A comparison between 64-projection and 32-projection myocardial perfusion scintigraphy

Area of Science:

• Nuclear Medicine
• Cardiology
• Medical Imaging

Background:

• Clinical guidelines often recommend 64-projection myocardial perfusion scintigraphy (MPS) but lack evidence for this preference.
• Protocols vary, with some not specifying between 32- and 64-projection methods, indicating a lack of consensus.

Purpose of the Study:

• To investigate the significant differences between 32- and 64-projection MPS techniques.
• To compare cardiac perfusion and functional indices obtained from both methods.

Main Methods:

• A pilot prospective, cross-sectional, cross-over study involving 69 patients.
• Patients underwent both 32- and 64-projection MPS at rest and stress using 99mTc-MIBI.
• Cardiac indices including summed scores, volumes, ejection fraction, peak filling rate (PFR), and time to peak filling rate (TTPF) were analyzed.

Main Results:

• No significant difference or excellent/good agreement was found between 32- and 64-projection MPS for most cardiac indices in stress and rest states.
• An exception was observed for TTPF and PFR, where agreement was poor.

Conclusions:

• Lower-projection techniques, such as 32-projection MPS, may be sufficient for routine clinical assessments without compromising diagnostic accuracy.
• The 64-projection protocol is preferable for precise evaluations, particularly when assessing diastolic function, due to better agreement for PFR and TTPF.