Gammagrafía ósea con captación abdominopélvica de 99mTc-difosfonatos / A bone scintigraphy with abdominopelvic uptake of 99mTc-diphosphonate

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Interpretación de incidentalomas tiroideos en estudios PET/TC con 18F-FDG / Interpretation of thyroid incidentalomas in 18F-FDG PET/CT studies

Objetivo: Los incidentalomas tiroideos en estudios PET/TC con 18F-FDG son relativamente frecuentes y su significado clínico es causa de controversia. El presente estudio muestra nuestra experiencia en la detección de incidentalomas tiroideos a partir de estudios PET/TC y de su seguimiento. Material y métodos: Estudio retrospectivo descriptivo de los pacientes que presentaron incidentalomas tiroideos en los estudios PET/TC con 18F-FDG, entre junio de 2010 y marzo de 2013. Se evaluaron los siguientes datos y antecedentes clínicos: edad, sexo, valor máximo estandarizado de captación (SUVmáx), enfermedades tiroideas, niveles de TSH y anticuerpos antitiroideos, ecografía, punción-aspiración con aguja fina (PAAF) y citología. Resultados: Se realizaron 4.085 PET/TC, de los cuales 83 (2,03%) mostraron incidentalomas tiroideos. Treinta y siete de estos pacientes presentaron un incremento difuso del metabolismo glicídico tiroideo y 46 un incremento focal. Cinco de los 46 pacientes con captación focal (11%) fueron diagnosticados de enfermedad neoplásica por citología. No se encontraron diferencias significativas entre los valores del SUVmáx de las enfermedades tiroideas benignas y de las malignas (media: 10,26 y 5,92 respectivamente). Conclusión: En nuestra experiencia, los incidentalomas tiroideos de características focales detectados en los estudios PET/TC con18F-FDG, presentan un considerable riesgo de malignidad (11%). Por este motivo, se debe indicar siempre el seguimiento de estos hallazgos mediante ecografía y PAAF. Por otra parte, y tal como está descrito en la literatura, el incremento difuso del metabolismo glicídico tiroideo se asocia casi siempre a patología tiroidea benigna (AU)

Objective: Thyroid findings or incidentalomas in 18F-FDG PET/CT studies are relatively frequent, being its clinical significance subject of controversy. The aim of this study was to show our experience in the detection of thyroid incidentalomas by PET/CT studies as well as its follow up. Material and methods: A retrospective and descriptive review was conducted on patients who had thyroid incidentalomas detected in18F-FDG PET/CT studies between June 2010 and March 2013. Patient’s medical records were reviewed for age, genre, maximum standardized uptake value (SUVmax), thyroid diseases, TSH and antithyroid antibodies levels, ultrasound, fine-needle aspiration (FNA) and cytology. Results: 4085 PET/CT studies for several purposes were performed. Eighty-three of these studies (2.03%) showed thyroid incidentalomas. Thirty-seven patients showed a diffuse increase of glucose metabolism in the thyroid gland and 46 showed a focal increase of glucose metabolism. Five out of 46 patients with focal uptake were diagnosed of a neoplastic disease by cytology (11%). The SUVmax of malignant pathology did not differ from that of benign thyroid diseases (Mean: 10,26 and 5,92 respectively). Conclusion: In our experience, focal thyroid incidentalomas detected in18F-FDG PET/CT studies are related to a significant risk of malignancy (11%). Therefore, in these situations, an ultrasound study with fine needle biopsy should be recommended. Moreover, a diffuse increase of glucose metabolism in the thyroid gland is often associated with benign thyroid pathology (AU)

[Interpretation of thyroid incidentalomas in (18)F-FDG PET/CT studies]. / Interpretación de incidentalomas tiroideos en estudios PET/TC con (18)F-FDG.

OBJECTIVE: Thyroid findings or incidentalomas in (18)F-FDG PET/CT studies are relatively frequent, being its clinical significance subject of controversy. The aim of this study was to show our experience in the detection of thyroid incidentalomas by PET/CT studies as well as its follow up. MATERIAL AND METHODS: A retrospective and descriptive review was conducted on patients who had thyroid incidentalomas detected in (18)F-FDG PET/CT studies between June 2010 and March 2013. Patient's medical records were reviewed for age, genre, maximum standardized uptake value (SUVmax), thyroid diseases, TSH and antithyroid antibodies levels, ultrasound, fine-needle aspiration (FNA) and cytology. RESULTS: 4085 PET/CT studies for several purposes were performed. Eighty-three of these studies (2.03%) showed thyroid incidentalomas. Thirty-seven patients showed a diffuse increase of glucose metabolism in the thyroid gland and 46 showed a focal increase of glucose metabolism. Five out of 46 patients with focal uptake were diagnosed of a neoplastic disease by cytology (11%). The SUVmax of malignant pathology did not differ from that of benign thyroid diseases (Mean: 10,26 and 5,92 respectively). CONCLUSION: In our experience, focal thyroid incidentalomas detected in (18)F-FDG PET/CT studies are related to a significant risk of malignancy (11%). Therefore, in these situations, an ultrasound study with fine needle biopsy should be recommended. Moreover, a diffuse increase of glucose metabolism in the thyroid gland is often associated with benign thyroid pathology.

Utilidad de la imagen precoz de la gammagrafía de inervación miocárdica en el diagnóstico de la demencia con cuerpos de Lewy / Utility of early imaging of myocardial innervation scintigraphy in the diagnosis of Lewy Body Dementia

La realización de un correcto diagnóstico inicial ayuda al manejo clínico de los pacientes con Demencia con Cuerpos de Lewy (DCLw). La imagen tardía de la gammagrafía cardíaca con 123I-MIBG permite diferenciar entre DCLw y otro tipo de demencias. El objetivo del estudio es valorar la utilidad de la imagen precoz de la gammagrafía cardíaca con 123I-MIBG para el diagnóstico diferencial entre DCLw y otras demencias neurodegenerativas. Material y métodos. Estudio retrospectivo de 106 pacientes (51 hombres, edad media 78 años) a los que se les realizó una gammagrafía de inervación miocárdica por estudio de demencia. Se obtuvieron imágenes planares en proyección anterior a los 15min (precoz) y a las 4h (tardía) de la administración del trazador. La captación miocárdica de 123I-MIBG se semicuantificó mediante la obtención del índice de captación corazón/mediastino (ICM) a los 15min (ICM15m) y a las 4h (ICM4h). Resultados. El diagnóstico clínico a los 4 años fue de 52 pacientes con DCLw. El ICM15m para los pacientes con DCLw fue significativamente inferior al de los otros pacientes (1,27±0,15 vs 1,76±0,15,p<0,05), así como el ICM4h (1,14±0,13 vs 1,68±0,19,p<0,01). A partir del análisis ROC se obtuvo un punto de corte del ICM15m de 1,56 con un área bajo la curva del 0,99, para poder diferenciar DCLw respecto a los otros tipos de demencia, con una sensibilidad y especificidad del 98%. Conclusión. La imagen precoz de la gammagrafía de inervación miocárdica con 123I-MIBG, puede ser útil para diferenciar la DCLw de otro tipo de demencias neurodegenerativas (AU)

The importance of accurate and early diagnosis of dementia with Lewy bodies (DLB) lies in its pharmacological management. Delayed imaging of cardiac 123I-MIBG scintigraphy allows differentiation between DLB and other neurodegenerative diseases with cognitive impairment. The aim of this study was to assess the utility of early imaging of cardiac 123I-MIBG scintigraphy for differentiating DLB from others neurodegenerative disease with cognitive impairment. Material and methods. We assess retrospectively 106 patients (51 men, mean age 78 years) with cognitive impairment that underwent a cardiac 123I-MIBG study. Planar images were acquired in anterior view of the thorax 15min (early) and 4h (delayed) after tracer administration. The heart-to-mediastinum ratios (HMR) at 15m (HMR15m) and at 4h (HMR4h) were obtained. Results. After four years, 52 patients were diagnosed of DLB.HMR15m and HMR4h were significantly inferior in DLB respect to the others neurodegenerative diseases (1,27±0,15 vs 1,76±0,15,p<0,05) and (1,14±0,13 vs 1,68±0,19,p<0.01), respectively. The ROC analysis showed a HMR15m cut off point of 1.56 to differentiated DLB from the other dementias with a sensitivity and a specificity of 98%. Conclusions. Early imaging of cardiac 123I-MIBG scintigraphy can help to differentiate DLB from other neurodegenerative diseases with cognitive impairment (AU)

[Utility of early imaging of myocardial innervation scintigraphy in the diagnosis of Lewy Body Dementia]. / Utilidad de la imagen precoz de la gammagrafía de inervación miocárdica en el diagnóstico de la demencia con cuerpos de Lewy.

UNLABELLED: The importance of accurate and early diagnosis of dementia with Lewy bodies (DLB) lies in its pharmacological management. Delayed imaging of cardiac (123)I-MIBG scintigraphy allows differentiation between DLB and other neurodegenerative diseases with cognitive impairment. The aim of this study was to assess the utility of early imaging of cardiac (123)I-MIBG scintigraphy for differentiating DLB from others neurodegenerative disease with cognitive impairment. MATERIAL AND METHODS: We assess retrospectively 106 patients (51 men, mean age 78 years) with cognitive impairment that underwent a cardiac (123)I-MIBG study. Planar images were acquired in anterior view of the thorax 15min (early) and 4h (delayed) after tracer administration. The heart-to-mediastinum ratios (HMR) at 15m (HMR15m) and at 4h (HMR4h) were obtained. RESULTS: After four years, 52 patients were diagnosed of DLB.HMR15m and HMR4h were significantly inferior in DLB respect to the others neurodegenerative diseases (1,27±0,15 vs 1,76±0,15,p<0,05) and (1,14±0,13 vs 1,68±0,19,p<0.01), respectively. The ROC analysis showed a HMR15m cut off point of 1.56 to differentiated DLB from the other dementias with a sensitivity and a specificity of 98%. CONCLUSIONS: Early imaging of cardiac (123)I-MIBG scintigraphy can help to differentiate DLB from other neurodegenerative diseases with cognitive impairment.

Cardiac sympathetic impairment parallels nigrostriatal degeneration in Probable Dementia with Lewy Bodies.

AIM: Dementia with Lewy Bodies (DLB) must be distinguished from other types of dementia because of important differences in patient management and outcome. Both reduction in cardiac 123I-metaiodobenzilguanidine (MIBG) uptake and decreased 123I-FP-CIT binding in basal ganglia have been described in DLB. The aim of this study was to assess the relationship between cardiac sympathetic activity and nigrostriatal degeneration in patients with probable DLB. METHODS: Twenty-eight patients (15 males; mean age 77 years, range 64-88 years) with clinical international criteria of probable DLB were included in the study. All patients underwent a cardiac MIBG scintigraphy and a FP-CIT SPECT. Global cardiac MIBG uptake was semiquantified by means of heart-to-mediastinum ratio (HMR) (normal >1.56). FP-CIT binding in basal ganglia was calculated and compared with an age-matched control group. The relation between cardiac MIBG uptake and FP-CIT uptake in basal ganglia, and the relationship of these two techniques with distinctive symptoms of DLB, features of past medical history and data from the neuropsychological examination were assessed. RESULTS: Cardiac MIBG uptake was decreased in 23 of 28 patients (HMR=1.32, range 0.95-1.85). The FP-CIT binding in basal ganglia was significantly lower than in control group (2.01±0.5 vs 2.62±0.2, P<0.05). All patients with reduced cardiac HMR showed decreased FP-CIT binding in basal ganglia. There was a positive correlation between the HMR and specific binding ratio of striatum (P<0.01). A high correlation between FP-CIT SPECT and the presence of parkinsonism also was found. No correlation between cardiac MIBG uptake and demographic, clinical or neuropsychological data was found. CONCLUSION: In probable DLB cardiac MIBG uptake and FP-CIT binding in basal ganglia are reduced. The positive correlation between both measures suggests that cardiac sympathetic degeneration and nigrostriatal degeneration parallel similarly in patients with probable DLB.

Emerging role of nuclear cardiology in heart failure.

The management of patients with heart failure requires the integration of clinical skills and accurate complementary tests for the correct diagnosis, treatment and estimation of individual prognosis. Identification of those patients most at risk of death, and those most likely to benefit from currently available treatment technologies, remains a challenge. Although the basic characterization of patients with heart failure is supported primarily by the assessment of the left ventricular function, there are several nuclear cardiology techniques and tracers, either available or under development, which can provide important noninvasive imaging insights into the pathophysiology, prognosis and management of patients with heart failure. Nuclear techniques for molecular imaging of the myocardium such as those involved in the processes of myocardial perfusion, metabolism and viability, cellular injury, dyssynchrony, intersticial dysregulation and neurohormonal receptor function may facilitate better clinical outcomes for patients with heart failure. This review mainly focuses on cardiac sympathetic imaging, as other modalities of nuclear cardiology in the assessment of patients with HF are reviewed more extensively in other sections of this issue.

The role of nuclear medicine technique in evaluating electrophysiology in diabetic hearts especially with 123I-MIBG cardiac SPECT imaging.

Diabetes mellitus is a risk factor for cardiovascular morbidity and death. Cardiac autonomic diabetic neuropathy (CADN) is a common and serious complication of diabetes mellitus, which consists of damage to the autonomic nerve fibres that innervate the heart and blood vessels, resulting in alterations in heart rate control and vascular dynamics, associated with disabling clinical manifestations and increased mortality and incidence of both silent myocardial ischaemia and infarction. In vivo non-invasive radionuclide assessment of cardiac sympathetic innervation is possible with the use of radioabelled analogues of norepinephrine, which are actively taken up by the postganglionic presynaptic sympathetic nerve fibres of the heart. The catecholamine analogue 123I-metaiodobenzylguanidine (123I-MIBG) is the most commonly used tracer for imaging myocardial presynaptic sympathetic innervation on a broad clinical basis. 123I-MIBG imaging provides unique insights into the effects of diabetes on cardiac sympathetic integrity and the pathophysiological consequences of cardiac sympathetic dysinnervation. It also allows the assessment of both glycemic control on the progression of autonomic neuropathy and the effects of the autonomic derangement on myocardial blood flow regulation, function and electrophysiology, showing even potential for the prediction of adverse outcome.

EANM/ESC guidelines for radionuclide imaging of cardiac function.

Radionuclide imaging of cardiac function represents a number of well-validated techniques for accurate determination of right (RV) and left ventricular (LV) ejection fraction (EF) and LV volumes. These first European guidelines give recommendations for how and when to use first-pass and equilibrium radionuclide ventriculography, gated myocardial perfusion scintigraphy, gated PET, and studies with non-imaging devices for the evaluation of cardiac function. The items covered are presented in 11 sections: clinical indications, radiopharmaceuticals and dosimetry, study acquisition, RV EF, LV EF, LV volumes, LV regional function, LV diastolic function, reports and image display and reference values from the literature of RVEF, LVEF and LV volumes. If specific recommendations given cannot be based on evidence from original, scientific studies, referral is given to "prevailing or general consensus". The guidelines are designed to assist in the practice of referral to, performance, interpretation and reporting of nuclear cardiology studies for the evaluation of cardiac performance.

[Dementia with Lewy bodies and Alzheimer's disease: differential diagnosis by cardiac sympathetic innervation MIBG imaging]. / Demencia con cuerpos de Lewy y enfermedad de Alzheimer: diagnóstico diferencial mediante estudio de la inervación simpática cardíaca con MIBG.

UNLABELLED: Dementia with Lewy bodies (DLB) is the second most common cause of degenerative dementia after Alzheimer's disease (AD). At present, pre-mortem diagnosis of DLB can only be made clinically using the International Consensus Criteria. However, an accurate differential diagnosis between these diseases could improve the therapeutic handling of patients with DLB, due to their supersensitivity to neuroleptic treatment and the difficult treatment of their psychotic symptoms. OBJECTIVE: To assess the utility of cardiac MIBG imaging as diagnostic study for DLB, to help in the differential diagnosis with AD. MATERIAL AND METHODS: Cardiac MIBG imaging was performed in 11 patients with clinical criteria of probable DLB (7 males, mean age 77 years [range 62-89 years], mean MMSE 17 [range 11-28], and in 9 patients with clinical criteria of probable AD (3 males, mean age 79 years [range 61-87 years], mean MMSE 17 [range 4-25]). Planar anterior images of the thorax were acquired at 15 minutes. (early study) and 4 hours (late study) after tracer injection. Myocardial MIBG activity was quantified by means of a heart-to-mediastinum ratio (HMR). A HMR > 1.8 was considered normal. RESULTS: Respect AD patients, patients with DLB showed decreased HMR in the early study (1.34 +/- 0.27 [range 1.03-1.98] vs. 1.84 +/- 0.22 [range 1.53-2.15], p<0.001) and in the late study (1.22 +/- 0.23 [range 0.95-1.75] vs. 1.73 +/- 0.08 [range 1.59-1.89], p<0.0001). CONCLUSIONS: Cardiac MIBG imaging could be a useful tool for differential diagnosis between DLB and AD.

Demencia con cuerpos de Lewy y enfermedad de Alzheimer: diagnóstico diferencial mediante estudio de la inervación simpática cardíaca con MIBG / Dementia with Lewy bodies and Alzheimer's disease: differential diagnosis by cardiac sympathetic innervation MIBG imaging

La demencia con cuerpos de Lewy (DCL) es la segunda causa de demencia degenerativa después de la enfermedad de Alzheimer (EA), basándose su diagnóstico en Criterios Clínicos de Consenso Internacional y siendo el diagnóstico de certeza post-mortem. El diagnóstico diferencial entre ambas enfermedades permite facilitar el manejo terapéutico de los pacientes con DCL, que presentan una sensibilidad especial a los neurolépticos y un tratamiento difícil de sus síntomas psicóticos. Objetivo. Valorar la utilidad del estudio cardíaco con MIBG en el diagnóstico diferencial entre DCL y EA. Material y métodos. Se realizó gammagrafía cardíaca con MIBG a 16 pacientes con criterios clínicos de probable DCL (7 hombres, edad media 77 años [rango 62-89 años], MMSE medio 17 [rango 11-28]) y a 9 pacientes con criterios clínicos de probable EA (3 hombres, edad media 79 años [rango 61-87 años], MMSE medio 17 [rango 4-25]). Se obtuvo imagen planar anterior de tórax a los 15 minutos (estudio precoz) y 4 horas (estudio tardío) post-administración del trazador. Se cuantificó la captación cardíaca de MIBG mediante el índice corazón/mediastino (ICM). Se consideró normal un ICM > 1,8. Resultados. La DCL mostró un ICM disminuido respecto a la EA, tanto en el estudio precoz (1,34 ± 0,27 [rango 1,03-1,98] respecto a 1,84 ± 0,22 [rango 1,53-2,15], p < 0,001) como en el tardío (1,22 ± 0,23 [rango 0,95-1,75] respecto a 1,73 ± 0,08 [rango 1,59-1,89], p < 0,0001). Conclusiones. El estudio cardíaco con MIBG puede ser un instrumento útil para establecer el diagnóstico diferencial entre DCL y EA

Dementia with Lewy bodies (DLB) is the second most common cause of degenerative dementia after Alzheimer's disease (AD). At present, pre-mortem diagnosis of DLB can only be made clinically using the International Consensus Criteria. However, an accurate differential diagnosis between these diseases could improve the therapeutic handling of patients with DLB, due to their supersensitivity to neuroleptic treatment and the difficult treatment of their psychotic symptoms. Objective. To assess the utility of cardiac MIBG imaging as diagnostic study for DLB, to help in the differential diagnosis with AD. Material and methods. Cardiac MIBG imaging was performed in 11 patients with clinical criteria of probable DLB (7 males, mean age 77 years [range 62-89 years], mean MMSE 17 [range 11-28], and in 9 patients with clinical criteria of probable AD (3 males, mean age 79 years [range 61-87 years], mean MMSE 17 [range 4-25]). Planar anterior images of the thorax were acquired at 15 minutes. (early study) and 4 hours (late study) after tracer injection. Myocardial MIBG activity was quantified by means of a heart-to-mediastinum ratio (HMR). A HMR > 1.8 was considered normal. Results. Respect AD patients, patients with DLB showed decreased HMR in the early study (1.34 ± 0.27 [range 1.03-1.98] vs. 1.84 ± 0.22 [range 1.53-2.15], p < 0.001) and in the late study (1.22 ± 0.23 [range 0.95-1.75] vs. 1.73 ± 0.08 [range 1.59-1.89], p < 0.0001). Conclusions. Cardiac MIBG imaging could be a useful tool for differential diagnosis between DLB and AD

Towards new understanding of the heart structure and function.

Structure and function in any organ are inseparable categories, both in health and disease. Whether we are ready to accept, or not, many questions in cardiovascular medicine are still pending, due to our insufficient insight in the basic science. Even so, any new concept encounters difficulties, mainly arising from our inert attitude, which may result either in unjustified acceptance or denial. The ventricular myocardial band concept, developed over the last 50 years, has revealed unavoidable coherence and mutual coupling of form and function in the ventricular myocardium. After more than five centuries long debate on macroscopic structure of the ventricular myocardium, this concept has provided a promising ground for its final understanding. Recent validations of the ventricular myocardial band, reviewed here, as well as future research directions that are pointed out, should initiate much wider scientific interest, which would, in turn, lead to reconciliation of some exceeded concepts about developmental, electrical, mechanical and energetical events in human heart. The benefit of this, of course, would be the most evident in the clinical arena.