The current method of quantifying coronary calcium (CC) with intravascular ultrasound (IVUS) measures the arc of calcium from the 2-dimensional (2D) cross-sectional image at the lesion site. Unfortunately, the 2D method neglects calcification at other sites within the artery and may not adequately represent the degree of total CC. We therefore used a new method, which has previously been pathologically validated, to quantify CC as a percent of the luminal surface area and compared it to the current 2D method. IVUS was performed with a motorized pullback and 2D images were digitized every 1 mm. Total and calcified luminal circumference was measured and, using Simpson's method, the total luminal and calcified luminal surface area was calculated. Standard 2D analysis of calcium arc was performed independently. Results: Pre-interventional IVUS was performed in 41 arteries in 40 pts (33 males, 7 females; 58.3±10.2 years) for a total of 2348 cross-sectional images analyzed. Calcified target lesions were detected in 16/41 coronaries (39%) with an average arc of 79.7±12.0 degrees; 18 of the remaining 25 (72%) had calcium elsewhere. There was no relationship (p=ns) between arc of calcium and either absolute calcified luminal surface area (46.1±45.0 mm2) or relative calcified surface area (7.8±8.0%). 2D calcium quantification underestimated total CC content in 23/40 (58%) pts but paradoxically overestimated calcification in 12 of the 16 (75%) pts with calcified lesions. Conclusions: Presence of lesion calcium does not predict calcification elsewhere nor does its arc adequately quantify the extent of coronary calcification. Calcified luminal surface area is an improved IVUS method that accurately quantifies total arterial calcification.
|Original language||English (US)|
|Number of pages||1|
|Journal||Journal of the American Society of Echocardiography|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine