ECG-gated 99mTc single-photon emission CT for assessment of right ventricular structure and function: is the information provided similar to echocardiography?
OBJECTIVE
(99m)Tc single-photon emission CT (SPECT) and ECG-gated SPECT can visualize well the right ventricle (RV) in most patients, but their utility for assessment of the RV has not been formally evaluated. We examined whether (99m)Tc SPECT/ECG-gated SPECT provide similar information to transthoracic two-dimensional Doppler echocardiography (2D-ECHO) regarding RV cavity size, wall thickness, and systolic function.


METHODS
Retrospective analysis.


METHODS
A major university teaching hospital.


METHODS
A consecutive series of 194 patients with good quality stress SPECT and 2D-ECHO studies performed within 1 day of each other and no significant interim cardiac events.


RESULTS
RV size and function were visually assessed by SPECT/ECG-gated SPECT and 2D-ECHO. RV wall thickness was visually assessed by SPECT and measured in mm in end-diastole by 2D-ECHO. Of 142 patients with normal RV cavity size by SPECT, 134 patients (94%) had normal RV cavity size by 2D-ECHO. However, of 52 patients with RV dilation by SPECT, only 9 patients (17%) had RV dilation by 2D-ECHO. A perfusion abnormality in the right coronary artery territory was significantly associated with RV dilation by SPECT (p < 0.005) and 2D-ECHO (p < 0.05). Among 150 patients with ECG-gated SPECT, only 2 patients had abnormal RV systolic function, as compared with 18 patients by 2D-ECHO. RV wall thickness measurements by SPECT and 2D-ECHO did not correlate.


CONCLUSIONS
For normal interpretations regarding RV cavity size, wall thickness, and systolic function, there is good agreement between (99m)Tc stress SPECT/ECG-gated SPECT and 2D-ECHO. However, there is poor overall agreement between gated SPECT/ECG-gated SPECT and 2D-ECHO regarding the presence of RV dilation, hypertrophy, and systolic dysfunction.
Aepfelbacher
Franz C
FC
Department of Medicine, Cardiovascular Division, Beth Israel Deaconess Medical Center, and Harvard Medical School, Boston, MA 02215, USA.
Yeon
Susan B
SB
Ho
Kalon K L
KK
Parker
J Anthony
JA
Danias
Peter G
PG
D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D017380:Hypertrophy, Right Ventricular / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013667:Technetium; D015899:Tomography, Emission-Computed, Single-Photon; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging; D016278:Ventricular Function, Right / Q000502:physiology*
D013667:Technetium