山口 弘次郎

Abnormal interventricular septal wall motion has been observed in various heart diseases. To assess the regional contractility of interventricular septum precisely, DANTE tagging cine MRI of septal slices parallel to the vertical long axis of left ventricle were acquired in 6normal volunteers and in 12 patients with a variety of heart diseases. DANTE tags were generated at end diastole with a 8 mm grid with about 60 intersection points on septal slice. Quadrangle area as a basic unit was calculated at end systole (S_ES) and end diastole (S_ES). Percent area contraction (PAC) was derived from the following formula: PAC= [(S_ES-S_ES)/S_ED]×100%. In addition, a quantitative map of the PAC was made to estimate regional contractility easily by visual inspection. The PAC was 29.4±1.3% in normal volunteers and the map of the PAC showed a homogeneous pattern. In patient with anteroseptal myocardial infarction reduced PAC units were localized at anterior site of interventricular septum, and in patients with inferior myocardial infarction, decreased PAC units were observed in inferoposterior site of interventricular septum. In a patient with dilated cardiomyopathy, the map demonstrated a diffused focal distribution of decreased PAC units. In conclusion, the PAC derived from DANTE-tagging cine MRI is a very useful index to evaluate regional contractility of interventricular septum, and the map of PAC can reflect regional abnormal contractility in accordance with clinical settings.

In this study, we investigated quantitative evaluation of aortic calcification employing thoracic images scanned by helical CT.<BR>To measure a volume of aortic calcification in a series of thoracic images, we developed a software on Apple Macintosh personal computer that extract calcification semiautomatically. The measurement process of calcification in this program consists of the following steps: (1)manual designation of an approximate center point in the aorta area on the first image, (2)semiautomatical extraction of aortic ROI by successive radial edge detection, (3) measurement of the sum of calcification pixels in the ROI and of the sum of scored calcification values that was weighted by the factors alloted to the CT numbers of the calcification pixels, and (4)calculation of the total sum of the number of the calcification pixels and the total sum of scored calcification values by applying(1)-(3) repeatedly to whole slice images of a patient.<BR>We proccessed 10 series of thoracic helical CT images containing aortic calcification at an interval of 2 years.<BR>In consequence, our evaluation method could quantitate the temporal change of amounts of aortic calcification.

We set up a server and client system with CTN server (Mallinkrodt Institute of Radiology) and personal computer (PC) client to evaluate medical image database from practical point of view. We prepared 189 CT images of a single study. The images had been stored in ACR-NEMA Ver.2 format. We transformed the image data to DICOM3 format using a batch program. The maximum number of images in a series was limited to a hundred in CTN software. On the PC client, the images were displayed in an unexpected order. The reason of the problem was that the DIC-OM3 has not a query and retrieve service for an acquisition number. It is necessary to set up a supplemental data-base system to retrieve proper images from the image server.

The DICOM standard is about to be in wide use. The authors have completed development of the software, "GAZO NO TATSUJINTTM(expert of Images for DICOM)" set on the DICOM standard, which runs on PC, a universal apparatus. This paper describes the outline of the DICOM standard which is required to develop the software. It also describes the introduction of CTN which is a software kit to grasp the DICOM standard, the concept of the software, some problems and their solutions in using the software, and summary, in this order. The DICOM standard is expected to be further developed to form a core element of PACS. This paper is announced to serve as a foothold toward further development of DICOM.