RESUMEN
BACKGROUND: The prognosis of patients with right ventricular (RV) arrhythmias remains uncertain. This study prospectively evaluated the prognostic value of RV and left ventricular (LV) involvement assessed by radionuclide angiography (RNA) as predictors for sudden death. METHODS AND RESULTS: Patients (n=188) with severe arrhythmias originating from the RV were followed up for a mean of 45+/-34 months. Data on clinical presentation, resting and stress ECG, signal-averaged ECG, 24-hour Holter monitoring, and programmed stimulation were collected along with RNA. Patients were classified as group I (n=82) with normal RNA or group II (n=106) with an abnormal RV suggestive of arrhythmogenic RV cardiomyopathy, classified as diffuse or localized disease, with or without associated LV abnormalities. During follow-up, 14 patients died suddenly, all in group II. None of the clinical and electrical data were predictive of death. An abnormal RNA study was a highly predictive factor for death (P<0.005), as well as the presence of LV abnormalities (P<0.01). CONCLUSIONS: The present study confirms that arrhythmogenic RV cardiomyopathy is a severe disease with a high risk for cardiac death. Evidence of RV abnormalities in patients presenting with RV arrhythmias is highly predictive for sudden death, as is its association with LV involvement.
Asunto(s)
Arritmias Cardíacas/diagnóstico , Angiografía por Radionúclidos , Disfunción Ventricular Derecha/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Arritmias Cardíacas/complicaciones , Muerte Súbita Cardíaca/etiología , Electrocardiografía , Eritrocitos/metabolismo , Femenino , Estudios de Seguimiento , Análisis de Fourier , Humanos , Funciones de Verosimilitud , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Medición de Riesgo , Volumen Sistólico , Tasa de Supervivencia , Tecnecio , Disfunción Ventricular Derecha/complicacionesRESUMEN
OBJECTIVES: The aim of this study was to assess the diagnosis of myocarditis in patients presenting with acute myocardial infarction (MI) and normal coronary angiograms. BACKGROUND: Most often in these patients, the etiologic diagnosis remains unclear once they are found to have normal coronary arteries. The diagnosis of myocarditis mimicking MI is clinically relevant, because numerous arguments suggest a relation between myocarditis and dilated cardiomyopathy. Myocardial indium-111 (111In)-antimyosin antibody (AMA)/rest thallium-201 (201Tl) imaging allows noninvasive detection of myocarditis. METHODS: Forty-five patients admitted to three intensive care units for suspicion of acute MI, with normal coronary angiograms, were investigated. Indium-111-AMA planar images and then a dual-isotope rest AMA/201Tl tomographic study were performed. Six-month echocardiographic follow-up was obtained in 80% of the patients with initial left ventricular (LV) wall motion abnormalities. RESULTS: In eight patients, AMA and 201Tl scintigraphy were negative. In two patients, a matched 201Tl defect and focal AMA uptake suggested acute MI (due to prolonged vasospasm or spontaneously reperfused coronary occlusion). In 17 patients, diffuse AMA uptake over the whole LV suggested diffuse myocarditis. In 18 patients, focal AMA uptake with a normal 201Tl scan suggested diffuse but heterogeneous, or focal myocarditis. Complete functional recovery was observed in 81% of the patients with a pattern of myocarditis. CONCLUSIONS: Among 45 patients presenting with acute MI and normal coronary angiograms, 38% had diffuse myocarditis and 40% had a scintigraphic pattern of heterogeneous or focal myocarditis. Short-term follow-up showed complete LV functional recovery in 81% of these patients.
Asunto(s)
Infarto del Miocardio/diagnóstico , Miocarditis/diagnóstico , Adulto , Anticuerpos Monoclonales/inmunología , Angiografía Coronaria , Electrocardiografía , Femenino , Humanos , Radioisótopos de Indio , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/fisiopatología , Miocarditis/diagnóstico por imagen , Miocarditis/fisiopatología , Compuestos Organometálicos/inmunología , Estudios Prospectivos , Cintigrafía , Ultrasonografía , Función Ventricular IzquierdaRESUMEN
In this review, we limit ourselves to original studies based on scintigraphic or MRI techniques performed in man. During the year 2004 we have learned several lessons from various interesting studies reported below, regarding different areas of cardiology including myocardial ischaemia, myocarditis, myocardial infarction and myocardial viability.
Asunto(s)
Cardiopatías/diagnóstico por imagen , Cardiopatías/patología , Imagen por Resonancia Magnética , Humanos , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/patología , CintigrafíaRESUMEN
UNLABELLED: Exercise lung 201 TI uptake calculated with planar imaging has an important diagnostic and prognostic value in patients with coronary artery disease (CAD). However, its value with SPECT imaging raises methodological concerns and is controversial. We studied its value for the discrimination between extensive (E) and limited (L) angiographic CAD with exercise SPECT. METHODS: Four methods of lung-to-heart ratio quantification were calculated in patients with a low likelihood (< 5%) of CAD (n = 62). Their dependent variables were defined, and corresponding correction equations were derived. Receiver operating characteristic (ROC) analysis was performed in a pilot group (L-CAD, n = 49; E-CAD, n = 126) to define the optimal method of calculation of the lung-to-heart ratio. Its best threshold providing the best sensitivity for a specificity of 90% was defined. After correction for dependent variables, the 4 methods were also compared by ROC analysis and the optimal corrected method was compared with the optimal uncorrected method using ROC analysis and the best threshold. The consistency of these results in the validation group (L-CAD, n = 41; E-CAD, n = 122) and of the results of visual analysis of lung 201TI uptake were then verified. RESULTS: On ROC analysis in the pilot group, the optimal method of calculation of the lung-to-heart ratio was the mean activity in a region of interest drawn at the base of the lungs to the mean activity over the heart (Lb/H). For the best threshold, Lb/H presented a sensitivity of 34%. Corrected Lb/H still remained the best method of calculation on ROC analysis compared with the other corrected methods. On ROC analysis, there was no difference between corrected and uncorrected Lb/H. For the best threshold, corrected Lb/H presented a similar sensitivity of 37% compared with uncorrected Lb/H. When applied to the validation group (L-CAD, n = 41; E-CAD, n = 122), the best-defined threshold in the pilot group for corrected Lb/H presented a diagnostic value similar to that in the pilot group (sensitivity, 41%; specificity, 90%), but uncorrected Lb/H presented a higher sensitivity (47%; P < 0.04) and a slightly lower specificity (80%). Results of lung 201TI uptake visual analysis were inconsistent between pilot and validation groups (42% versus 58% sensitivity, P = 0.012; 86% versus 66% specificity, P = 0.023). CONCLUSIONS: For evaluation of E-CAD versus L-CAD, quantification of the exercise lung-to-heart 201TI uptake ratio with SPECT is feasible, reproducible, more discriminate than simple visual analysis, and best calculated as Lb/H. It presents an intrinsic diagnostic value even after correction for other clinically valuable dependent variables.
Asunto(s)
Enfermedad Coronaria/diagnóstico por imagen , Pulmón/diagnóstico por imagen , Radioisótopos de Talio , Tomografía Computarizada de Emisión de Fotón Único , Estudios de Casos y Controles , Angiografía Coronaria , Enfermedad Coronaria/epidemiología , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Curva ROC , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
UNLABELLED: Somatostatin receptor scintigraphy (SRS) has been used for the detection of gastroenteropancreatic (GEP) tumors. This study evaluates the clinical impact of SRS in GEP tumor detection and its therapeutic implications on patient management. METHODS: We prospectively studied 160 patients with biologically and/or histologically proven GEP tumors. Before SRS, patients were classified into three groups: gastrointestinal (Group 1; n = 90) patients without known metastases; (Group 2; n = 59) patients with metastases limited to the liver; (Group 3; n = 11) patients with known extrahepatic metastases. The scintigraphic data were compared to the radiological findings. RESULTS: In Group 1, without known metastases, conventional imaging detected 53 primary sites in 44 patients: SRS was positive in 68% of these sites and discovered 4 additional primary tumors in 3 patients and 16 metastases in 14 patients. Conventional imaging was negative in 46 patients: SRS discovered 47 new sites in 36 patients. In Group 2, SRS confirmed liver metastases in 95% of patients and discovered 45 new sites in 36 of these patients. In Group 3, SRS disclosed 11 new sites in 7 patients. These results modified patient classification in 38 cases (24%). Surgical therapeutic strategy was changed in 40 patients (25%). CONCLUSION: Somatostatin receptor scintigraphy improves tumor detection, has major clinical significance and should be performed systematically for staging and therapeutic decision making in patients with GEP tumors.
Asunto(s)
Tumor Carcinoide/diagnóstico por imagen , Neoplasias Gastrointestinales/diagnóstico por imagen , Radioisótopos de Indio , Tumores Neuroendocrinos/diagnóstico por imagen , Neoplasias Pancreáticas/diagnóstico por imagen , Receptores de Somatostatina/análisis , Somatostatina/análogos & derivados , Síndrome de Zollinger-Ellison/diagnóstico por imagen , Tumor Carcinoide/secundario , Estudios de Casos y Controles , Diagnóstico por Imagen , Femenino , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/secundario , Metástasis Linfática , Masculino , Persona de Mediana Edad , Tumores Neuroendocrinos/secundario , Estudios Prospectivos , Sensibilidad y Especificidad , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
UNLABELLED: Somatostatin receptor scintigraphy (SRS) has been shown to reveal sarcoidosis sites. The aim of this study was to prospectively compare SRS and gallium scintigraphy in the evaluation of pulmonary and extrapulmonary involvement in patients with proven sarcoidosis. METHODS: Eighteen patients with biopsy-proven sarcoidosis were included. Nine were or recently had been receiving steroid therapy at the time of the examination. Planar gallium scintigraphy (head, chest, abdomen, and pelvis) and thoracic SPECT were performed at 48-72 h after injection of a mean dose of 138 +/- 21 MBq 67Ga. Planar SRS and thoracic SPECT were performed at 4 and 24 h after injection of a mean dose of 148 +/- 17 MBq 111n-pentetreotide. RESULTS: Gallium scintigraphy found abnormalities in 16 of 18 patients (89%) and detected 64 of 99 clinically involved sites (65%). SRS found abnormalities in 18 of 18 patients and detected 82 of 99 clinically involved sites (83%). Of the 9 treated patients, gallium scintigraphy found abnormalities in 7 (78%), detecting 23 of 39 clinically involved sites (59%), whereas SRS found abnormalities in 9, detecting 32 of 39 clinically involved sites (82%). CONCLUSION: This study suggests that, compared with gallium scintigraphy, SRS appears to be accurate and contributes to a better evaluation of organ involvement in sarcoidosis patients, especially those treated with corticosteroids.
Asunto(s)
Radioisótopos de Galio , Radioisótopos de Indio , Receptores de Somatostatina/análisis , Sarcoidosis Pulmonar/diagnóstico por imagen , Sarcoidosis/diagnóstico por imagen , Somatostatina/análogos & derivados , Tomografía Computarizada de Emisión de Fotón Único , Corticoesteroides/uso terapéutico , Adulto , Femenino , Humanos , Masculino , Estudios Prospectivos , Sarcoidosis/tratamiento farmacológico , Sarcoidosis/metabolismo , Sarcoidosis Pulmonar/tratamiento farmacológico , Sarcoidosis Pulmonar/metabolismoRESUMEN
UNLABELLED: The current major limitation to development of electrocardiographically (ECG) gated blood-pool SPECT (GBPS) for measurement of the left ventricular (LV) ejection fraction (LVEF) and volumes is the lack of availability of clinically validated automatic processing software. Recently, 2 processing software methods for quantification of the LV function have been described. Their LVEFs have been validated separately, but no validation of the LV volume measurement has been reported. METHODS: We compared 3 processing methods for evaluation of the LVEF (n = 29) and volumes (n = 58) in 29 patients: automatic geometric method (GBPS(G)), semiautomatic activity method (GBPS(M)), and 35% maximal activity manual method (GBPS(35%)). The LVEF provided by the ECG gated equilibrium planar left anterior oblique view (planar(LAO)) and the LV volumes provided by LV digital angiography (Rx) were used as gold standards. RESULTS: Whereas the GBPS(G) and GBPS(M) methods present similar low percentage variabilities, the GBPS(35%) method provided the lowest percentage variabilities for the LVEF and volume measurements (P < 0.04 and P < 0.02, respectively). The LVEF and volume provided by the 3 methods were highly correlated with the gold standard methods (r > 0.98 and r > 0.83, respectively). The LVEFs provided by the GBPS(35%) and GBPS(M) methods are similar and higher than those of the GBPS(G) method and planar(LAO) method, respectively (P < 0.0001). For the LVEF, there is no correlation between the average and paired absolute difference for the 3 GBPS methods against the planar(LAO) method, and the limits of agreement are relatively large. LV volumes are lower when calculated with the GBPS(M), GBPS(G), and Rx methods (P < 0.0001). However, the GBPS(35%) and Rx methods provide LV volumes that are similar. There is no linear correlation between the average and the paired absolute difference of volumes calculated with the GBPS(G) and GBPS(35%) methods against Rx LV volumes. However, a moderate linear correlation was found with the GBPS(M) method (r = 0.6; P = 0.0001). The 95% limits of agreement between the Rx LV volumes and the 3 GBPS methods are relatively large. CONCLUSION: GBPS is a simple, highly reproducible, and accurate technique for the LVEF and volume measurement. The reported findings should be considered when comparing results of different methods (GBPS vs. planar(LAO) LVEF; GBPS vs. Rx volume) and results of different GBPS processing methods.
Asunto(s)
Electrocardiografía , Imagen de Acumulación Sanguínea de Compuerta , Procesamiento de Imagen Asistido por Computador/métodos , Volumen Sistólico , Tomografía Computarizada de Emisión de Fotón Único , Función Ventricular Izquierda , Humanos , Masculino , Persona de Mediana Edad , Angiografía por Radionúclidos , Procesamiento de Señales Asistido por Computador , Programas Informáticos , Tomografía Computarizada de Emisión de Fotón Único/métodosRESUMEN
UNLABELLED: A lack of specificity for myocardial perfusion imaging has been widely reported, mostly related to false-positive defects on the inferior wall. The application of depth-dependent resolution recovery (RR), attenuation correction (AC) using external source devices, and scatter correction has been proposed to resolve this pitfall. METHODS: We studied the clinical benefit of depth-dependent RR, nonuniform AC using a scanning line source, and scatter correction (photon energy recovery [PER]) compared with filtered backprojection alone. Eighty-two patients were included: 40 healthy volunteers with a low likelihood of coronary artery disease (control group) and 42 patients with proven right or circumflex coronary artery disease but without involvement of the left anterior descending artery. Among these 82 patients, the images of 33 were also processed with PER. RESULTS: RR did not alter the performance of filtered backprojection alone. AC + RR greatly improved specificity and the rate of normal (201)Tl SPECT findings in the control population (from 56% to 95% and from 53% to 100%, respectively) but significantly decreased sensitivity (from 92% to 54%). AC + RR generated a false anteroapical defect in 21% of patients and reverse redistribution of the apex in 23%. AC + RR significantly decreased the extent of the stress defect (from 4.09 to 3.21 segments, P < 0.003) and increased the perfusion score of the stress defect (from 0.78 +/- 0.72 to 1.47 +/- 1.11, P < 0.00061). Moreover, AC + RR generated overcorrection on the inferior wall, leading to false estimation of viability for 11 of 15 patients with an old inferior myocardial scar without evidence of residual viability. PER decreased overcorrection on the inferior wall, but without improving sensitivity. PER did not significantly reduce the number of anteroapical false-positives or the number of apical reverse distribution cases. CONCLUSION: AC + RR improved the specificity and normalcy rate of (201)Tl SPECT myocardial perfusion imaging but generated overcorrection on the inferior wall, leading to low sensitivity and to false evaluation of myocardial viability in 73% of the patients with inferior infarction. AC + RR also generated anteroapical artifacts. The addition of scatter correction did not significantly reduce these drawbacks.
Asunto(s)
Circulación Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Radioisótopos de Talio , Tomografía Computarizada de Emisión de Fotón Único , Dipiridamol , Prueba de Esfuerzo , Humanos , Procesamiento de Imagen Asistido por Computador , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico por imagen , Sensibilidad y EspecificidadRESUMEN
UNLABELLED: Scintigraphy with somatostatin analogs is a sensitive method for the staging and therapeutic management of patients with endocrine gastroenteropancreatic (GEP) tumors. The aim of this study was to compare prospectively somatostatin receptor scintigraphy (SRS) using 111n-pentetreotide with bone scintigraphy using 99mTc-hydroxymethylene diphosphonate for the detection of bone metastases. METHODS: One-hundred-forty-five patients with proven endocrine GEP tumors were investigated. Patients were classified according to the presence of bone metastases as indicated by CT, MRI or histologic data. Group I included 19 patients with confirmed bone metastases, and group II included 126 patients without bone metastases. RESULTS: In group I, SRS was positive in all 19 patients with bone metastases, and bone scintigraphy was positive in 17 patients. Bone metastases were found to occur predominantly in patients with liver metastases. In group 11, 5 patients had recent bone surgery for fracture or arthritis. SRS showed bone uptake in 4 of these patients, and bone scanning showed abnormal uptake in 5. In 7 of the remaining 121 group II patients, SRS was negative and bone scanning showed abnormal bone uptake suggesting bone metastases. The detection of bone metastases was of major prognostic value, because 42% of group 1 patients died during a 2-y follow-up. CONCLUSION: In patients with GEP tumors, the accuracy of SRS appears to be similar to that of bone scintigraphy for the detection of bone metastases.
Asunto(s)
Neoplasias Óseas/secundario , Neoplasias del Sistema Digestivo/diagnóstico por imagen , Ácido Pentético/análogos & derivados , Receptores de Somatostatina/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Óseas/diagnóstico por imagen , Tumor Carcinoide/diagnóstico por imagen , Neoplasias del Sistema Digestivo/metabolismo , Femenino , Humanos , Radioisótopos de Indio , Masculino , Persona de Mediana Edad , Octreótido/análogos & derivados , Estudios Prospectivos , Cintigrafía , Radiofármacos , Somatostatina/análogos & derivados , Medronato de Tecnecio Tc 99m/análogos & derivados , Síndrome de Zollinger-Ellison/diagnóstico por imagenRESUMEN
Clinical, electrocardiographic, and thallium-201 single-photon emission computed tomography data were evaluated in 397 consecutive patients divided into 3 groups according to coronary hyperemic stimulation: 186 patients (group I; Ex) had maximal symptom-limited exercise ergometric stress testing, 93 patients (group II; Dip) had intravenous dipyridamole (0.7 to 0.8 mg/kg) stress testing, and 118 patients (group III; Dip+Ex) had dipyridamole (0.7 to 0.8 mg/kg) plus nonlimited (i.e., symptom-limited) exercise stress testing, achieving a maximal workload (mean +/- SD) of 102 +/- 37 W. Clinical tolerance was higher in Ex than in Dip groups (p < 0.01), and tended to be higher in Dip+Ex than in Dip groups (p = NS). Image quality--as judged by signal-to-noise ratios--was superior in Ex and Dip+Ex groups when compared with the Dip group (p < 0.01). Chest pain and electrocardiographic positivity were more frequent in the Dip+Ex group than in the Dip group (p < 0.05), despite more extensive coronary artery disease (CAD) in the Dip group; and reversible scintigraphic defects were more frequent in Dip+Ex versus Dip (p < 0.01) and in Ex versus Dip groups (p < 0.05) in patients with established CAD, as well as for the whole group. We conclude that, in patients unable to achieve 85% of their maximal predicted heart rate, the combination of high-dose dipyridamole plus nonlimited exercise stress testing is superior to dipyridamole stress testing alone, and comparable to maximal exercise testing.
Asunto(s)
Enfermedad Coronaria/diagnóstico por imagen , Dipiridamol , Prueba de Esfuerzo , Corazón/diagnóstico por imagen , Radioisótopos de Talio , Tomografía Computarizada de Emisión de Fotón Único , Vasodilatadores , Anciano , Distribución de Chi-Cuadrado , Circulación Coronaria/efectos de los fármacos , Enfermedad Coronaria/fisiopatología , Dipiridamol/administración & dosificación , Electrocardiografía , Prueba de Esfuerzo/métodos , Tolerancia al Ejercicio , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vasodilatadores/administración & dosificaciónRESUMEN
Submaximal exercise tests have been advocated to assess exercise capacity in chronic heart failure, but hemodynamic responses have not been characterized. To determine left ventricular (LV) responses during submaximal exercise, the LV ejection fraction (EF) and volumes were evaluated by using an ambulatory radionuclide detector in 13 patients with idiopathic dilated cardiomyopathy during upright maximal graded bicycle exercise, stair climbing and a 6-minute walk test. The 3 tests elicited different responses in volumes and, to a lesser degree, in LVEF. The maximal bicycle exercise led to a decrease in LVEF from 22 +/- 9% to 17 +/- 8% (p <0.05), with marked increases in both end-diastolic volume (EDV) (+15 +/- 10%, p <0.001) and end-systolic volume (ESV) (+23 +/- 18%, p <0.001). Stair climbing tended to reduce LVEF (from 24 +/- 11% to 21 +/- 10%, p = 0.05), with a lesser increase in volumes, which was more marked for ESV (+8 +/- 9%, p <0.01) than for EDV (+4 +/- 4%, p <0.01). The 6-minute walk test did not significantly change LVEF (23 +/- 10% vs 22 +/- 10%), but increased both EDV (+10 +/- 6%, p <0.001) and ESV (+8 +/- 8%, p <0.01) moderately and proportionally. Exercise capacity indexes (peak oxygen consumption, maximal bicycle work rate, stair climbing time, and the distance covered during the 6-minute walk test) correlated significantly with one another. There was no correlation between submaximal exercise tolerance indexes and resting or exercise LVEF. This study shows that (1) LVEF changes are inadequate to report on LV volume changes during exercise; (2) the 3 tests induce different LV volume changes; (3) the 6-minute walk test induces significant changes in LV volumes but no change in LVEF.
Asunto(s)
Cardiomiopatía Dilatada/fisiopatología , Ejercicio Físico/fisiología , Función Ventricular Izquierda/fisiología , Adulto , Anciano , Cardiomiopatía Dilatada/diagnóstico por imagen , Prueba de Esfuerzo , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno/fisiología , Ventriculografía con Radionúclidos , Volumen Sistólico/fisiologíaRESUMEN
The investigation of left ventricular contractile reserve usually requires the determination of left ventricular volume, but its measurement with radionuclide angiography is difficult. The aim of this study was to determine left ventricular volume directly during exercise by the simultaneous measurement of peak exercise left ventricular ejection fraction (LVEF) and oxygen consumption (VO2max) and to compare the results with another geometric method. In the absence of lung disease, the systemic arteriovenous oxygen difference (DAVmax) during maximal exercise converges to 0.13-0.14 ml O2 per ml blood. The measurement of VO2max allows maximal cardiac output (COmax) to be calculated as VO2max = COmax. DAVmax. By simultaneously determining LVEFex, exercise end-diastolic volume (EDVex) can then be expressed as a linear function of VO2max, maximal heart rate (HRmax), DAVmax and LVEFex. Then, the relationship between end-diastolic counts and true volume can be derived at rest. The two methods were closely correlated (r = 0.91, P < 0.001), despite the geometric method being less accurate when applied to low counting statistic acquisitions. We conclude that rest and exercise left ventricular volume can be determined non-invasively by the simultaneous measurement of VO2max and LVEFex. Furthermore, this method provides additional prognostic information which is clinically relevant in the staging of patients with heart failure.
Asunto(s)
Corazón/diagnóstico por imagen , Consumo de Oxígeno , Ventriculografía con Radionúclidos/métodos , Adulto , Anciano , Cardiomiopatía Dilatada/diagnóstico por imagen , Cardiomiopatía Dilatada/patología , Cardiomiopatía Dilatada/fisiopatología , Estudios de Casos y Controles , Prueba de Esfuerzo , Imagen de Acumulación Sanguínea de Compuerta/métodos , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/patología , Insuficiencia Cardíaca/fisiopatología , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/patología , Humanos , Masculino , Persona de Mediana Edad , Miocardio/metabolismo , Pronóstico , Función Ventricular IzquierdaRESUMEN
Myocardial scintigraphy is clinically relevant in the management of patients with previous myocardial infarction. The purpose of such investigation is first to quantify the infarcted area, secondly to detect and quantify a residual myocardial ischaemia and thirdly to evidence the presence of chronically hypoperfused and akinetic but potentially viable myocardium (hibernating myocardium). Thallium SPECT is to be preferred in this indication even if new tracers could be promising: fatty acids, 18Fluorodesoxyglucose imaged by PET or SPECT cameras. In such indications, stress tests should sometimes be completed with delayed or rest acquisitions. In case of negative stress and rest thallium SPECT, PET scans may be useful in patients with large myocardial infarction, severe left ventricular dysfunction, segmental wall motion asynergy, and absence of previously demonstrated residual ischaemia in order to select patients eligible for coronary revascularization or heart transplantation.
Asunto(s)
Infarto del Miocardio/complicaciones , Infarto del Miocardio/diagnóstico por imagen , Humanos , Infarto del Miocardio/prevención & control , Tomografía Computarizada de Emisión , Tomografía Computarizada de Emisión de Fotón ÚnicoAsunto(s)
Cardiotónicos , Dobutamina , Ecocardiografía Doppler/métodos , Aturdimiento Miocárdico/diagnóstico por imagen , Velocidad del Flujo Sanguíneo , Enfermedad Coronaria/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Disfunción Ventricular Izquierda/diagnóstico por imagenAsunto(s)
Enfermedad Coronaria/diagnóstico por imagen , Complicaciones de la Diabetes , Corazón/diagnóstico por imagen , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/terapia , Predicción , Humanos , Pronóstico , Tomografía Computarizada de Emisión/métodosRESUMEN
By implementing enterprise-wide networks with optimal cabling, health care organizations can avail themselves of the most powerful advances in information/communication systems.
Asunto(s)
Redes de Comunicación de Computadores/instrumentación , Telecomunicaciones/instrumentación , Diseño de Equipo , Tecnología de Fibra Óptica , Sistemas Multiinstitucionales , Estados UnidosRESUMEN
BACKGROUND: To overcome some of the limitations imposed by planar imaging, we aimed to optimize the use of first harmonic Fourier phase analysis (FPA) in electrocardiography-gated blood-pool single photon emission computed tomography (GBPS) by comparing different quantitative, 3-dimensional methods. METHODS AND RESULTS: Three groups of patients who underwent GBPS were evaluated: group 1, 8 patients with no heart disease; group 2, 10 patients with left ventricular disease; and group 3, 6 patients with right ventricular disease. Six different methods for FPA were compared: surface, cylindrical, spherical, and hybrid methods with fixed thresholding and spherical and hybrid methods with multiple thresholding. The hybrid method with multiple thresholding for the left ventricle and the spherical method for the right ventricle provided the highest discrimination score (phase) between normal and abnormal ventricles. Among methods with similar discrimination score for these 2 methods, the cylindrical and hybrid methods for the left ventricle and the spherical method for the right ventricle provided the best homogeneity of phase distribution histogram in normal ventricles. These were considered the optimal methods for FPA. CONCLUSIONS: The hybrid or cylindrical method for the left ventricle and the spherical method for the right ventricle with fixed thresholding are the optimal methods for FPA in GBPS.
Asunto(s)
Electrocardiografía/métodos , Análisis de Fourier , Imagen de Acumulación Sanguínea de Compuerta/métodos , Ventrículos Cardíacos/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único/métodos , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Derecha/diagnóstico , HumanosRESUMEN
BACKGROUND: Multiharmonic Fourier phase analysis of radionuclide angiography is a well-established method for the diagnosis of arrhythmogenic right ventricular cardiomyopathy. We sought to determine the optimal acquisition parameters: number of frames per cycle and number of counts per frame, with all other acquisition and processing parameters being fixed. METHODS AND RESULTS: Radionuclide angiography with list mode acquisition was performed in 10 normal subjects (pilot group) and 11 patients with arrhythmogenic right ventricular cardiomyopathy (validation group), allowing the reconstruction of electrocardiography-gated constant phase studies with different parameters: 16, 24, and 32 frames per cycle and 200, 400, 600, and 800 kcounts per frame. Three harmonics Fourier phase analysis was applied, and optimal acquisition parameters (defined as those providing best homogeneous phase distribution histogram in the pilot group) were defined as judged by the H3 right ventricular phase SD and delta 95%. These were 16 frames per cycle and 600 kcounts per frame. Then we verified in the validation group that these optimal acquisition parameters did not induce any significant relative loss of information compared with other acquisition parameters with more temporal resolution (24 and 32 frames per cycle) or more statistics (800 kcounts per frame). This result was realized by the calculation of normalized H3 right ventricular SD, right ventricular delta 95%, and (SD[left ventricle] - SD[right ventricle]). CONCLUSIONS: In practice, 16 frames per cycle and 600 kcounts per frame are optimal for multiharmonic Fourier phase analysis, with all other acquisition and processing variables being fixed as specified.
Asunto(s)
Displasia Ventricular Derecha Arritmogénica/diagnóstico por imagen , Imagen de Acumulación Sanguínea de Compuerta , Adulto , Femenino , Análisis de Fourier , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Proyectos Piloto , Estudios Prospectivos , Procesamiento de Señales Asistido por ComputadorRESUMEN
OBJECTIVE: To evaluate the efficiency of the new technique colour Doppler tissue imaging (DTI) by studying the concordance between dobutamine DTI, standard grey scale echocardiography (SE), and rest-reinjection TI-201 tomography (TI) in dysfunctional myocardium. PATIENTS: 23 patients with chronic wall motion abnormalities and proven coronary artery disease (> 70% diameter stenosis of at least one major coronary artery at angiogram). METHODS: The contractile reserve and the resting perfusion characteristics of dysfunctional myocardial segments were assessed with low dose dobutamine SE and/or DTI (2.5 up to 20 gamma/kg/min) and TI on a semiquantitative basis. The DTI or SE data were separately compared with TI, on the basis of a 13 segment ventricular model. The resulting score of combined DTI and SE was also compared with TI. Finally the results obtained from DTI were compared with SE. RESULTS: A total of 142 severely hypokinetic or akinetic segments were visualised. The viability study was feasible in 127 (89%) and 121 (85%) segments with DTI and SE, respectively. TI detected viability more frequently than DTI (84 v 61, p < 0.001) and SE (80 v 50, p < 0.001). However, as many viable segments were detected with combined DTI and SE as with TI (78 v 84, NS). The kappa values between TI and SE, DTI or combined SE and DTI were 0.38, 0.45, and 0.57, respectively, and increased to 0.52 and 0.76, respectively, for SE and DTI versus TI when mid-anterior and mid-inferior segments only were considered. The kappa value between SE and DTI was 0.34. CONCLUSIONS: DTI is a helpful adjunct to SE, when using low dose dobutamine. This combination revealed as many viable segments as TI and showed a better agreement than DTI or SE alone for the assessment of myocardial viable segments evidenced by TI.