Development of a pediatric differentiated thyroid carcinoma registry within the EuRRECa project: rationale and protocol.

Background: Although differentiated thyroid carcinoma (DTC) is the most frequent endocrine pediatric cancer, it is rare in childhood and adolescence. While tumor persistence and recurrence are not uncommon, mortality remains extremely low. Complications of treatment are however reported in up to 48% of the survivors. Due to the rarity of the disease, current treatment guidelines are predominantly based on the results of small observational retrospective studies and extrapolations from results in adult patients. In order to develop more personalized treatment and follow-up strategies (aiming to reduce complication rates), there is an unmet need for uniform international prospective data collection and clinical trials. Methods and analysis: The European pediatric thyroid carcinoma registry aims to collect clinical data for all patients ≤18 years of age with a confirmed diagnosis of DTC who have been diagnosed, assessed, or treated at a participating site. This registry will be a component of the wider European Registries for Rare Endocrine Conditions project which has close links to Endo-ERN, the European Reference Network for Rare Endocrine Conditions. A multidisciplinary expert working group was formed to develop a minimal dataset comprising information regarding demographic data, diagnosis, treatment, and outcome. We constructed an umbrella-type registry, with a detailed basic dataset. In the future, this may provide the opportunity for research teams to integrate clinical research questions. Ethics and dissemination: Written informed consent will be obtained from all participants and/or their parents/guardians. Summaries and descriptive analyses of the registry will be disseminated via conference presentations and peer-reviewed publications.

Detección de tejido paratiroideo hiperfuncionante mediante PET/TC con 18F-fluorocolina / Detection of hyperfunctioning parathyroid tissue by 18F-Fluorocholine PET/CT

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La tomografía por emisión de positrones-tomografía computarizada con 18F-fluordesoxiglucosa en los pacientes con cáncer diferenciado de tiroides en recurrencia y rastreo con radioyodo negativo. Rendimiento diagnóstico y relación con los niveles de tiroglobulina / Positron emission tomography-computed tomography with 18F-fluorodeoxyglucose in patients with recurrent differentiated thyroid carcinoma and negative radioiodine scan. Diagnostic performance and relation with tyroglobulin levels

Objetivo. Evaluar el rendimiento diagnóstico de la PET-TC con 18F-FDG y su relación con los niveles séricos de tiroglobulina (Tg) en los pacientes con cáncer diferenciado de tiroides con sospecha de persistencia o recurrencia de enfermedad y rastreo con radioyodo negativo. Material y métodos. Análisis retrospectivo de 35 estudios PET-TC en 25 pacientes (17 mujeres, edad media 48,8±15,2 años). Los resultados se comprobaron histológicamente, o mediante ecografía y seguimiento clínico. Se analizó la relación entre el rendimiento diagnóstico de la PET-TC y 3 niveles de Tg: ≤2ng/ml; entre 2 y 10 ng/ml, y >10ng/ml. Resultados. Se obtuvieron 26 verdaderos positivos, un falso positivo, 3 verdaderos negativos y 5 falsos negativos. De los 18 pacientes con una PET-TC clasificada como verdadero positivo, 3 mostraron lesiones en el lecho postiroidectomía, 15 mostraron afectación ganglionar y 5 presentaron metástasis a distancia. La sensibilidad fue del 83,9% (IC95%: 69,3-98,4%) y la especificidad del 75% (IC95%: 20-100%). Para 3 intervalos de Tg, la PET-TC mostró una tasa de verdaderos positivos del 37,5, del 83 y del 100% en los pacientes con niveles de Tg <2, entre 2 y 10, y >10 ng/ml, respectivamente. Conclusiones. La PET-TC con 18F-FDG muestra un alto rendimiento diagnóstico de la enfermedad locorregional y a distancia en la población de pacientes con cáncer diferenciado de tiroides en situación de persistencia de enfermedad y rastreo con yodo negativo con niveles de Tg >2ng/ml(AU)

Objective. To assess the diagnostic performance of 18F-FDG PET-CT scan and its relation to serum thyroglobulin (Tg) levels in patients with differentiated thyroid carcinoma with suspicion of persistence or recurrence of the disease and negative radioiodine scans. Materials and methods. This is a retrospective analysis of 35 PET-CT studies in 25 patients (17 women, average age 48.8±15.2 years). The results were confirmed by histology or by ultrasonography and clinical follow-up. We analyzed the relationship between the diagnostic performance of the PET-CT scans and three levels of Tg: ≤2ng/ml; between 2 and 10 ng/ml, and >10ng/ml. Results. We obtained 26 true-positives (TP), one false-positive (FP), 3 true-negatives (TN) and 5 false-negatives (FN). Of the 18 patients with PET-CTs classified as TP, 3 showed lesions at the post-thyroidectomy bed, 15 showed lymph node metastases and 5 were distant metastases. Sensitivity was 83.9% (95%CI: 69.3%-98.4%) and specificity was 75% (95%CI: 20%-100%). Regarding the three intervals of Tg, PET-CT scan showed TP rates of 37.5%, 83% and 100% in patients with Tg levels <2ng/ml, between 2 and 10ng/ml, and >10ng/ml, respectively. Conclusions. 18F-FDG PET-CT demonstrates high diagnostic yield in local disease and distant lesions for the population of patients with differentiated thyroid carcinoma and persistence of the disease with negative radioiodine scans at Tg levels above 2ng/ml(AU)

[Positron emission tomography-computed tomography with (18)F-fluorodeoxyglucose in patients with recurrent differentiated thyroid carcinoma and negative radioiodine scan. Diagnostic performance and relation with tyroglobulin levels]. / La tomografía por emisión de positrones-tomografía computarizada con (18)F-fluordesoxiglucosa en los pacientes con cáncer diferenciado de tiroides en recurrencia y rastreo con radioyodo negativo. Rendimiento diagnóstico y relación con los niveles de tiroglobulina.

OBJECTIVE: To assess the diagnostic performance of (18)F-FDG PET-CT scan and its relation to serum thyroglobulin (Tg) levels in patients with differentiated thyroid carcinoma with suspicion of persistence or recurrence of the disease and negative radioiodine scans. MATERIALS AND METHODS: This is a retrospective analysis of 35 PET-CT studies in 25 patients (17 women, average age 48.8±15.2 years). The results were confirmed by histology or by ultrasonography and clinical follow-up. We analyzed the relationship between the diagnostic performance of the PET-CT scans and three levels of Tg: ≤2ng/ml; between 2 and 10 ng/ml, and >10ng/ml. RESULTS: We obtained 26 true-positives (TP), one false-positive (FP), 3 true-negatives (TN) and 5 false-negatives (FN). Of the 18 patients with PET-CTs classified as TP, 3 showed lesions at the post-thyroidectomy bed, 15 showed lymph node metastases and 5 were distant metastases. Sensitivity was 83.9% (95%CI: 69.3%-98.4%) and specificity was 75% (95%CI: 20%-100%). Regarding the three intervals of Tg, PET-CT scan showed TP rates of 37.5%, 83% and 100% in patients with Tg levels <2ng/ml, between 2 and 10ng/ml, and >10ng/ml, respectively. CONCLUSIONS: (18)F-FDG PET-CT demonstrates high diagnostic yield in local disease and distant lesions for the population of patients with differentiated thyroid carcinoma and persistence of the disease with negative radioiodine scans at Tg levels above 2ng/ml.

[Adrenal cortex scintigraphy with and without dexamethasone suppression in the study of primary aldosteronism]. / Gammagrafía suprarrenal cortical con frenación y supresión de la frenación con dexametasona en el estudio del hiperaldosteronismo primario.

AIM OF THE STUDY: To evaluate the diagnostic performance and efficacy of adrenal scintigraphy in primary aldosteronism following the protocol that combines adrenal suppression scintigraphy plus non-suppression study. METHODS AND PROCEDURES: 20 patients referred to our service with the suspicion of primary aldosteronism were studied by combined scintigraphy. Thirteen men and 7 women, mean age of 52 years, aged from 31 to 73 years, were included. Uptake of free iodine by the thyroid was inhibited by oral Lugol 5 % administration. Dexamethasone 4 mg per day was administered from day 7 to the third day of detection, when administration was stopped. Adrenal scintigraphy was performed after intravenous injection of I-131-norcolesterol (37 MBq). Images were taken at 24 and/or 48 hours and on the third day. Afterwards, dexamethasone administration was stopped and late images on 5th and/or 7th days were obtained. The scintigraphic result was confirmed with the final clinical evaluation (FCE) of the patient. RESULTS: 11 patients presented pathological studies, 9 adenomas (8TP + 1FP) and 2 bilateral adrenal hyperplasia (2TP); 7 normal scintigraphies (6TN and 1 non-conclusive FCE) and 2 non-conclusive scintigraphies (1 incidentaloma and 1 non-conclusive FCE). Normal adrenal glands were visualized in all cases on the 5th and/or 7th day scintigraphy. CONCLUSION: The study of adrenal functionalism by the combined protocol of adrenal suppression study plus later non-suppression study made it possible to identify with high precision primary aldosteronism and to confirm the function of normal adrenal glands.

Standard provocative manoeuvres in patients with and without left bundle branch block studied with myocardial SPECT.

BACKGROUND: The objective of this study was to determine the prevalence of anterior and septal defects in patients with left bundle branch block (LBBB), and to assess the diagnostic accuracy of myocardial single photon emission computed tomography (SPECT) with technetium compounds in patients with and without LBBB using standard provocative manoeuvres. METHODS: Five hundred and nine consecutive patients (456 without LBBB and 53 with LBBB) without previous infarction who had a coronary angiography performed within <3 months of the scintigraphic study were retrospectively evaluated. The same stress procedures were followed in all patients. (1) Only exercise when it was sufficient; and (2) exercise + simultaneous administration of dypiridamole if exercise was insufficient. Only reversible defects were considered positive and > or =50% of coronary stenosis was considered significant. RESULTS: Prevalence of reversible anterior and septal defects was low (33% and 12%, respectively) in patients with LBBB. Although lower values of global sensitivity (81%) and specificity (73%) were obtained in these patients, there were no significant differences with respect to the patients without LBBB (89% and 86%, respectively). Specificity values for the diagnosis of stenosis of left anterior descending (78%), left circumflex (96%) and right coronary artery (74%) in patients with LBBB were lower, but without significant statistical differences with respect patients without LBBB (90%, 96% and 82%, respectively). CONCLUSIONS: Myocardial SPECT with technetium compounds, using standard provocation manoeuvres, can be used in patients with LBBB with only a mild decrease in diagnostic accuracy as compared to patients without LBBB.

Differential uptake of myocardial perfusion radiotracers in normal, infarcted, and acutely ischemic peri-infarction myocardium.

OBJECTIVES: We measured the uptake of technetium-99m tetrofosmin (99m Tc) and thallium-201 (201 TI) in areas of healed transmural myocardial infarction and in the regions of acute peri-infarction ischemia. METHODS: Anesthetised pigs with a 1-month old transmural infarction elicited by permanent ligature of the left anterior descending (LAD) coronary artery below the first branch underwent one hour of proximal LAD occlusion followed by injection of 99m Tc-tetrofosmin and 201TI either in the left atrium (GI, n= 19) or in the jugular vein (GII, n = 6). Twelve other pigs (GIII) with similar acute peri-infarction ischemia received 99m Tc-tetrofosmin and 201Tl into the left ventricle during cardiocirculatory arrest to rule out the effect of coronary collaterals. Radiotracer counting was determined in samples from normal, acute ischemic and necrotic regions. RESULTS: Uptake of 99m Tc-tetrofosmin and 201 Tl was greater in the infarct scar (median % of normal tissue: 20 for 99m Tc and 8.6 for 201 Tl in GI; 22 and 15 in GII) than in acute ischemic myocardium (3.2 and 2.5 in GI; 6.4 and 3.3 in GII). Radiotracer injection in arrested hearts (GIII) depicted a similar pattern (median % of injected dose: 6.2 for 99m Tc and 10 for 201Tl in the scar; 2.3 and 4.0 in acute ischemia; 2.9 and 3.5 in normal tissue). The infarcted region showed connective tissue and lack of viable myocardium. CONCLUSION: A 1-month old infarct scar with no viable myocardial tissue can take up significant fractions of 99mTc-tetrofosmin and 201Tl even in the absence of coronary collateral perfusion. Data suggest that the infarct scar can extract these radiotracers from the intraventricular blood.

Technetium-99m-HMPAO brain SPECT in Behçet's disease.

UNLABELLED: Behçet's disease (BD) is an idiopathic multisystem disorder. Involvement of the central nervous system (CNS) occurs in 4%-48% of cases. The aim of this study was to evaluate 99mTc-hexamethyl propyleneamine oxime (HMPAO) SPECT findings in BD patients and eventually to detect CNS involvement by depicting cerebral blood flow disturbances. METHODS: Technetium-99m-HMPAO brain SPECT was performed on 33 consecutive BD patients. Qualitative and quantitative evaluation of the cortical uptake was done using an automatic program that generated 32 regions of interest (ROIs). An uptake index for each ROI was obtained. Reference values were obtained from a healthy control group (n = 20). Twenty-five patients also had an MRI study. RESULTS: Twelve of 32 patients (36%) presented with a clinical neurological disorder. SPECT and visual evaluation revealed that 17 patients (51.5%) had abnormalities; 9 of 25 MRI studies (36%) were abnormal. Using the quantitative approach for SPECT, 23 patients (69.7%) had abnormally low values. Six of 12 patients with neurological symptoms had a visually abnormal SPECT scan, whereas quantitative analysis showed abnormalities in 11 patients. Of the 21 patients with no neurological findings, 9 had abnormal SPECT results, and 12 had low uptake indexes. CONCLUSION: HMPAO brain SPECT shows high rates of cerebral blood flow abnormalities in BD patients presenting with neuropsychiatric symptoms, and it also is frequently abnormal in asymptomatic BD patients who have no abnormalities on MR scans. Compared with visual analysis, quantitative analysis detects an even higher rate of SPECT changes in BD patients.

Diagnostic accuracy of technetium-99m-MIBI myocardial SPECT in women and men.

UNLABELLED: Noninvasive diagnosis of coronary artery disease in women has some limitations due to a higher percentage of false-positive results. In addition, a lower prevalence of disease can be observed in this population. In this study, we evaluated the diagnostic accuracy of 99mTc-methoxy-isobutyl-isonitrile (MIBI) SPECT in women and men, in a group of patients with proven coronary artery disease by coronary angiography (select minority) and in all patients where a noninvasive test (silent majority) was performed. METHODS: Seven hundred and two consecutive patients without previous myocardial infarction were studied with 99mTc-MIBI myocardial SPECT. One hundred sixty-three patients had coronary angiography (select minority) and 539 did not (silent majority). All patients underwent exercise stress testing, and simultaneous dipyridamole was administered in 32% of patients who did not achieve maximum predicted heart rates. Diagnostic accuracy of the test was calculated for the select minority. Then, sensitivity and specificity of the silent majority were recalculated according to the Diamond criteria. RESULTS: Prevalence of coronary artery disease (32% versus 80%, p = 0.0001) and peak O2 consumption achieved in exercise tests (watts, exercise duration) were lower in women. The probability of positive results of 99mTc-MIBI SPECT also was lower in women (34% versus 65%). The sensitivity of 99mTc-MIBI SPECT in women of the select minority was lower (85% versus 93%, p = 0.01), whereas there was no significant difference for specificity (91% versus 89%). After correcting the results for the silent majority, there were no significant differences in sensitivity (87% versus 88%) and specificity (91% versus 96%) between women and men. These results were not different for patients who achieved maximum predicted heart rates during stress testing (without dipyridamole administration). CONCLUSION: The sensitivity of 99mTc-MIBI myocardial SPECT in women was lower than in men when only the select minority was considered. When the silent majority was considered (correction of selection bias) sensitivity and specificity results did not differ significantly between the sexes.

[Painful tibial swelling in a young patient. Findings of radiology and radionuclide scanning. Anatomopathological correlation]. / Tumoración tibial dolorosa en paciente joven. Hallazgos radiológicos y gammagráficos. Correlación anatomopatológica.

We report on the case of a young man with a longstanding tumor in the left proximal tibia, in whom we had the opportunity to correlate both radiologic (plain films plus MRI) and bone scintigraphic findings with those of biopsy and clinical follow-up. The final diagnosis was bone fibrous dysplasia. The correlation between noninvasive diagnostic findings is discussed, and the convenience of using such test combination is also stressed in order to endorse a noninvasive approach to such patients, given the low malignant potential, the exception being those patients in whom there is a definite fractures risk.

Acute ischemic ventricular arrhythmias in pigs with healed myocardial infarction: comparative effects of ischemia at a distance and ischemia at the infarct zone.

BACKGROUND: The myocardium bordering a healed infarction undergoes electrophysiological and autonomic neural derangements that may interact with a new ischemic episode to promote arrhythmias. Therefore, peri-infarction ischemia may be more arrhythmogenic than ischemia at a distance from the infarct zone, but this is not known. METHODS AND RESULTS: Forty-two anesthetized open-chest pigs with a 1-month-old myocardial infarction induced by permanent ligature of the distal left anterior descending coronary artery (LAD) underwent a coronary reocclusion at either the proximal LAD (group 1, peri-infarction ischemia, n=21) or at the circumflex coronary artery (group 2, ischemia at a distance, n=21). Ventricular arrhythmias were analyzed during 60 minutes of coronary reocclusion and during programmed electrical stimulation. Infarct size was measured, and underperfusion at the occluded area was estimated by recording 99mTc-tetrofosmin activity. Weights of acute ischemic (23+/-9 versus 21+/-9 g) and healed infarction (10+/-6 versus 10+/-3 g), baseline LV pressure and peak of LV dP/dt, and radiotracer activity at the occluded area (3+/-2% versus 5+/-2% of normal tissue) were comparable between the two groups. Compared with group 2, group 1 showed more ventricular premature beats (median, 136 versus 59; P=.008), a higher incidence of spontaneous sustained ventricular tachycardia (57% versus 19%, P=.02) and ventricular fibrillation (76% versus 47%, P=.05), and greater electrical inducibility of sustained ventricular tachycardia (65% versus 28%, P=.03) but comparable induction of ventricular fibrillation. CONCLUSIONS: Ischemia superimposed at the border of a 1-month-old myocardial infarction is more arrhythmogenic than ischemia at a distance from the infarct zone in swine. Data suggest the presence of electrophysiological instability at the peri-infarction zone.

Simultaneous dipyridamole/maximal subjective exercise with 99mTc-MIBI SPECT: improved diagnostic yield in coronary artery disease.

OBJECTIVES: We attempted to demonstrate that simultaneous dipyridamole administration and maximal subjective exercise in patients who are unable to achieve a good exercise level can improve the diagnostic efficacy of technetium-99m methoxy isobutyl isonitrile (99mTc-MIBI) myocardial single-photon emission computed tomography (SPECT). BACKGROUND: The results of myocardial perfusion scintigraphy are unsatisfactory if the level of exercise achieved by the patient is insufficient. The use of dipyridamole with maximal subjective stress testing has been shown to improve the quality of the thallium-201 myocardial perfusion images, but there are no studies demonstrating that this combination improves the diagnostic accuracy of myocardial perfusion SPECT. METHODS: Two hundred thirty-one consecutive patients, without a previous myocardial infarction, were classified into three groups: group 1, 91 patients with an adequate exercise test; group 2, 68 patients with an inadequate exercise test; group 3, 72 patients with an inadequate exercise test who then received intravenous dipyridamole (0.56 mg/kg body weight over 4 min) simultaneously with exercise. RESULTS: Results for sensitivity (89%) and negative predictive value (83%) in group 3 were significantly better than those in group 2 (71% [p = 0.03] and 56% [p = 0.002], respectively) and not significantly different from those in group 1. The polar maps of 20 patients studied with an without dipyridamole at the same exercise level revealed a significantly greater extent of ischemia in each territory and in a global assessment (19 + 20% vs. 8 + 11%, p < 0.0001) when dipyridamole was administered during physical exercise. CONCLUSIONS: Intravenous dipyridamole administration during exercise testing is advisable in all patients who are unable to achieve an adequate exercise level. This approach permits physicians to avoid missing ergometric information while optimizing myocardial SPECT results.

[Stress myocardial gammatomography in the diagnosis of multivessel coronary disease]. / La tomogammagrafía miocárdica de esfuerzo en el diagnóstico de la enfermedad coronaria multivaso.

OBJECTIVE: The aim of the study was to evaluate the diagnostic yield of 99m-Technetium-methoxy-isobutyl-isonitrile (MIBI) SPET for identification of individual coronary artery disease and in the prediction of multivessel involvement. METHODS: Stress/rest myocardial SPET and coronary arteriography were evaluated in 231 consecutive patients (age 58 +/- 10 years, 26% women) without prior myocardial infarction. 149 patients had coronary narrowing > 50%: 104 with multivessel disease and 45 with one vessel disease. Tomographic stress defect score was obtained by semiquantitative analysis (maximal score 65). Univariate and multivariate analysis was performed to identify discriminant parameters between one vessel and multivessel patients. RESULTS: The sensitivity and specificity for the identification of individual artery disease was 74% and 85% for left anterior descending artery, 79% and 85% for right coronary and 45% and 96% for circumflex artery. In the prediction of multivessel involvement the sensitivity was 65%, specificity 87%, positive predictive value 81% and negative predictive value 76%. In the bivariate analysis, four parameters differed significantly between one vessel and multivessel disease patients: ST downslope > 1 mm (p = 0.01), ST downslope/heart rate corrected (p = 0.005), reversible defects in two or more regions (p = 0.009) and SPET score (p = 0.002). In the multivariate analysis the probability of multivessel disease was 90% when ST depression > 1 mm and SPET score > 20 were associated and the probability was lowered to 16% when these criteria were not present. CONCLUSION: Myocardial SPET with MIBI offers an accurate localization of individual coronary artery disease, mainly in left anterior descending artery and right coronary artery lesions. Combined evaluation of ST depression and extension of myocardial stress defects improved prediction of multivessel involvement.

[Influence of ergometric parameters on the results of myocardial perfusion tomographic scintigraphy]. / Importancia de los parámetros ergométricos en los resultados de la tomogammagrafía de perfusión miocárdica.

BACKGROUND: The percentage of peak predicted heart rate that is accepted to consider as sufficient a given exercise test is 85%. However, the optimal value of such rate and other exercise parameters for the purposes of myocardial single-photon emission tomography is not well established. PATIENTS AND METHODS: With the aim of establishing the minimal levels of maximal heart rate, product heart rate x systolic blood pressure and ventilatory oxygen uptake to obtain an adequate diagnostic efficacy of myocardial perfusion scintigraphy, 159 patients with coronary artery disease or suspicion of this without previous myocardial infarction were studied with stress test single photon emission tomography with 99mTc-methoxi-isobutil-isonitrile. All the patients were coronary angiography tested. RESULTS: Sensitivity and negative predictive value were significantly higher at levels of heart rate > 80% (93 vs 78%; p = 0.002 and 94 vs 56%; p = 0.0004), product heart rate x systolic blood pressure > 18,000 (88 vs 78%; p = 0.04 and 84 vs 52%; p = 0.004) and > 5 METs (85 vs 77%; p = 0.002 and 74 vs 69%; p = 0.03). CONCLUSIONS: Sensitivity and negative predictive value of stress test single photon emission tomography with 99mTc-methoxi-isobutil-isonitrile are low if levels higher than 80% of heart rate, 18,000 of product of heart rate x systolic blood pressure and 5 METs have not been achieved.

[Diagnosis of coronary disease by means of stress gamma-tomography with 99m-technetium-isonitriles]. / Diagnóstico de la enfermedad coronaria mediante la tomogammagrafía de esfuerzo con isonitrilos-tecnecio-99m.

BACKGROUND: To assess the yield of exercise myocardial stress tomogammagraphy (SPET) with methoxy-isobutyl-isonitrile-technetium-99m (99mTc-MIBI) in the diagnosis of coronary artery disease. METHODS: Seventy-two consecutive patients, without previous myocardial infarction and with coronary angiography, were investigated. All underwent a symptom-limited exercise test with intravenous infection of 15 mCi of 99mTc-MIBI 30-60 seconds before the end of exercise. Detection of tomographic images was performed after one hour. Rest images were detected 24 hours later. Images with exercise perfusion defects which became normal at rest were considered as positive. RESULTS: Sensitivity (84%), specificity (93%), global value (87%), positive predictive value (95%), and negative predictive value (79%) of 99mTc-MIBI were significantly higher than those of conventional exercise electrocardiogram (46%, 69%, 55%, 69% and 46%, respectively). These values were lower when exercise test was insufficient (peak heart rate below 80% in the absence of angina). The sensitivity values were similar for the diagnosis of one (81%), two (76%), and three (93%) vessel disease. The application of Bayes' theorem disclosed that the highest yield of MIBI was achieved with prevalences ranging between 30% and 70%. CONCLUSION: The efficacy of 99mTc-MIBI SPET for the diagnosis of coronary artery disease was satisfactory, particularly when exercise was sufficient and with a prevalence of coronary artery disease ranging between 30% and 70%.

[Myocardial contractility and viability. A radionuclide tomography study using technetium-99m labeled isonitriles]. / Contractilidad y viabilidad miocárdicas. Estudio mediante tomogammagrafía con isonitrilos marcados con tecnecio-99m.

BACKGROUND: There are comparatively few studies evaluating the patterns of myocardial viability and its relation with contractility in patients with coronary artery disease. The aim of the present study was to quantify the viable and nonviable myocardium, using 99m-technetium isonitriles SPET, as related with left ventricular regional wall motion abnormalities. METHOD: 61 consecutive patients with coronary artery disease were investigated. The severity and extension of the defects were evaluated using a qualitative and quantitative analysis of the 99mTc-isonitriles SPET and compared with ventricular wall motion in contrast ventriculography. An uptake level of 40% of peak uptake or higher was considered as indicating viable myocardium. RESULTS: Of the 244 evaluated regions (4 per patient), 72 (29%) had normal perfusion, 100 (41%) were ischemic, 25 (10%) had a mild irreversible defect and 47 (19%) had a severe irreversible defect. Wall motion was normal in 176 regions (72%), 29 (12%) were hypokinetic, and 39 (16%) were akinetic of dyskinetic. The amount of viable myocardium in akinetic and dyskinetic regions (64.8%) was significantly different (p < 0.05) from that in hypokinetic (86.1%) and normokinetic (98.8%) regions. Visual assessment of uptake underestimated myocardial viability, as quantitative analysis disclosed that in 61% of akinetic and dyskinetic regions with severe irreversible defects there was more than 50% of viable myocardium. CONCLUSIONS: In 61% of akinetic and dyskinetic regions with a severe irreversible defect in perfusion scintigraphy positive viability criteria were found. Therefore, visual assessment of the myocardial perfusion studies using 99mTc-MIBI SPET underestimates viable myocardium. Tomographic studies with quantification of the uptake and defect extension are required for a proper evaluation of viable myocardium.