Evaluation of myocardial perfusion and function by gated single-photon emission computed tomography technetium-99m methoxyisobutylisonitrile in children and adolescents with severe congenital heart disease.
OBJECTIVE
The value of gated single-photon emission computed tomography technetium-99m methoxyisobutylisonitrile (gated SPECT (99m)Tc-MIBI) in children is not yet established probably because gated SPECT (99m)Tc-MIBI has rarely been used in pediatric clinical and research studies. The purpose of this study was to evaluate perfusion abnormalities and left ventricular (LV) function by gated SPECT (99m)Tc-MIBI in children and adolescents with severe congenital heart disease (CHD).


METHODS
Seventeen children and adolescents with severe CHD (11 boys and six girls, mean age 11+/-4 years) underwent 2-day rest-stress (11 boys) or 1-day rest (six girls) gated SPECT (99m)Tc-MIBI. Myocardial perfusion was evaluated by a 17-segment model with a 5-point score to derive the summed stress score, the summed rest score (SRS), and the summed difference score based on the 4D-MSPECT software results. The extent of myocardial perfusion abnormalities was also expressed as a percentage of the LV size. The 4D-MSPECT software was used to calculate LV end-diastolic volume, end-systolic volume (ESV), and ejection fraction (EF).


RESULTS
Reversible myocardial perfusion defect was found in 7 of 11 children (64%) who underwent rest-stress gated SPECT (99m)Tc-MIBI. The LV segments involved were anterior, anteroseptal, anterolateral, apical and inferior. These seven children showed significantly larger perfusion abnormalities on stress compared with rest study (18+/-5 vs. 7+/-4%, P<0.01) and higher summed stress score compared to SRS (11+/-4 vs. 4+/-2, P<0.01). Children and adolescents with myocardial ischemia had significantly lower poststress EF than rest EF (53+/-12 vs. 59+/-11%, P<0.05) and significantly higher poststress ESV than rest ESV (81+/-24 vs. 61+/-25 ml, P<0.05). In six children evaluated only at rest, perfusion defects involved anterior, anteroseptal and apical, or inferolateral segments, accounting for 31+/-12% of LV and with SRS of 12+/-5. Their global LV parameters were: end-diastolic volume 118+/-23 ml, ESV 56+/-16 ml, EF 51+/-10%.


CONCLUSIONS
Poststress and rest-gated SPECT (99m)Tc-MIBI results indicate that children and adolescents with severe CHD show a range of abnormalities in myocardial perfusion and LV function, which is useful for determining functional importance of morphological malformations. Thus, gated SPECT (99m)Tc-MIBI provides complementary information that may guide clinical decision making in children and adolescents with severe CHD.
Sobic-Saranovic
Dragana P
DP
Institute for Nuclear Medicine, Clinical Center of Serbia, Belgrade, Serbia. dsobic@EUnet.rs
Pavlovic
Smiljana V
SV
Jovanovic
Ida V
IV
Stefanovic
Igor D
ID
Artiko
Vera M
VM
Djukic
Milan M
MM
Obradovic
Vladimir B
VB
D000293:Adolescent; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; D002648:Child; D002675:Child, Preschool; D003326:Coronary Circulation; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000503:physiopathology*; D006331:Heart Diseases / Q000151:congenital / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D008297:Male; D009570:Nitriles / Q000737:chemistry*; D015609:Organotechnetium Compounds / Q000737:chemistry; D012146:Rest; D013312:Stress, Physiological; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging
D009570:Nitriles; D015609:Organotechnetium Compounds; C055887:2-methoxyisobutylisonitrile