[Clinical study with angiography system using a flat panel detecter]

[Angiography: clinical evaluation and physical characteristics of FPD - the clinical impact caused by detector characteristics]

We have been engaged in clinical work using DSA, the first in the world, under a joint study agreement with Hitachi Medical Corporation on the use of the Flat Panel Detector (FPD) since 2001. We are now in the stage where a certain evaluation process has been finished, but the FPD performance study in angiography has just begun, and, therefore, its clinical evaluation results are very few. Therefore, we studied the relativity between clinical images and physical characteristics in order to examine the characteristics of FPD by referencing them to clinical images. We did an evaluation of the clinical images to which their physical characteristics such as granularity, resolution, contrast, etc., are reflected by comparing FPD and I.I. images.

[Evaluation of FOV size on cerebral three-dimensional rotational digital subtraction angiography with flat panel detector system]

In interventional neuroradiology, three-dimensional rotational digital subtraction angiography (3D-DSA) is very useful for the spatial grasp of the location and size of an intracranial cerebral aneurysm. The purposes of this study were to evaluate the property of three-dimensional image dependence on the respective field of view (FOV) size in a flat-panel detector (FPD) using vessel phantoms, and to optimize clinically. The indices of three-dimensional image properties such as profile curve (FWHM, FWTM), digital value, and image noise were evaluated using a vessel phantom with a different diameter. As a result, in the case of a 6-inch FOV size of the FPD, the relative diametral rate of change from the actual value of the vessel phantom was least for all FOV sizes. This study demonstrated that the difference in FOV size in 3D-DSA affects the three-dimensional object's reproducibility. Furthermore, as for this 3D-DAS system, three-dimension images such as a VR image might be processed more faithfully, since an FOV size of 6 inches has the highest reproducibility of objects.