Assessment of left ventricular ejection fraction using low radiation dose computed tomography

Area of Science:

• Cardiovascular Imaging
• Radiology
• Medical Diagnostics

Background:

• Cardiac CT offers non-invasive left ventricular ejection fraction (LVEF) estimation.
• Initial resistance to CT for LVEF measurement due to temporal resolution and radiation concerns.
• Need for accurate, fast, low-radiation dose protocols for CT-based LVEF assessment.

Purpose of the Study:

• To demonstrate the feasibility and accuracy of a low-radiation dose 64-slice cardiac CT protocol for LVEF measurement.
• To compare the radiation dose of the low-dose CT protocol with radionuclide angiography (RNA).

Main Methods:

• Prospective enrollment of patients undergoing RNA.
• Comparison of LVEF measurements, study duration, and radiation dose between low-dose CT and RNA.
• Analysis of 77 patients (mean age 61.8 ± 12.2 years, 58 men).

Main Results:

• Mean LVEF by CT (41.9 ± 15.2%) and RNA (39.4 ± 13.9%) showed good correlation (r=0.863) and agreement.
• CT demonstrated good agreement with RNA for identifying low (≤30%) and high (≥50%) LVEF.
• Mean effective radiation dose for CT (4.7 ± 1.6 mSv) was significantly lower than RNA (9.5 ± 1.0 mSv).
• CT LVEF imaging duration (4:32 ± 3:05 min) was significantly shorter than RNA (9:05 ± 2:36 min).

Conclusions:

• Low-dose CT LVEF protocol is feasible and accurate.
• The protocol delivers a lower radiation dose compared to traditional RNA.
• The CT protocol is faster than RNA for LVEF assessment.