Fabrizio Del Buono MD, Abstract Co-Author: Nothing to Disclose

Davide Ippolito MD, Abstract Co-Author: Nothing to Disclose

Cammillo Roberto Giovanni Leopoldo Talei Franzesi, Abstract Co-Author: Nothing to Disclose

Pietro Andrea Bonaffini MD, Abstract Co-Author: Nothing to Disclose

Davide Fior MD, Presenter: Nothing to Disclose

Sandro Sironi MD, Abstract Co-Author: Nothing to Disclose

To evaluate image quality and radiation dose exposure of low-kV (100KV) CT angiography (CTA) in patients candidate to Transcatheter Aortic Heart Valve Implantation (TAVI), in comparison with standard CT angiography protocol.

A total of 49 patients (18 males; mean age 83.8 years, range 78-90 years), candidate for TAVI, were prospectively enrolled in this study and examined with 256-row scanner (iCT, Philips) with 80mL of iso-osmolar contrast medium volume (350mgI/mL). Twenty-eight patients (group A; 8 males;mean age 83.6 years,range 78-89 years) were evaluated using low-KW (100kV) retrospective ECG-gated protocol, with automated tube current modulation, while 21 patients (group B; 10 male;mean age 84.3 years,range 81-90 years) underwent a standard CTA study (120kV;retrospective ECG-gated protocol;automated tube current modulation). Overall image quality was evaluated using a 4-point scale (4 excellent, 3 good, 2 acceptable, 1 low). Vascular enhancement(HU) was then assessed in each patient by manually drawing on axial arterial images multiple regions of interest (ROIs) in lumen of aortic root, ascending aorta, arch, descending and abdominal aorta, common and external iliac arteries. The radiation dose exposure of both groups, in terms of dose-length product (DLP, mGy*cm), was calculated and all data were compared and statistically analyzed.

On low-kV protocol significant higher mean attenuation values were achieved in all the measurements (aortic root 347+19.78 HU; external iliac arteries 305+18.36 HU) as compared to the standard kV protocol (aortic root 269+23.91 HU; external iliac arteries 226+11.64 HU). There were no significant differences in the image quality evaluation in both groups (groupA 3.7 vs groupB 3.8). Mean DLP of groupA was significantly lower (mean DLP 1600mGy*cm) than in groupB (mean DLP 2044mGy*cm), with an overall radiation dose reduction of 22%.

Low-kV CTA protocol permits to correctly perform TAVI planning with high quality images and significant reduction of radiation dose exposure, as compared to standard CTA protocol.

Low-kV CTA may be a valid imaging tool for the pre-operative assessment of thoraco-abdominal aorta and iliac arteries in patients candidate to TAVI, with a reduced radiation dose exposure.

Del Buono, F, Ippolito, D, Talei Franzesi, C, Bonaffini, P, Fior, D, Sironi, S, Low kV MDCT Angiography for Transcatheter Aortic Valve Implantation (TAVI) Planning: Image Quality and Radiation Dose Exposure.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011057.html