| | Patient doses and dosimetric evaluations in interventional cardiologyReceived 23 November 2007; received in revised form 29 January 2008; accepted 13 March 2008. published online 28 April 2008. Abstract Interventional cardiological examinations may be associated with excessive radiation exposures which may cause skin injuries and higher probabilities of stochastic effects. Dose–area product (DAP) and skin doses of 325 patients were measured using alternative dosimetric techniques for different cardiological examinations. Data were collected from five different systems with the involvement of 11 cardiologists. All these dosimetric information has been collected separately for each of 10 projections together with the exposure parameters of X-ray systems. Mean DAP values measured with a transparent ion chamber were 49.1 Gycm2, 66.8Gycm2, 106.9Gycm2 and 124.7Gycm2, respectively, for coronary angiography (CA), percutaneous transluminal coronary angioplasty (PTCA) or stent (PT-SI), coronary angiography and/or PTCA and/or stent (CA-PT-SI), and ablation examinations. Radiochromic films, thermoluminescent dosimeters (TLD) and point measurement of air kerma (AK) were carried out for skin dose assessments. Skin doses of 23 patients measured with radiochromic films were found to be between 2Gy and 6Gy. Although the complexity of the procedures was the major reason for these excessive doses, considerable contributions of high X-ray output of some fluoroscopy units were also noticed. In addition to the direct measurement of DAP, alternative DAP values were also determined from the skin dose measurement techniques; exposed areas were summed on digitized radiochromic films in one technique, The product of AK reading with X-ray field size measured at the patient entrance using slow X-ray films was taken as another DAP. Good correlations were found among the DAP results and also between the entrance skin doses calculated from AK measurements and direct DAP readings (R2=0.91). A trigger DAP value of 130Gycm2 for the 2Gy of skin doses was derived from this relationship. Collection of dosimetric data for each projection was also investigated regarding a possible standardization of clinical techniques; in the case of coronary angiography examinations LAO 45 and RAO 30 were found as the dominant projections which may also simplify the dosimetric technique. Introduction  Interventional cardiology procedures are known to give high radiation doses to patients because of prolonged use of fluoroscopy, multiple digital runs and the complexity of the procedures. There is a growing concern about these radiation doses and severe skin reactions have been reported [1], [2]. Dose measurements can be categorized as either direct or indirect techniques [3]. Thermoluminescent dosimeters (TLDs) can be used as a direct measurement of skin doses; however a point measurement with a TLD chip requires a priori knowledge of the maximum skin exposure location. The use of TLD arrays has been attempted to better characterize the dose distribution. However, the difficulties in routine applications and lack of online dose information are the main limitations of the TLD technique. Slow radiographic films have also been used for a direct measurement of skin doses. Although they provide distribution of skin doses quantitatively, they suffer from limited dose range, film processing problems and also do not give online information [4]. Mosfet radiation sensors and scintillation dosimeters provide immediate dose information and have been used by some groups for skin dose measurements in fluoroscopic examinations [5], [6], [7]. But they suffer from several drawbacks (i.e. energy dependency, directional sensitivity, positioning difficulties and interference with the image, etc.). Dose estimation can also be made indirectly by measuring the dose at a specific point in the X-ray beam (IRP-interventional reference point, at the collimator port) [8], [9]. A recently introduced radiochromic film was designed as a wide area dosimeter for use in quantitative mapping of patient skin dose received during the fluoroscopic examinations. This dosimeter is a chemical radiation sensor that changes color upon exposure to radiation and requires no post exposure process. Availability of a previously prepared calibration strip enables the user to visually estimate doses immediately after the procedure. They can be easily used in routine work and have very good dosimetric features [10]. On the other hand dose–area product (DAP) is a well accepted dosimetric technique for the comparison of patient doses received in fluoroscopic examinations and is also used for the estimation of effective doses. Measurement of patient skin doses and DAP values with different dosimetric techniques was the main purpose of this investigation. Data were collected from different cardiological procedures and cardiology centers in order to see the variation of radiation received by the patient with the complexity of the procedure, design and handling of the X-ray equipment, and the experience/training of the cardiologist. Online measurements and retrospective calculation of DAP were performed. TLD, ion chamber and radiochromic film have been used for patient skin dose assessments. Collection of dosimetric information separately for each projection was the other research objective of this study. Efficiency of dosimetric techniques and also the possibility to purpose a standard clinical protocol were investigated from projection based information [11]. Materials and methods Patient dose measurements were carried out at the cardiology departments of three university hospitals. Data from five angiographic units have been collected by the involvement of five groups of nine cardiologists. All these departments were also offering training programs for cardiologists; one junior cardiologist together with a senior one carried out all the clinical examinations at each center. Two Philips Integris H 3000 (Philips Medical Systems, The Netherlands), two General Electric Advantx LC+DLX (GE Medical Systems, Milwaukee, WI, USA), and one Siemens Bicor Plus (Siemens Erlangen, Germany) were the X-ray angiographic systems. Performance tests of all these equipments were carried out according to the protocols given by the IPEM [12]. Patient input exposures were measured both for fluoroscopy (for continuous and pulsed modes) and radiography (for all dose modes) and repeated for different image intensifier field of views (FOV). Measurements of half value layer (HVL) for each X-ray tube, accuracy of peak tube voltage (kVp) settings and function of the automatic brightness control (ABC) were also tested using a Radcal Inspection kit (MDH-Radcal Monrovia, CA) which was initially calibrated at a secondary standard laboratory. Table attenuation for each system was also measured and used to correct DAP and air kerma results for the related projections. The oblique path of X-rays passing through the table was calculated and subsequently used for attenuation calculation of projection rather than the AP one. Cardiac procedures were categorized into four groups: coronary angiography (CA), percutaneous transluminal coronary angioplasty (PTCA) or stent (PT-SI), coronary angiography and/or PTCA and/or stent (CA-PT-SI), and ablation. Patients who had only one intervention either PTCA or stent were included in the second group. The third group covers the patients who underwent more than one intervention and/or CA. Ablation patients were included in the last group. Dosimetric techniques Online measurement of dose–area product (DAPmeas) was carried out for all the procedures at each system. A transparent ion chamber (Diamentor M4KDK Freiburg, Germany) for three X-ray units and built in DAP meters of the other two systems were used for this purpose. In the meantime, the accuracy of alternative DAP determined from the skin dose measurements was also investigated. The size of the exposed area at the patient entrance was measured for each field of view (FOV) of each system at PA projection using a slow radiographic film (Kodak X-Omat V), and this field was multiplied with the patient input exposure (measured from the small ion chamber of the DAP meter) to calculate another dose–area product (DAPcalc). Both of these DAP values were determined separately for each projection of the examinations. Additionally, a total DAPrchf. for the whole examination was also determined by summing up the exposed areas on the digitized radiochromic film using simple image processing techniques. The dose ranges for radiographic and radiochromic films are reported as 10–500mGy [4] and 0.1–15Gy [10], respectively. Regarding skin dose measurements, radiochromic films and TLDs were used together with a small ion chamber (1.7cm×1.7cm) which is in the middle of the transparent chamber of the DAP meter [13]. Online connection of the DAP meter to a personal computer was provided using Diasoft Software (PTW Freiburg). Recording of the complete procedure was possible with this software and fluoroscopy time, air kerma and DAP for fluoroscopy and radiography, air kerma rate and DAP rate and number of images for radiography can be extracted following the study. This software was designed to record fluoroscopic and radiographic exposures to separate files which improved the accuracy of the assessment of relative contributions. Since air kerma measurements of the small ion chamber are given for a specific distance, in order to determine the doses at the patient entrance, readings were first distance-corrected using the recorded position of table and image intensifier and then multiplied by the backscatter factor and the mass energy absorption coefficient ratio for tissue to air (1.06). A backscatter factor of 1.31 obtained from the mean of all views was used [14]. Lithium fluoride TLD chips (3.7×3.7×0.9mm) (Model: TLD 100: Harshaw Chemical Solon, OH) in plastic handling pockets (three for each) were used to measure the skin doses, and a Model 3500 Reader (Harshaw Chemical) was used for TLD readout; the dose range for these TLDs are reported to be between 0.01mGy and 10Gy by the manufacturer. These sachets were attached to a single point on the patient's skin for each projection where the exposure was expected to be at its highest level. In order to minimize batch to batch variability, a pre selected group of TLDs was calibrated initially and variations of the sensitivities were kept within ±5%. Calibration of Diamentor and TLDs was carried out for each angiographic system using the same X-ray beam qualities with patient studies. A Radcal ion chamber (Model 10x-60, MDH–Radcal, Monrovia, CA) was taken as reference chamber, and manufacturer recommendations were considered for these calibrations. New dosimeter radiochromic films (International Specialty Product, IPS, Wayne, NU, USA) were used for a limited number of patients (28 CA, 7 PT-SI, 32 CA-PT-SI, 7 ablation) of all the systems. Their sizes were 35cm×43cm and they were fit to the patient's back. For the calibration, 3×3cm2 cut pieces of an unexposed radiochromic film were exposed to air kerma of 5Gy, in steps of about 200mGy, using an X-ray system at 80kVp, 42cm source film distance. Air kerma was assessed with a calibrated dosimeter, Radcal 2026C, and ion chamber, Radcal 20x6-6 (MDH-Radcal Monrovia, CA). The image of the exposed pieces of the radiochromic detector, including a non-irradiated piece for the offset evaluation, was acquired with a reflective A3 flatbed scanner (Microtek ScanMaker 1000XL, Carson, CA, USA). To avoid the maximum density growth, the acquisition has occurred at least 48h after the irradiation of the last piece [10]. The automatic optimization of the acquisition parameters was recorded and then used for all the subsequent acquisitions of exposed films. Although the image acquisitions were performed in the red, green, blue (RGB) mode, the film response was evaluated in its red component. The mean red values for each calibration piece versus air kerma were interpolated with a square function using a dedicated software package (PicoDose programme from TA, Torino, Italy, and Systat10, SPSS inc, USA). The calibration curve was then applied to all the patient dosimetry films. Data acquisition Following the initial observation of all the clinical procedures at the cardiology departments and discussions with the cardiologists, irradiation geometries used in patient studies were assigned to 10 different projections (Fig. 1). Acquisition of fluoroscopic and radiographic exposures from the DAP meter to separate files on Diasoft for each projection was carried out by one staff. Image intensifier magnification factor and angle, average values of tube potential for fluoroscopic exposures and mode of fluoroscopic exposures were noted continuously during the course of the examination for each projection by the second staff. Table-to-focus distances were also recorded from the gantry display for the calculation of focus-to-skin distances for each view. Since distance information was only available for the vertical position of the C arm, an average source to skin distance was used for the lateral and oblique views. Radiographic exposure parameters for each projection such as tube voltage, field of view, and number of radiographic frames were extracted from the archive data of system computers after the completion of the study. Effective doses (Eff.D) for each projection were calculated from DAPmeasreadings and Monte Carlo conversion factors given by the PCXMC software (STUK, Helsinki, Finland) [15]. Results Patient input exposure rates (PIER) used for clinical practice both for fluoroscopic and radiographic exposures are given together with HVL and table attenuation factors in Table 1. If the total DAPmeas is taken as a comparison criterion, 17cm2 FOV for S1 and S2, 16cm2 FOV for S3 systems were in dominant use regardless of the examination type. But the users of the S4 system also selected 22cm2 FOV in addition to 16cm2 FOV especially for CA examinations. The mean kVp values for the fluoroscopic exposures of all the procedures for the S1, S2, S3, S4 systems were 99kVp, 97kVp, 107kVp and 116kVp. For radiographic exposures these values were 85kVp, 88kVp, 93kVp and 101kVp, respectively. | a Table attenuation factor. bSelected FOV in cm2. cFluoro continuous. Normal pulsed. dDigital pulse fluoroscopy 25 pulse/s; 25 frame/s. eDX standard/normal fluoroscopy 25 pulse/s. DA mode: C 25 frame/s. fDX standard/normal fluoroscopy. DA mode: C 25 frame/s. For FOV: 16 PIER: 25.9mGy/min; 0.15mGy/fr. gMode2: fluoro continuous. Mode3: FOV: 18 PIER: 41mGy/min at (72kVp–17.5 mA). hHVLs were measured around 80kVp and for the fluoro mode. |
None of the users collimated the X-ray beam during the examinations probably due to the use of smaller FOVs. Distribution of the number of patients according to the procedures and fluoroscopic units is given in Table 2. The number of cardiologists who worked with these units is also indicated. Comparison of average patient doses among the procedures and fluoroscopic systems Total DAPmeas values have been taken into account as the first step for these comparisons (Table 3). In order to understand the reasons for dose differences, fluoroscopic and radiographic DAP values, DAPmeas(FL) and DAPmeas(DA) measured for each procedure and system, have been considered together with fluoroscopy time (TFL) and number of radiographic frames (NDA). Tube output of the fluoroscopic systems and some of the exposure factors manipulated during the patient examination such as kVp and FOVs were also taken into account. Considering the means of all systems, if the patient DAP values for PT-SI, CA-PT-SI and ablation examinations are compared with CA results, 1.36, 2.17 and 2.54 times higher DAP values are found, respectively, which indicates that the complexity of the procedure is one of the main factors for high patient doses. This is also confirmed by the high fluoroscopy times observed in complex examinations. | a This system was used only for RF ablation examinations. |
Skin doses measured from radiochromic films (ESDrchf) are also presented in Table 3. A similar variation of these doses with the DAP results has been noticed among the procedures and systems. But increases in skin doses with the complexity of the procedures were more pronounced in comparison to DAP increase. Variations of maximum skin doses measured with this technique are given in Table 4 for the procedures and systems. As is given in this table, more patients received excessive skin doses due to the higher X-ray output of the S3 system. High skin doses were also measured for ablation examinations (S5 system), although long fluoroscopy times were used in these procedures, further investigation on this system revealed that its larger collimator opening and extremely high X-ray output at the other fluoroscopy mode were also important reasons for these doses. Comparison of projection data for the procedures and fluoroscopic units Fig. 2 gives the mean values of DAPmeas for each projection of CA examinations for each system in which the weighting of each projections can be seen. Projection LAO 45 was the dominant one for all the systems and RAO 30 was also frequently used. This is in good agreement with the findings of [16], [17], [18], [19], and a standardization for CA examinations can be thought of. Although the figures are not given, there were more variations on the weightings of projections for PT-SI and CA-PT-SI procedures, but in general LAO 45 was again the dominant one and CRAN 30, CAUD 30, and RAO 30-CAUD 30 also had higher contributions. The least used projections were LAO 45-CRAN 30 and LLAT for CA, and AP, LLAT for the other examinations. One other finding was the higher number of projections used for PT-SI and CA-PT-SI procedures in comparison to CA examinations. A good correlation of projection weightings was also noticed by visual analysis of radiochromic films. In Table 5, the DAP measured with a transparent chamber (DAPmeas), skin doses measured with TLD (ESDTLD) and the small ion chamber (ESDAK) as well as effective doses (calculated from DAPmeas) are given for each projection of CA, PT-SI and CA-PT-SI examinations for S1 system. Maximum skin doses over 900mGy (LAO 45 projection) were measured with the ion chamber for three patients. Although the results for the other systems are not presented in this table, the air kerma readings of four patients were found to be between 1.2Gy and 3.27Gy for CA-PT-SI examinations. TLD readings were lower than the AK results and only for few patients the doses exceed 1Gy for some projections. Comparison of dosimetric techniques Dosimetric techniques have been compared both on projection basis as well as for the whole examination. DAPmeas and DAPcalc (product of measured FOV with ESDAK) measured for each projection were summed up and compared with each other and also with DAPrchf for different procedures. DAPmeas and DAPrchf values were close to each other but DAPcalc values were 1.2–1.6 times higher than these findings. Correlations of DAPmeas–DAPcalc were 0.81, 0.78, 0.95, 0.97 for CA, PT-SI, CA-PT-SI and ablation examinations, respectively. Similarly, the correlations for DAPmeas–DAPrchf results were found as 0.88, 0.96, 0.87 and 0.91 for these examinations. Regarding the DAP-skin dose correlations based on projection, a very good agreement was obtained for DAPmeas–ESDAK (0.92<R2<0.99) plots among the procedures and systems. However DAPmeas–ESDTLD, and ESDTLD,–ESDAK correlations were poor. Similar to DAP evaluations, total values of all projections for each patient were also calculated for ESDAK and ESDTLD. As is shown in Fig. 3, the correlation of DAPmeas with ESDAK readings (R2=0.91) was found to be much better than the DAPmeas–ESDTLD correlation (R2=0.48), similar to projection based findings. Correlation of DAPmeas with fluoroscopy time was also investigated and found to be 0.53 if the whole procedures and systems are considered. Discussion The mean of patient DAPmeas values are almost equal for the S1 and S2 systems both for the CA and CA-PT-SI examinations (Table 3). For CA procedures, the DAPmeas(FL) for the S1 system, and the DAPmeas(DA) for the S2 systems are higher and they are in good agreement with the longer TFL of the S1 system and higher number of NDA of the S2 system. However this does not hold for CA-PT-SI procedures, because as is given in Table 3 the higher DAPmeas(DA) value of the S2 system is not coincident with the number of radiographic frames (NDA is equal to 1154 and 1061, respectively, for S1 and S2 systems). This of course can be explained with the different experiences of cardiologists and complexity of the procedures. Patient doses could be even reduced for the S1 system if a higher exposure mode (Table 1) for some cases was not selected. Total DAPmeas value for the S4 system for CA procedures is 1.5 times more than the results of the S2 and S1 systems (Table 3). However TFL and NDA values are approximately the same for these systems. This can be explained with the investigation of system outputs and exposure parameters. As is shown in Table 1 fluoroscopic exposure rate at the patient entrance is two times more for the S4 system, and also higher kVp values were used for the patient studies in this system. In the case of CA-PT-SI procedures for the S4 system, the total DAPmeas is higher than the DAP values of the S1 and S2 systems due to the use of a higher number of radiographic frames. It is also worth mentioning that total DAPmeas as well as DAPmeas(FL) and DAPmeas(DA) results for the S3 System are higher than S1 and S2 for all the procedures; however TFL and NRAD values of these system are almost the same as the other two. The reason for these higher doses can easily be explained with the higher input patient exposure values of the S3 system both for fluoroscopic and radiographic exposure modes. On the other hand, the lower HVL of this system should also be considered. The S3 and S4 systems belong to the same manufacturer but higher doses were measured for the S3 system for all the procedures. The higher value of DAPmeas(FL) can be explained by the differences in fluoroscopy times; however differences in frame numbers do not reflect the higher DAPmeas(DA) of the S3 system. The PIER values of these two systems in the fluoroscopy mode are quite close to each other, but the system output in the radiographic mode for the S3 system is higher (Table 1). The less use of smaller FOVs for S4 system is also an important reason for the lower doses of this system. We also investigated the distribution of DAPmeas(FL) and DAPmeas(DA) among the projections; fluoroscopic exposures were mainly concentrated on LAO 45 for all the procedures and systems; there is also a weighting of AP projection. However, more projections have been used for radiographic exposures (mainly CRAN 30, RAO 30, CRAN 30, RAO 30, LAO 45, and CAUD 30). These results are in good agreement with those reported by Efstathopoulos et al. [20]. Regarding the DAP measurements, the use of a transparent flat chamber is found to be the most reliable technique. It is online, excessive skin doses can be prevented by setting trigger DAP values, results can be used in patient records and data can be obtained separately for each projection. However this chamber is usually given by the manufacturers as an option and ignored to be purchased by many users. In the case of lack of this dosimeter, gross estimations of DAP can be made from the knowledge of the size of exposed area at the patient entrance using a slow film and air kerma measurement at a specific point on the central ray of X-ray beam. Although these films have a limited dose range a brief decision can be made about the weighting of projections and we found good correlations both for projection based (DAPmeas–DAPcalc) and also for the total DAP results (total DAPmeas–DAPrchf and total DAPcalc–DAPrchf). But total DAPcalc values were found to be higher than total DAPmeas and DAPrchf. Different factors may affect these results; for DAPcalc, radiographic films exposures for area determination were made only for PA projection, so the same exposed area on the film was used for DAP calculation for the other projections. Although each step of the clinical examinations was carefully observed during the course of the study, uncertainties in distance measurements caused some errors in AK readings. It was difficult in some cases to exactly determine the border of exposed areas on both radiographic and radiochromic films. The dead zone of the small ion chamber of the DAP meter used in this study also caused an underestimation of the DAPmeas data [13]. On the other hand, some of the exposed body parts may remain out of the radiochromic film during the procedure for some projections (i.e. LLAT) causing an underestimation of DAPrchf but this was negligible in our study due to the very low use of the LLAT projection. Calculation of total DAP from the radiochromic film also enables the estimation of effective dose by using a single Monte Carlo conversion coefficient. However, due to the overlapping of exposed areas on the film, dose information cannot be obtained for separate projections, and using a single representative coefficient for the whole study introduces errors in effective dose results up to 30%. Although there are considerable uncertainties in effective dose calculations, such as deviations of individual patient anatomies and exposure parameters from those used in simulation studies, the mean of our Eff.D/DAPmeas ratio of 0.24 (0.21–0.27) is close to 0.19 [19], 0.18 [20] and 0.26 (average of CA and PTCA results) [18]. Considering the deterministic effects of radiation, the projection based dose information could be useful for patient dose reduction. For example the primary X-ray beam may be slightly orientated to less sensitive body parts in the case of extensive exposures if the clinical procedure permits. Although a number of TLDs were placed at different points around the patient's body to measure the projection doses, less accurate results were obtained with this technique. Errors in TLD locations were noticed when their position was marked on the exposure maps obtained from the radiochromic films. The poor correlation (R2=0.48) found in total DAPmeas versus ESDTLD plot confirms this finding. Measurement of AK at a specific point (i.e. IRP center) is recommended as a dosimetric technique [21], and is beginning to be offered as an option by some manufacturers. Reliability of this method was also investigated by taking the advantages of small ion chambers and results were compared with TLD readings. Although the skin doses were calculated from the AK readings in this study, this method is not easy to implement in routine applications since it requires distance correction for each irradiation geometry. Results should be considered as an upper limit of the skin doses since AK readings with the ion chamber were based on the assumption that the same skin area was continually exposed to X-ray beams. Although some TLD readings were found to be higher for some projections due to the contribution of exposures coming from the other projections, when the maximum skin doses are considered ESDAK was always higher than ESDTLD. Remembering the high correlation of ESDAK with DAPmeas in projection based data, this method can be used for skin dose estimation if there is an initial knowledge of dominant projection or alternatively, total air kerma of the examination could be assigned to a certain projection. It should be kept in mind that AK readings were not affected by the exposure of other views. The use of radiochromic films for skin dose assessment should be the method of choice for the interventional procedures since the contribution of doses from overlapped projections and scatter is better included and a map of the exposed body parts also obtained. They can be easily handled; however their high cost may be a drawback for routine use. Obtaining the DAP versus skin dose relationship can be quite useful for the derivation of the DAP trigger value corresponding to threshold skin dose. A trigger value of 130Gycm2 can be suggested for the 2Gy of skin dose if the total DAPmeas with ESDAK relationship is used. But it should be kept in mind that these AK values were the total of all projection readings and a lower value of DAP may be selected. A trigger value of 100Gycm2 was reported by McFadden [22]. The comparison of our data with the literature is given in Table 6a–c for CA, PT-SI, CA-PT-SI and ablation procedures. The average of four systems has been taken for the procedures (with the exception of ablation studies). In general, all the findings were within the range of reported values with the exception of maximum skin doses. This was probably due to the recording of dose data from the overlapping of exposed areas through the use of radiochromic films, and reasons stated above. Acknowledgements The authors would like to acknowledge the support of the International Atomic Energy Agency (IAEA) for providing radiochromic films under the support of the CRP project (12380/R0). The co-operation of the Cardiologists of Cardiology Departments of the Ankara University Faculty of Medicine and Gazi University Faculty of Medicine is greatly appreciated. References [1]. [1]Koenig TR, Wolff D, Mettler FA, Wagner LK. Skin injuries from fluoroscopically guided procedures I. Characterization of radiation injury. Am J Roentgenol. 2001;177:3–11. [2]. [2]Koenig TR, Mettler FA, Wagner LK. Skin injuries from fluoroscopically guided procedures. I Review of 73 cases and recommendations for minimizing dose delivered to patient. Am J Roentgenol. 2001;177:13–20. [3]. [3]Geise RA, O'Dea TJ. Radiation dose in interventional fluoroscopic procedures. Appl Radiat Isot. 1999;50(1):173–184. MEDLINE |
CrossRef
[4]. [4]Vano E, Guibelalde E, Fernandez JM, Gonzalez L. Patient dosimetry in interventional radiology using slow films. Br J Radiol. 1997;70:195–200. MEDLINE [5]. [5]Bower MW, Hintenlag DE. The characterization of a commercial MOSFET dosimeter system for use in diagnostic X ray. Health Phys. 1988;75:197–204. MEDLINE |
CrossRef
[6]. [6]Hwang E, Gaxiola E, Vlietstra RE, Brenner A, Ebersole D, Browne K. Real-time measurement of skin radiation during cardiac catheterization. Cathet Cardiovasc Diagn. 1998;43:367–370. MEDLINE |
CrossRef
[7]. [7]Wagner LK, Pollock JJ. Real time portal monitoring to estimate dose to skin of patients from high dose fluoroscopy. Br J Radiol. 1999;72:846–855. MEDLINE [8]. [8]Gkanatsios NA, Huda W, Peters KR, Freeman JA. Evaluation of an on-line patient exposure meter in neuroradiology. Radiology. 1997;203:837–842. MEDLINE [9]. [9]Den Boer A, Feijter PJ, Serruys PW, Roelandt JR. Real-time quantification display of skin radiation during coronary angiography. Circulation. 2001;104:1770–1784. [10]. [10]Giles ER, Murphy PH. Measuring skin dose with radiochromic dosimetry film in the cardiac catheterization laboratory. Health Phys. 2002;82(6):875–880. MEDLINE |
CrossRef
[11]. [11]Bor D, Sancak T, Olgar T, Elcim Y, Adanali A, Sanlidilek U, et al. Comparison of effective doses obtained from dose-area product and air kerma measurements in interventional radiology. Br J Radiol. 2004;77:315–322. MEDLINE |
CrossRef
[12]. [12]Institute of Physics and Engineering in Medicine. Recommended standards for the routine performance testing of diagnostic X-ray imaging systems. Report No 77. York: IPEM; 1997. [13]. [13]Gfirtner H, Stieve FE, Wild J. A new diamentor for measuring kerma–area product and air kerma simultaneously. Med Phys. 1997;24:1954–1959. MEDLINE |
CrossRef
[14]. [14]Jones DG, Wall BF. Organ doses from medical X-ray examinations calculated using Monte Carlo techniques. London: HMSO; 1985;. [15]. [15]Tapiovaara M, Lakkisto M, Servomaa A. PCXMC – A PC-based Monte Carlo program for calculating patient doses in medical X-ray examinations. Helsinki: Radiation and Nuclear Safety Authority (STUK); 1997;. [16]. [16]Leung KC, Martin CJ. Effective doses for coronary angiography. Br J Radiol. 1996;69:426–431. MEDLINE |
CrossRef
[17]. [17]Clark AL, Brennan AG, Robertson LJ, McArthur JD. Factors affecting patient radiation exposure during routine coronary angiography in a tertiary referral centre. Br J Radiol. 2000;73:184–189. MEDLINE [18]. [18]Delichas MG, Psarrakos K, Molyvda Athanassopoulou E, Giannoglou G, Hatziioannou K, Papanastassiou E. Radiation doses to patients undergoing coronary angiography and percutaneous transluminal coronary angioplasty. Radiat Prot Dosimetry. 2003;103(2):149–154. MEDLINE [19]. [19]Broadhead DA, Chapple CL, Faulkner K, Davies ML, McCallum H. The impact of cardiology on the collective effective dose in the North of England. Br J Radiol. 1997;70:492–497. MEDLINE [20]. [20]Efstathopoulos EP, Makrygiannis SS, Kottou S, Karvouni E, Giazitzoglou E, Korovesis S, et al. Medical personnel and patient dosimetry during coronary angiography and intervention. Phys Med Biol. 2003;48(18):3059–3068. MEDLINE |
CrossRef
[21]. [21]Balter S. Methods for measuring fluoroscopic skin dose. Radiat Prot Dosimetry. 2006;36(2):136–140. [22]. [22]McFadden SL, Money RB, Shepherd PH. X-ray dose and associated risks from radiofrequency catheter ablation procedures. Br J Radiol. 2002;75:253–265. MEDLINE [23]. [23]Park TH, Eichling SO, Schechtman KB, Bromberg BI, Smith JM, Lindsay BD. Risk of radiation induced skin injuries from arrhythmia ablation procedures. Pacing Clin Electrophysiol. 1996;19(9):1363–1369. MEDLINE |
CrossRef
[24]. [24]Mooney RB. Skin dose to patients from international radiology and cardiology procedures with potentially long fluoroscopy times. Radiat Prot Dosimetry. 2000;90(1–2):123–126. [25]. [25]Webster CM, Hayes D, Horrocks J. Investigation of radiation skin dose in interventional cardiology. IAEA-CN-85/71. Vienna; 2001. p. 272–6. [26]. [26]Padovani R. Radiation protection in interventional radiology: experience in Italy in neuroradiology and cardiology. In: Vano E, Guidelalbe E editor. Radiation protection in interventional radiology. Proc. ERPET course, Madrid. Brussels: European Commission; June 1998;. [27]. [27]Maccia C. An optimization study of cardiac interventional radiology procedures: an experience in France, ERPET in Madrid; 1997. p. 113–9. [28]. [28]Cusma JT, Malcolm RB, Wondrow MA, Taubel JP, Holmes DR. Real-time measurement of radiation exposure to patients during diagnostic coronary angiography and percutaneous interventional procedures. J Am Coll Cardiol. 1999;33:427–435. Abstract | Full Text |
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CrossRef
[29]. [29]Hansson B, Karambatsakidou A. Relationships between entrance skin dose, effective dose and dose area product for patients in diagnostic and interventional cardiac procedures. Radiat Prot Dosimetry. 2000;90:141–144. [30]. [30]Van de Putte S, Verhaegen F, Taeymans Y, Thierens H. Correlation of patient skin doses in cardiac interventional radiology with dose–area product. Br J Radiol. 2000;73:504–513. MEDLINE [31]. [31]Vano E, Gonzalez L, Ten JI, Fernandez JM, Guibelalde E, Macaya C. Skin dose and dose–area product values for interventional cardiology procedures. Br J Radiol. 2001;74:48–55. MEDLINE [32]. [32]Lobotessi H, Karoussou A, Neofotistou V, Louisu A, Tsapaki V. Effective dose to a patient undergoing coronary angiography. Radiat Prot Dosimetry. 2001;94:173–176. MEDLINE [33]. [33]Sandborg M, Fransson SG, Pettersson H. Evaluation of patient and staff absorbed doses during coronary angiography and intervention by femoral and radial artery access routes. Eur Radiol. 2004;14(4):653–658. MEDLINE |
CrossRef
a Ankara University, Institute of Nuclear Science, Department of Medical Physics, Dogol, 06100 Tandoğan, Ankara, Turkey b Medical Physics Department, S. Maria della Misericordia Hospital, 33100 Udine, Italy  Corresponding author. Tel.: +90 (312) 212 0384x1525, (533) 211 9961 (mobile); fax: +90 (312) 212 7343.
PII: S1120-1797(08)00045-8 doi:10.1016/j.ejmp.2008.03.002 © 2009 Associazione Italiana di Fisica Medica. Published by Elsevier Inc. All rights reserved. | |
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