Recently, electronic storage of clinical data, such as images, charts, and various data of clinical tests, has been developed and used in hospitals. These systems are, however, apt to ignore specificity inherent to facilities and to force burdens upon operating persons more than before. Therefore, systems have been desired in which hand writing environment is replaced with computer based one, keeping the fundamental structure as much as possible. We have developed computerized reporting system and applied it to daily clinical use in the division of nuclear medicine of Saitama Medical School. The system has been constructed in accordance with practical clinical study and film reading using general purpose database software which are commercially available. Patient information necessary for reporting, such as patient name, patient ID, birth date and etc, is transferred from the database for study administration to the database for reporting through local area network(LAN). So, procedure of inputting patient information is not needed when doctors are making report. Most of the keying manipulation for input is omitted and menu input system is adopted. Reports written by hand was replaced by the computerized one. The computerized system was taken over the conventional one smoothly by inheriting structure and forms of conventional one as long as possible. This computerization leads to the simplification of reception jobs and to more efficient reporting system.
A histogram transformation method was applied to enhance the blood vessels in abdominal digital angiography (DA). These angiography images contain shadows of blood bessel in addition to bones and soft tissues. The gray level transformation tables were obtained from linear transformation in lower gray level region and from histogram formalization in higher gray level region (HHF). These transformations were found to improve the image contrast. The image quality depends on the fraction of processed image area by HHF. The optimal fraction was obtained by evaluating the processed images with various values of fractions. The exponential function fitting was used to connect smoothly the two types of transformation curves in different gray level areas. These methods were shown to be usefull for enhancing the image contrast of blood bessels and for reducing unnecessary shadows at high gray level area in abdominal angiography.
We developed diagnosis support system and examined its utility. Numata Neurosurgery &Heart Disease Hospital and Josai Clinic has introduced PACS (Picture Archiving and Communication System), that uses HOPE/Dr ABLE from Fujitsu Ltd. The PACS of Numata Neurosurgery & Heart Disease Hospital connects a film digitizer to a workstation. The PACS of Josai Clinic connects two digital imaging modalities (MRI, X ray CT) with a workstation by using an ethernet. The PACS of these hospitals is interconnected by ISDN (INS64). Our system was able to transmit images from a hospital withou t a medical specialist to another hospital where the medical specialist is available to diagnose the images at a reasonable speed. The system can create a date base which will be useful for educating medical do ctors, radiological technologists and so on. Our Diagnosis Support System has been evaluated to be an effective system.
Several methods have been proposed by different authors and recommended with the associations to specify the beam quality. We have repeated measurements on some combinations of ionization chambers and phantom materials including to get the measurements. To calculate using a ±2% variation of TPR value, the variation of MV number are 18.5 % (6MV) and 40.2 %(18MV). The variation of dose in that situation was a spread of 0.5∼1.08 % in a mean coefficient of variance. We have to use a “MV number” for a proper choice of mass collision stopping power ratios and perturbation factors used in the conversion of ionization measurements into absorbed dose, and have to choose the “quality index” like the ratio of ionizations for quality assurance of the beam quality.
Spatial coordinates of interest points for intracavitary radiotherapy is usually decided on the basis of radiographic projections obtained in two different directions. Errors or inconsistencies in the image coordinates read from the radiographs happen for such reasons as patient's movement between the two images, uncertainties in magnification and the mutual angle between the two radiographic projections. A position calculated by a theoretically correct geometrical formula sometimes has a greater error than one obtained by the approximation method with constant magnification because of a large propagation of the errors. This report indicates useful geometrical solutions and least squares methods for an optimun determination of spatial coordinates.
The items of physical and technical quality assurance (QA) for radiation treatment planning are 1) calibration of monitor unit and/or timer,2) radiation treatment equipment,3) simulators and other devices and systems providing patient anatomical data,4) dosimetric systems for dose and dose distributions,5) radiation treatment planning system, and 6) documentation and records. The items of 1)-4) are discribed in other chapter of this special number. In this paper mainly discuss the items of 5) and 6). QA for the treatmen planni ng system depends on the computational algorithms being used: the aquisition of basic beam data, the patient's anatomical information, spacing of the points in the matrices, the interpolation routine, inhomogeneity corrections, etc. This paper describes QA program and points to be noted in using 'treatment planning system. Survey results of one JASRO task groups showed that about 50% of the institutions used measured data obtained by themselves. Basic beam data aquisition should be self-contained.
The quality assurance (QA) is important and necessary in brachytherapy as well in external beam therapy. However, comprehensive brachytherapy QA has not been established because it contains not only source strength calibration but integrity of sources and applicators, localization of source position, treatment planning, delivery process, and radiation protection. Brachytherapy differs from external beam therapy in that the treatment planning is more difficult and the dose specification is less precise due to the high dose gradients within a target volume. Moreover, advanced remote controlled afterloading system (RALS) developed recently has been increasingly used in Japan and consists of the equipments with new technology. Therefore, it requires practical and effective QA for maintaining the integrity and accuracy to execute the treatment. The QA procedures depend on the equipments and personel which can be dedicated to brachytherapy. To develop an adequate brachytherapy treatment delivery system, the procedures and endpoints of each treatment step must be clearly identified and QA process should be established in each step having its own checklists, instructions and documentation.
The textbook titled Maintenance and management program for external irradiation equipment was published in 1992. Radiological technologists and persons perform quality control (QC) depending on the textbook as a standard. It is difficult to perform the QC executes completely. It is caused by insufficient human power, lack of understanding about the QC and unemployed qualitative analysis for radiotherapy. The first step of the QA of users is pre working check. The attitude towered pre working check is important. Obligated recording could not find out early changes or little disorder. The most important thing is to recognize the meaning of Why we perform the QC. If the pre working check were filled up, sufficient daily check would be possible in the items for radiation therapy within practical use. Other check ite ms except pre w orking check are dose monitoring system, rotation center of a gantry, irradiation field limited system and treatment couch. Especially, check of the dose monitoring system and the irradiation field limited system are need to frequent. Methods of the QC are developed from discussion of entire radiation treatment staffs. Suitable QC methods to their institution and their time distribution are performed, as not being Top Down system. The most important thing to continue performing the QC.