Journal of nuclear medicine : official publication, Society of Nuclear Medicine
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The aim of this study was to use 99mTc-TRODAT-1 brain SPECT for investigation of the binding of dopamine transporter (DAT) in the nigrostriatal dopaminergic pathway of symptomatic Machado-Joseph disease (MJD) and to compare the results with the abnormal cytidylate, adenylate, and guanylate (CAG) expansion in the MJD1 gene and other clinical factors. ⋯ Our findings indicate that 99mTc-TRODAT-1 brain SPECT is an appropriate method for evaluating damage to the nigrostriatal DAT in symptomatic MJD patients with and without extrapyramidal signs. The decreased binding of 99mTc-TRODAT-1 in the nigrostriatal dopaminergic pathway in symptomatic MJD patients correlates with the phenotype of extrapyramidal signs but not with the abnormal CAG repeat length, age at disease onset, or disease duration.
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Scintillation cameras with options for detecting positron annihilation quanta in the coincidence acquisition mode may be the most innovative diagnostic devices introduced in nuclear medicine during the last few years. Besides conventional low-energy imaging in the collimated single-photon mode, these options offer a relatively inexpensive opportunity to perform uncollimated PET by switching into the coincidence acquisition mode. Instead of collimators, scatter frames (with 2 optional configurations: axial or open scatter frame) can be mounted to reduce the amount of quanta reaching the detectors from parts of the patient's body outside the field of view. This study investigates the coincidence imaging properties of the scintillation camera by measuring spatial resolution, scatter fraction, sensitivity, and count-rate response for 18F. ⋯ The spatial resolution of the scintillation camera is sufficient for high-resolution coincidence imaging. Compared with a dedicated PET scanner, the scatter fraction is relatively high and should therefore be corrected adequately. The relatively low sensitivity and the rather low maximum true coincidence counting rate are considerably inferior compared with a conventional PET scanner. However, these drawbacks can be partially compensated for, facilitating its clinical use.