Generation of myocardial factor images directly from the dynamic oxygen-15-water scan without use of an oxygen-15-carbon monoxide blood-pool scan.
The measurement of regional myocardial blood flow (MBF) with H2(15)O and PET requires an additional C15O blood-pool scan for the purpose of region of interest (ROI) definition. This additional scan results in a substantially increased radiation dose, study duration and risk of movement artifacts. Therefore, a method was developed to generate myocardial factor images directly from the dynamic H2(15)O study without the need for a C15O scan.


METHODS
The factor sinograms were generated by means of linear dimension reduction of the dynamic sinograms, where the required variate and covariate factors (myocardial and blood time-activity curves) were modeled from the lung time-activity curve. The factor images were generated by iterative reconstruction.


RESULTS
No significant difference was found between MBF values from ROIs drawn on the traditional images (using the C15O scan) and those drawn on the factor images.


CONCLUSIONS
It is possible to generate myocardial images directly from the dynamic H2(15)O study, so that the C15O scan can be omitted from MBF studies. The proposed method is robust and results in nearly optimal signal-to-noise ratios in the factor images.
Cyclotron Unit, MRC Clinical Sciences Centre, Hammersmith Hospital, London, United Kingdom.
F
F
Hermansen
J
J
Ashburner
T J
TJ
Spinks
J S
JS
Kooner
P G
PG
Camici
A A
AA
Lammertsma
D002248:Carbon Monoxide; D016022:Case-Control Studies; D003326:Coronary Circulation / Q000502:physiology; D015637:Gated Blood-Pool Imaging; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging; D010104:Oxygen Radioisotopes; D014867:Water
D010104:Oxygen Radioisotopes; D014867:Water; D002248:Carbon Monoxide