Japanese Journal of Radiological Technology
Online ISSN : 1881-4883
Print ISSN : 0369-4305
ISSN-L : 0369-4305
Search
Advanced search
OR
Browse
Search
Volume 63, Issue 10
Displaying 1-15 of 15 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Opening Article
Original
  • Evaluation of Imaging Parameters for T1 Dynamic Contrast Enhanced MRI with Fast Spin-echo
    Yuuki Kanazawa, Tosiaki Miyati, Yusuke Inoue, Osamu Sato
    2007 Volume 63 Issue 10 Pages 1127-1132
    Published: October 20, 2007
    Released on J-STAGE: January 10, 2008
    DOIhttps://doi.org/10.6009/jjrt.63.1127
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    For the purpose of continual measurement of the T1 value using the FSE (fast spin-echo) sequence and evaluation of the hemodynamics, we assessed T1 values when the imaging parameters were changed. Moreover, with the imaging parameters derived from this study, dynamic contrast-enhanced MR imaging (MRI) was examined in prostatic disease. First, the T1 value before contrast agent injection was measured with imaging parameters that had different TR and fixed TE. Next, dynamic contrast-enhanced imaging data were acquired for the imaging parameters using TE and TR in the same way as before contrast agent injection, and the T1 value of the tissue at contrast enhancement was measured. In the phantom studies, the TSE imaging parameters with short TE, long TR, and few ETL were connected with the mixed sequence. In dynamic study of the prostate, the difference between normal prostate and prostate cancer became clearer with the time-relaxation rate curve than the time-signal curve. This method using TSE is able to evaluate in greater detail information on hemodynamics and to perform dynamic study with the spin-echo sequence in extensive tissues. [Article in Japanese]
    View full abstract
    Download PDF (139K)
Notes
  • Evaluation of Cardiac Function with 32DAS MDCT—Fundamental Examination
    Sumito Maruyama, Toshiyuki Takahashi, Yoshimasa Takahashi, Naoyuki Aji ...
    2007 Volume 63 Issue 10 Pages 1133-1137
    Published: October 20, 2007
    Released on J-STAGE: January 10, 2008
    DOIhttps://doi.org/10.6009/jjrt.63.1133
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Cardiac images were taken in altered pulse counts on a pulsating cardiac phantom, revolving speed of X-ray tube, image reconstructing mode, and beam pitch with 32 DAS MDCT. The objective of this study was to determine whether conditions of image taking affect calculated values of ejection fraction (EF). Moreover, the EF values measured by left ventriculography (LVG) and by coronary computed tomography (CT) were compared using clinical data of 4 patients who underwent both coronary CT and LVG. On evaluating the pulsating cardiac phantom images, the EF values measured by coronary CT were generally smaller than those measured by LVG. On evaluation of the pulsating cardiac phantom images, the values of end-diastolic volume (EDV) and end-systolic volume (ESV) measured by coronary CT were smaller than those measured by LVG. On the contrary, the EF values measured by coronary CT were bigger than those measured by LVG. The maximal difference between the EF values measured by LVG and those measured by coronary CT was approximately 10% based upon the values measured by LVG. [Article in Japanese]
    View full abstract
    Download PDF (92K)
  • Quantitative Evaluation of Block-iterative Reconstruction Image in PET: Comparison of the Dynamic RAMLA Algorithm and OSEM Algorithm
    Keiichi Matsumoto, Keishi Kitamura, Keiji Shimizu, Kenya Murase
    2007 Volume 63 Issue 10 Pages 1138-1144
    Published: October 20, 2007
    Released on J-STAGE: January 10, 2008
    DOIhttps://doi.org/10.6009/jjrt.63.1138
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Purpose: Iterative reconstruction has been successfully used in whole-body PET imaging because of reductions in noise and scanning time. However, there are plural algorithms for image reconstruction such as OSEM, RAMLA and Dynamic RAMLA. Dynamic RAMLA (DRAMA) is an iterative algorithm similar to RAMLA, but the relaxation parameter is controlled in such a way that the propagation of noise from projection data to the reconstructed image. The purpose of this study was to investigate differences in the DRAMA and OSEM algorithms, in terms of real space and frequency space. Method: A whole-body torso phantom (NEMA image-quality phantom) filled with F-18 was scanned with a dedicated PET scanner. The smallest four spheres, with internal diameters of 10, 13, 17, and 22 mm, were filled with F-18 at an 8:1 concentration with respect to the background. The two largest spheres, with diameters of 28 and 37 mm, were not filled with water (empty). The emission scan for a 50 cm axial range varied from 5-20 minutes, to examine the effect of the count statistics on the quality of the reconstructed images. The images were reconstructed with OSEM by changing the number of subsets from 1 to 128 in each study. As to the number of iterations, both iterative reconstruction algorithms were one. As a reference standard, images with maximum counts (60 minutes) were reconstructed with a filtered-back projection method. The quality of the reconstructed images was evaluated in terms of contrast, background variability, and two-dimensional power spectrum analysis. Results: As for the real space results, OSEM with more than 32 subsets decreased contrast because of images with checkerboard noise. The DRAMA algorithm provided stable contrast even when count statistics were poor. A two-dimensional power spectrum analysis also revealed that the OSEM algorithm enhanced noise components in reconstruction with more than 32 subsets. Conclusion: Our preliminary data suggested that the OSEM algorithm requires few iterations with a small number of subsets for whole-body imaging. However, the DRAMA algorithm provides a reasonable signal-to-noise ratio with satisfactory spatial resolution even with one iteration. Especially in clinical whole-body PET, DRAMA was most useful because of its fast convergence and small computer burden. [Article in Japanese]
    View full abstract
    Download PDF (120K)
  • Radiologic-anatomic Correlation of Thoracic Vertebrae and Rib Shadows in Chest Digital Radiograph
    Isao Yamaguchi, Harumi Itoh
    2007 Volume 63 Issue 10 Pages 1145-1151
    Published: October 20, 2007
    Released on J-STAGE: January 10, 2008
    DOIhttps://doi.org/10.6009/jjrt.63.1145
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The purpose of this study was to provide an introduction to parsing the radiologic appearance of thoracic vertebrae and ribs. In the study, the radiologic-anatomic correlation technique was applied to promote further understanding of normal chest radiographs. The thoracic vertebrae and ribs of chest radiographs were compared with each macroscopic radiologic and computed tomography (CT) image. The rib parsed the linear shadow of the body of the rib. The macroscopic and radiologic images of thoracic vertebrae and ribs were evaluated to explain their normal radiologic findings. The results of such correlation were summarized as follows: 1) The lamina of the vertebral arch was visualized due to anterior rotation of the upper thoracic vertebrae. 2) The density ratio of the thoracic-vertebrae shadow was almost the same in the vertebral body and vertebral arch. 3) The linear shadow superimposed on the rib corresponded to the inferior margin of the rib. The radiologic-anatomic correlation technique was useful to evaluate normal radiologic findings, and the study was useful to radiological technologists. [Article in Japanese]
    View full abstract
    Download PDF (119K)
Clinical Technology
  • Basic and Clinical Studies of Visualizing Right Inferior Phrenic Artery by Multi Detector Row-CT
    Yusuke Okumura, Masayuki Suzuki, Akihiro Takemura, Tadanori Takada, Ka ...
    2007 Volume 63 Issue 10 Pages 1152-1161
    Published: October 20, 2007
    Released on J-STAGE: January 10, 2008
    DOIhttps://doi.org/10.6009/jjrt.63.1152
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    To perform transcatheter arterial embolization (TAE) successfully, it is important to obtain information about parasitic arterial supply to the hepatocellular carcinoma (HCC). Among these extrahepatic collateral vessels, the right inferior phrenic artery (RIPA) is the most frequent and important extrahepatic collateral artery supplying the HCC. In the present study, we obtained multi-planar reformation (MPR) images of RIPA using multi detector row computed tomography (MDCT), assessed the ability of MDCT to demonstrate the origin of RIPA, and then analyzed the morphology of the origin. In a basic study using an original phantom simulating vessel origin, the origin was poorly visualized depending on the phantom diameter and angle of the origin to the scanned section. A clinical study was performed in 28 patients with HCC who underwent both MDCT and angiography within a short period. In 19 of 28 patients, RIPA originated at the celiac artery. In 3 patients, RIPA originated at the right renal artery, and in 6, directly at the abdominal aorta. The origin of RIPA was categorized into four patterns according to the inclination of the origin on transverse sections of MDCT. RIPA that originated at the right renal artery and showed an upward course perpendicular to the scan section of MDCT were most clearly visualized at the origin. In addition, RIPA could be observed in an optional direction on the workstation. Pre-angiographic visualization of the origin of RIPA may save angiographic time, curtail contrast medium, and reduce radiation exposure. [Article in Japanese]
    View full abstract
    Download PDF (214K)
The 34th Autumn Scientific Congress
Educational Lecture—Interpreting Medical Images for Radiological Technologists
Basic Lectures—The Image Processing Technology that You Should Learn on Examination
Clinical Technology Course
Series—Law and Medicine (5)
Science Exchanges Committee Report
Report of Research Group
JIRA Topics
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top