present, as well as their cause, when using the MLC, as it allows easy real-time observation and evaluation of MLC movements. An additional benefit is that collecting the MLC logfile during actual treatment also allows it to be evaluated retrospectively after continuous MLC operation.
    View full abstract
    Download PDF (2547K)
Clinical Technologies
  • Proposal for an Auxiliary Tool Designed to Reduce Retake Rates for Lateral Radiography of the Knee Joint
    Yu Yasuda, Hisaya Sato, Miwa Ohsawa, Kanji Takahashi, Chikara Noda, Sy ...
    2013 Volume 69 Issue 10 Pages 1140-1145
    Published: October 20, 2013
    Released on J-STAGE: October 21, 2013
    DOIhttps://doi.org/10.6009/jjrt.2013_JSRT_69.10.1140
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The reproducibility of lateral radiography of the knee joint in the lateral position is low because patient positioning can be easily affected by passive rotation of the knee joint. We calculated the correction angle of the femoral external rotation and the lower leg elevation and developed our own auxiliary tool for obtaining a lateral view image. We were able to obtain, in a single attempt, an image with misalignment of the condyle limited to less than 7 mm. Our tool also contributed to the reduction of the re-imaging rate, suggesting its usefulness in contributing to a lower re-imaging rate for lateral radiography of the knee joint.
    View full abstract
    Download PDF (1446K)
  • Can Fruits and Vegetables Be Used as Substitute Phantoms for Normal Human Brain Tissues in Magnetic Resonance Imaging?
    Daisuke Teramoto, Yuichi Ushioda, Ayaka Sasaki, Yuki Sakurai, Hiroshi ...
    2013 Volume 69 Issue 10 Pages 1146-1152
    Published: October 20, 2013
    Released on J-STAGE: October 21, 2013
    DOIhttps://doi.org/10.6009/jjrt.2013_JSRT_69.10.1146
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Various custom-made phantoms designed to optimize magnetic resonance imaging (MRI) sequences have been created and subsequently reported in JSRT. However, custom-made phantoms that correctly match the T1-value and T2-values of human brain tissue (gray matter and white matter) cannot be made easily or quickly. The aim of this project was to search for alternative materials, such as fruits and vegetables, for optimizing MRI sequences. The following eight fruits and vegetables were investigated: apple, tomato, melon, apple mango (Mangifera indica), banana, avocado, peach, and eggplant. Their potential was studied for use in modeling phantoms of normal human brain tissues. MRI (T1- and T2-weighted sequences) was performed on the human brain and the fruits and vegetables using various concentrations of contrast medium (gadolinium) in the same size tubes as the custom-made phantom. The authors compared the signal intensity (SI) in human brain tissue (gray matter and white matter) with that of the fruits and the custom-made phantom. The T1 and T2 values were measured for banana tissue and compared with those for human brain tissue in the literature. Our results indicated that banana tissue is similar to human brain tissue (both gray matter and white matter). Banana tissue can thus be employed as an alternative phantom for the human brain for the purpose of MRI.
    View full abstract
    Download PDF (1011K)
Data
  • Accuracy Estimation of Non-invasive X-ray Output Analyzer
    Yoshiyuki Ioka, Eiji Ariga, Naomi Nishio, Takashi Ooshima
    2013 Volume 69 Issue 10 Pages 1153-1160
    Published: October 20, 2013
    Released on J-STAGE: October 21, 2013
    DOIhttps://doi.org/10.6009/jjrt.2013_JSRT_69.10.1153
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    This study estimated the accuracy of an X-ray analyzer by comparing it with an ionization chamber and a tube voltage current meter, and investigated whether it was usable as a substitute for a reference meter for output measurements for quality control purposes. The X-ray output analyzer used was a Piranha (RTI Electronics), a non-invasive instrument. The two subjects of measurements were as follows: the tube voltage, exposure, and half-value layer used in ordinary X-ray radiographic system equipment, and the exposure and half-value layer in X-ray equipment for mammographic systems. The results for a conventional radiographic system showed the error rates for tube voltage, exposure, and half value layer to be within ±1.0%, ±1.8%, and ±4.3%, respectively. The Piranha is not influenced by the dependence of the beam quality in a range of the tube voltage in clinical use. In X-ray equipment for mammographic system results, error rates for exposure and half value layer were ±2.2% and within ±4.0%, respectively. We conclude that it is possible to use the Piranha as an alternative reference meter for quality control of X-ray equipment for typical radiographic and mammographic systems.
    View full abstract
    Download PDF (792K)
Works in Progress
Basic Lecture—Heart Disease: From Diagnosis to Treatment
Clinical Technology Course
Science Exchanges Committee News
JIRA Topics
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top