Search PubMed⌕ Search

Biomedical subjects

T T Yoshizumi

Publications and source records attributed to T T Yoshizumi.

6 recordsLinked to original sources

CT fluoroscopy--guided interventional procedures: techniques and radiation dose to radiologists.

PURPOSE: To determine the radiation dose to radiologists who perform computed tomographic (CT) fluoroscopic interventional procedures by using a quick-check method and a low-milliampere technique. MATERIALS AND METHODS: Two hundred twenty CT fluoroscopy--guided interventional procedures were performed in 189 patients. Procedures included 57 spinal injections, 17 spinal biopsies, 24 chest biopsies, 20 abdominal aspirations, 44 abdominal biopsies, and 58 abdominal drainages. Procedure details were prospectively recorded and included site, depth, target diameter, milliampere value, kilovolt peak, fluoroscopic time, and CT technique (continuous CT fluoroscopy, quick-check method, or a combination of these techniques). An individual collar and finger radiation detector were worn by each radiologist during each procedure to determine the dose per procedure. RESULTS: The quick-check technique was performed in 191 (87%) of 220 procedures. Four procedures were performed with continuous CT fluoroscopy, and a combination technique was used for 25 (11%) procedures. The overall mean CT fluoroscopic time was 17.9 seconds (range, 1.2--101.5 seconds). The mean milliampere value was 13.2 mA (range, 10--50 mA). The overall mean radiologist radiation dose per procedure was 2.5 mrem (0.025 mSv) (whole body). Individual procedure doses ranged from 0.66 to 4.75 mrem (0.007--0.048 mSv). The finger radiation dose was negligible. CONCLUSION: By using a low-milliampere technique and the quick-check method, CT fluoroscopic time and radiation exposure can be minimized.

Adult↗

Design and development of a radioactive gas monitoring system in the positron emission tomography center.

This paper presents experiences in developing a simple, inexpensive radioactive gas monitoring system that proved to be practical and useful at a clinical and research Positron Emission Tomography (PET) Center. The system is described from four key aspects: (1) design of radiation detectors and calibrations; (2) use of an existing PC-based hospital-wide facility management network; (3) placement and oversight of real-time PC monitor stations; and (4) modification of a ventilation system in the PET center. The radiation safety oversight efficacy of a real-time PC-based radioactive gas monitoring system in the academic PET center also is discussed.

Calibration↗

Practical CT dosimetry.

The dose from computed tomography (CT) examinations is not negligible from a radiation safety standpoint. Occasionally, one encounters a case in which an unsuspected pregnant woman undergoes a CT pelvic scan, and the radiologist is required to estimate the dose to the fetus. This article addresses practical methods of CT dosimetry with a specific discussion on fetal dose estimate. Three methods are described: (1) the use of a dose chart, (2) the pencil ionization chamber method, and (3) the thermoluminescence dosimetry (TLD) method.

Female↗

Radiation safety and protection of neonates in radiological examinations.

Radiation reduction methods in neonatal radiographic examinations are discussed. Studies performed on radiation exposures to the neonates, scattered radiation level, exposure to the nursery personnel, effectiveness of the various shielding methods, uniformity of the x-ray field, heel effect, and skin exposure estimation are described. In summary, recommendations for exposure reduction based on our experimental findings as well as on the ALARA concept of radiation safety are provided.

Humans↗