Publications by authors named "Katsuhiko Maeda"

Objective: We devised a split-bolus injection and imaging protocol for pulmonary artery and vein separation computed tomography (CT) angiography based on time enhancement curve characterization. Furthermore, we aimed to evaluate the contrast enhancement effect and success rate of blood vessel separation between the pulmonary artery and vein of this proposed protocol.

Methods: In this study, 102 patients (45 patients with the standard protocol and 57 patients with the proposed protocol) who underwent pulmonary arteriovenous computed tomography angiography were included.

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This study evaluated the effects of three types of hybrid iterative reconstruction (IR) on image quality of pediatric body computed tomography images. The image quality components evaluated were noise power spectrum (NPS), task-based modulation transfer function (TTF), and system performance function (SPF). As the IR strength was increased while reducing the radiation dose, the NPS increased in a low-frequency range and the TTF decreased in low-contrast regions.

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The role of the X-ray fluoroscopic image during interventional radiology (IVR) is not only the real-time dynamic image for the catheter operation but also to confirm the vascular anatomy using stored image, so that the importance increases more. For the purpose of measuring the time sequence characteristics of X-ray fluoroscopic image, we sampled the digital value of the same coordinate from each X-ray fluoroscopic image and calculated the frequency properties of the noise for the time sequence order as NPStime by performing Fourier transform on the digital value. The parameters, except k-factor which is the time sequence filter, did not influence NPStime.

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Purpose: When brain angiography was performed, we devised the calculation theory for rectifying magnifying power, and produced the auxiliary tool.

Method: We produced the frame with a size of 300 x 300 x 15 mm from the thin board made from carbon. The frame is around arranged for every 1 cm in Pb-ball of the diameter of 1 mm.

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