Diagnostic performance of IQ·SPECT with high-speed scanning: A preliminary quality control study in obese patients

Rudolf A. Werner, Ricardo Bello Martinez, Charles Marcus, Matthew J. Kruse, Sara Sheikhbahaei, Lilja B. Solnes, Takahiro Higuchi, Mehrbod S. Javadi, Steven P. Rowe

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Background: IQ·SPECT is a recently introduced collimator design for myocardial perfusion imaging (MPI). Little data exist on use of this collimator type in obese patients, particularly Class 2 or 3 [body mass index (BMI) > 35 kg/m2]. Methods: Two consecutive rest–stress MPI scans were prospectively acquired using a conventional collimator and IQ·SPECT (acquisition times of 20 and 7 minutes, respectively) in 20 patients with a BMI of >30 kg/m2. Assigned by two blinded, independent readers, image quality (on a 5-point scale) and metrics of myocardial perfusion [summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS)] were compared. Software-based left ventricular ejection fraction (EF) was also correlated. Results: Mean BMI was 39.6 ± 7.6 kg/m2. Class 2 or 3 obesity was present in 12 patients (BMI, 44.1 ± 6.8 kg/m2). Gated/non-gated images from IQ·SPECT revealed fair to good quality scores (median ≥ 3.25), which were inferior to the conventional collimator (median ≥ 4.0; P ≤ 0.01). Significant correlative indices were achieved when comparing IQ·SPECT and conventional collimators for EF values (r = 0.86, P < 0.01), SSS (r = 0.75, P < 0.0001) and SRS (r = 0.60, P < 0.005), but not for SDS (r = 0.15). Conclusion: IQ·SPECT was comparable to conventional SPECT in obese patients. The reduced acquisition time of IQ·SPECT may allow for improved throughput with no loss in diagnostic accuracy.

Original languageEnglish
JournalJournal of Nuclear Cardiology
Publication statusAccepted/In press - 2022
Externally publishedYes


  • image quality
  • MPI
  • myocardial perfusion imaging
  • Single-photon emission computed tomography

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Cardiology and Cardiovascular Medicine


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