Catherine D'Helft BSc, Presenter: Nothing to Disclose

Allison Mc Gee, Abstract Co-Author: Nothing to Disclose

Louise Ann Rainford PhD, Abstract Co-Author: Nothing to Disclose

Sonyia Lorraine Mc Fadden MS, Abstract Co-Author: Nothing to Disclose

John Winder, Abstract Co-Author: Nothing to Disclose

Patrick C. Brennan PhD, Abstract Co-Author: Nothing to Disclose

Ciara Hughes DPhil, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

Radiological interventional procedures in cardiology are becoming increasingly common in the Western World, with approximately 5 million procedures being performed each year in the U.S. alone. Since skin injuries are often reported due to long fluoroscopic exposures, procedural and technical optimization often focuses on dose rather than image quality (IQ). Certain cardiovascular lesions are subtle and often occur within large patients and also require clear visualization for diagnosis and assessment. The current investigation explores ways of improving IQ whilst keeping radiation doses below deterministic threshold levels.

IQ was analyzed using the NEMA cardiology phantom, assessing spatial & dynamic resolution, low-contrast iodine detectability and working thickness range. The impact of various procedural factors such as frame rate, magnification, dose mode and radiation grid employment on IQ were quantified. Both screening and cine radiation doses were recorded for each variable using a calibrated DAP and Unfors PSD reader.

High magnification and high dose mode were associated with high spatial and dynamic resolution scores. Low contrast iodine detection was highest when a secondary radiation grid was employed and images were recorded at 30 frames per second. Working thickness range was best without a secondary grid and at higher levels of magnification. Unfortunately variables such as higher magnification & frame rates which are associated with superior IQ also demonstrated increased dose levels.

The data provided demonstrate ways for enhancing IQ in a parameter-specific way. Whilst recommendations for significant improvement in quality scores are relatively straightforward, such recommendations are often associated with high radiation doses making optimization strategies difficult to implement. This IQ/dose dilemma is well established in radiology, but this work presents a method for defining optimized protocols using the current findings and published sub-deterministic threshold data.

The current work identifies methods in which IQ can be maximized whilst keeping radiation doses below levels which would result in deterministic effects.

D'Helft, C, Mc Gee, A, Rainford, L, Mc Fadden, S, Winder, J, Brennan, P, Hughes, C, et al, , et al, , Enchancing Image Quality for Cardiac Interventional Procedures.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5006897.html