High-pitch low-voltage CT coronary artery calcium scoring with tin filtration: accuracy and radiation dose reduction.
OBJECTIVES
To investigate diagnostic accuracy and radiation dose of high-pitch CT coronary artery calcium scoring (CACS) with tin filtration (Sn100kVp) versus standard 120kVp high-pitch acquisition.


METHODS
78 patients (58% male, 61.5±9.1 years) were prospectively enrolled. Subjects underwent clinical 120kVp high-pitch CACS using third-generation dual-source CT followed by additional high-pitch Sn100kVp acquisition. Agatston scores, calcium volume scores, Agatston score categories, percentile-based risk categorization and radiation metrics were compared.


RESULTS
61/78 patients showed coronary calcifications. Median Agatston scores were 34.9 [0.7-197.1] and 41.7 [0.7-207.2] and calcium volume scores were 34.1 [0.7-218.0] for Sn100kVp and 35.7 [1.1-221.0] for 120kVp acquisitions, respectively (both p<0.0001). Bland-Altman analysis revealed underestimated Agatston scores and calcium volume scores with Sn100kVp versus 120kVp acquisitions (mean difference: 16.4 and 11.5). However, Agatston score categories and percentile-based risk categories showed excellent agreement (ĸ=0.98 and ĸ=0.99). Image noise was 25.8±4.4HU and 16.6±2.9HU in Sn100kVp and 120kVp scans, respectively (p<0.0001). Dose-length-product was 9.9±4.8mGy*cm and 40.9±14.4mGy*cm with Sn100kVp and 120kVp scans, respectively (p<0.0001). This resulted in significant effective radiation dose reduction (0.13±0.07mSv vs. 0.57±0.2mSv, p<0.0001) for Sn100kVp acquisitions.


CONCLUSION
CACS using high-pitch low-voltage tin-filtered acquisitions demonstrates excellent agreement in Agatston score and percentile-based cardiac risk categorization with standard 120kVp high-pitch acquisitions. Furthermore, radiation dose was significantly reduced by 78% while maintaining accurate risk prediction.


KEY POINTS
• Coronary artery calcium scoring with tin filtration reduces radiation dose by 78%. • There is excellent correlation between high-pitch Sn100kVp and standard 120kVp acquisitions. • Excellent agreement regarding Agatston score categories and percentile-based risk categorization was achieved. • No cardiac risk reclassifications were observed using Sn100kVp coronary artery calcium scoring.
['Apfaltrer|Georg|G|', 'Albrecht|Moritz H|MH|', 'Schoepf|U Joseph|UJ|http://orcid.org/0000-0002-6164-5641', 'Duguay|Taylor M|TM|', 'De Cecco|Carlo N|CN|', 'Nance|John W|JW|', 'De Santis|Domenico|D|', 'Apfaltrer|Paul|P|', 'Eid|Marwen H|MH|', 'Eason|Chelsea D|CD|', 'Thompson|Zachary M|ZM|', 'Bauer|Maximilian J|MJ|', 'Varga-Szemes|Akos|A|', 'Jacobs|Brian E|BE|', 'Sorantin|Erich|E|', 'Tesche|Christian|C|']
D000368:Aged D002114:Calcinosis D002118:Calcium D017023:Coronary Angiography D003324:Coronary Artery Disease D005260:Female D005374:Filtration D006801:Humans D008297:Male D008875:Middle Aged D011379:Prognosis D011446:Prospective Studies D011829:Radiation Dosage D011857:Radiographic Image Interpretation, Computer-Assisted D015203:Reproducibility of Results D018570:Risk Assessment D014001:Tin D014057:Tomography, X-Ray Computed
High-pitch Coronary artery calcium Tin filtration Radiation dose Computed tomography