Development of a z-axis tilting technique using a chest phantom to reduce radiation exposure during computed tomography coronary angiography.

Japan has the highest estimated exposure frequency of diagnostic X-rays in the world. Furthermore, the volumetric computed tomography dose index (CTDIvol) and dose length product (DLP) of computed tomography coronary angiography are relatively high in Japanese diagnostic reference levels, and it is important to reduce both dose indices. This study proposed a new exposure reduction technique, the vanishing liver position (VLP), where the body is tilted to the right in the z-axis.

SIMPLE METHOD OF MEASURING SSDE FOR HEAD CT: FACILITATING PRE-CT SCAN DOSE CALCULATION USING SPECIALIZED HEAD SCAN BAND.

In this study, scaled scan band was developed to provide size-specific dose estimation (SSDE) values based on head circumference of patients undergoing computed tomography (CT) scans. The scan band was tested in 40 consecutive head CT examinations. The accuracy of the specialized scan band method was determined by comparing SSDEband with SSDE293,forehead, SSDEmean and SSDEcenter.

DEVELOPMENT OF A SPECIALISED TAPE MEASURE TO ESTIMATE THE SIZE-SPECIFIC DOSE ESTIMATE.

The risk in computed tomography (CT) examinations is radiation exposure. We aimed to develop a specialised tape measure for determining the size-specific dose estimate (SSDE) for patients undergoing CT scans. The scanning parameters used were those of the abdominal protocol in our institute.

[Clinical Preparations: Status Quo and Challenges in the Future].

Dispensing clinical preparations requires the professional ability of pharmacists as specialists who understand the physicochemical properties of drugs. Clinical preparations contribute to the support of drug therapy and to commercialization by pharmaceutical companies. The Japanese Society of Hospital Pharmacists published the Guidelines on Hospital Preparations and Use in 2012.

DEVELOPMENT OF RADIATION DOSE CALCULATION SOFTWARE USING THE SIZE-SPECIFIC DOSE ESTIMATE.

We aimed to develop a software for facilitating absorbed dose per pixel (pixel dose) calculation using a size-specific dose estimate (SSDE). We calculated the pixel dose at nine equal points inserted into the radiophotoluminescence glass dosemeter (RPLD) and compared the pixel dose with the measured doses using RPLD. With this method, the relative errors of average pixel dose was -0.

A new shielding calculation method for X-ray computed tomography regarding scattered radiation.

The goal of this study is to develop a more appropriate shielding calculation method for computed tomography (CT) in comparison with the Japanese conventional (JC) method and the National Council on Radiation Protection and Measurements (NCRP)-dose length product (DLP) method. Scattered dose distributions were measured in a CT room with 18 scanners (16 scanners in the case of the JC method) for one week during routine clinical use. The radiation doses were calculated for the same period using the JC and NCRP-DLP methods.

Analysis of Image Gently Abdominal CT Protocol With the Use of Body Phantom Adapted to the Japanese Size.

Objective: The purpose of this study was to analyze in detail the quality of abdominal CT images obtained using three protocols reported by Image Gently in 2014 (hereafter referred to as Image Gently 2014), with the use of a handmade body phantom adapted to typical body sizes of the Japanese population. Moreover, we converted the findings of Image Gently 2014 to match Japanese body sizes and referred to our converted findings as Image Gently Japan.

Materials And Methods: We scanned each phantom in a mechanical isocenter in accordance with the Image Gently 2014 abdominal imaging protocol.

[Development of computer code PIETAII, for analysis of exposure dose from portable X-ray in neonatal intensive care unit].

The patients in NICU (Neonatal Intensive Care Unit) are more likely to get portable X-ray often while they are in the hospital. These patients potentially may get relatively more exposure dose in total in a short period of time. We developed a software to analyze the exposure dose for the patients in the incubator, which is called PIETAII (Patient Information of Exposure dose Total Analysis in NICU).

[Usefulness of criterion on which to operate coronary computed tomography angiography used dual source computed tomography comparisons with exposure dose of prospective electrocardiogram high-pitch spiral mode, low-pitch spiral mode, and step and shoot mode].

We believe that the patient exposure dose differs by heart rate for a coronary computed tomography angiography (CCTA), and we attempted to reduce patient exposure dose of the CCTA. Specifically, we made a clear difference of exposure dose between heart rate and optimal cardiac phase or some imaging methods. Next, we established criterion of the CCTA in our hospital, and usefulness was discussed.

[Evaluation of low dose chest expiratory high resolution computed tomography for diagnosis of air trapping].

In our hospital, expiratory high resolution computed tomography (HRCT) is being performed in patients with chronic obstructive pulmonary disease (COPD). Because expiratory HRCT is used in combination with inspiratory HRCT, it can provide less exposure according to diagnostic purposes. In the present study, we tried low-dose expiratory HRCT in terms of visual assessment and analysis software of phantom experiments.

[Development of a new method to estimate patient surface dose distributions in IVR].

Recently, the angiography system used for interventional radiology (IVR) provides a device for measuring dose-area product (DAP), which is compulsory in European countries. The usefulness of DAP is that one can observe patient dose in real time during IVR and can obtain an integral dose by overall IVR procedure without a dosimeter directly placed on a patient. It is important to know the most irradiated region (hot spot) of the patient's skin and its maximum value in the dose management of IVR, but this information cannot be obtained only in DAP.

[MR venography using the 3D-MEDIC (multi echo data imaging combination) sequence for lower extremities].

It is possible to diagnose varicose vein from medical history and physical examinations including inspection and palpation. Non-contrast enhanced MRV (magnetic resonance venography) is becoming popular because it can be easily performed without being affected by the radiographer's skill. We thought that the use of MEDIC (multi echo data imaging combination) would enable us to delineate varicose veins within a short acquisition time and without need for synchronization or contrast enhancement.

[Measurement of patient skin absorbed dose in ablation of paroxysmal atrial fibrillation and examination of treatment protocol].

The ablation for atrial fibrillation minute movement done in our hospital is 250 minutes or less, within an average time of 150 minutes during a fluoroscopic time of about 7 hours, with very large average inspection times numerical values. However, the skin-absorbed dose could be understood only from the numerical value of the area dosimeter. It was considered that the total dose that reached the threshold was sufficient, although radiation injury would not be reported from the ablation currently done at our hospital.