Large variation in blood flow between left ventricular segments, as detected by adenosine stress dynamic CT perfusion.
BACKGROUND
Dynamic cardiac CT perfusion (CTP) is based on repeated imaging during the first-pass contrast agent inflow. It is a relatively new method that still needs validation.


OBJECTIVE
To evaluate the variation in adenosine stress dynamic CTP blood flow as compared to (99m) Tc SPECT. Secondarily, to compare manual and automatic segmentation.


METHODS
Seventeen patients with manifest coronary artery disease were included. Nine were excluded from evaluation for various reasons. All patients were examined with dynamic stress CTP and stress/rest SPECT. CTP blood flow was compared with SPECT on a per segment basis. Results for manual and automated AHA segmentation were compared.


RESULTS
CTP showed a positive correlation with SPECT, with correlation coefficients of 0·38 and 0·41 for manual and automatic segmentation, respectively (P<0·0001). There was no significant difference between the correlation coefficients of the manual and automated segmentation procedures (P = 0·75). The average per individual global CTP blood flow value for normal segments varied by a factor of 1·9 (manual and automatic segmentation). For the whole patient group, the CTP blood flow value in normal segments varied by a factor of 2·9/2·7 (manual/automatic segmentation). Within each patient, the average per segment blood flow in normal segments varied by a factor of 1·3-2·0/1·2-2·1 (manual/automatic segmentation).


CONCLUSIONS
A positive but rather weak correlation was found between CTP and (99m) Tc SPECT. Large variations in CTP blood flow suggest that a cut-off value for stress myocardial blood flow is inadequate to detect ischaemic segments. Dynamic CTP is hampered by a limited coverage.
Faculty of Health Sciences, Department of Medical and Health Sciences, Department of Radiology in Linköping, Center for Medical Image Science and Visualization (CMIV), Linköping University, County Council of Östergötland, Linköping, Sweden.
Jakob
J
De Geer
Faculty of Health Sciences, Department of Medical and Health Sciences, Department of Cardiology in Linköping, Center for Medical Image Science and Visualization (CMIV), Linköping University, County Council of Östergötland, Linköping, Sweden.
Marcus
M
Gjerde
Faculty of Health Sciences, Department of Medical and Health Sciences, Department of Clinical Physiology in Kalmar, Linköping University, County Council of Kalmar, Kalmar, Sweden.
Lars
L
Brudin
Faculty of Health Sciences, Department of Medical and Health Sciences, Department of Clinical Physiology, Center for Medical Image Science and Visualization (CMIV), Linköping University, County Council of Östergötland, Linköping, Sweden.
Eva
E
Olsson
Faculty of Health Sciences, Department of Medical and Health Sciences, Department of Radiology in Linköping, Center for Medical Image Science and Visualization (CMIV), Linköping University, County Council of Östergötland, Linköping, Sweden.
Anders
A
Persson
Faculty of Health Sciences, Department of Medical and Health Sciences, Department of Clinical Physiology, Center for Medical Image Science and Visualization (CMIV), Linköping University, County Council of Östergötland, Linköping, Sweden.
Jan
J
Engvall
D000241:Adenosine; D000368:Aged; D001783:Blood Flow Velocity; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000503:physiopathology*; D005080:Exercise Test / Q000379:methods; D006801:Humans; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014665:Vasodilator Agents; D018754:Ventricular Dysfunction / Q000000981:diagnostic imaging* / Q000503:physiopathology*
D014665:Vasodilator Agents; D000241:Adenosine
AHA segmentation; contrast agent; correlation; ischaemia; tetrofosmin