The EANM practice guidelines for parathyroid imaging.

INTRODUCTION: Nuclear medicine parathyroid imaging is important in the identification of hyperfunctioning parathyroid glands in primary hyperparathyroidism (pHPT), but it may be also valuable before surgical treatment in secondary hyperparathyroidism (sHPT). Parathyroid radionuclide imaging with scintigraphy or positron emission tomography (PET) is a highly sensitive procedure for the assessment of the presence and number of hyperfunctioning parathyroid glands, located either at typical sites or ectopically. The treatment of pHPT is mostly directed toward minimally invasive parathyroidectomy, especially in cases with a single adenoma. In experienced hands, successful surgery depends mainly on the exact preoperative localization of one or more hyperfunctioning parathyroid adenomas. Failure to preoperatively identify the hyperfunctioning parathyroid gland challenges minimally invasive parathyroidectomy and might require bilateral open neck exploration. METHODS: Over a decade has now passed since the European Association of Nuclear Medicine (EANM) issued the first edition of the guideline on parathyroid imaging, and a number of new insights and techniques have been developed since. The aim of the present document is to provide state-of-the-art guidelines for nuclear medicine physicians performing parathyroid scintigraphy, single-photon emission computed tomography/computed tomography (SPECT/CT), positron emission tomography/computed tomography (PET/CT), and positron emission tomography/magnetic resonance imaging (PET/MRI) in patients with pHPT, as well as in those with sHPT. CONCLUSION: These guidelines are written and authorized by the EANM to promote optimal parathyroid imaging. They will assist nuclear medicine physicians in the detection and correct localization of hyperfunctioning parathyroid lesions.

Patterns of extension of gastrointestinal stromal tumors (GIST) treated with imatinib (Gleevec®) by 18F-FDG PET/CT.

BACKGROUND AND AIM: currently it is recognized the usefulness of 18F-FDG PET in assessing response to therapy with imatinib (Gleevec®) in the gastrointestinal tract sarcomas (GIST). To facilitate the follow-up of these studies is important to know the patterns of metastatic spread. The aim of this paper is to describe patterns observed in the 18F-FDG PET/CT. METHOD: retrospective study included 29 patients who underwent 18F-FDG PET/CT after being diagnosed with unresectable or metastatic GIST. In total, 87 PET/CT studies were performed (1-6 controls per patient) with a mean time of follow-up 6-36 months. We analyzed the location of the lesions evidenced in PET, CT and fusion. Images were evaluated visually and semiquantitatively (SUV). In cases in which has been considered necessary, additional images have been undertaken: PET delayed imaging, intravenous contrast CT and inspiratory chest CT. RESULTS: the most common primary site was the stomach (41%), small bowel (35%), and rectum (24%). Significant changes in the location of metastatic disease between pre-treatment and the monitoring were observed, with the appearance of more extra-abdominal disease. CONCLUSIONS: individualization of protocol studies and interpretation of PET, CT and fused images were required for evaluation of treatment response to imatinib. Hybrid 18F-FDG PET/CT provides an accurate determination of the extent of GIST. While the most common metastatic site is the liver and peritoneum, in the following cases are common extra-abdominal disease.

Patrones de extensión de los tumores del estroma gastrointestinal (GIST) tratados con imatinib (Gleevec®) mediante PET/TC con 18F-FDG / Patterns of extension of gastrointestinal stromal tumors (GIST) treated with imatinib (Gleevec)® by 18F-FDG PET/CT

Introducción y objetivo: actualmente está reconocida la utilidad de la 18F-FDG-PET en la evaluación de la respuesta a la terapia con imatinib (Gleevec®) en los sarcomas del tracto gastrointestinal (GIST). Para facilitar la valoración comparativa de estos estudios es importante conocer sus patrones de diseminación metastásica. El objetivo de este trabajo es describir estos patrones evidenciados en la 18F-FDG-PET/TC. Método: estudio retrospectivo de 29 pacientes a los que se les realizó una 18F-FDG-PET/TC, tras haber sido diagnosticados de un GIST irresecable o metastásico. En total se realizaron 87 estudios PET/TC (1-6 controles por paciente) con tiempo medio posterior de seguimiento entre 6-36 meses. Se analizó la localización de las lesiones evidenciadas en las imágenes PET, TC y de fusión, y se valoraron las imágenes de forma visual y semicuantitativa (SUV). En aquellos casos en los que para la valoración de las imágenes se ha considerado necesario se han realizado exploraciones adicionales: imágenes tardías PET, TC con contraste endovenoso y TC inspiratorio torácico. Resultados: la localización primaria más frecuente fue la gástrica (41%), el intestino delgado (35%) y el recto (24%). Son muy significativos los cambios en la localización de la enfermedad metastásica entre el estudio pre-tratamiento y los controles de seguimiento, observándose evolutivamente la aparición de mayor enfermedad extra-abdominal. Conclusiones: para la evaluación de la respuesta a la terapia es necesaria la valoración de las imágenes integradas y la individualización del protocolo de la exploración. La exploración híbrida PET/TC proporciona una precisa determinación de la extensión del GIST. Si bien la localización metastásica más habitual es el hígado y el peritoneo, en el seguimiento son frecuentes los casos con enfermedad extra-abdominal(AU)

Background and aim: currently it is recognized the usefulness of 18F-FDG PET in assessing response to therapy with imatinib (Gleevec ®) in the gastrointestinal tract sarcomas (GIST). To facilitate the follow-up of these studies is important to know the patterns of metastatic spread. The aim of this paper is to describe patterns observed in the 18F-FDG PET/CT. Method: retrospective study included 29 patients who underwent 18F-FDG PET/CT after being diagnosed with unresectable or metastatic GIST. In total, 87 PET/CT studies were performed (1-6 controls per patient) with a mean time of follow-up 6-36 months. We analyzed the location of the lesions evidenced in PET, CT and fusion. Images were evaluated visually and semiquantitatively (SUV). In cases in which has been considered necessary, additional images have been undertaken: PET delayed imaging, intravenous contrast CT and inspiratory chest CT. Results: the most common primary site was the stomach (41%), small bowel (35%), and rectum (24%). Significant changes in the location of metastatic disease between pre-treatment and the monitoring were observed, with the appearance of more extra-abdominal disease. Conclusions: individualization of protocol studies and interpretation of PET, CT and fused images were required for evaluation of treatment response to imatinib. Hybrid 18F-FDG PET/CT provides an accurate determination of the extent of GIST. While the most common metastatic site is the liver and peritoneum, in the following cases are common extra-abdominal disease(AU)

The sequence of regional ventricular motion.

OBJECTIVE: The chronology of electrical events that mechanically activate the myocardium has been described as initiating at the level of the septum, spreading to the apex, then to the bodies of both ventricles and eventually to the base of the heart (apex-to base activation). It has recently been suggested that the myocardium is a single muscular band that conforms a double-loop helicoid. Contraction of the myocardium would follow the trajectory of the muscular fibers that originate at the pulmonary artery towards the body of the left ventricle and to the aorta (base-to apex contraction). This would explain the movements of the base of the heart and the twisting motion of the ventricles seen at magnetic resonance studies. METHODS: Temporal Fourier analysis of equilibrium radionucleide angiocardiography, by studying the topography of the regional myocardial mechanical displacement corresponding to the wave front of electro-mechanical activation, provides information on the sequence of regional ventricular contraction was used in 29 normal individuals to observe the sequence of myocardial motion. RESULTS: Analysis disclosed that the base of the heart first moves (right then left ventricle) and mechanical movement later descends to involve the apex and the septum. These findings are in concordance with the proposed activation of the helical myocardium and open the way to more complex studies. CONCLUSIONS: Although electrical activation of the myocardium (QRS complex) follows a septum-apex-body-base of the left ventricle sequence, mechanical activation follows a base-to-apex sequence. This is likely to be related to anisotropic propagation of the electromechanical stimulus throughout the myocardial band once the electrical stimulus has been delivered at the base of the heart.

Nefrourología y medicina nuclear en la actualidad / Nephrourology and nuclear medicine: state of the art

OBJETIVO: El objetivo de este trabajo es presentar los estudios isotópicos dedicados a la Nefrourología, que se realizan más frecuentemente en un Servicio de Medicina Nuclear y destacar sus aplicaciones clínicas más habituales, así como su rentabilidad diagnóstica. MÉTODOS Y RESULTADOS. Los estudios isotópicos en Nefrourología permiten la valoración de la función renal bajo diferentes aspectos. La función renal se puede cuantificar en unidades de volumen por unidad de tiempo (ml/min), a partir de muestras de sangre obtenidas después de la administración endovenosa de un radiofármaco (filtrado glomerular, flujo plasmático renal efectivo) o se puede visualizar en forma de imágenes o de gráficas, obtenidas también después de la administración endovenosa de un radiofármaco (gammagrafía renal, estudio secuencial, renograma), que permiten obtener a su vez la función renal diferencial. También es posible realizar el estudio secuencial y el renograma bajo estímulo farmacológico, bien sea de un diurético o de fármacos inhibidores de la enzima convertidora de la angiotensina (IECAs), valorando los cambios provocados por estos fármacos en la función renal. Además, la cistografía isotópica permite detectar el reflujo vésicoureteral. Las aplicaciones más frecuentes de estos estudios isotópicos se han agrupado en 4 apartados clínicopatológicos: nefropatía por reflujo y detección de cicatrices renales (gammagrafía renal y cistografía isotópica), nefropatía obstructiva (renograma diurético), hipertensión renovascular (renograma con IECAs) y transplante renal (estudio secuencial, renograma, renograma diurético y renograma con IECAs). CONCLUSIONES. Los estudios isotópicos tienen diferentes aplicaciones en Nefrourológia, algunas de las cuales tienen la categoría de exploración diagnóstica de referencia o "gold-standard". Estas exploraciones son la gammagrafía renal con DMSA para detectar anormalidades corticales, el renograma bajo estímulo farmacológico con IECAs para valorar que pacientes hipertensos no se beneficiarán de una cirugía revascularizadora y la determinación de la tasa de filtrado glomerular. La falta de estandarización de protocolos no permite que algunas exploraciones, como es el caso del renograma diurético, puedan ser consideradas estudio de referencia (AU)