Body mass index-adapted prospective coronary computed tomography angiography. Determining the lowest limit for diagnostic purposes

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• 作者：Waldemar Hosch^a ; ^{waldemar.hosch@med.uni-heidelberg.de} ; Nina P. Hofmann^c ; Dirk Mueller^b ; Johannes Iwan^c ; Gitsios Gitsioudis^c ; Stefan Siebert^a ; Evangelos Giannitsis^c ; Hans U. Kauczor^a ; Hugo A. Katus^c ; Grigorios Korosoglou^c ; ^{gkorosoglou@hotmail.com}
• 关键词：256-Slice computed tomography angiography ; Image quality ; Radiation exposure ; Prospective ECG-triggering ; Ultra-low dose coronary CTA
• 刊名：European Journal of Radiology
• 出版年：2013
• 出版时间：May, 2013
• 年：2013
• 卷：82
• 期：5
• 页码：e232-e239
• 全文大小：788 K

文摘

Purpose

To investigate the value of 4 different protocols for prospectively triggered 256-slice coronary computed tomography angiography (coronary CTA).

Methods

Two hundred and ten patients underwent prospectively triggered coronary CTA for suspected or known coronary artery disease (CAD). Patients with heart rate >75 bps before the scan despite ?-blocker administration and with arrhythmia were excluded. From January to September 2010, 60 patients underwent coronary CTA using a non-tailored protocol (120 kV; 200 mAs) and served as our ¡®control¡¯ group. From September 2010 to April 2012, based on the body mass index (BMI) of the examined patients (BMI subgroups of < 25; 25-28; 28-30, and ¡Ý 30 kg/m²) current tube voltage and tube current were: (1) slightly, (2) moderately or (3) strongly reduced, resulting into the 3 following BMI-adapted acquisition groups: (1) a ¡®standard¡¯ (100/120 kV; 100-200 mAs; n = 50), 2) a ¡®low dose¡¯ (100/120 kV; 75-150 mAs; n = 50), and 3) an ¡®ultra-low dose¡¯ (100/120 kV; 50-100 mAs; n = 50) protocol.

Results

Patients examined using the non-tailored protocol exhibited the highest radiation exposure (3.2 ¡À 0.4 mSv), followed by the standard (1.6 ¡À 0.7 mSv), low-dose (1.2 ¡À 0.6 mSv) and ultra-low dose protocol (0.7 ¡À 0.3 mSv) (radiation savings of 50 % , 63 % and 78 % respectively). Overall image quality was similar with standard dose (1.9 ¡À 0.6) and low-dose (2.0 ¡À 0.5) compared to the non-tailored group (1.9 ¡À 0.5) (p = NS for all). In the ultra-low dose group however, image quality was significant reduced (2.7 ¡À 0.6), p < 0.05 versus all other groups).

Conclusion

Using BMI-adapted low dose acquisitions image quality can be maintained with simultaneous radiation savings of ¡«65 % (dose of ¡«1 mSv). This appears to be the lower limit for diagnostic coronary CTA, whereas ultra-low dose acquisitions result in significant image degradation.