All previously reported comparative studies of 511 keV single-photon emission computed tomography (SPECT) and positron emission tomography (PET) have used one fluorine-18-fluorodeoxyglucose (FDG) dose, followed by PET and SPECT on the same day. This approach is inherently biased against the second imaging study. Therefore, we prospectively compared conventional PET and 511 keV SPECT in 23 patients with proven malignancy using separate 370 MBq FDG doses on different days employing an ECAT 951/31R PET scanner and a Trionix XLT-20 for SPECT. Discrepancies were evident in twelve of 23 patients (52%). In eight of these (66%) findings were seen exclusively on PET and represented the only metabolic evidence of disease. Thirty-seven of the 52 lesions (71%) detected at PET were also defined by SPECT, most above 2 cm. In 4 cases of extrahepatic abdominal disease (3 colorectal, 1 melanoma), both PET and SPECT missed small recurrent omental and perivesical lesions; several lesions up to 1.2 cm were also missed by CT and MRI.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s1095-0397(99)00007-2 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Feasibility of PET-enabled dual-energy CT imaging: First physical phantom and initial patient study results.
Eur J Nucl Med Mol Imaging
November 2024
Department of Radiology, UC Davis Health, 95817, Sacramento, CA, USA.
Purpose: Dual-energy (DE) CT enables material decomposition by using two different x-ray energies and may be combined with PET for improved multimodality imaging. However, this increases radiation dose and may require a hardware upgrade due to the added second x-ray CT scan. The recently proposed PET-enabled DECT method allows dual-energy imaging using a conventional PET/CT scanner without the need to change scanner hardware or increase radiation exposure.
View Article and Find Full Text PDFTwisted clustered pinhole collimation for improved high-energy preclinical SPECT/PET.
Phys Med Biol
November 2024
Department of Radiation Science and Technology, Delft University of Technology, Delft, The Netherlands.
Advanced pinhole collimation geometries optimized for preclinical high-energyimaging facilitate applications such asandemitter imaging, simultaneous multi-isotope PET and PET/SPECT, and positron range-free PET. These geometries replace each pinhole with a group of clustered pinholes (CPs) featuring smaller individual pinhole opening angles (POAs), enabling sub-mm resolution imaging up to ∼1 MeV. Further narrowing POAs while retaining field-of-view (FOV) may enhance high-energy imaging but faces geometrical constraints.
View Article and Find Full Text PDFCombining PET and Compton imaging with edge-on CZT detectors for enhanced diagnostic capabilities.
Adv Radiother Nucl Med
June 2024
Department of Electrical and Computer Engineering, Baskin School of Engineering, University of California, Santa Cruz, United States of America.
The key metrics for positron emission tomography (PET) imaging devices include the capability to capture the maximum available amount of annihilation photon information while generating high-quality images of the radiation distribution. This capability carries clinical implications by reducing scanning time for imaging, thus reducing radiation exposure for patients. However, imaging quality is degraded by positron range effects and the non-collinearity of positron annihilation photons.
View Article and Find Full Text PDFSegmented readout for Cherenkov time-of-flight positron emission tomography detectors based on bismuth germanate.
ArXiv
October 2024
Department of Biomedical Engineering, University of California, Davis, USA.
Positron emission tomography (PET) is the most sensitive biomedical imaging modality for non-invasively detecting and visualizing positron-emitting radiopharmaceuticals within a subject. In PET, measuring the time-of-flight (TOF) information for each pair of 511-keV annihilation photons improves effective sensitivity but requires high timing resolution. Hybrid materials that emit both scintillation and Cherenkov photons, such as bismuth germanate (BGO), recently offer the potential for more precise timing information from Cherenkov photons while maintaining adequate energy resolution from scintillation photons.
View Article and Find Full Text PDFStudy of modulation in complex refractive indices induced by ultrafast relativistic electrons using infrared and THz probe pulses.
Phys Med Biol
November 2024
Department of Radiology, Stanford University, Stanford, CA, United States of America.
Achieving ultra-precise temporal resolution in ionizing radiation detection is essential, particularly in positron emission tomography, where precise timing enhances signal-to-noise ratios and may enable reconstruction-less imaging. A promising approach involves utilizing ultrafast modulation of the complex refractive index, where sending probe pulses to the detection crystals will result in changes in picoseconds (ps), and thus a sub-10 ps coincidence time resolution can be realized. Towards this goal, here, we aim to first measure the ps changes in probe pulses using an ionizing radiation source with high time resolutionWe used relativistic, ultrafast electrons to induce complex refractive index and use probe pulses in the near-infrared (800 nm) and terahertz (THz, 300m) regimes to test the hypothesized wavelength-squared increase in absorption coefficient in the Drude free-carrier absorption model.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!