Images come out of one of two algorithm families:
- Filtered Back Projection (FBP). Analytical, fast, the historical default.
- Iterative Reconstruction. Dramatically lower image noise at the same dose — enabling lower kV/mA protocols.
Standard reformats:
- MPR — Multiplanar Reformatted images
- MIP — Maximum Intensity Projection (tracks bright vessels)
- MinIP — Minimum Intensity Projection (visualizes valves / thrombus)
- CPR — Curved Multiplanar Reconstruction (bends a vessel into one straight plane)
1 Common artifacts
- Motion (stepoff) artifact. A break or “step” in the vessel due to cardiac motion. Fix: reconstruct at a different cardiac phase.
- Breathing artifact. Unlike stepoff, breathing artifacts will noticeably misalign the sternum as well as the heart. Fix: rescan.
- Beam hardening & streak. Caused by extremely dense materials (calcium, pacemaker leads) absorbing all low-energy photons. Appears as dark hypoattenuated spots and bright radial streaks.
- Blooming. Calcium volume averaging makes bright plaques visually “bloom,” causing readers to overestimate stenosis severity. Fix: thinner slices, wider windowing, sharper kernels.