Objectives: The value of gated single-photon emission computed tomography technetium-99m methoxyisobutylisonitrile (gated SPECT 99mTc-MIBI) in children is not yet established probably because gated SPECT 99mTc-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 99mTc-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 99mTc-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 99mTc-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%.
Conclusion: Poststress and rest-gated SPECT 99mTc-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 99mTc-MIBI provides complementary information that may guide clinical decision making in children and adolescents with severe CHD.
aInstitute for Nuclear Medicine, Clinical Center of Serbia
bUniversity Children's Hospital, School of Medicine, University of Belgrade, Belgrade, Serbia
Correspondence to Dragana P. Sobic-Saranovic, MD, PhD, Institute for Nuclear Medicine, Clinical Center of Serbia, Visegradska 26, Belgrade 11000, Serbia
Tel: +381 11 36 35 352; fax: +381 11 36 15 641;
Received 19 December 2008 Revised 14 January 2009 Accepted 14 January 2009