Cineangiógrafo para el manejo de lesiones vasculares cerebrales / Cineangiographer for the management of cerebral vascular lesions

INTRODUCCIÓN: Los procedimientos intervencionistas cerebrales vasculares o neuroangiografías, son herramientas fundamentales en el diagnóstico y manejo de las lesiones vasculares cerebrales. Cuadro clínico: Entre estos procedimientos se encuentran la colocación de stents, clipping, embolizaciones, entre otros. Para realizar la neuroangiografía es necesario acceder a la arteria femoral común a e introducir un catéter a la zona afectada. Además, se necesita un dispositivo para la visualización del procedimiento en pantalla. Usualmente el dispositivo que se utiliza para visualización del procedimiento en una pantalla es el Arco en C o Brazo en C que se basa en tecnología de rayos X. Tecnología sanitaria: El cinengiógrafo es un dispositivo que utiliza para la grabación de imágenes en movimiento con el objetivo de rastrear el paso del material de contraste a través de los vasos sanguíneo. Este equipo obtiene imágenes digitales multidimensionales en alta calidad en tiempo real. No se ha encontrado una fuente de información oficial que reporte marcas de cineangiógrafos disponibles en el país. Sin embargo, a partir de una búsqueda genérica se ha encontrado que la marca PHILLIPS Biplano Allura Xper FD20/10. OBJETIVO: Evaluar la eficacia y seguridad, así como documentos relacionados a la decisión de cobertura del cineangiografo para manejo de lesiones vasculares cerebrales. METODOLOGÍA: Se realizó una búsqueda en las principales bases de datos bibliográficacas: MEDLINE, LILACS, COCHRANE, así como en buscadores genéricos de Internet incluyendo Google Scholar y TRIPDATABASE. Adicionalmente, se hizo una búsqueda dentro de la información generada por las principales instituciones internacionales de neurocirugía y agencias de tecnologías sanitarias que realizan revisiones sistemáticas (RS), evaluación de tecnologías sanitarias (ETS) y guías de práctica clínica (GPC). RESULTADOS: No se identificaron ensayos clínicos aleatorizados, revisiones sistemáticas o estudios observacionales que proporcionaran datos comparativos de la tecnología de interés versus el comparador. Complementariamente, se identificaron una serie de casos y un reporte de casos. No se encontraron guías de prácticas clínicas, evaluaciones de tecnología ni evaluaciones económicas que evaluaran a la tecnología de interés. CONCLUSIONES: La evidencia con respecto al uso de cineangiógrafo para el manejo de lesiones vasculares cerebrales es escasa. Si bien no se identificó estudios comparativos del uso de esta tecnología, existen escasas series de casos y reportes de casos que utilizan la tecnología evidenciándose el éxito en los procedimientos sin reporte de eventos adversos asociados a la intervención. Las guías de práctica clínica recabadas recomiendan a la angiografía para el manejo de pacientes con lesiones vasculares según sea el caso, pero no especifican una técnica preferencial para el procedimiento. No se encontraron evaluaciones de tecnología ni evaluaciones económicas que evaluaran a la tecnología de interés.

Variability in radiation dose and image quality: A comparison across fluoroscopy-system vendors, generations of equipment and institutions.

OBJECTIVES: To evaluate differences in radiation dose and image quality across institutions, fluoroscope vendors and generations of fluoroscopes for pediatric cardiac catheterization. BACKGROUND: Increased recognition of the potentially harmful effects of ionizing radiation has spurred technological advances in fluoroscopes, as well as increased focus on optimizing fluoroscope performance. There is currently little understanding of variability in the dose-image quality relationship across institutions, fluoroscope vendor and/or generation of equipment. METHODS: We evaluated latest generation fluoroscopes from Phillips, Siemens, GE, and Toshiba, and an older generation Phillips fluoroscope (release date 2003) at three different institutions. Radiation dose was measured using an anthropomorphic dose-assessment phantom with effective dose in mSv estimated from Monte Carlo simulations. Image quality phantom images were scored on a 12-point scale by three blinded reviewers. RESULTS: Fluoroscope effective doses ranged from 0.04 to 0.14 mSv/1,000 pulses for fluoroscopy with associated composite image quality scores ranging from 8.0 ± 0.6 to 10.4 ± 1.3. For cineangiography, effective doses ranged from 0.17 to 0.57 mSv/1,000 frames with image quality scores ranging from 10.1 ± 0.3 to 11.1 ± 0.3. There was modest correlation between effective dose and image quality (r = 0.67, P = 0.006). The older generation fluoroscope delivered consistently higher doses than the newer generation systems (2.3- to 3.5-fold higher for fluoroscopy; 1.1- to 3.4-fold higher for cineangiography) without appreciable differences in image quality. CONCLUSION: Technological advances have markedly improved fluoroscope performance. Comparing latest generation systems across vendors and institutions, we found variability in the dose-IQ relationship and speculate that this reflects both equipment and institutional optimization practices.

Radiation Protocol for Three-Dimensional Rotational Angiography to Limit Procedural Radiation Exposure in the Pediatric Cardiac Catheterization Lab.

BACKGROUND: Three-dimensional rotational angiography (3DRA) offers more detailed anatomic information than 2D digital acquisition (2DDA). Concerns over potentially higher contrast and radiation doses have limited its routine use. OBJECTIVE: The primary objective of this study was to compare radiation doses required to obtain 3DRA using a customized low dose radiation protocol with 2DDA. The secondary objective was to compare total procedural radiation in pediatric cardiac catheterization procedures utilizing 3DRA to those that do not. STUDY DESIGN: Phantom studies were conducted to establish customized 3DRA protocols for radiation reduction. Comparison of 3DRA and non-3DRA procedures in age-, size- and diagnosis-matched controls was performed. Radiation doses were indexed to body surface area (BSA) to account for differing body habitus as validated from the phantom study. RESULTS: Study (n = 100) and control (n = 100) groups were matched for age (10.2 vs. 9.98 years; P = .239) and BSA (1.23 vs. 1.09 m2 ; P = .103). The dose area product (DAP) to acquire a 3DRA was similar to a 5 s, 15 frames/second 2DDA (278 vs. 241 cGy/cm2 ; P = .14). Despite the 3DRA group consisting of more complex interventions, no difference was found in the total procedural Air Kerma and DAP indexed to BSA (244 vs. 249 mGy/m2 ; P = .79 and 3348 vs. 3176 cGy/cm2 /m2 ; P = .48, respectively). The contrast volume to acquire a 3DRA compared to a 2DDA was greater (1.59 vs. 1.01 mL/kg; P < .001). However, no difference was found for the entire procedure (3.8 vs. 4 mL/kg, P = .494). This could have resulted from the need to obtain multiple 2DDAs to achieve the detail of a single 3DRA (11 vs. 7 per study; P < .001). CONCLUSIONS: When 3DRA, using the proposed protocols is employed, total procedural contrast and radiation doses are comparable with the sole use of biplane cine-angiograms. These protocols may allow for routine use of 3DRA for congenital cardiac catheterizations.

Comparison of radiation dose between different fluoroscopy systems in the modern catheterization laboratory: Results from bench testing using an anthropomorphic phantom.

BACKGROUND: Variations in radiation dose between various X-ray systems have received limited study. OBJECTIVE: We examined the impact of X-ray system type on patient radiation dose during cardiac catheterization. METHODS: An anthropomorphic phantom was used in a series of standardized experiments that involved 15 sec of continuous cineangiography in 7 projections. Three to seven experiments were performed in four commonly used X-ray systems: Innova IGS (GE Healthcare), Integris Allura FD20 (Philips), Allura Clarity (Philips), and Artis one (Siemens). Phantom radiation dose was measured with a dedicated X-ray dosimetry system (Gafchromic radiology film and Film QA XR software, Ashland) that was precalibrated at 0, 1, 2, 3, and 4 Gray, and with the X-ray system built-in functions. RESULTS: Radiation dose was lowest with the Allura Clarity system [average film dose 4.2±0.1 cGray, peak film dose 18.3±1.6 cGray, Air Kerma (AK) dose 0.310±0.002 Gray, Dose Area Product (DAP) dose 23.72±0.84 Gray*cm2], intermediate with the Integris Allura FD20 (average film dose 4.4±1.1 cGray, peak film dose 29.4±15.5 cGray, AK 0.482±0.189 Gray, DAP 45.18±21.90 Gray*cm2), and highest with the Artis one system (average film dose 7.4±0.8 cGray, peak film dose 66.9±0.09 cGray, AK 0.746±0.085 Gray, DAP 75.93±9.11 Gray*cm2) and the Innova IGS system (average film dose 7.2±1.0 cGray, peak film dose 49.3±28.9 cGray, AK 0.874±0.340 Gray, DAP 92.28±14.73 Gray*cm2; P=0.011 for average film dose, P=0.019 for maximum film dose, P=0.033 for AK, and P=0.008 for DAP). CONCLUSIONS: The X-ray system type has significant impact on patient radiation dose during cardiac catheterization.

Novel X-ray imaging technology enables significant patient dose reduction in interventional cardiology while maintaining diagnostic image quality.

OBJECTIVES: The purpose of this study was to quantify the reduction in patient radiation dose during coronary angiography (CA) by a new X-ray technology, and to assess its impact on diagnostic image quality. BACKGROUND: Recently, a novel X-ray imaging technology has become available for interventional cardiology, using advanced image processing and an optimized acquisition chain for radiation dose reduction. METHODS: 70 adult patients were randomly assigned to a reference X-ray system or the novel X-ray system. Patient demographics were registered and exposure parameters were recorded for each radiation event. Clinical image quality was assessed for both patient groups. RESULTS: With the same angiographic technique and a comparable patient population, the new imaging technology was associated with a 75% reduction in total kerma-area product (KAP) value (decrease from 47 Gycm2 to 12 Gycm2, P<0.001). Clinical image quality showed an equivalent detail and contrast for both imaging systems. On the other hand, the subjective appreciation of noise was more apparent in images of the new image processing system, acquired at lower doses, compared to the reference system. However, the higher noise content did not affect the overall image quality score, which was adequate for diagnosis in both systems. CONCLUSIONS: For the first time, we present a new X-ray imaging technology, combining advanced noise reduction algorithms and an optimized acquisition chain, which reduces patient radiation dose in CA drastically (75%), while maintaining diagnostic image quality. Use of this technology may further improve the radiation safety of cardiac angiography and interventions.

Dynamic volumetric CT angiography for the detection and classification of endoleaks: application of cine imaging using a 320-row CT scanner with 16-cm detectors.

PURPOSE: To assess the feasibility and diagnostic performance of dynamic volumetric computed tomography (CT) angiography with large-area detectors in the detection and classification of endoleaks after endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: Low-dose dynamic volumetric CT angiography performed with the patient in Fowler position was used to scan the entire stent graft with a 16-cm-area detector during the first follow-up examination after EVAR. There were 39 consecutive patients (36 men and 3 women; mean age, 74 y ± 8.7) examined with approximately 14-20 intermittent scans (temporal resolution, 2 s; scan range, 160 mm). The effective radiation dose, image quality, interobserver and intraobserver agreement for endoleak detection, and time delay between peak enhancement of the aorta and endoleaks were evaluated. RESULTS: All examinations with the patient in Fowler position enabled the entire stent graft to be scanned and were rated as diagnostic. The mean effective radiation dose was 13.1 mSv. Endoleaks were detected in eight patients (type Ia, n = 1; type II, n = 6; type III, n = 1). Interobserver agreement (κ = 0.794) and intraobserver agreement (κ = 1.00) for detection of endoleaks were excellent. The mean time delay between peak enhancement of the aorta and the endoleaks was significantly less for type I/III endoleaks (2.0 s ± 0) compared with type II endoleaks (5.3 s ± 1.0; P < .001). CONCLUSIONS: Low-dose dynamic volumetric CT angiography performed with the patient in Fowler position is feasible after EVAR. Dynamic information, including cine imaging, the timing of peak enhancement, and the Hounsfield units index, is useful in detecting and classifying endoleaks.

The usefulness of ICG video angiography in the surgical treatment of superior cluneal nerve entrapment neuropathy: technical note.

Superior cluneal nerve (SCN) entrapment neuropathy is a known cause of low back pain. Although surgical release at the entrapment point of the osteofibrous orifice is effective, intraoperative identification of the thin SCN in thick fat tissue and confirmation of sufficient decompression are difficult. Intraoperative indocyanine green video angiography (ICG-VA) is simple, clearly demonstrates the vascular flow dynamics, and provides real-time information on vascular patency and flow. The peripheral nerve is supplied from epineurial vessels around the nerve (vasa nervorum), and the authors now present the first ICG-VA documentation of the technique and usefulness of peripheral nerve neurolysis surgery to treat SCN entrapment neuropathy in 16 locally anesthetized patients. Clinical outcomes were assessed with the Roland-Morris Disability Questionnaire before surgery and at the latest follow-up after surgery. Indocyanine green video angiography was useful for identifying the SCN in fat tissue. It showed that the SCN penetrated and was entrapped by the thoracolumbar fascia through the orifice just before crossing over the iliac crest in all patients. The SCN was decompressed by dissection of the fascia from the orifice. Indocyanine green video angiography visualized the SCN and its termination at the entrapment point. After sufficient decompression, the SCN was clearly visualized on ICG-VA images. Low back pain improved significantly, from a preoperative Roland-Morris Questionnaire score of 13.8 to a postoperative score of 1.3 at the last follow-up visit (p < 0.05). The authors suggest that ICG-VA is useful for the inspection of peripheral nerves such as the SCN and helps to identify the SCN and to confirm sufficient decompression at surgery for SCN entrapment.

Flat panel digital detector cinefluoroscopy late following SES or BMS implantation for detection of coronary stent fracture in asymptomatic patients.

BACKGROUND: Coronary stent fracture (SF), is rare and confined mainly in patients treated with sirolimus eluting stents (SES). The role of flat panel digital detector (FPDD) fluoroscopy in detecting SF has not been investigated. METHODS: Assessment with FPDD fluoroscopy of asymptomatic patients, with 200 SES (Cypher, Cordis, J&J, Miami, Florida, US), and 200 bare metal stents (BMS), at 45.5 ± 15.7 and 38.4 ± 3.9 months post-stenting respectively. SF was defined as discontinuity of stent struts on fluoroscopy. Coronary angiography was reserved for patients with documented SF. RESULTS: Effective radiation dose was 0.26 ± 0.14 mSv. SF was depicted in 6 (3%) SES, and 1 BMS (0.5%). Stent length was an independent predictor of SF (OR 1.19, 95% CI 1.03-1.4, p=0.024). RCA location and vessel angulation were marginally significant (OR 7.7, 95% CI 0.8-74.2, p=0.077 and OR 5.1, 95% CI 0.8-34, p=0.089). Significant angiographic restenosis was detected in 4 SES (66.6%), and 1 BMS (0.5%). Re-intervention was needed in 3 (42.8%) cases, (2 SES and 1 BMS). CONCLUSION: Detection of SF with FPDD cinefluoroscopy late following coronary stenting is feasible, involves low radiation and is confined mainly to SES compared to BMS. Application of cinefluoroscopy as part of a routine stent surveillance programme in asymptomatic patients may be more appropriate in "high risk" settings (SES, long stents and adverse angiographic characteristics). The role of invasive imaging and subsequent management of such patients need further studying.

Physician-received scatter radiation with angiography systems used for interventional radiology: comparison among many X-ray systems.

Radiation protection for interventional radiology (IR) physicians is very important. Current IR X-ray systems tend to use flat-panel detectors (FPDs) rather than image intensifiers (IIs). The purpose of this study is to test the hypothesis that there is no difference in physician-received scatter radiation (PRSR) between FPD systems and II systems. This study examined 20 X-ray systems in 15 cardiac catheterisation laboratories (11 used a FPD and 9 used an II). The PRSR with digital cineangiography and fluoroscopy were compared among the 20 X-ray systems using a phantom and a solid-state-detector electronic pocket dosemeter. The maximum PRSR exceeded the minimum PRSR by ~12-fold for cineangiography and ~9-fold for fluoroscopy. For both fluoroscopy and digital cineangiography, the PRSR had a statistically significant positive correlation with the entrance surface dose (fluoroscopy, r = 0.87; cineangiography, r = 0.86). There was no statistically significant difference between the average PRSR of FPDs and IIs during either digital cineangiography or fluoroscopy. There is a wide range of PRSR among the radiography systems evaluated. The PRSR correlated well with the entrance surface dose of the phantom in 20 X-ray units used for IR. Hence, decreasing the dose to the patient will also decrease the dose to staff.

Bench top evaluation and clinical experience with the Szabo technique: new questions for a complex lesion.

BACKGROUND: The Szabo technique has been described as a method to ensure accurate ostial stent placement. We sought to investigate this novel technique in detail both in vitro and in vivo. METHODS AND RESULTS: The technique was subjected to bench testing and also undertaken in 26 patients. Each step was recorded with cine angiography and the stents imaged by microcomputed tomography. The ostial LAD was treated in 81% and a DES was implanted in 92%. Angiographic success was 88.5% (one case of stent dislodgement). Repeat angiography was performed in 78% and restenosis observed in two patients. MACE rate at 15.5 ± 5.1 months was 13% (1 TLR, 1 MI, 1 cardiac death). Despite a seemingly excellent immediate angiographic result, we report one case of restenosis at follow up and one case of IVUS examination (performed in four patients) in which significant stent protrusion, into the proximal main vessel, was observed. In vitro bench testing confirmed a significant and asymmetric (carina side) stent protrusion into the main branch, with the last cell of the stent undergoing significant deformation. CONCLUSIONS: The Szabo technique is not a precise technique to implant a stent at the level of the ostium. The proximal end of the stent undergoes significant and asymmetric deformation, protruding into main branch. Additional concerns with this complex technique include the potential for stent damage or contamination before implantation and the risk of stent dislodgement. We conclude that there are more disadvantages than benefits to this technique which only partially addresses the difficulties encountered in the treating ostial lesions.

Validity and variability in visual assessment of stenosis severity in phantom bifurcation lesions: a survey in experts during the fifth meeting of the European Bifurcation Club.

OBJECTIVES: To investigate the adequacy of visual estimate regarding the percent diameter stenosis (DS) in bifurcation lesions. BACKGROUND: Quantitative coronary angiography (QCA) is more accurate and precise compared to visual estimate in assessing stenosis severity in single-vessel lesions. METHODS: Thirty-six experts in the field of bifurcation PCI visually assessed the DS in cine images of five precision manufactured phantom bifurcation lesions, experts being blinded to the true values. Expert DS estimates were compared with the true values and they were also used to define the Medina class of each individual bifurcation. Results were pooled together both for proximal main vessel (PMV), distal main vessel (DMV) and side-branch (SB) segments and for vessel segments with similar DS values. RESULTS: Individual performance was highly variable among observers; pooled values and range of accuracy and precision were 2.79% (-6.67% to 17.33%) and 8.69% (4.31-16.25%), respectively. On average, DS was underestimated in the PMV (-1.08%, P = 0.10) and overestimated in the DMV (3.86% P < 0.01) and SB segments (5.58%, P < 0.01). Variability in visual estimates was significantly larger in lesions of medium severity compared to the clearly obstructive ones (P < 0.01); the latter were consistently overestimated. Inter-observer agreement was moderate (κ = 0.55) over the entire number of estimates. However, if the segments with true DS = 0% were excluded, agreement was diminished (κ = 0.27). Inter-observer agreement in Medina class was rather low (κ = 0.21). True bifurcation lesions were misclassified as non-true ones in 14/180 estimates. CONCLUSIONS: Visual assessment by experts is more variable and less precise in the analysis of bifurcation lesions compared to bifurcation QCA software.

Concomitant one-stage unifocalization and bidirectional Glenn procedure.

A concomitant one-stage unifocalization and bidirectional Glenn procedure was performed in a patient with a functionally single ventricle, pulmonary atresia, and major aortopulmonary collateral arteries (MAPCAs). Reconstruction of the absent central pulmonary artery was achieved using the MAPCAs as well as the autologous pericardium. After 1 year, cineangiography and cardiac catheterization showed an excellent result: well-developed pulmonary arteries as well as low pressure in the superior vena cava. To the best of our knowledge, this is the first report of a successful concomitant one-stage unifocalization and bidirectional Glenn procedure.

Radiation dose of interventional radiology system using a flat-panel detector.

OBJECTIVE: Currently, cardiac interventional radiology equipment has tended toward using flat-panel detectors (FPDs) instead of image intensifiers (IIs) because FPDs offer better imaging performance. However, the radiation dose from an FPD in cardiac interventional radiology is not clear. The purpose of our study was to measure the radiation doses during cineangiography and fluoroscopy of many cardiac radiology systems that use FPDs or IIs, in clinical settings. MATERIALS AND METHODS: This study examined 20 radiology systems in 15 cardiac catheterization laboratories (11 used FPD and nine used II). The entrance surface doses with digital cineangiography and fluoroscopy were compared for the 20 systems using acrylic plates (20-cm thick) and a skin dose monitor. RESULTS: For fluoroscopy, the average entrance surface doses of the 20-cm-thick acrylic plates were identical for FPD (average +/- SD, 16.63 +/- 7.89 mGy/min; range, 5.7-26.4 mGy/min; maximum/minimum, 4.63) and II (17.81 +/- 12.52 mGy/min; range, 6.5-42.2 mGy/min; maximum/minimum, 6.49) (p = 0.799). For digital cineangiography, the average entrance surface dose of the 20-cm-thick acrylic plate was slightly lower with FPD (29.68 +/- 16.40 mGy/10 s; range, 8.9-58.5 mGy/10 s; maximum/minimum, 6.57) than with II (38.50 +/- 33.71 mGy/10 s; range, 15.2-117.1 mGy/10 s; maximum/minimum, 7.70), although the difference was not significant (p = 0.487). CONCLUSION: We found that the average entrance doses of cineangiography and fluoroscopy in FPD systems were not significantly different from those in II systems. Hence, FPDs did not inherently reduce the radiation dose, although FPDs possess good detective quantum efficiency. Therefore, to reduce the radiation dose of cardiac interventional radiology systems, even FPD systems, practical measures are necessary.

A robust 3-D IVUS transducer tracking using single-plane cineangiography.

During an intravascular ultrasound (IVUS) intervention, a catheter with an ultrasound transducer is introduced in the body through a blood vessel, and then, pulled back to image a sequence of vessel cross sections. Unfortunately, there is no 3-D information about the position and orientation of these cross-section planes, which makes them less informative. To position the IVUS images in space, some researchers have proposed complex stereoscopic procedures relying on biplane angiography to get two X-ray image sequences of the IVUS transducer trajectory along the catheter. To simplify this procedure, we and others have elaborated algorithms to recover the transducer 3-D trajectory with only a single view X-ray image sequence. In this paper, we present an improved method that provides both automated 2-D and 3-D transducer tracking based on pullback speed as a priori information. The proposed algorithm is robust to erratic pullback speed and is more accurate than the previous single-plane 3-D tracking methods.

Three-dimensional motion tracking of coronary arteries in biplane cineangiograms.

A three-dimensional (3-D) method for tracking the coronary arteries through a temporal sequence of biplane X-ray angiography images is presented. A 3-D centerline model of the coronary vasculature is reconstructed from a biplane image pair at one time frame, and its motion is tracked using a coarse-to-fine hierarchy of motion models. Three-dimensional constraints on the length of the arteries and on the spatial regularity of the motion field are used to overcome limitations of classical two-dimensional vessel tracking methods, such as tracking vessels through projective occlusions. This algorithm was clinically validated in five patients by tracking the motion of the left coronary tree over one cardiac cycle. The root mean square reprojection errors were found to be submillimeter in 93% (54/58) of the image pairs. The performance of the tracking algorithm was quantified in three dimensions using a deforming vascular phantom. RMS 3-D distance errors were computed between centerline models tracked in the X-ray images and gold-standard centerline models of the phantom generated from a gated 3-D magnetic resonance image acquisition. The mean error was 0.69 (+/- 0.06) mm over eight temporal phases and four different biplane orientations.

Coronary artery dynamics in vivo.

There is considerable evidence that the localization and evolution of vascular disease are mediated, at least in part, by mechanical factors. The mechanical environment of the coronary arteries, which are tethered to the beating heart, is influenced by cardiac motion; the motion of the vessels must be described quantitatively to characterize fully the mechanical forces acting on and in the vessel wall. Several techniques that have been used to characterize coronary artery dynamics from biplane cineangiograms are described and illustrated. There is considerable variability in dynamic geometric parameters from site to site along a vessel, between the right and left anterior descending arteries, and among individuals, consistent with the hypotheses that variations in stresses mediated by geometry and dynamics affect the localization of atherosclerosis and individual risk of coronary heart disease. The few frankly atherosclerotic vessels that have been examined exhibit high torsions in the neighborhood of lesions, an observation which may have etiologic or diagnostic implications.

Significant reduction of radiation exposure to operator and staff during cardiac interventions by analysis of radiation leakage and improved lead shielding.

The objectives of this study were to disclose and to reduce occupational radiation leakage in invasive cardiology. Prospectively, we analyzed various dose parameters for 330 coronary procedures. We used a Rando phantom to measure scatter entrance skin air kerma to the operator (S-ESAK-O) during fluoroscopy for all standard tube angulations, and to plot isodose lines for 0 degrees /0 degrees -posterior anterior angulation. The patient's measured dose area product due to diagnostic catheterization and elective percutaneous transluminal coronary angioplasty was 6.2 and 10.4 Gycm(2), which represents 11% and 13% of currently typical values, respectively. With use of 0.5- and 1.0-mm overcouch and undercouch shielding, it was possible to reduce the mean of 4,686 nSv/Gycm(2) to 677 and 277 nSv/Gycm(2), respectively. Closure of radiation leakage up to 897 microSv/hour at the operator's gonadal height (80 to 105 cm), not heretofore described, was achieved by an additional 1.0-mm, lead-equivalent undercouch-top and overcouch-flap adjacent to the table, down to a S-ESAK-O/dose area product level of 47.5 nSv/Gycm(2). With use of a 0.5-mm lead apron, collar, glasses, foot-switch shield and 1.0-mm lead cover around the patient's thighs, the operator received a mean S-ESAK-O of 8.5, while his forehead, eyes, thyroid, chest, gonads, and hands were exposed to 68.2, 1.2, 1.2, 1.2, 0.8, and 58.2 nSv/Gycm(2), respectively. In conclusion, radiation-attenuating intervention techniques and improved lead protection can effectively contribute to a new state of the art in invasive cardiology, with reduction of operator radiation exposure to 0.8% of typical S-ESAK-O levels in advanced catheterization laboratories.

[Secondary ionizing radiation generated by digital and analog coronary cineangiographic equipment: influence of external systems of radiologic protection]. / Radiación ionizante secundaria generada en equipos de cineangiografía coronaria digital y analógica: influencia de los sistemas externos de protección radiológica.

BACKGROUND: Exposure to ionizing radiation is a known hazard of radiological procedures. AIM: To compare the emission of secondary ionizing radiation from two coronary angiographic equipment, one with digital and the other with analog image generation. To evaluate the effectiveness of external radiological protection devices. MATERIAL AND METHODS: Environmental and fluoroscopy generated radiation in the cephalic region of the patient was measured during diagnostic coronary angiographies. Ionizing radiation generated in anterior left oblique projection (ALO) and in anterior right oblique projection (ARO) were measured with and without leaded protections. In 19 patients (group 1), a digital equipment was used and in 21 (group 2), an analog equipment. RESULTS: Header radiation for groups 1 and 2 was 1194 +/- 337 and 364 +/- 222 microGray/h respectively (p < 0.001). During fluoroscopy and with leaded protection generated radiation for groups 1 and 2 was 612 +/- 947 and 70 +/- 61 microGray/h respectively (p < 0.001). For ALO projection, generated radiation for groups 1 and 2 was 105 +/- 47 and 71 +/- 192 microGray/h respectively (p < 0.001). During filming the radiation for ALO projection for groups 1 and 2 was 7252 +/- 9569 and 1671 +/- 2038 microGray/h respectively (p = 0.03). Out of the protection zone, registered radiation during fluoroscopy for groups 1 and 2 was 2800 +/- 1741 and 1318 +/- 954 microGray/h respectively (p < 0.001); during filming, the figures were 15,500 +/- 5840 and 18,961 +/- 10,599 microGray/h respectively (NS). CONCLUSIONS: Digital radiological equipment has a lower level of ionizing radiation emission than the analog equipment.