Performance of the dynamic single photon emission computed tomography (dSPECT) method for decreasing or increasing activity changes

Radionuclide imaging is now widely used whenever Functional information is required. We present a new approach to dynamic SPECT imaging (dSPECT method ) that uses a single slow rotation of a conventional camera and allows us t o reconstruct a series of 3D images corresponding to the radiotracer distri bution in the body at various times. Using simulations of various camera co nfigurations and acquisition protocols, we have shown that this method is a ble to reconstruct washout half-lives with an accuracy greater than 90% whe n used with triple-head SPECT cameras. Accuracy decreases when using fewer camera heads, but dual-head geometries still give an accuracy greater than 80% for short and 90% for long hair-lives and about 50-75% for single-head systems. Dynamic phantom experiments have yielded similar results. Presence of attenuation and background activity does not affect the accuracy of the dSPECT reconstructions. In all situations investigated satisfactory dynami c images were produced. A preliminary normal volunteer study measuring rena l function was performed. The reconstructed dynamic images may he presented as a three-dimensional movie showing movement of the tracer through the ki dneys and the measurement of the regional renal function can he performed. The time-activity curves determined from this dSPECT data are very similar to those obtained from dynamic planar scans.