[Improved Protective Equipment for NICU Portable Radiography].

We have been developing protective equipment for portable radiography in neonatal intensive care units because the portable radiography's X-ray tube is in close proximity to the head of the nurse who is assisting the patient. Although our initial protective-equipment design was highly effective, there were some concerns that it obstructed the view of the patient and was difficult to handle. To overcome this problem, we have developed two new types of protective device: a narrow-type 0.13 mmPb device, 17 cm long and 45 cm wide (weight 200 g); and a wide type with a wider core material, 45 cm long and 25 cm wide (weight 300 g), both of which can be hung from the collimator cover of mobile X-ray equipment. The measured protective effectiveness was 80.6% at head height for the wide type and 76.8% for the narrow type. A survey of nurses regarding the new protective devices revealed no significant differences between the two types in terms of visibility and whether the devices would be an obstacle when assisting patients. The nurses preferred the wider type, which offered better protection. Radiological technologists also liked that both types were easy to handle because the irradiation field could be adjusted even after the device was fitted. Both types of the new protective device are thus expected to be useful in clinical practice in terms of their high protective effect and improved ease of handling.

[Creation of Protective Equipment for Portable Radiography in Neonatal Intensive Care Unit].

Portable imaging in the NICU requires the assistance of a nurse, and the nurse is in close proximity to the X-ray tube, In all, 64 percent of our nurses thought that additional protective equipment was needed. Therefore, a radiation protection device was created and its usefulness was verified. A protective equipment of 0.13 mmPb with a width of 38 cm and a length of 70 cm was made and hung from the mono-tank X-ray unit of the mobile X-ray unit. The position of the nurse was set at 30 cm outward from the center of the irradiation field, and the protective effect was measured at three points: (a) the patient's height, (b) 30 cm above the patient, and (c) 60 cm above the patient. For the imaging conditions, a 2-liter plastic bottle filled with water was placed in the incubator, and measurements were taken with an SID of 100 cm, irradiated field of 20.3 cm×25.4 cm, tube voltage of 58 kV, and tube current-time product of 10 mAs, which was converted to the actual imaging condition of 1 mAs. Based on the results obtained, a questionnaire survey was conducted on nurses' thoughts for the protective equipment created for them. Only 3% reduction in height of (a) where no protective equipment is reached but (b) 50% and (c) 92%, respectively. In all, 82 percent of the nurses had a favorable impression of the new protective equipment. It is expected that the protective equipment designed to control lens dose and reduce anxiety of nurses will be useful.

[Usefulness of Radiation Protection Cloths in Fluoroscopy with Clean Areas].

Lowering the dose limit for the lens of the eye incorporated into the Regulation on Prevention of Ionizing Radiation Hazards, effective on April 2021, and dose reduction will become more and more important in the field of radiation. Radiation protective cloth is used as a protective equipment in fluoroscopy rooms. Although it is usually used to protect staff from radiation exposure during endoscopic retrograde cholangiopancreatography, we investigated whether there is a way to use it for procedures in clean areas. Assuming ureterostomy fistula replacement in urology, the protective cloth was suspended on the side of the patient's head and posterior aspect of the tube, and the distance between the anterior aspect of the X-ray tube and the patient's foot was 55 cm. As a result of measuring the dose rate, a 10% dose reduction was obtained for the lens of the eye of the surgeon, and the distribution of air dose rate in the examination room was significantly reduced. Although scattered radiation from the radiation protection cloth appeared in some areas, the radiation dose to the patient was reduced throughout the body, and a high degree of radiation protection was obtained, especially for the lens of the eye. It is expected that the radiation protection cloths may be useful even when the length of the cloths is limited due to the cleanliness of the area.

[Comparison of Frontal and Lateral Measurements of Bone Mineral Density of the Lumbar Spine with Dual-energy X-ray Absorptiometry (DXA) in Spinal Deformity: a Phantom Study].

The bone mineral density (BMD) measurement of the lumbar spine with dual-energy X-ray absorptiometry (DXA) has the advantage of being able to detect early changes in BMD, which is usually used for the evaluation of drug therapy. However, DXA is not considered suitable for spinal deformity because it is a two-dimensional measurement. The aims of this study were to compare frontal and lateral measurements with a phantom and to examine the possibility of the evaluation of lumbar spine BMD in spinal deformity. The values of frontal and lateral measurements were compared when the lumbar phantom was tilted by 10 degrees from 0 to 40 degrees, assuming kyphosis, and when it was tilted by 5 degrees from 0 to 10 degrees to the right and left, assuming scoliosis. We revealed that in the case of kyphosis, the frontal is more accurate, and in the case of scoliosis, the lateral is more accurate; small rotation of subjects on the plane parallel to the image receiving surface could be acceptable. In general, the two-directional BMD measurement is useful for the improvement of the accuracy and may have a potential to measure patients with spinal deformity, which was previously thought to be impossible.