Biomedical subjects

A Robert Schleipman

Publications and source records attributed to A Robert Schleipman.

5 recordsLinked to original sources

PubMed2004

Patient radiation dose at CT urography and conventional urography.

PURPOSE: To measure and compare patient radiation dose from computed tomographic (CT) urography and conventional urography and to compare these doses with dose estimates determined from phantom measurements. MATERIALS AND METHODS: Patient skin doses were determined by placing a thermoluminescent dosimeter (TLD) strip (six TLD chips) on the abdomen of eight patients examined with CT urography and 11 patients examined with conventional urography. CT urography group consisted of two women and six men (mean age, 55.5 years), and conventional urography group consisted of six women and five men (mean age, 58.9 years). CT urography protocol included three volumetric acquisitions of the abdomen and pelvis. Conventional urography protocol consisted of acquisition of several images involving full nephrotomography and oblique projections. Mean and SD of measured patient doses were compared with corresponding calculated doses and with dose measured on a Lucite pelvic-torso phantom. Correlation coefficient (R(2)) was calculated to compare measured and calculated skin doses for conventional urography examination, and two-tailed P value significance test was used to evaluate variation in effective dose with patient size. Radiation risk was calculated from effective dose estimates. RESULTS: Mean patient skin doses for CT urography measured with TLD strips and calculated from phantom data (CT dose index) were 56.3 mGy +/- 11.5 and 54.6 mGy +/- 4.1, respectively. Mean patient skin doses for conventional urography measured with TLD strips and calculated as entrance skin dose were 151 mGy +/- 90 and 145 mGy +/- 76, respectively. Correlation coefficient between measured and calculated skin doses for conventional urography examinations was 0.95. Mean effective dose estimates for CT urography and conventional urography were 14.8 mSv +/- 90.0 and 9.7 mSv +/- 3.0, respectively. Mean effective doses estimated for the pelvic-torso phantom were 15.9 mSv (CT urography) and 7.8 mSv (conventional urography). CONCLUSION: Standard protocol for CT urography led to higher mean effective dose, approximately 1.5 times the radiation risk for conventional urography. Patient dose estimates should be taken into consideration when imaging protocols are established for CT urography.

Adult↗

PubMed2004

Radiation disaster response: preparation and simulation experience at an academic medical center.

OBJECTIVES: A mass casualty disaster drill involving the simulated explosion of a radiation dispersal device (dirty bomb) was performed with the participation of multiple hospitals, emergency responders, and governmental agencies. The exercise was designed to stress trauma service capacities, communications, safety, and logistic functions. We report our experience and critique of the planning, training, and execution of the exercise, with special attention to the integrated response of the Departments of Nuclear Medicine, Health Physics, and Emergency Medicine. METHODS: The Health Physics Department presented multiple training sessions to the Emergency Medicine Department, Operating Room, and ancillary staff; reviewing basics of radiation biology and risk, protection standards, and detection of radiocontamination. Competency-based simulations using Geiger-Müller detectors and sealed sources were performed. Two nuclear medicine technologists played an important role in radiation discrimination-that is, assessment of radioactive contamination with survey meters and radionuclide identification based on gamma-spectroscopy of wipe smears from patients' clothing, skin, and orifices. Three Health Physics personnel and one senior Nuclear Medicine staff member were designated the radiation control officers for assigned teams triaging or treating patients. Patients were triaged and, when indicated, decontaminated. RESULTS: Within a 2-h period, 21 simulated victims arrived at our institution's Emergency Room. Of these, 11 were randomized as noncontaminated, with 10 as contaminated. Decontamination procedures were implemented in a hazardous materials (HAZMAT) decontamination trailer and, for the 5 patients with simulated serious injuries, in a designated trauma room. A full debriefing took place at the conclusion of the exercise. Staff largely complied with appropriate radiation protection protocols, although decontamination areas were not effectively controlled. The encountered limitations included significant lapses in communications and logistics, lack of coordination in the flow of patients through the HAZMAT trailer, insufficient staff to treat acute patients in a radiation control area, additional personnel needed for transport, and insufficient radiation safety personnel to control each decontamination room. CONCLUSION: Nuclear Medicine personnel are particularly well qualified to assist Health Physics and Emergency Medicine personnel in the preparation for, and management of, mass casualty radiation emergencies. Simulation exercises, though resource intensive, are essential to an institution's determination of response capability, performance, and coordination with outside agencies.

Academic Medical Centers↗

PubMedDate not supplied

Occupational radiation dose associated with Rb-82 myocardial perfusion positron emission tomography imaging.

BACKGROUND: We determined staff radiation dose during rest and stress rubidium 82 myocardial perfusion positron emission tomography (PET) imaging. METHODS AND RESULTS: Patients received 1,587 +/- 163 MBq (42.9 +/- 4.4 mCi) Rb-82 during rest or pharmacologic stress. A pressurized ion chamber was used to monitor radiation exposure in 50 examinations. For comparison, staff exposure during pharmacologic stress in 20 other patients receiving 1,204 +/- 55.5 MBq (32.54 +/- 1.5 mCi) technetium 99m 2-methoxy isobutyl isonitrile (MIBI) was measured. For Rb-82 infusion and PET acquisition, the mean dose was 0.45 +/- 0.25 microSv (0.045 +/- 0.025 mrem). Exposure for routine stress testing at variable distances from the patient was equivalent to background. Similar exposure for pharmacologic stress testing through 7 minutes after injection of Tc-99m MIBI at variable distances was 1.075 +/- 0.32 microSv (0.108 +/- 0.03 mrem). However, exposure for stress tests starting 7 minutes after Rb-82 infusion at 0.5 m was estimated at 0.4 microSv (0.04 mrem). To determine the potential radiation dose for those responding to a medical emergency or otherwise in close proximity to a patient, we measured the mean cumulative dose at 0.5 m from 0 to 7 minutes of Rb-82 infusion, which resulted in 19.1 +/- 5.8 microSv (1.9 +/- 0.58 mrem). CONCLUSIONS: Radiation doses for all tasks during routine Rb-82 stress-rest PET are lower than measured Tc-99m MIBI values. However, the radiation dose in close proximity to the patient during or immediately after Rb-82 infusion can be considerably higher, underscoring the need for strict attention to source distance and contact times.

Exercise↗

PubMedDate not supplied

Occupational radiation exposure: population studies.

Occupational exposure to ionizing radiation in the medical setting differs from the acute exposure received by survivors of atomic bomb blasts. Yet, atomic bomb survivors' disease and mortality outcomes have been the standard data source on the effects of ionizing radiation on humans. Therefore, the prevailing estimated risks of ionizing radiation may not apply to radiologic technologists and other medical radiation workers. Carefully designed epidemiological trials provide evidence that helps determine the strength of association between exposure and onset of disease in selected populations. This article reviews radiation effects, explains some basic design concepts of epidemiologic trials and surveys the epidemiology literature related to radiation exposure to humans, with special attention to radiology staff.

Epidemiologic Studies↗

PubMedDate not supplied

Determining radiology staffing requirements in the operating room: a radiation protection compliance perspective.

The use of radionuclides and x-ray equipment is highly regulated, and in many states, only a licensed technologist or physician may operate the equipment. These regulatory requirements, coupled with persistent radiologic technologist (RT) vacancy rates, can make adequate staffing a difficult task. While there are numerous reports describing nurse workforce requirements, there is a paucity of published information on what constitutes appropriate staffing levels for RTs. In consideration of future operating room (OR) expansion, the institution determined to measure how its current staffing plan was meeting the needs of the OR as well as to empirically develop a plan that met all radiation safety and regulatory requirements. A 4-week tracking study (N=244 cases) of C-arm and other x-ray utilization was performed by 3 RT full-time equivalents (FTE) assigned to operate or assist with 10 x-ray devices in 40 ORs. The logs demonstrated that a RT was present during 181 cases (181/244 = 74%), while in 63 other cases (63/244 = 26%), the RT only delivered the C-arm for physician use. No nurses were observed operating the equipment. In some instances, simultaneous requests necessitated extra coverage by additional RTs. Regulatory and market forces constrain hospitals to make difficult decisions regarding staffing. Objective documentation of radiology resource utilization in the OR provided evidence leading to improvement opportunities and adjustments to the staffing plan.

Guideline Adherence↗