Author + information
- Shikhar Agarwal,
- Akhil Parashar,
- Imran Khan,
- Navkaranbir Bajaj,
- Dhruv Modi,
- Matthew Bunte,
- E. Murat Tuzcu and
- Samir Kapadia
Radiation scatter (RS) in the catheterization laboratory is a function of beam angulation, among other factors. RS is an important determinant of total radiation dose, although has undergone limited clinical study. To model radiation dosimetry during diagnostic catheterization (DC) and percutaneous coronary intervention (PCI), we created spatial maps to predict how beam angulation affects dose scatter during fluoroscopy and cine-acquisition (cine).
Prospectively captured radiation acquisition data were extracted from an institutional database of 1975 DC and 755 PCI procedures that included 138,342 fluoroscopic and 35,440 cine sequences. Total radiation dose per second at the standard interventional reference point (15 cm below isocenter) was used as the surrogate for total RS. Fluoroscopy and cine sequences were categorized into tertiles based on the radiation dose. Radiation maps were modeled according to the relative proportion of exposure in each projection.
The median dose during DC and PCI was 677 mGy and 2188 mGy, respectively. Fluoroscopy contributed to 66.3% of total dose during DC as compared to 39.7% during PCI (p<0.001). Fluoroscopy was more sensitive to changes in angulation with rapid increase in RS on small increases in beam angulation. High-dose acquisitions associated with specific beam projections (high radiation zones) differed between fluoroscopy and cine. The LAO caudal and RAO caudal projections produced the largest RS during cine. Most acquisitions during fluoroscopy were performed in low or medium scatter zones. Only 7.9% of the fluoroscopic acquisition was in the high radiation zone (Straight LAO >40 degrees). Complex spatial maps were created to study the impact of angulation and other covariates upon total radiation scatter, with a good predictive accuracy (R2=0.81). Besides beam angulation, body surface area was the strongest predictor of the total RS
High-dose acquisitions occurred at extreme angulations. Radiation dose delivered by fluoroscopy was more sensitive to change in beam angulation compared to cine acquisition. Body surface area was a strong secondary predictor of total RS.
Poster Sessions, Expo North
Sunday, March 10, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Contemporary Issues in Cath Lab Performance
Abstract Category: 22. Performance Improvement
Presentation Number: 1218-272
- 2013 American College of Cardiology Foundation