Influence of extracardiac activity and perfusion abnormalities on myocardial perfusion gated SPECT parameters: Interobserver analysis

La actividad extracardíaca (AEC) puede afectar la interpretación del SPECT de perfusión miocárdica (SPM); los softwares disponibles incluyen delimitación de bordes para resolver este problema. Objectivo. Evaluar la influencia de AEC en detección automática de bordes miocárdicos en condiciones normales y perfusión anormal y evaluar reproducibilidad del procesamiento semi-automático. Métodos. Se analizaron 100 SPM, 50 con AEC; cada sub-grupo incluyó 25 casos con alteraciones de perfusión. Los casos fueron procesados automáticamente y por 4 operadores independientes con diferente nivel de experiencia. Se empleó software QGS y QPS con enmascaramiento y reubicación del ventrículo izquierdo y se analizaron parámetros funcionales (volumen final diastólico y sistólico, fracción de eyección) y parámetros de perfusión como el score sumado de reversibilidad y la extensión del defecto de perfusión en reposo. Los datos se compararon con correlación de Pearson y test de student. Resultados. La correlación interobservador empeoró considerablemente con AEC y fue moderadamente afectada por alteraciones de perfusión. Los observadores más experimentados mostraron mejor correlación. La reproducibilidad fue mayor para los parámetros funcionales de perfusión, independiente de la experiencia del observador. Conclusiones. La AEC afecta de manera significativa la delimitación automática de bordes miocárdicos, influyendo en los valores de SPM. La reproducibilidad interobservador con procesamiento manual fue más afectada en parámetros funcionales que en scores de perfusión. Las alteraciones de perfusión no interfieren con la reproducibilidad del software, y cuando estaban presentes, se observó una mejor correlación. Si no existe AEC importante, la intervención manual en el procesamiento debe evitarse(AU)

Objective. Extracardiac activity (ECA) may affect interpretation of gated SPECT myocardial perfusion studies (MPSs). To solve this problem, available softwares include myocardial edge delimitation. Purpose. To evaluate the influence of ECA in automatic myocardial edge detection under normal conditions and with abnormal perfusion and also evaluate the reproducibility of semi-automatic processing. Methods. A total of 100 MPSs, 50 with ECA, were analyzed. Each subgroup included 25 cases with perfusion abnormalities. The cases were processed automatically and by 4 independent operators with different levels of experience. Commercial QGS and QPS softwares were used with tools to mask and relocate the left ventricle area. Functional parameters (final diastolic and systolic volumes and ejection fraction) and perfusion parameters such as the reversibility perfusion score and rest perfusion defect extension were analyzed. The data were compared with Pearson's correlation and Student's test. Results. Interobserver correlation significantly worsened with the presence of ECA and was moderately affected by perfusion abnormalities. More experienced observers presented better correlation. Reproducibility was greater for the functional perfusion parameters, independently of the observer's experience. Conclusions. ECA significantly affects automatic edging delimitation, affecting the MPS values. Interobserver reproducibility with manual processing was more altered regarding funtional parameters than in the perfusion scores. Perfusion abnormalities did not interfere with software reproducibility, and when present, better correlation was found. If ECA is not present, manual intervention should be avoided(AU)

Influence of extracardiac activity and perfusion abnormalities on myocardial perfusion gated SPECT parameters: interobserver analysis.

OBJECTIVE: Extracardiac activity (ECA) may affect interpretation of gated SPECT myocardial perfusion studies (MPSs). To solve this problem, available softwares include myocardial edge delimitation. PURPOSE: To evaluate the influence of ECA in automatic myocardial edge detection under normal conditions and with abnormal perfusion and also evaluate the reproducibility of semi-automatic processing. METHODS: A total of 100 MPSs, 50 with ECA, were analyzed. Each subgroup included 25 cases with perfusion abnormalities. The cases were processed automatically and by 4 independent operators with different levels of experience. Commercial QGS and QPS softwares were used with tools to mask and relocate the left ventricle area. Functional parameters (final diastolic and systolic volumes and ejection fraction) and perfusion parameters such as the reversibility perfusion score and rest perfusion defect extension were analyzed. The data were compared with Pearson's correlation and Student's test. RESULTS: Interobserver correlation significantly worsened with the presence of ECA and was moderately affected by perfusion abnormalities. More experienced observers presented better correlation. Reproducibility was greater for the functional perfusion parameters, independently of the observer's experience. CONCLUSIONS: ECA significantly affects automatic edging delimitation, affecting the MPS values. Interobserver reproducibility with manual processing was more altered regarding functional parameters than in the perfusion scores. Perfusion abnormalities did not interfere with software reproducibility, and when present, better correlation was found. If ECA is not present, manual intervention should be avoided.

[Agreement between observers with different experience in the interpretation of the stress myocardial perfusion electrocardiogram in SPECT]. / Concordancia entre observadores con distinta experiencia en interpretación de electrocardiograma de esfuerzo en SPECT de perfusión miocárdica.

UNLABELLED: Coronary artery disease (CAD) is the leading cause of death in many countries. Stress electrocardiogram (ECG) is able to detect myocardial ischemia and also has prognostic value, which may be impaired in presence of electrical baseline abnormalities. Stress myocardial single photon emission tomography (SPECT) has recognized utility yield in assessment of CAD, requiring independent interpretation of ECG and myocardial images. PURPOSE: To analyze stress ECG interpretation reproducibility among observers with different training level, including pre- and post-graduate medical students, compared to an experienced cardiologist and also with SPECT. METHOD: We studied 95 patients under CAD evaluation, mean age 61+/-9.3 years (range: 42-85), 56% male. Interobserver correlation kappa (k) between perfusion gated (99m)Tc-Sestamibi SPECT and exercise ECG were calculated as normal/abnormal, presence of necrosis, ischemia or mixed pattern. Interobserver kappa (k) analysis was made. RESULTS: 49.5% stress ECG and 45% SPECT studies were abnormal at the initial report with 62.1% concordance (k: 0.24) for normal/abnormal and 58.9% for ischemia (k: 0.14). Agreement between stress ECG initial report and independent cardiologist was 89.5% (k: 0.78). The correlation between independent observers and the initial report ranged between 62.1% and 48.4%, for baseline ECG between 41.1% and 90.5% considering normal/abnormal, and between 80% and 93.7% (k: 0.59-0.87) for the presence of ischemia. CONCLUSION: Stress ECG interpretation presented adequate interobserver reproducibility with greater agreement in the most experienced observers, confirming the importance of training.

Concordancia entre observadores con distinta experiencia en interpretación de electrocardiograma de esfuerzo en SPECT de perfusión miocárdica / Agreement between observers with different experience in the interpretation of the stress myocardial perfusion electrocardiogram in SPECT

ResumenLa enfermedad coronaria (EC) es la principal causa de muerte en muchos países. El electrocardiograma (ECG) de esfuerzo permite evaluar la isquemia miocárdica y agrega valor pronóstico, con rendimiento limitado en presencia de alteraciones eléctricas basales. La SPECT (single photon emission computed tomography ‘tomografía computarizada por emisión de fotón único’) en esfuerzo se utiliza para evaluación de EC, con reconocido buen rendimiento, que requiere interpretación independiente del ECG y de las imágenes miocárdicas.ObjetivoAnalizar la concordancia en la interpretación del ECG de esfuerzo entre observadores en entrenamiento, incluyendo alumnos de pre y posgrado de Medicina, con un cardiólogo experimentado y con SPECT miocárdica.MétodoSe incluyeron 95 pacientes enviados para evaluación de EC, edad: 61 ± 9,3 años (rango: 42–85), 56%: hombres. Se calculó la concordancia entre la SPECT de perfusión sincronizada con 99mTc-Sestamibi y ECG de esfuerzo según resultado normal/anormal, necrosis, isquemia o patrón mixto. Se efectuó un análisis interobservador kappa (k).ResultadosFueron anormales el 49,5% de los ECG de esfuerzo según informe inicial y el 45% de los estudios SPECT; la concordancia para normal/anormal fue del 62,1% (κ: 0,24) y para isquemia del 58,9% (κ: 0,14). La concordancia entre informe ECG de esfuerzo inicial y el del cardiólogo independiente fue del 89,5% (κ: 0,78). Las concordancias interobservador con este informe variaron entre el 62,1 y el 48,4%; para ECG basal, entre el 41,1 y el 90,5% considerando normal/anormal; y entre el 80 y el 93,7% (κ: 0,59–0,87) para isquemia entre éste y otros observadores.ConclusiónEn la interpretación del ECG de esfuerzo se encontró adecuada reproducibilidad entre observadores, con mayor acuerdo en los más experimentados, lo que confirma la importancia del entrenamiento(AU9

AbstractCoronary artery disease (CAD) is the leading cause of death in many countries. Stress electrocardiogram (ECG) is able to detect myocardial ischemia and also has prognostic value, which may be impaired in presence of electrical baseline abnormalities. Stress myocardial single photon emission tomography (SPECT) has recognized utility yield in assessment of CAD, requiring independent interpretation of ECG and myocardial images.PurposeTo analyze stress ECG interpretation reproducibility among observers with different training level, including pre- and post-graduate medical students, compared to an experienced cardiologist and also with SPECT.MethodWe studied 95 patients under CAD evaluation, mean age 61±9.3 years (range: 42–85), 56% male. Interobserver correlation kappa (k) between perfusion gated 99mTc-Sestamibi SPECT and exercise ECG were calculated as normal/abnormal, presence of necrosis, ischemia or mixed pattern. Interobserver kappa (k) analysis was made.Results49.5% stress ECG and 45% SPECT studies were abnormal at the initial report with 62.1% concordance (k: 0.24) for normal/abnormal and 58.9% for ischemia (k: 0.14). Agreement between stress ECG initial report and independent cardiologist was 89.5% (k: 0.78). The correlation between independent observers and the initial report ranged between 62.1% and 48.4%, for baseline ECG between 41.1% and 90.5% considering normal/abnormal, and between 80% and 93.7% (k: 0.59–0.87) for the presence of ischemia.ConclusionStress ECG interpretation presented adequate interobserver reproducibility with greater agreement in the most experienced observers, confirming the importance of training(AU)

[Interobserver correlation in the interpretation of 99mTc-sestamibi SPECT in reperfused acute myocardial infarction]. / Correlación interobservadores en interpretación de SPECT de perfusión con 99mTc-sestamibi en infarto agudo de miocardio reperfundido.

INTRODUCTION AND OBJECTIVES: The correct interpretation of myocardial perfusion single photon emission computed tomography (SPECT) requires knowledge of the technique reproducibility. The objective was analyze the interobserver correlation of different experience in the interpretation of myocardial perfusion SPECT in patients following acute myocardial infarction (AMI) in order to improve the quality of our site. METHODS: Sixty cases (56 +/- 11 years, 87 % men) with transmural AMI who had recently undergone successful thrombolysis were included. Resting perfusion with (99m)Tc-sestamibi was performed at one week post-AMI. ANALYSIS: Semiquantitative interpretation using 17 segment-model by 2 independent specialists and 5 observers, was performed blindly. Left ventricular ejection fraction (LVEF) was measured with isotopic ventriculography one month after AMI, with a mean of 38 %. RESULTS: Using independent and then agreed on perfusion analysis, average involved segments/patient was 9.3 +/- 4 and the sum of severity 25 +/- 13. Readings of other observers ranged from 7 +/- 3.7 to 9.4 +/- 3.9 and 16.7 +/- 9.7 to 24.6 +/- 13, respectively, consistent with the reading of the specialists of between 0.779-0.871 (kappa: 0.565-0.741). There was no significant difference when the number of segments were analyzed in 40 % of the cases and for intensity in 60 % of them in more experienced observers. Correlation with consensus reading for the number of segments ranged from 0.84 to 0.94 and for severity from 0.79 to 0.89. Identification of culprit arteries was acceptable, with r values between 0.612 and 0.683 and kappas between 0.629 and 0.656. Correlation of the number of involved segments and severity with LVEF performed one month after AMI was 0.73 and 0.74, respectively. CONCLUSIONS: There was good correlation in the interpretation of myocardial perfusion SPECT, with a significantly better fit in more experienced observers. This academic exercise was also helpful in improving our residents' skills in cardiology.

Correlación interobservadores en interpretación de SPECT de perfusión con 99mTc-sestamibi en infarto agudo de miocardio reperfundido / Interobserver correlation in the interpretation of 99mTc-sestamibi SPECT in reperfused acute myocardial infarction

Introducción y objetivos. La interpretación de la tomografía de emisión de fotón único (SPECT) de perfusión miocárdica requiere conocer la reproducibilidad de la técnica. El objetivo fue analizar la correlación interobservadores de distinta experiencia en interpretación de SPECT en pacientes post-infarto agudo de miocardio (IAM) en un contexto de mejora de la calidad de nuestros centros. Métodos. Se incluyeron 60 casos (56 ± 11 años, 87 % hombres) con infarto transmural reciente sometidos a trombolisis exitosa. Una semana después del IAM se efectuó perfusión de reposo con 99mTc-sestamibi. Análisis. Semicuantitativo mediante lectura ciega por 2 especialistas independientes y 5 observadores utilizando 17 segmentos. La fracción de eyección ventricular izquierda (FEVI) promedio medida con ventriculografía isotópica al mes fue del 38 %. Resultados. En análisis consensuado, el promedio de segmentos comprometidos/paciente fue 9,3 ± 4 y la sumatoria de severidad 25 ± 13; los otros observadores variaron entre: 7 ± 3,7-9,4 ± 3,9 y 16,7 ± 9,7-24,6 ± 13, respectivamente, concordando con los especialistas entre 0,779 y 0,871 (kappa: 0,565-0,741). No hubo diferencia significativa en el 40 % de los análisis para el número de segmentos comprometidos y en el 60 % para intensidad, en observadores con mayor experiencia. La correlación con consenso para el número de segmentos varió entre 0,84 y 0,94, y para severidad entre 0,79 y 0,89. La asignación de arterias fue adecuada (r: 0,612-0,683 y kappas 0,629-0,656). La correlación de segmentos comprometidos y su severidad con la FEVI efectuada al mes del IAM fueron de 0,73 y 0,74, respectivamente. Conclusiones. Existió buena correlación en interpretación de SPECT, con mejor ajuste en observadores experimentados. Este ejercicio sirvió para mejorar habilidades de interpretación en cardiología

Introduction and objectives. The correct interpretation of myocardial perfusion single photon emission computed tomography (SPECT) requires knowledge of the technique reproducibility. The objective was analyze the interobserver correlation of different experience in the interpretation of myocardial perfusion SPECT in patients following acute myocardial infarction (AMI) in order to improve the quality of our site. Methods. Sixty cases (56 ± 11 years, 87 % men) with transmural AMI who had recently undergone successful thrombolysis were included. Resting perfusion with 99mTc-sestamibi was performed at one week post-AMI. Analysis. Semiquantitative interpretation using 17 segment-model by 2 independent specialists and 5 observers, was performed blindly. Left ventricular ejection fraction (LVEF) was measured with isotopic ventriculography one month after AMI, with a mean of 38 %. Results. Using independent and then agreed on perfusion analysis, average involved segments/patient was 9.3 ± 4 and the sum of severity 25 ± 13. Readings of other observers ranged from 7 ± 3.7 to 9.4 ± 3.9 and 16.7 ± 9.7 to 24.6 ± 13, respectively, consistent with the reading of the specialists of between 0.779-0.871 (kappa: 0.565-0.741). There was no significant difference when the number of segments were analyzed in 40 % of the cases and for intensity in 60 % of them in more experienced observers. Correlation with consensus reading for the number of segments ranged from 0.84 to 0.94 and for severity from 0.79 to 0.89. Identification of culprit arteries was acceptable, with r values between 0.612 and 0.683 and kappas between 0.629 and 0.656. Correlation of the number of involved segments and severity with LVEF performed one month after AMI was 0.73 and 0.74, respectively. Conclusions. There was good correlation in the interpretation of myocardial perfusion SPECT, with a significantly better fit in more experienced observers. This academic exercise was also helpful in improving our residents' skills in cardiology