Quantitative analysis of blooming artifact caused by calcification based on X-ray energy difference using computed...

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Blooming artifacts in computed tomography (CT) images, caused by coronary artery calcifications, can lead to inaccurate lumen size measurements.
• Higher X-ray energy levels have been subjectively suggested to mitigate these artifacts.

Purpose of the Study:

• To quantitatively evaluate the impact of varying X-ray energy levels (kilovoltage peak [kVp] and kilo-electron volts [keV]) on reducing blooming artifacts adjacent to coronary calcifications in CT images.

Main Methods:

• A two-part study involving phantom and clinical data acquisition using dual-energy CT scanners.
• Quantitative measurement of adjacent pixels affected by calcification using the full width at third maximum (FWFM) method.
• Analysis of changes in brightened length (excluding actual calcified length) across different kVp and keV settings.

Main Results:

• Neither changes in kVp nor keV levels significantly reduced the number of adjacent pixels affected by calcification in clinical studies.
• Phantom studies showed varied effects of keV changes across different vendors, with some showing no significant difference, increases, or decreases in affected pixels.
• Quantitative measurements indicated no significant relationship between higher X-ray energy levels and a reduction in adjacent pixels affected by calcification.

Conclusions:

• Higher X-ray energy levels, specifically adjustments in kVp and keV, do not significantly reduce blooming artifacts adjacent to coronary calcifications on CT scans.
• The quantitative findings contradict subjective assessments, suggesting that manipulating X-ray energy alone may not be an effective strategy for improving the accuracy of coronary artery lumen measurements in the presence of calcifications.