Utilidad de la tomografía de coherencia óptica como guía en el tratamiento del síndrome coronario agudo: reporte de un caso / Utility of optical coherence tomography to guide treatment in acute coronary syndromes: case report / Utilidade da tomografia de coerência óptica como guia no tratamento da síndrome coronariana aguda: relato de um caso

La tomografía de coherencia óptica (OCT) es una técnica de imagen endovascular con elevada resolución espacial que permite evaluar las diferentes estructuras que componen la pared de las arterias coronarias, caracterizar morfológicamente la placa aterosclerótica y establecer el mecanismo fisiopatológico subyacente en los síndromes coronarios agudos (SCA). Se presenta el caso clínico de un paciente con infarto agudo de miocardio, donde la OCT evidenció que la reducción de la luz arterial estaba determinada principalmente por la presencia de trombo, a la vez que demostró una disrupción endotelial (ruptura de placa) como mecanismo fisiopatológico subyacente. Se adoptó una estrategia invasivo-conservadora, donde finalmente no se implantó stent. La información surgida de la OCT en este caso particular fue fundamental en la toma de decisiones.

Optical coherence tomography (OCT) is an endovascular imaging technique with high spatial resolution. It allows to evaluate the different structures that compose coronary arteries' wall, morphologically characterize atherosclerotic plaques and establish the underlying pathophysiological mechanism in acute coronary syndromes (ACS). The case of a patient with acute myocardial infarction is presented, in which OCT showed that the reduction of arterial lumen was determined mainly by the presence of thrombus, while also demonstrated endothelial disruption (plaque rupture) as the underlying pathophysiological mechanism. An invasive-conservative strategy was adopted and finally stent was not implanted. The information that emerged from the OCT in this particular case was fundamental in decision-making.

A tomografia de coerência óptica (OCT) é uma técnica de imagem endovascular com alta resolução espacial que permite a avaliação das diferentes estruturas que compõem a parede das artérias coronárias, a caracterização morfológica da placa aterosclerótica e o estabelecimento do mecanismo fisiopatológico subjacente de síndrome coronariana aguda (SCA). Apresentamos o caso clínico de um paciente com enfarte agudo do miocárdio, onde a OCT mostrou que a redução do lúmen arterial foi determinada principalmente pela presença de trombo, ao mesmo tempo que demonstrou uma ruptura endotelial (ruptura da placa) como causa fisiopatológica subjacente. Adotou-se uma estratégia invasiva-conservadora, onde finalmente o stent não foi implantado. As informações obtidas da OCT neste caso específico foram fundamentais na tomada de decisão.

Perfil clínico, dados do procedimento e achados angiográficos de pacientes submetidos à exame diagnóstico de cateterismo cardíaco esquerdo e cineangiocoronariografia em um centro de referência terciário de grande volume / Clinical profile, procedural data, and angiographic findings of patients undergoing diagnostic examination for left heart catheterization and coronary angiography at a high-volume tertiary referral center

INTRODUÇÃO: O estudo angiográfico invasivo permanece como o exame diagnóstico padrão-ouro para a determinação e quantificação da gravidade e extensão da doença arterial coronária (DAC) obstrutiva. No geral, a maioria das indicações para realização do exame na atualidade inclui procedimentos eletivos em pacientes com suspeita de DAC obstrutiva significativa e pacientes com quadro clínica agudo ou recente de síndrome coronária aguda (SCA). OBJETIVO Determinar o perfil clínico, os dados do procedimento e os achados angiográficos em termos de gravidade e extensão da DAC em pacientes submetidos à exame diagóstico de cateterismo cardíaco esquerdo e cineangiocoronariografia em um centro de referência terciário de grande volume na prática diária. MÉTODOS: Entre 2007 e 2021, foram realizados cerca de 80.572 exames diagnósticos de cateterismo cardíaco esquerdo mais cineangiocoronariografia na rotina da prática diária em um centro de referência terciário de grande volume. Os dados demográficos basais, perfil de risco, apresentação clínica e achados angiográficos foram obtidos a partir do banco de dados dedicado do Serviço de Cardiologia Invasiva da instituição, cujo preenchimento é atrelado a elaboração e liberação do laudo do exame. RESULTADOS: A média das idades era 68,2±11,7 anos e 61,2% eram do sexo masculino. Em relação aos fatores de risco para DAC, 29,5% tinham diabetes (4,6% insulino dependente), 69,9% hipertensão arterial sistêmica, 53,9% dislipidemia, 23,9% infarto agudo do miocárdio prévio, 10,2% intervenção coronária percutânea prévia, 1,7% acidente vascular encefálico prévio, 2,4% doença vascular periférica (diagnosticada previamente), 1,8% com insuficiência cardíaca descompensada e 18,5% insuficiência renal crônica. Tabagismo atual e histórico foram encontrados em 12,7% e 21,3%, respectivamente. O diagnóstico prévio de doença valvar associada foi encontrado em 4,2% e a média do índice de massa corpórea era de 27,7±5,9 kg/m2. No geral, a apresentação clínica de SCA (fase aguda ou recente) foi encontrada em um 40% dos casos. Em termos de procedimento, a via de acesso radial foi utilizada em cerca de um terço dos casos, introdutores 5-Fr. e 6-Fr foram utilizados em 24,8 e 74,8%, respectivamente, e a média de volume total de contraste foi de 64,5±29,9 mL. Sobre os achados angiográficos, o padrão de dominância foi direita em 80%, esquerda em 8,5% e co-dominância em 11,5%. A ventriculografia esquerda foi realizada em 96% dos casos e observou-se algum grau de disfunção em 41,7%. Cerca de 60% dos casos evidenciaram a presença de DAC obstrutiva significativa (>50%), sendo 24% uniarterial, 18% biarterial e 18% triarterial ou tronco da coronária esquerda. CONCLUSÕES: Nesta análise, observa-se um elevado perfil de risco incluindo múltiplas comorbidades e apresentação clínica aguda em grande proporção. Ademais, a maioria dos pacientes apresentou DAC significativa.

Niveles de referencia de dosis para adultos en procedimientos de cardiología intervencionista en Ecuador. / Reference even of dose for adults in procedures of cardiology interventionist in Ecuador

Antecedents and objective: The knowledge of the reference levels for diagnoses and therapeutic studies is important, because it contributes to the optimization of the radiological protection of the patients, avoiding them to be exposed to unnecessarily high doses. However, there was no evidence of these levels in interventionist cardiology procedures in Ecuador, so the objective of this study was to estimate the diagnostic reference levels of dose at the entrance surface in adult patients undergoing interventional cardiology procedures (cinecoronariography, catheterization and coronary percutaneous interventionism) in the Unit of Hemodynamic of the Hospital of Specialties Carlos Andrade Marín in Ecuador. Materials and methods: The measurements of product dose-area, dose in input surface, number of images and the time of fluoroscopy performed using the Axiom Artis angiographer, and the obtained data was tabulated and processed with the Excel computer program. For this study, 145 patients older than 18 years were selected, and the values obtained from diagnostic reference dose levels were compared with others reported in previous investigations and with the permissible limits for the appearance of deterministic effects on the skin. Results: This study made it possible to establish reference levels for diagnosis in interventional cardiology procedures (coronary angiography, catheterization and percutaneous coronary intervention) in the Hemodynamics Unit of the Carlos Andrade Marín Specialty Hospital in Ecuador. Conclusions: The results showed that the intake surface doses obtained were lower than the maximum levels recommended by the International Atomic Energy Agency.

Antecedentes y objetivo: El conocimiento de los niveles de referencia para estudios diagnósticos y terapéuticos es importante, dado que contribuye a la optimización de la protección radiológica de los pacientes y evita que se expongan a dosis innecesariamente altas; sin embargo, no se encontraron evidencias de estos niveles en procedimientos de cardiología intervencionista en Ecuador, por lo cual el objetivo de este estudio fue calcular los niveles de referencia diagnósticos de dosis en la superficie de entrada en pacientes adultos sometidos a procedimientos intervencionistas de cardiología (cinecoronariografía, cateterismo e intervencionismo percutáneo coronario) en la Unidad de Hemodinámica del Hospital de Especialidades Carlos Andrade Marín de Ecuador. Materiales y métodos: Las mediciones del producto dosis-área, dosis en superficie de entrada, número de imágenes y tiempo de fluoroscopia se realizaron con el angiógrafo Axiom Artis y los datos obtenidos se tabularon y procesaron con el programa informático Excel. Para este estudio se seleccionó a 145 pacientes mayores de 18 años y los valores obtenidos de niveles de referencia diagnósticos de dosis se compararon con otros informados en investigaciones anteriores y con los límites permisibles para la aparición de efectos deterministas en piel. Resultados: Este estudio permitió establecer los niveles de referencia para diagnóstico en los procedimientos intervencionistas de cardiología (cinecoronariografía, cateterismo e intervencionismo percutáneo coronario) en la Unidad de Hemodinámica del Hospital de Especialidades Carlos Andrade Marín de Ecuador. Conclusiones: Los resultados mostraron que las dosis en superficie de entrada obtenidas fueron menores a los niveles máximos recomendados por la International Atomic Energy Agency.

Efficacy of intraoperative cine-portogram for complicated portal vein reconstruction in pediatric living donor liver transplantation.

Sufficient PV flow is necessary to achieve successful PV reconstruction in pediatric LDLT. IOCP can be used to assess the severity of PV stenosis and to identify potential portosystemic collateral pathways. The present study reviewed the utility of IOCP and the outcomes of patients who underwent assessment with an IOCP. Consecutive primary LDLTs were performed in 488 pediatric recipients between November 2005 and October 2019. IOCP was used in patients who were unable to achieve sufficient PV flow after the ligation of collaterals. In total, 11 patients underwent IOCP to assess potential portosystemic collateral pathways. The median age and body weight was 8 months (IQR, 6-11 months) and 6.6 kg (IQR, 5.7-8.9 kg), respectively. The reasons for using the IOCP were recurrent PV thrombus in seven patients and insufficient PV flow in four patients. IOCP revealed remaining collaterals in six patients and residual hypoplastic PV in eight patients. Two patients required additional interruption of the potential collaterals under IOCP, which were unable to be recognized as a dominant portosystemic collateral pathway on preoperative imaging. All eight patients with residual hypoplastic PV required vein graft interposition for the complete removal of the hypoplastic PV. All the patients are currently doing well with a median follow-up period of 4.9 years (IQR, 2.2-5.6 years). IOCP can be an effective tool for precisely detecting occult portosystemic collateral pathways and for assessing the patency of the PV anastomosis in pediatric LDLT.

Fístula coronário-cavitária da artéria coronária circunflexa para o átrio esquerdo como provável etiologia de insuficiência cardíaca: relato de caso / Coronary­cavitary fistula of the circumflex coronary artery to the left atrium as a probable etiology of heart failure: a case report

Fístulas de artérias coronárias têm incidência baixa, sendo diagnosticadas mais frequentemente pelo ecocardiograma ou angiotomografia coronariana, embora a cineangiocoronariografia seja o método padrão-ouro. Têm origem mais comumente na artéria coronária direita, sendo a drenagem para câmaras de baixa pressão o mais habitual. O tratamento pode ser expectante, cirúrgico ou percutâneo. Este relato descreve o caso de uma rara apresentação de insuficiência cardíaca, dada por fístula da coronária circunflexa com drenagem para o átrio esquerdo. (AU)

Coronary artery fistulas have a low incidence and are often diagnosed by echocardiography or coronary computed tomography angiography, although coronary angiography is the gold standard. They commonly originate in the right coronary artery, with drainage to low-pressure chambers being the most frequent finding. Treatment can be expectant, surgical, or percutaneous. This report describes a case of a rare presentation of heart failure due to a fistula of the circumflex coronary artery with drainage into the left atrium. (AU)

Inter- and intra-core laboratory variability in the quantitative coronary angiography analysis for drug-eluting stent treatment and follow up.

AIM: To evaluate inter-core laboratory variability of quantitative coronary angiography (QCA) parameters in comparison with intra-core laboratory variability in a randomized controlled trial evaluating drug-eluting stents. METHODS: A total of 50 patients with 62 coronary lesions were analyzed by four analysis experts belonging to an Angiographic Core Laboratory (ACL: 1 expert) and a Cardiovascular Imaging Core Laboratory (CICL: 3 experts). QCA was based on the same standard operating procedure, but selections of projection and cine frames were at the discretion of each analyst. Inter- and intra-core laboratory variabilities were evaluated by accuracy, precision, Bland Altman analysis, and coefficient of variation. RESULTS: Pre-MLD (minimal lumen diameter) was significantly smaller in results from ACL than those from all CICL experts. Number of analyzed projections did not affect pre-MLD results. Acute gain was larger in ACL than in CICL2. No significant difference was observed in late loss and loss index between inter-core laboratories. Agreement between core labs in the Bland-Altman analysis for each QCA parameter was as follows (mean difference, 95% limits of agreement): pre-MLD (-0.32, -0.74 to 0.10), stent MLD (0.08, -0.28 to 0.44), acute gain (0.22, -0.44 to 0.88), and late loss (-0.07, -0.69 to 0.55). Agreement between analysts in CICL (mean difference, 95% limits of agreement) was: pre MLD (-0.03, -0.37 to 0.31), stent MLD (0.15, -0.15 to 0.45), acute gain (0.05, -0.45 to 0.55), and late loss (0.04, -0.52 to 0.60). The widest limits of agreement among three analyses were shown in both analyses. Width of limited agreement in the intra-core laboratory analysis tended to be smaller than the inter-core laboratory analysis with these parameters. Coefficient of variation tended to be larger in lesion length (LL), acute gain, late loss, and loss index in inter- and in intra- core laboratory comparisons. CONCLUSION: Inter-core laboratory QCA variability in late loss and loss index analysis could be similar to intra-core laboratory variability, but more strict alignment between core laboratories would be necessary for initial procedural data analysis.

Use of Large Balloon Catheter to Treat Infants With Pulmonary Valve Stenosis.

Balloon pulmonary valvuloplasty is a safe and effective treatment for isolated pulmonary valve stenosis. Several balloon catheters are available for this procedure in neonates and infants. However, obtaining additional vascular access for the double-balloon technique in this population is troublesome, and tricuspid valve injury is a concern. We used a TMP PED balloon catheter to perform valvuloplasty in 2 infants with isolated pulmonary valve stenosis. This thin-walled, relatively large 12-mm balloon catheter can be delivered through a small-diameter sheath. In both cases, the transpulmonary pressure gradient was reduced without causing any valvular or vascular injuries. Neither patient had recurrent pulmonary valve stenosis. Together, these cases highlight the suitability and feasibility of using the 12-mm TMP PED balloon catheter for treating young infants with valvular stenosis.

A randomized comparison of estimated radiation exposure between Low and conventional dose protocol during invasive coronary angiography (ERICA trial): Pilot study.

PURPOSE: Radiation exposure during coronary angiography is potentially harmful to patients and operators. However, there are limited data on the effects of a low-dose radiation angiography. We evaluated the feasibility and effectiveness of a reduced radiation dose protocol during invasive coronary angiography. METHODS: One hundred three consecutive patients who underwent coronary angiography were enrolled and randomized to low- or conventional dose protocols (LDP versus CDP). The LDP consists of 10 frames per second during fluoroscopy and half the radiation dose of CDP during cineangiography. Image quality was assessed using a Likert rating scale by an independent radiologist. The radiation dose was estimated with dose-area product (DAP) and air-kerma (AK). RESULTS: Body weight and waist circumference are well correlated with the level of DAP and AK. Exposure time and total images and frame counts in cineangiography were similar in both groups. There was a marked reduction of the estimated radiation dose (DAP and AK) in the LDP group compared to the CDP group without significant compromise in image quality (total DAP: LDP 1980.1 ±â€¯1163.7 vs. CDP 3434.2 ±â€¯2188.1 µGym2 p = 0.001; total AK: 279.6 ±â€¯159.3 vs. 493.8 ±â€¯280.6 mGy, p < 0.001). CONCLUSION: The LDP reduced the total estimated radiation dose compared to the CDP without a significant loss of diagnostic information. A LDP may be a viable strategy to protect patients and medical staff from the hazards of radiation in the cardiac catheterization laboratory.

Isquemia miocárdica sin lesiones coronarias obstructivas: MINOCA-INOCA: Revisión para la toma de decisiones GREECO (Grupo de Estudio de Enfermedades Coronarias) / Myocardial ischemia without coronary obstructions: MINOCA-INOCA. Review for decision making

Una de cada 4 coronariografías realizadas por isquemia miocárdica presenta lesiones menores al 50% Este dato desencadenó un creciente interés en la comunidad médica. La Sociedad Americana de Cardiología publicó recientemente un artículo que describe la posición consensuada de un grupo de expertos sobre la fisiopatología, el diagnóstico y el tratamiento de esta entidad. Nuestro trabajo refleja una revisión narrativa y la posición de un grupo de expertos pertenecientes a diferentes instituciones con servicios de Cardiología jerarquizados. Aborda aspectos fisiopatológicos y diagnósticos para comprender el enfoque actual del tratamiento, tanto en pacientes que ingresan con diagnóstico de MINOCA (infa rto de miocardio con lesiones angiográficas no graves) o de INOCA (angina e isquemia demostradas, pero sin lesiones coronarias que justifiquen este síndrome).

One in every four coronarographies performed to study myocardial ischemia shows coronary angiographic stenosis less than 50%. This data triggered an increasing interest in the medical community. The American Society of Cardiology recently published a position paper about the pathophysiology, diagnosis and treatment of this entity. Our group performed a narrative review reflecting the opinion of cardiology experts from different centers in Argentina. It aims physiopatologic and diagnostic aspect to understand the current approach in patients with MINOCA (myocardial infarction with non-obstructive coronary arteries) e INOCA (demonstrated angina and ischemia but without coronary lesions that justify this syndrome).

The Low-Flow-Mediated Arterial Constriction in the Upper Limbs of Healthy Human Subjects are Artery Specific and Handedness Independent.

Low-flow-mediated constriction (LFMC) has been used to assess resting endothelial function in peripheral conduit arteries. The literature describes discrepancies in the behaviour of radial versus brachial artery in response to low-flow state, the reasons for which were not addressed in a systematic and scientific way. Moreover, the influence of handedness on observed LFMC responses has not been investigated. The present study aimed at systematic measurement and comparison of the LFMC responses in radial and brachial arteries of both dominant and non-dominant arms of healthy human volunteers. We also investigated the physiological factors associated with differential LFMC response of radial versus brachial artery in the same group of subjects. Longitudinal B mode ultrasonographic cine loops of radial and brachial arteries were acquired at baseline and after producing distal circulatory arrest. Cine loops were screen grabbed and analyzed later using automated edge detection algorithms to measure end-diastolic diameters. Distal circulatory arrest was produced over the proximal forearm (for the brachial artery) and over the wrist (for the radial artery) at 250 mm Hg for 5 min after baseline measurements. Results suggested that arterial location (p = 0.0001) and baseline diameter (p < 0.0021) emerged as independent predictors of LFMC response. Differences in the LFMC responses are handedness independent and could be attributed to the arterial location along with the differences in their baseline diameters.

Evaluation of Cerebral Blood Flow Dynamics in Transient Ischemic Attacks Patients with Fast Cine Phase Contrast Magnetic Resonance Angiography.

Fast cine phase contrast magnetic resonance angiography (PC-MRA) has the potential to provide a quantitative measurement method for the diagnosis and treatment of cerebrovascular disease. To evaluation the changes of cerebral blood flow and the characteristics of artery lesion distribution in the patients of transient ischemic attacks (TIA). In all, 98 normal subjects and 106 TIA patients who underwent MRI examination within 72 h after the last symptom onset including the DWI sequence to exclude acute cerebral infarction were enrolled. The blood flow of the cranial total, the area of the internal carotid artery and vertebral artery, the average velocity, and the average blood flow were obtained and compared in normal subjects and TIA group. Analysis of Variance (ANOVA), t-test, and Kruskal-Wallis test were used for statistical assessments. The total cerebral blood flow of the TIA group and normal control group was no significant statistical difference (P > 0.05). The total blood flow decreased with increasing age, and the TIA group was much lower than the control group. The blood flow of the right internal carotid artery in the TIA group had a significant difference compared with controls (P < 0.05). However, the same situation did not happen in both of the left internal carotid artery and vertebral artery. Phase contrast magnetic resonance imaging has the potential to evaluate the change of cerebral blood flow in TIA patients. The decrease in the total blood flow and the symptom onset of TIA is consistent. Phase contrast magnetic resonance imaging could provide guidance to the diagnosis of TIA.

The Impact of Novel X-Ray Systems and X-Ray System Optimization on Patient Radiation Dose Administered During Cardiac Catheterization.

INTRODUCTION: The effect of x-ray system optimization on patient radiation dose has received limited study. METHODS: We analyzed patient radiation dose in 1786 cardiac catheterization procedures (diagnostic coronary angiography and/or percutaneous coronary intervention [PCI]) performed at a single tertiary-care center before and after x-ray system optimization. RESULTS: After optimization, cineangiography dose-area product (DAP) dose was lower in the overall group of patients who underwent diagnostic angiography and/or PCI (1347 µGy•m² [IQR, 645-2345 µGy•m²] vs 1658 µGy•m² [IQR, 640- 2757 µGy•m²]; P=.03), as well as in the diagnostic angiography group (1795 µGy•m² [IQR, 1140-2994 µGy•m²] vs 2356 µGy•m² [IQR, 311-3576 µGy•m²]; P<.01) and PCI group (2152 µGy•m² [IQR, 1338-3477 µGy•m²] vs 2562 µGy•m² [IQR, 1681-3859 µGy•m²]; P=.02). Cineangiography DAP per exposure was also lower in the overall group (143 µGy•m² [IQR, 91-212 µGy•m²] vs 164 µGy•m² [IQR, 106-233 µGy•m²] per exposure; P<.01) and in the diagnostic angiography group (158 µGy•m² [IQR, 102-225 µGy•m²] vs 184 µGy•m² [IQR, 125-271 µGy•m²] per exposure; P<.01). After optimization, cineangiography air kerma (AK) dose (319 mGy [IQR, 197-531 mGy] vs 421 mGy [IQR, 241-600 mGy]; P=.01) and cineangiography AK per exposure (20.7 mGy [IQR, 12.9-29.0 mGy] vs 23.6 mGy [IQR, 14.1-32.9 mGy] per exposure; P=.03) were also lower in the PCI group. There was no significant change in fluoroscopy AK dose after optimization (20.7 mGy [IQR, 12.7-30.1 mGy] vs 20.4 mGy [IQR, 12.8-31.3 mGy] per minute; P=.71) and fluoroscopy DAP dose (156 µGy•m² [IQR, 101-242 µGy•m²] vs 156 µGy•m² [IQR, 102-236 µGy•m²] per minute; P=.91). CONCLUSION: X-ray system optimization was associated with lower cineangiography DAP, but similar fluoroscopy radiation dose.

[Myocardial ischemia without coronary obstructions: MINOCA-INOCA. Review for decision making]. / Isquemia miocárdica sin lesiones coronarias obstructivas: MINOCA-INOCA. Revisión para la toma de decisiones.

One in every four coronarographies performed to study myocardial ischemia shows coronary angiographic stenosis less than 50%. This data triggered an increasing interest in the medical community. The American Society of Cardiology recently published a position paper about the pathophysiology, diagnosis and treatment of this entity. Our group performed a narrative review reflecting the opinion of cardiology experts from different centers in Argentina. It aims physiopatologic and diagnostic aspect to understand the current approach in patients with MINOCA (myocardial infarction with non-obstructive coronary arteries) e INOCA (demonstrated angina and ischemia but without coronary lesions that justify this syndrome).

Una de cada 4 coronariografías realizadas por isquemia miocárdica presenta lesiones menores al 50% Este dato desencadenó un creciente interés en la comunidad médica. La Sociedad Americana de Cardiología publicó recientemente un artículo que describe la posición consensuada de un grupo de expertos sobre la fisiopatología, el diagnóstico y el tratamiento de esta entidad. Nuestro trabajo refleja una revisión narrativa y la posición de un grupo de expertos pertenecientes a diferentes instituciones con servicios de Cardiología jerarquizados. Aborda aspectos fisiopatológicos y diagnósticos para comprender el enfoque actual del tratamiento, tanto en pacientes que ingresan con diagnóstico de MINOCA (infa rto de miocardio con lesiones angiográficas no graves) o de INOCA (angina e isquemia demostradas, pero sin lesiones coronarias que justifiquen este síndrome).

Radiation dose reduction and static image quality assessment using a channelized hotelling observer on an angiography system upgraded with clarity IQ.

The goal of this paper was the comparison of radiation dose and imaging quality before and after the Clarity IQ technology installation in a Philips AlluraXper FD20/20 angiography system using a Channelized Hotelling Observer model (CHO). The core characteristics of the Allura Clarity IQ technology are its real-time noise reduction algorithms (NRT) combined with state-of-the-art hardware; this technology allows to implement acquisition protocols able to significantly reduce patient entrance dose. To measure the system performances in terms of image quality we used a contrast detail phantom in a clinical scatter condition. A Leeds TO10 phantom has been imaged between two 10 cm thick homogeneous solid water slabs. Fluoroscopy images were acquired using a cerebral protocol at 3 dose levels (low, medium and high) with a field- of view (FOV) of 31 cm. Cineangiography images were acquired using a cerebral protocol at 2 fps. Thus, 4 acquisitions were obtained for the conventional technology and 4 acquisitions were taken after the Clarity IQ upgrade, for a total of 8 different image sets. A validated 40 Gabor channels CHO with an internal noise model compared the image sets. Human observers' studies were carried out to tune the internal noise parameter. We showed that the CHO did not detect any significant difference between any of the image sets acquired using the two technologies. Consequently, this x-ray imaging technology provides a non-inferior image quality with an average patient dose reduction of 57% and 28% respectively in cineangiography and fluoroscopy. The Clarity IQ installation has certainly allowed a considerable improvement in patient and staff safety, while maintaining the same image quality.