[Effect of Kiken-Yochi training (KYT) induction on patient safety at the department of radiological technology].

PURPOSE: In this report, we evaluated whether radiological technologists' (RTs') awareness of patient safety would improve and what kind of effects would be seen at the department of radiological technology by introducing KYT [K: kiken (hazard), Y: yochi (prediction), T: (training)]. METHODS: KYT was carried out by ten RTs based on a KYT sheet for the department of radiological technology. To evaluate the effects of KYT, we asked nine questions each to ten participants before and after KYT enforcement with regard to their attitude to patient safety and to operating procedures for working safely. RESULTS: Significant improvements after KYT enforcement were obtained in two items concerning medical safety: It is important for any risk to be considered by more than one person; The interest in preventive measures against medical accident degree conducted now) and one concerning operating procedures (It is necessary to have a nurse assist during testing with the mobile X-ray apparatus) (p<0.05). CONCLUSIONS: Performing KYT resulted in improved awareness of the importance of patient safety. KYT also enabled medical staffers to evaluate objectively whether the medical safety measures currently performed would be effective for patients.

[Examination of patient dose reduction in cardiovasucular X-ray systems with a metal filter].

In interventional X-ray for cardiology of flat panel digital detector (FPD), the phenomenon that exposure dose was suddenly increased when a subject thickness was thickened was recognized. At that time, variable metal built-in filters in FPD were all off. Therefore, we examined whether dose reduction was possible without affecting a clinical image using metal filter (filter) which we have been conventionally using for dose reduction. About 45% dose reduction was achieved when we measured an exposure dose at 30 cm of acrylic thickness in the presence of a filter. In addition, we measured signal to noise ratio/contrast to noise ratio/a resolution limit by the visual evaluation, and there was no influence by filter usage. In the clinical examination, visual evaluation of image quality of coronary angiography (40 cases) using a 5-point evaluation scale by a physician was performed. As a result, filter usage did not influence the image quality (p=NS). Therefore, reduction of sudden increase of exposure dose was achieved without influencing an image quality by adding filter to FPD.

[Development of a prevention of body movement fixation appliance in leg digital subtraction angiography].

In the peripheral angiography to evaluate blood flow below the knee levels in patients with arteriosclerosis obliterans, a motion artifact occurs as a result of body movements of a patient in normal fixation. This sometimes makes a correct evaluation difficult. Therefore, we developed a fixed appliance which can restrain body movement without affecting image quality and blood flow in digital subtraction angiography of a leg. The appliance is filled with the styrofoam of 1 mm diameter in a sealed bag, after air is aspirated from inside the bag. The appliance is stiffened to fit the shape of the crus. We measured signal to noise ratio / contrast to noise ratio / a resolution limit by visual evaluation to examine the influence of the image before and after usage of this appliance. In addition, the blood velocity of the dorsalis artery in ultrasound was measured to examine the effect on the blood flow. As a result, the fixed appliance did not affect blood flow in peripheral angiography to evaluate the clinical significance, the usual 5-point evaluate scale was used. The scale was significantly improved (p <0.01) after usage of this appliance. The newly developed fixed appliance for digital subtraction angiography of a leg is useful to avoid motion artifacts in clinical settings.