Effect of cardiac resynchronization therapy on septal perfusion and septal thickening: Association with left ventricular function, reverse remodelling and dyssynchrony.

BACKGROUND: We evaluated the effect of cardiac resynchronization therapy (CRT) on septal perfusion and thickening at 6 months post implantation assessed on Tc99m-MIBI Gated myocardial perfusion SPECT (GMPS).We also studied the association of change in septal perfusion and thickening with primary outcome defined as at least one [improvement in ≥1NYHA class, left ventricular ejection fraction (LVEF) by ≥ 5%, reduction of end-systolic volume (ESV) by ≥ 15%, and improvement ≥ 5 points in Minnesota living with heart failure questionnaire (MLHFQ)]. METHOD: One hundred and five patients underwent clinical and GMPS evaluation before and at 6 months post CRT. RESULT: Post CRT there was significant improvement in mean normalized septal perfusion uptake and in septal thickening (P value = 0.001, both). There was no significant relation between improvement in septal perfusion and primary outcome. However, improvement in septal thickening was statistically significant with favorable primary outcome (P = 0.001).There was no significant correlation between improvement of septal perfusion and improvement in LVEF, reduction in End diastolic volume (EDV), ESV, and Left ventricular Dyssynchrony (LVD). But, there was significant correlation between improvement of septal thickening and these parameters. CONCLUSION: Improvement in septal thickening was associated with reverse remodeling, improvement in LVEF, and reduction of LVD.

Estratificación de riesgo de enfermedad coronaria con métodos isotópicos. Estado actual de la práctica clínica / Risk stratification of coronary artery disease using radionuclides. Current status of clinical practice

Se discute el uso actual de los radioisótopos para la evaluación de la enfermedad coronaria con relación a otras técnicas disponibles. La revisión se centra en la estratificación de riesgo de enfermedad coronaria mediante tomografía de fotón único y de doble fotón, y su la aplicación en viabilidad miocárdica y miocardiopatía isquémica. Se presentan conceptos sobre flujo absoluto y reserva de flujo coronario, valor diagnóstico y pronóstico, así como criterios de uso apropiados de las pruebas y también los métodos actuales para disminuir la radiación innecesaria de los pacientes, optimizando la práctica de la cardiología nuclear (AU)

A discussion is presented on the current use of radioisotopes for evaluation of coronary artery disease in relation to other available techniques. The review is focused on coronary artery disease risk stratification employing single photon emission computed tomography and positron emission tomography, as well as on ischaemic cardiomyopathy and myocardial viability applications. Concepts are presented regarding coronary blood flow reserve, diagnostic and prognostic values, criteria for its appropriate use, as well as current methods to reduce unnecessary patient irradiation, in order to optimise nuclear cardiology practice (AU)

Risk stratification of coronary artery disease using radionuclides. Current status of clinical practice. / Estratificación de riesgo de enfermedad coronaria con métodos isotópicos. Estado actual de la práctica clínica.

A discussion is presented on the current use of radioisotopes for evaluation of coronary artery disease in relation to other available techniques. The review is focused on coronary artery disease risk stratification employing single photon emission computed tomography and positron emission tomography, as well as on ischaemic cardiomyopathy and myocardial viability applications. Concepts are presented regarding coronary blood flow reserve, diagnostic and prognostic values, criteria for its appropriate use, as well as current methods to reduce unnecessary patient irradiation, in order to optimise nuclear cardiology practice.

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

Utilidad del PET 18F-fluordeoxiglucosa en melanoma maligno / 18F-fluorodeoxyglucose positron emission tomography in patients with malignant melanoma

Está establecida en la literatura la utilidad de la tomografía por emisión de positrones (PET) con 18F-flúordeoxiglucosa (FDG) en la etapificación, reetapificación y seguimiento del melanoma maligno. Objetivo: Evaluar los resultados del PET FDG en melanoma maligno en nuestro centro. Material y Método: Entre febrero 2003 y julio 2004, se estudiaron 33 pacientes (edad 49±14 años, 52% sexo masculino) referidos para etapificación y reetapificación de melanoma maligno. El examen fue realizado en equipo de alta resolución Siemens Ecat Exact HR+ con dosis de 13±3 mCi de FDG y glicemias en ayunas preinyección de 96±16 mg/dL. Se adquirieron imágenes de cuerpo entero, incluyendo cabeza y extremidades inferiores. El informe se basó en el análisis visual e índice cuantitativo de captación (SUV). Se comparó con otros estudios de imágenes e histología cuando estaban disponibles y se realizó seguimiento clínico. Resultados: Nueve pacientes fueron derivados para etapificación y 24 para reetapificación. En 29 casos, la localización inicial del primario era conocida y en 4 la enfermedad se diagnosticó por la presencia de metástasis ganglionares. Respecto de la localización tumoral, 6 fueron en cabeza y cuello (2 metástasis ganglionares), 5 en coroides, 5 en tronco, 5 en extremidades superiores, 11 en extremidades inferiores y 1 en mucosa (rectal). En 13 pacientes, el PET fue positivo para presencia de actividad tumoral hipermetabólica, 7 en ubicación próxima al primario y 6 alejados de éste, correspondiendo uno de estos últimos a un segundo primario (carcinoma rectal confirmado con histología). De este grupo, en 11 pacientes se confirmó tumor: en 7 hubo confirmación histológica postcirugía y en los restantes, hubo concordancia con imágenes anatómicas y clínica (1 paciente falleció); además, el PET demostró lesiones no sospechadas por otros estudios, las que no han sido confirmadas con histología. Dos fueron falsos positivos, uno por hematoma y otro por ...

Background: The usefulness of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) for the staging and follow up of malignant melanoma, is well established. Aim: To assess the results of PET FDG in patients with malignant melanoma. Patients and Methods: Thirty three patients with malignant melanoma (aged 49 ± 14 years, 17 males), referred for staging and restaging, were studied. The tomography was performed using a Siemens Ecat Exat high resolution equipment. The dose of FDG was 13 ± 3 mCi and the blood glucose levels prior to injection were 96 ± 16 mg/dl. Whole body images, including the head and legs were acquired. The report was based on the visual analysis and standardized uptake value (SUV). Results: Nine patients were referred for staging and 24 for restaging. The location of the primary tumor was known in 29 cases and in four, the disease was diagnosed due to the presence of lymph node metastases. The tumor was located in the head and neck in six patients (including two lymph node metastases), in the choroid in five, in the trunk in five, in the superior limbs in five, in the inferior limbs in 11 and in the rectal mucosa in one. In 13 patients, PET was positive for the presence of hypermetabolic tumor activity. In seven, the location was near the primary tumor and in six, it was distant. In seven patients the presence of tumor was confirmed by surgery and in four, there was concordance between the anatomical imaging and clinical outcome. Two false positive images were detected, one hematoma and one due to the presence of lymph node inflammation. In 16 cases, PET was negative and in four it was not conclusive, all these patients do not have evidence of tumor in the clinical follow up. The primary location of the tumor was not identified in patients referred for lymph node metastases. Conclusions: FDG PET is useful for the staging and re staging of patients with malignant melanoma.

Evaluación de nódulos y masas pulmonares con PET FDG de alta resolución / 18-Fluorodeoxyglucose positron emission tomography in patients with pulmonary nodules

Introducción: El diagnóstico y etapificación de pacientes portadores de lesiones pulmonares con PET-FDG permite optimizar el manejo y seleccionar la terapia más adecuada para cada uno. Objetivo: Analizar nuestra experiencia preliminar con PET-FDG en la caracterización metabólica de nódulos o masas pulmonares, correlacionándolo con histología cuando estaba disponible y evaluando el impacto en la conducta terapéutica. Material y Método: Se analizaron 58 pacientes referidos para evaluación de nódulo o masa pulmonar (62±7 años de edad; 48% sexo masculino; 40% fumadores). Los PET se realizaron en ayunas, utilizando 13 mCi de FDG-F18, con glicemia preinyección de 101± 5 mg/dl. Se adquirieron imágenes de cuerpo entero con análisis visual de cortes coronales, sagitales y transaxiales e imágenes 3D, así como análisis cuantitativo del índice de captación estandarizada SUV. Los estudios se compararon con histología y seguimiento clínico. Resultados: En 22 pacientes (38%), las lesiones pulmonares fueron hipermetabólicas y en 64%, no hubo evidencias de actividad tumoral. En 24% de los pacientes, se encontraron además lesiones extrapulmonares no sospechadas por otras técnicas de imágenes. El rango de tamaño de los nódulos/masas pulmonares era de 0,5 a 7 cm; en el grupo de PET positivo, el tamaño era mayor a 0,8 cm. Se obtuvo histología en 16/58: en 12 de ellos, se confirmó la presencia de neoplasia (75%), correspondiendo la mayoría a adenocarcinoma. Dos pacientes fueron falsos positivos, demostrándose en uno, un schwanoma abscedado y en el otro, un hamartoma. En 2 pacientes con nódulos sin actividad hipermetabólica al PET (estudio normal), sometidos a cirugía por las características del nódulo al TC, se corroboraron lesiones benignas. En los restantes pacientes con lesiones negativas, el seguimiento clínico no ha demostrado eventos hasta la fecha. Un paciente referido por nódulo pulmonar no fue incluido en el análisis debido a que en el PET presentaba ...

Background: The diagnosis and staging of pulmonary lesions with positron emission tomography (PET) with 18fluorodeoxyglucose (FDG) helps in the selection of the optimal therapy. Aim: To analyze the usefulness of FDG PET in the characterization of pulmonary nodules. Patients and Methods: Fifty eight patients referred for the assessment of a pulmonary nodule or mass (aged 62 ± 7 years, 28 males, 40% smokers), were studied. The imaging study was perfomed in the fasting state injecting 13 mCi of 18FDG. Pre injection blood glucose was 101 ± 5 mg/dl. Whole body images were acquired with visual analysis of coronal, sagittal and trans axial slices and three dimensional images. The standardized uptake value (SUV) was also calculated. Results: Pulmonary lesions were hypermetabolic in 22 patients (38%) and in the rest, there was no evidence of tumor activity. Extrapulmonary lesions were detected in 24% of patients. The size of the nodules ranged from 0.5 to 7 cm. in diameter. Those with positive PET had lesions over 0.8 cm diameter. In 12 of 16 patients with pathological study, the presence of cancer was confirmed. Two patients had false positive images. One had an abscessed Schwanoma and the other, a hamartoma. Two patients with PET images not suspicious of tumor, were operated and the pathology confirmed the absence of cancer. In the rest of patients with a negative study, the clinical follow up has been uneventful. In one patient with multiple hypermetabolic lesions with a pattern suggestive of sarcoidosis, the diagnosis was pathologically confirmed. Conclusions: FDG PET is useful for the characterization of pulmonary lesions and nodules.

201Tl myocardial SPECT detects significant coronary artery disease between 50% and 75% angiogram stenosis.

UNLABELLED: Coronary angiography is the "gold standard" for the diagnosis of coronary artery disease (CAD). The aim of this work was to compare 201Thallium SPECT with different coronary angiographic cutoff values. METHODS: Data pertaining to 145 patients were tabulated. All patients underwent stress ECG, 201Thallium SPECT and coronary angiography. To assess the cutoff impact, two criteria for coronary angiography diagnosis were used: a) > or = 50% and b) > or = 75% stenosis, and applied to data from patients and vessels. RESULTS: On a patient basis, 201Thallium SPECT sensitivity, specificity and accuracy were 87%, 57% and 81% with > or = 50% cutoff and 93%, 51% and 79% with > or = 75% cutoff, respectively (NS). When performing individual vessel analysis, sensitivity, specificity and accuracy were 59%, 78% and 68% for > or = 50% cutoff and 70%, 75% and 74% for > or = 75% cutoff, respectively (p < 0.029 for sensitivity). As expected, the severer the stenosis the higher the detection rate. There were 19 patients who had stenosis between 50% and 74%. Of these, 21% had abnormal stress ECG and 58% abnormal Thallium-201 SPECT. CONCLUSION: 201Thallium SPECT results support the use of > or = 50% stenosis cutoff criteria for CAD diagnosis and evaluation. Combined with coronary angiography, myocardial SPECT offers an excellent management strategy to patients.

201Tl myocardial SPECT detects significant coronary artery disease between 50 % and 75 % angiogram stenosis

La angiografía coronaria es el estándar de oro para diagnosticar enfermedad coronaria. El objetivo de este trabajo fue comparar los resultados del SPECT con Talio 201 con los diversos valores de estenosis coronaria a la angiografía. Métodos: Se tabularon resultados de 145 pacientes. A todos ellos se les realizó una prueba de esfuerzo, SPECT de perfusión miocárdica con Talio 201 y angiografía coronaria. Para hacer la valoración se utilizaron 2 criterios angiográficos para estenosis coronaria: a) >= 50 % b) >= 75 %, los que se aplicaron a los pacientes y vasos coronarios estudiados por individual. Resultados: En una evaluación individual por paciente la sensibilidad (S), especificidad (E) y exactitud (Ex) fue de 87 %, 57 % y 81 % con criterio de estenosis de >= 50 % y de 93 %, 51 % y 79 % usando criterio de >= 75 %, respectivamente (NS). Al analizar los vasos individualmente la S, E y Ex fue de 59 %, 78 % y 68 % para criterio >= 50 % y 70 %, 75 % y 74 % para criterio >= 75 % (p < 0,029 para S). Como era esperado a mayor severidad de estenosis, mayor incidencia de detección. Hubo 19 pacientes que presentaron estenosis entre 50 y 74 %. De ellos 21 % presentó prueba de esfuerzo anormal y 58 % SPECT de perfusión miocárdica anormal. Conclusión: Los resultados con el estudio de perfusión miocárdica con Talio 201 avalan el uso del valor de 50 % o más de estenosis en el diagnóstico y evaluación de enfermedad coronaria. En conjunto con la angiografía coronaria el SPECT miocárdico ofrece una excelente estrategia para el manejo de los pacientes

Coronary angiography is the "gold standard" for the diagnosis of coronary artery disease (CAD). The aim of this work was to compare 201Thallium SPECT with different coronary angiographic cutoff values. Methods: Data pertaining to 145 patients were tabulated. All patients underwent stress ECG, 201Thallium SPECT and coronary angiography. To assess the cutoff impact, two criteria for coronary angiography diagnosis were used: a) >= 50 % and b) >= 75 % stenosis, and applied to data from patients and vessels. Results: On a patient basis, 201Thallium SPECT sensitivity, specificity and accuracy were 87 %, 57 % and 81 % with >= 50 % cutoff and 93 %, 51 % and 79 % with >= 75 % cutoff, respectively (NS). When performing individual vessel analysis, sensitivity, specificity and accuracy were 59 %, 78 % and 68 % for >= 50 % cutoff and 70 %, 75 % and 74 % for >= 75 % cutoff, respectively (p = 50 % stenosis cutoff criteria for CAD diagnosis and evaluation. Combined with coronary angiography, myocardial SPECT offers an excellent management strategy to patients

Concordancia interobservadores en la interpretación en forma ciega de cintigrafía de ventilación perfusión en pacientes con sospecha clínica de tromboembolismo pulmonar / Interobserver concordance in the interpretation of ventilation-perfusion scintigraphy in patients with clinically suspected pulmonary embolism

La pesquisa adecuada del tromboembolismo pulmonar (TEP) tiene importancia en el manejo terapéutico y en el pronóstico de los pacientes. El cintigrama de ventilación y perfusión (VQ) es un método bien establecido en la evaluación de esta patología. La concordancia interobservador puede ser bastante variable y debieran minimizarse las discordancias dentro de un mismo grupo. Objetivo: Conocer la concordancia entre observadores formados en nuestro centro y correlacionarlos con el informe oficial emitido con los antecedentes clínicos y radiológicos. Método: Se analizaron retrospectivamente 401 estudios de 382 pacientes con sospecha de TEP de diferente probabilidad clínica, informados por 6 observadores independientes con distinta experiencia. Se realizó lectura en forma ciega informando como alta, baja o intermedia probabilidad de TEP, basado en la experiencia individual y en criterios PIOPED modificados. Se aplicó kappa ponderado. Resultados: En los informes existió 27.2 por ciento de alta probabilidad de TEP, 5.5 por ciento fueron intermedia o indeterminada y 67.3 por ciento de baja probabilidad, casi normal o normal. La concordancia entre los observadores varió entre 72.6 y 86 por ciento con variación de índice kappa entre 0.582 y 0.743. La correlación con el informe emitido varió entre 74.3 y 81.8 por ciento y (k: 0.582 y 0.675). Hubo mayor concordancia entre los observadores con mayor experiencia. Conclusión: En nuestro centro existe una excelente concordancia interobservador con buenos índices kappa en la interpretación ciega de los VQ solicitados por TEP. Este ejercicio además, sirvió como entrenamiento práctico para los residentes del centro.

An assessment of wall motion, perfusion and glucose metabolism in recent myocardial infarction: a comparison in patients with and without revascularization.

The aim of this study was to compare the extent and severity of wall motion abnormalities, perfusion and glucose metabolism, in recent myocardial infarction in patients with and without revascularization. Forty-nine patients were studied (82% men; mean age 58 years) by using echocardiography, 201Tl single photon emission computed tomography (SPECT) rest and redistribution, and 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) SPECT at a mean of 9.2 days (range, 1-24 days) after myocardial infarction. Twenty-seven of the 49 patients underwent revascularization while the other 22 received medical therapy before echocardiography and studies using radionuclides. A contrast angiogram was obtained for each patient. A follow-up echocardiogram at 3 months was obtained for 44 patients. Images were read blindly, using a 17 segment model, with semi-quantitative analysis. In the whole group, the extent of hypokinesia was 15%+/-14 (mean+/-SD); the extent of mild defects was determined as 5%+/-6 by using 201Tl at rest, 6%+/-9 by using 201Tl redistribution, and 4%+/-6 by using 18F-FDG (P<0.0005, echocardiogram/radionuclides). Echocardiography showed that the extent of akinesia-dyskinesia was 16%+/-18 in revascularized patients and 28%+/-18 in non-revascularized patients (P=0.017). With regard to moderate and severe defects, 201Tl rest showed 19%+/-16 and 28%+/-17, respectively (P=0.047); 201Tl redistribution 17%+/-15 and 26%+/-15, respectively (P=0.043); and 18F-FDG 17%+/-13 and 24%+/-15, respectively (NS). In echocardiography, the extent of hypokinetic segments decreased from 16%+/-15 at baseline to 10%+/-11 at 3 months (P=0.045), in revascularized patients. It is concluded that, in recent myocardial infarction, hypokinesia extent on echocardiogram is greater than mild perfusion or metabolic defect extent, reflecting stunning and so the use of radionuclide techniques appear more accurate for defining the extent of myocardial infarction. Non-revascularized patients showed a significantly greater extent of akinesia-dyskinesia and moderate-severe perfusion defects than did revascularized patients, which can be considered a result of therapy. It is suggested that 201Tl rest perfusion be used for the assessment of myocardial infarction soon after revascularization.

Is (99m)Tc-sestamibi scintimammography complementary to conventional mammography for detecting breast cancer in patients with palpable masses?

UNLABELLED: The aim of this trial was to evaluate in developing countries from different regions the diagnostic performance of (99m)Tc-sestamibi scintimammography (SM) in palpable breast lesions and to verify the clinical usefulness of a joint evaluation with mammography and SM. METHODS: From 10 countries, a total of 238 patients with palpable breast masses (n = 245) were included in this prospective multicenter trial. Prone SM was performed 10 min and 60-90 min (157 patients) after injection using an isotime acquisition of 10 min. Mammography was assessed by the same dedicated imaging radiologist according to breast imaging reporting and data system (BI-RADS) categories for malignancy and breast density. Masked SM findings and mammography findings were checked for a correlation with histopathology findings for excisional biopsy samples. Diagnostic values for breast cancer detection were calculated per lesion. RESULTS: Histopathology revealed 189 cancerous lesions and 56 benign lesions. The sensitivity and specificity of SM were 0.83 and 0.77, respectively. SM diagnostic values did not depend on the incidence of breast cancer in the country of origin or on the timing of imaging (early vs. delayed scans). On mammography, the technique yielded a sensitivity and specificity of 0.85 and 0.66, with 27 mammograms classified as BI-RADS category 1, 33 as category 2, 5 as category 3, 56 as category 4, and 124 as category 5. Thirty-seven lesions were considered to show increased radiologic density. No significant difference was found in SM diagnostic values among different BI-RADS categories or between the groups with low and high breast density. A sensitivity of 96% was calculated when SM and mammography results were combined, with 75% of all false-negative mammography findings classified as true-positive results by SM. CONCLUSION: SM complements mammography in patients with palpable masses and negative mammography findings.

[Treatment of hyperthyroidism with radioiodine: effects of administered dose on complications and thyroid function]. / Tratamiento del hipertiroidismo con radioyodo: efecto de la dosis administrada sobre la función tiroidea y complicaciones asociadas.

BACKGROUND: Radio-iodine is a definite therapy for Graves disease hyperthyroidism. However, the optimal dosage is still debatable. AIM: To assess the effects of different radioiodine doses on thyroid function and complications in patients with hyperthyroidism. MATERIAL AND METHODS: A retrospective analysis of 139 patients with hyperthyroidism, treated with ratio-iodine between 1988 and 1998. Radio iodine dose used was classified as low (< 10 mCi), intermediate (10-14.9 mCi) or high (> or = 15 mCi). RESULTS: Thirty-five patients were treated with low doses, 33 with intermediate doses and 71 with high doses. There were no differences between these patients in age, disease severity, frequency of post treatment euthyroidism or complications. Patients treated with low doses had a higher frequency of persistent hyperthyroidism than patients treated with high doses (25.7 and 4.2% respectively, p < 0.001). Likewise, the frequency of subsequent hypothyroidism was 60% in patients treated with low doses and 84.5% of those with high doses, in whom it also appeared earlier. Associated complications were clinically irrelevant. In seven patients, Graves ophthalmopathy progressed after treatment, but this progression was not associated with the dose used. CONCLUSIONS: Radio iodine in high doses is useful, safe and effective for the treatment of Graves hyperthyroidism.

[SPECT tomography with F 18-fluorodeoxyglucose in a recent myocardial infarction clinical case]. / Tomografía SPECT con F18-fluorodeoxiglucosa en infarto reciente del miocardio. Caso clínico.

We report a 50-year-old woman with a recent myocardial infarction in whom a myocardial perfusion single photon emission computed tomography (SPECT) with Thallium201 was done simultaneously with a F18-fluorodeoxyglucose (FDG) SPECT to study glucose metabolism. Myocardial infarction was located in the anteroseptal and apical regions and an echocardiography, done at the second day of evolution, showed a septo-apical hypokinesia. On the tenth day, a coronary angiography showed a critical lesion of the anterior descending coronary artery and an angioplasty with stent placement was performed on the next day. On the twelfth day, a resting, redistribution 201Tl SPECT to study viability and a FDG-SPECT with a dual head high-energy collimator camera were done. Images, acquired 45 min after injection, were analyzed visually. In anterior and medial apical sectors, discordance between flux and metabolism, considered a classical mismatch, was observed. Echocardiographic hypokinesia disappeared three month after revascularization.

Optimal imaging time for delayed images in the diagnosis of abnormal parathyroid tissue with Tc-99m sestamibi.

PURPOSE: Double-phase scintigraphy with Tc-99m sestamibi is a good method to detect hyperfunctioning parathyroid glands. This study tried to determine the best time for delayed images: 2 or 4 hours. METHODS: Fifty-six patients were studied, and 35 of them had primary hyperparathyroidism (mean age, 53 +/- 13 years; 54% were women). Cervical ultrasonography was performed on 29 of 56 (52%) patients and surgery in 16 of 56 (29%) patients. The dose was 740 MBq (20 mCi) given intravenously, and the acquisition was performed at 10 minutes, 2 h, and 4 h using anterior views, including the mediastinum. Studies that had positive results were analyzed blindly by two independent observers, who selected the best definition for abnormal activity. RESULTS: Nineteen of 56 (34%) studies were negative and 37 of 56 (66%) were positive, 25 of them with one focus and 12 with two or more parathyroid foci. Analysis revealed 76% agreement between the observers (the rest was classified by consensus). In 70% of the cases, the best delayed image was obtained at 2 hours, in 16% at 4 hours (P < 0.00001), and in 14% both images were similar. In those cases with better images at 4 hours, the 2-hour images also showed the lesions. In two patients, lesions were seen only at 2 hours. These results could be explained by tracer decay, washout of parathyroid activity, or both. CONCLUSIONS: The best protocol should include the early 10-minute image and the 2-hour delayed view. Further controls do not appear necessary. This may be important for patient throughput.

Simultaneous assessment of function and perfusion during dipyridamole-handgrip Tc-99m sestamibi imaging in chronic coronary artery disease.

The main goal of this work was to know the value of ventricular function in addition to perfusion Tc-99m sestamibi images in the assessment of coronary artery disease (CAD) when using dipyridamole (DIP) associated to isometric exercise. We analyzed 52 patients with suspected CAD; 40 of them had coronary lesions > or = 50% and 12 patients without CAD, conforming study and control groups, respectively. Twenty-eight patients had prior myocardial infarction. A two-day sestamibi protocol was employed with i.v. DIP-handgrip and rest injections, acquiring ECG-gated first pass and planar perfusion images. Sensitivity for perfusion images was 85% and specificity was 91.7%. There was no change between rest and DIP ejection fraction (EF) in controls. CAD patients presented a significant EF decrease with DIP (p: 0.0015). Patients with ischemia in perfusion images had larger EF decrease (p: 0.0001). For the analysis, an EF drop > or = 5% and any wall motion abnormality (WMA) were considered as having an abnormal response to DIP. CAD sensitivity improved significantly to 92.5% when adding EF drop and to 90% when adding WMA parameters, but specificity decreased to 75% with EF drop, and to 58.3% with WMA. In conclusion, first pass parameters from DIP-isometric exercise in addition to perfusion images are not a significant help in the assessment of CAD.