title: Rapid dual-injection single-scan 13N-ammonia PET for quantification of rest and stress myocardial blood flows.
abstract: Quantification of myocardial blood flows at rest and stress using 13N-ammonia PET is an established method; however, current techniques require a waiting period of about 1 h between scans. The objective of this study was to test a rapid dual-injection single-scan approach, where 13N-ammonia injections are administered 10 min apart during rest and adenosine stress. Dynamic PET data were acquired in six human subjects using imaging protocols that provided separate single-injection scans as gold standards. Rest and stress data were combined to emulate rapid dual-injection data so that the underlying activity from each injection was known exactly. Regional blood flow estimates were computed from the dual-injection data using two methods: background subtraction and combined modelling. The rapid dual-injection approach provided blood flow estimates very similar to the conventional single-injection standards. Rest blood flow estimates were affected very little by the dual-injection approach, and stress estimates correlated strongly with separate single-injection values (r=0.998, mean absolute difference=0.06 ml min-1 g-1). An actual rapid dual-injection scan was successfully acquired in one subject and further demonstrates feasibility of the method. This study with a limited dataset demonstrates that blood flow quantification can be obtained in only 20 min by the rapid dual-injection approach with accuracy similar to that of conventional separate rest and stress scans. The rapid dual-injection approach merits further development and additional evaluation for potential clinical use.
authors.affiliation: Utah Center for Advanced Imaging Research, Department of Radiology and Department of Bioengineering, CAMT, 729 Arapeen Drive, University of Utah, Salt Lake City, UT 84108-1218, USA.
authors.forename: T C
authors.initials: TC
authors.lastname: Rust
authors.forename: E V R
authors.initials: EV
authors.lastname: DiBella
authors.forename: C J
authors.initials: CJ
authors.lastname: McGann
authors.forename: P E
authors.initials: PE
authors.lastname: Christian
authors.forename: J M
authors.initials: JM
authors.lastname: Hoffman
authors.forename: D J
authors.initials: DJ
authors.lastname: Kadrmas
mesh_terms: D000641:Ammonia / Q000008:administration & dosage / Q000493:pharmacokinetics; D001783:Blood Flow Velocity / Q000502:physiology*; D002247:Carbon Isotopes / Q000008:administration & dosage / Q000493:pharmacokinetics; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007269:Injections, Intra-Arterial; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011865:Radioisotope Dilution Technique; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D015203:Reproducibility of Results; D012146:Rest; D012680:Sensitivity and Specificity
chemical_list: D002247:Carbon Isotopes; D019275:Radiopharmaceuticals; D000641:Ammonia