La tomografía computerizada por emisión de fotón único (single photon emission computed tomography, SPECT) es una técnica de imagen tomográfica de medicina nuclear que utiliza rayos gamma que son captados por una gamma cámara. La Imagen en general y la Neuroimagen en particular se han convertido en una técnica ampliamente utilizada en Medicina Molecular, y, con el advenimiento de los equipos preclínicos, permite realizar estudios en animales experimentales in vivo.
La técnica requiere la administración de un radiosiótopo emisor gamma (un radionúclido) al sujeto a estudiar, normalmente mediante la inyección en el torrente sanguíneo. Ocasionalmente, el radioisótopo es un simple ión soluble en disolución. Sin embargo, en general el radioisótopo está unido a una molécula específica para crear un radioligando, cuyas propiedades permiten su unión a ciertos tipos de tejido.
Para adquirir imágenes SPECT, la cámara gamma gira alrededor del sujeto para obtener imágenes 3D.
Single photon emission computerized tomography (SPECT)
Description Single-photon emission computed tomography (SPECT) is a nuclear medicine tomographic imaging technique using gamma rays, which are captured by a gamma camera. Imaging in general, and Brain Imaging in particular had become a widely used technique in Molecular Medicine, and, with the advent of preclinical equipments, it allows to perform studies in experimental animals in vivo. The technique requires the delivery of a gamma-emitting radioisotope (a radionuclide) into the subject under study, normally through injection into the bloodstream. Occasionally, the radioisotope is a simple soluble dissolved ion. However, in general, a radioisotope is attached to a specific molecule to create a radioligand, whose properties allows binding to certain types of tissues. To acquire SPECT images, the gamma camera is rotated around the subject to obtain 3D images. Projections are acquired at defined points during the rotation, typically every 3¿6 degrees. In most cases, a full 360-degree rotation is used to obtain an optimal reconstruction. The time taken to obtain each projection is also variable, and related with the characteristics of the radioligand. The Cajal institute Brain Imaging Unit has acquired an Albira SPECT (Oncovision, Spain) that allows the study of different functions. It is equipped with a computerized tomographer (CT), that allows anatomical imaging. We are focused on the development of methods to assess different brain functions. For instance, cerebral blood flow to be assessed with 99mTc-HMPAO (hexamethylpropylene amine oxime), a parameter that may be changed in neurodegenerative disorders, tumours etc...Dopamine transporters could be labeled with DatScan (123I-BICIT), an application useful in Parkinson¿s disease models where those transporters are reduced. Neuroinflammation is present in the majority of the disorders of the brain, and anti-inflammatory molecules are actively studied for those conditions, therefore we intend to image neuroinflammation by means of 123I-PK11195. Service conditions The user will contact the Brain Imaging Unit requesting the studies to select the most appropriate radioligand for SPECT images acquisitions. The animals should be housed in the quarantine room in the animal house of the IC, since they will return to that room following the experiments. In case the service would be requested by a researcher from other Institute/Center a veterinary report will be required before the admission to the facilities. The price of each study will depend on the price of the radioligand dose for each animal. A price list of the services is available. Following the image acquisitions, they will be reconstructed, analyzed and a report will be delivered.