Implantación de un protocolo de angio-TC coronaria basado en el índice de masa corporal: reducción de dosis, calidad de imagen y rendimiento diagnóstico / Implementing a coronary CT angiography protocol based on the body mass index: radiation dose reduction, image quality, and diagnostic performance

Objetivos: Valorar la relación entre el score de calcio coronario y la elección posterior del kilovoltaje según el criterio del radiólogo en un protocolo estándar (PE) de angio-TC coronaria (aTCC) para descartar enfermedad coronaria. Cuantificar la reducción de la radiación ionizante después de vincular el kilovoltaje al índice de masa corporal en un protocolo de baja dosis (PBD) con reconstrucción iterativa de modelado. Valorar la calidad de imagen y el rendimiento diagnóstico del PBD. Material y método: Las características antropométricas, el score de calcio, los niveles de kilovoltaje y los valores de dosis estimada específica para el tamaño (SSDE) y del producto dosis-longitud fueron comparados entre un grupo de 50 pacientes con PBD reclutados prospectivamente y una cohorte histórica adquirida con el PE. Estos parámetros, el número de segmentos coronarios no valorables sin y con tolerancia de fase, la atenuación y la relación señal-ruido en la aorta ascendente en el PBD fueron correlacionados con una calidad de imagen de nivel excelente según una escala semicuantitativa. El rendimiento diagnóstico por paciente fue calculado usando la revaloración clínica a los 24 meses como el método diagnóstico de referencia, incluyendo las pruebas derivadas. Resultados: En el PE existía una relación entre la presencia de calcio coronario y la elección de kilovoltajes altos (p=0,02), que desaparecía en el PBD (p=0,47). Los valores de SSDE y de DLP en el PBD fueron significativamente inferiores y presentaron menor dispersión que en el PE (9,22 mGy [RIQ 7,84-12,1 mGy] y 97 mGy*cm [RIQ 78-134 mGy*cm] contra 26,5 mGy [RIQ 21,3-36,3 mGy] y 253 mGy*cm [RIQ 216-404 mGy*cm]; p <0,001 para las comparaciones de las medianas y de las dispersiones entre ambos grupos)...(AU)

Objectives: To evaluate the relation between the coronary calcium score and the posterior choice of kilovoltage according to radiologists’ criteria in a standard coronary CT angiography protocol to rule out coronary disease. To quantify the reduction in ionizing radiation after linking kilovoltage to patients’ body mass index in a low-dose protocol with iterative model reconstruction. To evaluate the image quality and diagnostic performance of the low-dose protocol. Material and methods: We compared anthropometric characteristics, calcium score, kilovoltage levels, size-specific dose estimates (SSDE), and the dose-length product (DLP) between a group of 50 patients who were prospectively recruited to undergo coronary CT angiography with a low-dose protocol and a historical group of 50 patients who underwent coronary CT angiography with the standard protocol. We correlated these parameters, the number of coronary segments that could not be evaluated with and without temporal padding, the attenuation, and the signal-to-noise ratio in the ascending aorta in the low-dose protocol with excellent imaging quality according to a semiquantitative scale. To calculate the diagnostic performance per patient, we used 24-month clinical follow-up including all tests as the gold standard. Results: In the standard protocol, the presence of coronary calcium correlated with the selection of high kilovoltage (P=0.02); this correlation was not found in the low-dose protocol (P=0.47). Median values of SSDE and DLP were significantly (P<0.001) lower and less dispersed in the low-dose protocol [9.22 mGy (IQR 7.84-12.1 mGy) vs. 26.5 mGy (IQR 21.3-36.3 mGy) in the standard protocol] and [97mGy*cm (IQR 78-134mGy*cm) vs. 253mGy*cm (IQR 216-404mGy*cm) in the standard protocol], respectively...(AU)

Implementing a coronary CT angiography protocol based on the body mass index: Radiation dose reduction, image quality, and diagnostic performance.

OBJECTIVES: To evaluate the relation between the coronary calcium score and the posterior choice of kilovoltage according to radiologists' criteria in a standard coronary CT angiography protocol to rule out coronary disease. To quantify the reduction in ionizing radiation after linking kilovoltage to patients' body mass index in a low-dose protocol with iterative model reconstruction. To evaluate the image quality and diagnostic performance of the low-dose protocol. MATERIAL AND METHODS: We compared anthropometric characteristics, calcium score, kilovoltage levels, size-specific dose estimates (SSDE), and the dose-length product (DLP) between a group of 50 patients who were prospectively recruited to undergo coronary CT angiography with a low-dose protocol and a historical group of 50 patients who underwent coronary CT angiography with the standard protocol. We correlated these parameters, the number of coronary segments that could not be evaluated with and without temporal padding, the attenuation, and the signal-to-noise ratio in the ascending aorta in the low-dose protocol with excellent imaging quality according to a semiquantitative scale. To calculate the diagnostic performance per patient, we used 24-month clinical follow-up including all tests as the gold standard. RESULTS: In the standard protocol, the presence of coronary calcium correlated with the selection of high kilovoltage (p = 0.02); this correlation was not found in the low-dose protocol (p = 0.47). Median values of SSDE and DLP were significantly (p < 0.001) lower and less dispersed in the low-dose protocol [9.22 mGy (IQR 7.84-12.1 mGy) vs. 26.5 mGy (IQR 21.3-36.3 mGy) in the standard protocol] and [97 mGy cm (IQR 78-134 mGy cm) vs. 253 mGy cm (IQR 216-404 mGy cm) in the standard protocol], respectively. The overall quality of the images obtained with the low-dose protocol was considered good or excellent in 96% of the studies. The parameters associated with image quality in a multivariable model (C statistic = 0.792) were heart rate (estimated coefficient, -0,12 [95% confidence interval: -0.2, -0.04]; p < 0.01) and the SSDE (estimated coefficient, -0,26 [95% confidence interval: -0.51, -0.01]; p < 0.05). The CAD-RADS modifier for a not fully evaluable or diagnostic study was used on two occasions (4%); the final measures for the diagnosis of coronary disease were sensitivity 100%, specificity 94%, and efficacy 94%. CONCLUSIONS: In the standard protocol, the radiologist selects higher kilovoltage for CT angiography studies for patients whose previous calcium score indicates the presence of coronary calcium. In the low-dose protocol, linking kilovoltage with body mass index enables the dose of radiation to be reduced by 65% while obtaining excellent or good image quality in 96% of studies and excellent diagnostic performance.

Subclinical cardiovascular disease and Systemic Sclerosis: A comparison between risk charts, quantification of coronary calcium and carotid ultrasonography.

BACKGROUND AND OBJECTIVES: Recently published population-based cohort studies have shown a high prevalence of cardiovascular disease in Systemic Sclerosis (SSc) patients. The aim of this study is to compare three different methods to measure cardiovascular risk in patients with scleroderma. METHODS: Forty-three SSc patients were included. A prospective study was performed for evaluation of cardiovascular risk and subclinical atheromatosis using 3 non-invasive methods: cardiovascular risk tables, carotid Doppler ultrasonography and quantification of coronary calcium by computerized tomography (CT). RESULTS: The cardiovascular risk charts for the Spanish population did not identify patients at high cardiovascular risk. Framingham-REGICOR identified 13 intermediate-risk patients. Twenty-two patients (51.2%) had plaques on carotid ultrasonography. We performed a ROC curve to identify the best cutoff point for the quantification of coronary artery calcium (CACscore), the value of CACscore > 28 AU (Agatston Units) had the highest sensitivity (73%) and specificity (81%) for the diagnosis of subclinical atheromatosis. In the multiple regression study, age and decreased HDL cholesterol levels were identified as independent factors for subclinical atherosclerotic disease. No disease-related factors were associated with increased subclinical arteriosclerosis. CONCLUSION: Carotid ultrasound and CACscore are useful for identifying subclinical atheromatosis in patients with SSc and are superior compared to risk charts used for general population. HDL cholesterol and age were independent factors for the presence of subclinical atherosclerotic disease. A carotid ultrasound or CT should be performed for early detection of subclinical atheromatosis if these factors are present.

Metodología de la PET/TC con 18F-FDG cardíaca para el diagnóstico de la endocarditis protésica y de dispositivos intracardíacos / Cardiac 18F-FDG PET/CT procedure for the diagnosis of prosthetic endocarditis and intracardiac devices

La endocarditis infecciosa (EI) es una patología grave y con mal pronóstico cuya mortalidad no se ha modificado significativamente a pesar de los avances en su diagnóstico y tratamiento en los últimos 30años. La capacidad diagnóstica de los criterios de Duke modificados en la endocarditis protésica y/o de dispositivos no supera el 50%, por lo que se hacen necesarias nuevas herramientas para el diagnóstico de esta entidad en dicho contexto. La 18F-FDG PET/aTC combina una técnica con gran sensibilidad para detectar actividad inflamatoria-infecciosa y una técnica con gran resolución anatómica para valorar las lesiones estructurales asociadas a la endocarditis. Con una sensibilidad diagnóstica entre el 91 y el 97%, esta técnica híbrida se ha convertido en una herramienta de diagnóstico útil en la sospecha de EI de pacientes con válvulas protésicas o dispositivos, convirtiéndose en un criterio mayor en el algoritmo diagnóstico de las guías actuales. Esta excelente capacidad diagnóstica depende de forma directa de la calidad de la exploración obtenida y del conocimiento a la hora de interpretar las imágenes. El objetivo de esta revisión es describir y estandarizar la metodología de la 18F-FDG-PET/aTC cardíaca en el diagnóstico de endocarditis protésica y de dispositivos intracardíacos, haciendo especial énfasis en las particularidades de la preparación del paciente, de la adquisición de los estudios PET y TC, y del posterior posprocesado e interpretación de las imágenes

Infective endocarditis (IE) is a serious condition with a poor prognosis, its mortality unchanged significantly despite diagnostic and therapeutic advances in the last 30years. The diagnostic ability of the modified Duke criteria in prosthetic endocarditis and/or devices does not exceed 50%, so new tools are necessary for the diagnosis of this entity in this context. The 18F-FDG PET/CTA combines a highly sensitive technique to detect inflammatory-infectious activity with a technique with high anatomical resolution to assess the structural lesions associated with endocarditis. With a diagnostic sensitivity between 91-97%, this hybrid technique has become a useful diagnostic tool for patients with prosthetic valves or devices and suspicion of IE, becoming a major criterion in the diagnostic algorithm of current guidelines. This excellent diagnostic ability depends directly on the quality of the obtained exploration and the knowledge at the time of interpreting the images. The aim of this review is to describe and standardize the methodology of cardiac 18F-FDG PET/CTA in the diagnosis of endocarditis in prosthetic valves and intracardiac devices, with special emphasis on the particularities of the patient's preparation, the PET and CT acquisition procedures, and the subsequent imaging postprocessing and interpretation

Cardiac 18F-FDG PET/CT procedure for the diagnosis of prosthetic endocarditis and intracardiac devices. / Metodología de la PET/TC con 18F-FDG cardíaca para el diagnóstico de la endocarditis protésica y de dispositivos intracardíacos.

Infective endocarditis (IE) is a serious condition with a poor prognosis, its mortality unchanged significantly despite diagnostic and therapeutic advances in the last 30years. The diagnostic ability of the modified Duke criteria in prosthetic endocarditis and/or devices does not exceed 50%, so new tools are necessary for the diagnosis of this entity in this context. The 18F-FDG PET/CTA combines a highly sensitive technique to detect inflammatory-infectious activity with a technique with high anatomical resolution to assess the structural lesions associated with endocarditis. With a diagnostic sensitivity between 91-97%, this hybrid technique has become a useful diagnostic tool for patients with prosthetic valves or devices and suspicion of IE, becoming a major criterion in the diagnostic algorithm of current guidelines. This excellent diagnostic ability depends directly on the quality of the obtained exploration and the knowledge at the time of interpreting the images. The aim of this review is to describe and standardize the methodology of cardiac 18F-FDG PET/CTA in the diagnosis of endocarditis in prosthetic valves and intracardiac devices, with special emphasis on the particularities of the patient's preparation, the PET and CT acquisition procedures, and the subsequent imaging postprocessing and interpretation.

18F-FDG-PET/CT Angiography for the Diagnosis of Infective Endocarditis.

PURPOSE OF REVIEW: This article reviews the current imaging role of 18F-fluordeoxyglucose positron emission computed tomography (18F-FDG-PET/CT) combined with cardiac CT angiography (CTA) in infective endocarditis and discusses the strengths and limitations of this technique. RECENT FINDINGS: The diagnosis of infective endocarditis affecting prosthetic valves and intracardiac devices is challenging because echocardiography and, therefore, the modified Duke criteria have well-recognized limitations in this clinical scenario. The high sensitivity of 18F-FDG-PET/CT for the detection of infection associated with the accurate definition of structural damage by gated cardiac CTA in a combined technique (PET/CTA) has provided a significant increase in diagnostic sensitivity for the detection of IE. PET/CTA has proven to be a useful diagnostic tool in patients with suspected infective endocarditis. The additional information provided by this technique improves diagnostic performance in prosthetic valve endocarditis when it is used in combination with the Duke criteria. The findings obtained in PET/CTA studies have been included as a major criterion in the recently updated diagnostic algorithm in infective endocarditis guidelines.

Utilidad de la 18F-FDG PET/cardio-TC en el diagnóstico de endocarditis protésica aórtica tardía con absceso periprotésico / Diagnostic value of 18F-FDG PET/cardiac CT in late prosthetic aortic endocarditis with periprosthetic abscess

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SPECT, angio-TC coronaria, coronariografía invasiva e imágenes de fusión en la cardiopatía isquémica estable / SPECT, coronary angio-CT, invasive coronary angiography and fusion images in stable coronary disease

Objetivos: Valorar la información de la SPECT, de la angio-TC coronaria y de las imágenes híbridas de fusión en los pacientes con cardiopatía isquémica estable en los que se practica una coronariografía invasiva (CI). Material y métodos: Se ha incluido en forma prospectiva a 46 pacientes (65,98 ± 8,3 años) con enfermedad coronaria, valorándose la información de dichas técnicas en el diagnóstico de la enfermedad multivaso, en la detección del vaso culpable y en el manejo de los pacientes. Resultados: En la CI, 29 de los 46 pacientes (63%) presentaban enfermedad multivaso: la SPECT la diagnosticó en un 48,2% y la angio-TC en un 89,6%. La concordancia entre la angio-TC y la CI en el diagnóstico del vaso culpable fue del 77% (kappa 0,6) y entre la SPECT y la CI del 73% (kappa 0,56). Las imágenes híbridas obtenidas después del cateterismo no habrían aportado nueva información a la ya obtenida mediante la SPECT y la CI de cara al manejo terapéutico. Conclusiones: La angio-TC destaca en el diagnóstico de la enfermedad multivaso y en la detección del vaso culpable respecto a la CI. La SPECT resulta un buen complemento funcional de la CI en la detección del territorio más isquémico. No obstante, en los pacientes con cardiopatía isquémica estable en los que se ha realizado una SPECT como primer estudio no invasivo, si la decisión de practicar posteriormente una CI es clara, la realización de una angio-TC y la obtención de imágenes de fusión SPECT-TC no parecen indicadas, ya que no cambiaría el manejo terapéutico que se adopta sobre la base de la información de la SPECT y la CI (AU)

Objectives: To evaluate the usefulness of the information obtained with SPECT, coronary angio-CT and fusion images, in patients with stable ischemic disease who need invasive coronary angiography (IA). Material and methods: Forty-six patients (65.98 ± 8.3 years) with coronary disease were prospectively included. The fusion images generated after undergoing IA were used to evaluate the performance of these techniques in the diagnosis of multi-vessel coronary disease, the detection of the culprit vessel and the therapeutic management of these patients. Results: In the IA, 29 of the 46 patients (63%) had multi-vessel disease. SPECT could detect it in 48.2% and coronary angio-CT could detect it in 89.6%. Concordance between coronary angio-CT and IA in the diagnosis of the culprit vessel was 77% (kappa 0.6), and between SPECT and IA it was 73% (kappa 0.56). Although fusion images could have been obtained prior to IA, they would not have changed the therapeutic approach derived from SPECT and IA. Conclusions: Coronary angio-CT has a high ability for the diagnosis of multi-vessel disease and the culprit lesion, and SPECT is a good functional complement of the IA in the detection of the most ischemic territory. However, the performance of fusion images in patients with stable ischemic disease, who have undergone a SPECT as the first non-invasive study and need IA, does not seem indicated because they would not have changed the therapeutic management derived from SPECT and IA information (AU)

[SPECT, coronary angio-CT, invasive coronary angiography and fusion images in stable coronary disease]. / SPECT, angio-TC coronaria, coronariografía invasiva e imágenes de fusión en la cardiopatía isquémica estable.

OBJECTIVES: To evaluate the usefulness of the information obtained with SPECT, coronary angio-CT and fusion images, in patients with stable ischemic disease who need invasive coronary angiography (IA). MATERIAL AND METHODS: Forty-six patients (65.98±8.3 years) with coronary disease were prospectively included. The fusion images generated after undergoing IA were used to evaluate the performance of these techniques in the diagnosis of multi-vessel coronary disease, the detection of the culprit vessel and the therapeutic management of these patients. RESULTS: In the IA, 29 of the 46 patients (63%) had multi-vessel disease. SPECT could detect it in 48.2% and coronary angio-CT could detect it in 89.6%. Concordance between coronary angio-CT and IA in the diagnosis of the culprit vessel was 77% (kappa 0.6), and between SPECT and IA it was 73% (kappa 0.56). Although fusion images could have been obtained prior to IA, they would not have changed the therapeutic approach derived from SPECT and IA. CONCLUSIONS: Coronary angio-CT has a high ability for the diagnosis of multi-vessel disease and the culprit lesion, and SPECT is a good functional complement of the IA in the detection of the most ischemic territory. However, the performance of fusion images in patients with stable ischemic disease, who have undergone a SPECT as the first non-invasive study and need IA, does not seem indicated because they would not have changed the therapeutic management derived from SPECT and IA information.

Fusión de imágenes de gated-SPECT y angiotomografía computarizada en la enfermedad coronaria. Importancia de la correlación anatomicofuncional / Image fusion of gated-SPECT and CT angiography in coronary artery disease. Importance of anatomic-functional correlation

Paciente de 77 años de edad ingresado por un síndrome coronario agudo sin elevación del segmento ST. Se estratificó su riesgo mediante gated-SPECT de perfusión miocárdica, evidenciándose una ligera isquemia inferior, por lo cual se optimizó el tratamiento médico y recibió el alta hospitalaria. El paciente continuó con disnea de esfuerzo, y se le realizó una angiotomografía computarizada coronaria que mostró lesiones intensas en la arteria coronaria derecha (CD) proximal. La fusión SPECT-tomografía computarizada correlacionó el defecto de perfusión miocárdica con la arteria descendente posterior proveniente de la arteria CD en un territorio de irrigación codominante. Posteriormente se indicó un cateterismo cardiaco para su tratamiento. El uso actual de los estudios de fusión de imágenes se limita a pacientes en los cuales es difícil la asignación de un defecto de perfusión a una determinada arteria coronaria. En nuestro paciente, las imágenes de fusión contribuyeron a discernir la arteria responsable del territorio isquémico entre la arteria CD y la arteria circunfleja(AU)

A 77-year old patient was admitted for acute coronary syndrome without ST elevation. His risk was stratified using the myocardial perfusion gated SPECT, mild inferior ischemia being observed. Thus, medical therapy was optimized and the patient was discharged. He continued with exertional dyspnea so a coronary CT angiography was performed. It revealed severe lesions in the proximal RCA. SPECT-CT fusion images correlated the myocardial perfusion defect with a posterior descending artery from the RCA, in a co-dominant coronary area. Subsequently, cardiac catheterism was indicated for his treatment. The current use of image fusion studies is limited to patients in whom it is difficult to attribute a perfusion defect to a specific coronary artery. In our patient, the fusion images helped to distinguish between the RCA and the circumflex artery as the culprit artery of ischemia(AU)

[Image fusion of gated-SPECT and CT angiography in coronary artery disease. Importance of anatomic-functional correlation]. / Fusión de imágenes de gated-SPECT y angiotomografía computarizada en la enfermedad coronaria. Importancia de la correlación anatomicofuncional.

A 77-year old patient was admitted for acute coronary syndrome without ST elevation. His risk was stratified using the myocardial perfusion gated SPECT, mild inferior ischemia being observed. Thus, medical therapy was optimized and the patient was discharged. He continued with exertional dyspnea so a coronary CT angiography was performed. It revealed severe lesions in the proximal RCA. SPECT-CT fusion images correlated the myocardial perfusion defect with a posterior descending artery from the RCA, in a co-dominant coronary area. Subsequently, cardiac catheterism was indicated for his treatment. The current use of image fusion studies is limited to patients in whom it is difficult to attribute a perfusion defect to a specific coronary artery. In our patient, the fusion images helped to distinguish between the RCA and the circumflex artery as the culprit artery of ischemia.