An audit of patient radiation doses during interventional cardiology procedures in Uttarakhand, India, and establishment of local diagnostic reference levels.

The objective of this study was to investigate patient radiation doses by a dose audit of three common interventional cardiology (IC) procedures: coronary angiography (CA), percutaneous transluminal coronary angioplasty (PTCA) and CA-PTCA procedures performed in IC centres in the Uttarakhand state of India, for the establishment of local diagnostic reference levels (DRLs) and the estimation of average effective dose (Eav) for these procedures. For each procedure, the values of kerma-area product (PKA), reference air kerma (Ka,r), fluoroscopy time (FT) and the number of cine images were recorded from 1233 CA, 458 PTCA and 736 CA-PTCA procedures performed over a 12-month period at 13 IC centres of the state. From the recorded dose data, 0.6%, 1.53% and 7.9% patients were identified to have exceeded the PKA trigger level of 500 Gy cm2 for possible skin injury for CA, PTCA and CA-PTCA procedures, respectively. The 3rd quartile of the distribution of the recorded PKA values for each type of procedure was calculated to estimate local DRL values. The estimated values of DRLs and Eav were 37, 153 and 224 Gy cm2, and 6.72, 23.97 and 34.79 mSv for CA, PTCA and CA-PTCA procedures, respectively. For about 77% of the surveyed centres, the recorded patient doses were in agreement with the international standards. The local DRLs proposed in this study may be used to achieve patient dose optimization during IC procedures and the obtained patient dose data may also be archived into national dose database for the establishment of national DRLs.

Technical specifications of dose management systems: An international atomic energy agency survey.

PURPOSE: Dose management systems (DMS) have been introduced in radiological services to facilitate patient radiation dose management and optimization in medical imaging. The purpose of this study was to gather as much information as possible on the technical characteristics of DMS currently available, regarding features that may be considered essential for simply ensuring regulatory compliance or desirable to fully utilize the potential role of DMS in optimization of many aspects of radiological examinations. METHODS: A technical survey was carried out and all DMS developers currently available (both commercial and open source) were contacted and were asked to participate. An extensive questionnaire was prepared and uploaded in the IAEA International Research Integration System (IRIS) online platform which was used for data collection process. Most of the questions (93%) required a "Yes/No" answer, to facilitate an objective analysis of the survey results. Some free text questions and comments' slots were also included, to allow participants to give additional information and clarifications where necessary. Depending on the answer, they were considered either as "Yes" or "No." RESULTS: Given the way that the questions were posed, every positive response indicated that a feature was offered. Thus, the percentage of positive responses was used as a measure of adherence. The percentages of positive answers per section (and sub-section) are presented in graphs and limitations of this type of analysis are discussed in detail. CONCLUSIONS: The results of this survey clearly exhibit that large differences exist between the various DMS developers. Consequently, potential end users of a DMS should carefully determine which of the features available are essential for their needs, prioritize desirable features, but also consider their infrastructure, the level of support required and the budget available before selecting a DMS.

Optimal 99mTc activity ratio in the single-day stress-rest myocardial perfusion imaging protocol: A multi-SPECT phantom study.

BACKGROUND: This investigation used image data generated by an anthropomorphic phantom to determine the minimal 99mTc rest-stress activity concentration ratio (R) able to minimize the ghosting effect in the single-day stress-first myocardial perfusion imaging, using different positions of the perfusion defect (PD), scanners and reconstruction protocols. METHODS: A cardiac phantom with a simulated PD was imaged under different R using different gamma cameras and reconstruction algorithms. The residual activity from precedent stress administration was simulated by modeling effective half-times in each compartment of the phantom and assuming a delay of 3 hours between the stress and rest studies. The net contrast (NC) of the PD in the rest study was assessed for different R, PD positions and scanner/software combinations. The optimal R will be the one that minimize the NC in the rest images RESULTS: The activity concentration ratio R, the position of the PD and the scanner/software combinations were all main effects with a statistically significant impact on the NC, in decreasing order of relevance. The NC diminished significantly only for R values up to 2. No further improvement was observed for NC for R values above 2 and up to 3. NC was significantly higher in anteroseptal than in posterolateral positions of the PD and higher for solid-state cameras. CONCLUSIONS: A rest-stress activity concentration ratio R of 2 in single-day stress-first myocardial perfusion imaging is enough to achieve the maximum net contrast in the PD. This ratio should be used to optimize patient's radiation exposure.

Evaluation of patient and staff exposure with state of the art X-ray technology in cardiac catheterization: A randomized controlled trial.

INTRODUCTION: Cardiac catheterization procedures result in high patient radiation exposure and corresponding staff doses are reported to be among the highest for medical staff. The purpose of current randomized controlled study was to quantify the potential radiation dose reduction for both patient and staff, enabled by recent X-ray technology. This technology is equipped with advanced image processing algorithms, real-time dose monitoring, and an acquisition chain optimized for cardiac catheterization applications. METHODS: A total of 122 adult patients were randomly assigned to one of two cath labs, either the reference X-ray modality (Allura Xper FD10, Philips Healthcare, the Netherlands) or the new X-ray system (AlluraClarity FD20/10 Philips Healthcare, the Netherlands). Exposure parameters and staff dosimeter readings were recorded for each exposure. Technical measurements were performed to define the radiation scatter behavior. RESULTS: With the newer equipment, patient radiation dose is reduced (as total dose-area product) by 67% based on geometric means with 95%CI of 53%, 77% for diagnostic and interventional procedures. The C-arm and leg dosimeter readings were both reduced with 65% (P < 0.001), while for the collar and chest dosimeter readings no statistically significant reduction was noticed. CONCLUSION: The new x-ray and image processing technology, significantly reduces patient dose in coronary angiographies, and PCIs by 67%. In general, scatter dose was also reduced, yet for some dosimeters the reduction was limited and not statistically significant. This study clearly indicates that the scatter behavior is highly dependent on C-arm rotation, operator movement and height, dosimeter position, beam filtration, clinical procedure type and system geometry.

Comparison of the patient radiation exposure during coronary angiography and angioplasty procedures using trans-radial and trans-femoral access.

INTRODUCTION: Cardiac catheterization procedure through the trans-radial access (TRA) have shown many clinical advantages over the trans-femoral (TFA), but despite its advantages, there are serious concerns regarding higher possible radiation dose for the patients and operators in TRA. This study was planned to compare the patients' radiation dose associated with TRA and TFA during coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA). METHODS: Of 700 candidates for angiography, 326 patients were entered the study. All the procedures were carried out by one interventional cardiologist employing the same angiography unit in Aalinasab hospital and the patients' dose area product (DAP), air kerma (AK), fluoroscopy time (FT) and cine film time (CFT) were then determined in both access groups (TRA,TFA) in CA, PTCA and CA+PTCA procedures. RESULTS: The mean FT, CFT and AK values in both TRA & TFA groups were the same in all procedures (P>0.05). The mean DAP in CA+PTCA procedures was 6704.01±3243.23 µGym(2) in femoral access compare with 5647.46±2797.74 µGym(2) in radial access, which were significantly less than that in TFA with P= 0.02. CONCLUSION: On the basis of the results obtained in this study, no differences were found in patients' radiation dose in both access groups, therefore with regard to comparatively more clinical advantages associated with the Trans-radial access technique it might be a good substitute for Trans-femoral access.

Observations and Considerations on Patient X-ray Exposure in the Electrophysiology Lab.

To assess patient radiation during catheter ablation procedures and operator differences. From 84 patients (51 males, age 63 ± 10 years) undergoing complex catheter ablation by three experienced operators we collected: body mass index (BMI), procedure type and time, fluoroscopy time, dose area product (DAP), air kerma and X-ray system setting (cine, collimation and angiographic imaging angle). A new factor, fluoroscopy DAP-fluoroscopy time ratio, was introduced to compare operator differences. The results show the average procedure time was 179 (± 57) minutes (min), fluoroscopy time was 31 (± 21) min, DAP was 26.4 (± 19.6) Gy.cm(2) and air kerma was 0.26 (± 0.19) Gy. Procedure types were: pulmonary vein isolation (PVI) (52 %), redo PVI (11 %), pulmonary vein ablation catheter (PVAC) (14 %), ventricular tachycardia (VT) (8 %) and others (15 %). Inter-operator difference was observed in fluoroscopy and cine usage. Fluoroscopy DAP-time ratios showed a similar level of patient radiation dose rate by operator A and B (correlation: 0.89), and a significantly higher dose rate by operator C (correlation: 0.20, p<0.001; 0.26, p<0.01, to operator A and B). In conclusion, operators should be aware of patient radiation exposure levels and the influencing factors. Inter- and intra-operator differences can be measured and bench marked for improvement in X-ray efficiency and patient radiation reduction.

Percepción de la población respecto a los riesgos asociados a los estudios de imágenes / Public perception of radiation-related risks of imaging studies

Introduction: In recent years, diagnostic procedures using ionizing radiation have achieved a great boom, although patients are often unaware of the risks they involve. Objectives: To know how is ionizing radiation perceived by the population attending Clínica Dávila, Department of Radiology (DRCD).Methods: A voluntary and anonymous survey was conducted on patients and / or companions. Results: A total of 330 adults were surveyed. An 57 percent had completed higher education, whereas 7.9 percent had only finished elementary schooling; 78.8 percent had undergone three or more imaging tests. CT examination was considered to pose the highest levels of risk (42.4 percent), followed by Ultrasonography (30.6 percent). Discussion: The survey group was made up of young adults, mostly college graduates, and predominantly female. Surprinsingly enough, considering that obstetric sonography is commonly used during pregnancy, US was ranked second in terms of associated health risks. There is an evident interest in the subject, since 90 percent of responders would like to receive further information.

Introducción: Los procedimientos diagnósticos que usan radiación ionizante están en auge, aunque conllevan riesgos muchas veces desconocidos por los pacientes. Objetivos: Conocer la percepción de la población que acude al Departamento de Radiología de Clínica Dávila (DRCD) sobre la radiación. Material y métodos: Se aplicó una encuesta voluntaria y anónima a pacientes y/o acompañantes. Resultados: Se encuestó a 330 adultos. El 57 por ciento poseía estudios superiores y 7,9 por ciento sólo estudios básicos. El 78,8 por ciento se había efectuado 3 o más estudios radiológicos. La TC fue el examen considerado con mayor riesgo (42,4 por ciento), luego la US (30,6 por ciento). Discusión: El grupo encuestado fueron adultos jóvenes, con estudios superiores en su mayoría y con predominio femenino. Sorprendió que la US se considerara como el segundo examen de mayor riesgo, ya que las mujeres poseen mayor contacto con este estudio durante el embarazo. Hay interés en el tema, porque el 90 por ciento desea recibir información.