PT  - JOURNAL ARTICLE
AU  - Hiroto Yoneyama
AU  - Takayuki Shibutani
AU  - Takahiro Konishi
AU  - Asuka Mizutani
AU  - Ryosuke Hashimoto
AU  - Masahisa Onoguchi
AU  - Koichi Okuda
AU  - Shinro Matsuo
AU  - Kenichi Nakajima
AU  - Seigo Kinuya
TI  - Validation of Left Ventricular Ejection Fraction with the IQ•SPECT System in Small-Heart Patients
AID  - 10.2967/jnmt.116.188680
DP  - 2017 Sep 01
TA  - Journal of Nuclear Medicine Technology
PG  - 201--207
VI  - 45
IP  - 3
4099  - http://tech.snmjournals.org/content/45/3/201.short
4100  - http://tech.snmjournals.org/content/45/3/201.full
SO  - J. Nucl. Med. Technol.2017 Sep 01; 45
AB  - The IQ•SPECT system, which is equipped with multifocal collimators (SMARTZOOM) and uses ordered-subset conjugate gradient minimization as the reconstruction algorithm, reduces the acquisition time of myocardial perfusion imaging compared with conventional SPECT systems equipped with low-energy high-resolution collimators. We compared the IQ•SPECT system with a conventional SPECT system for estimating left ventricular ejection fraction (LVEF) in patients with a small heart (end-systolic volume < 20 mL). Methods: The study consisted of 98 consecutive patients who underwent a 1-d stress–rest myocardial perfusion imaging study with a 99mTc-labeled agent for preoperative risk assessment. Data were reconstructed using filtered backprojection for conventional SPECT and ordered-subset conjugate gradient minimization for IQ•SPECT. End-systolic volume, end-diastolic volume, and LVEF were calculated using quantitative gated SPECT (QGS) and cardioREPO software. We compared the LVEF from gated myocardial perfusion SPECT to that from echocardiographic measurements. Results: End-diastolic volume, end-systolic volume, and LVEF as obtained from conventional SPECT, IQ•SPECT, and echocardiography showed a good to excellent correlation regardless of whether they were calculated using QGS or using cardioREPO. Although LVEF calculated using QGS significantly differed between conventional SPECT and IQ•SPECT (65.4% ± 13.8% vs. 68.4% ± 15.2%) (P = 0.0002), LVEF calculated using cardioREPO did not (69.5% ± 10.6% vs. 69.5% ± 11.0%). Likewise, although LVEF calculated using QGS significantly differed between conventional SPECT and IQ•SPECT (75.0 ± 9.6 vs. 79.5 ± 8.3) (P = 0.0005), LVEF calculated using cardioREPO did not (72.3% ± 9.0% vs. 74.3% ± 8.3%). Conclusion: In small-heart patients, the difference in LVEF between IQ•SPECT and conventional SPECT was less when calculated using cardioREPO than when calculated using QGS.