Personalization of injection protocols to the individual patient’s blood volume and automated tube voltage selection (ATVS) in coronary CTA

Abstract

PurposeThe aim was to assess personalised contrast media (CM) protocols—based on patient’s blood volume (BV) and automated tube voltage selection (ATVS)—in coronary computed tomography angiography (CCTA).MethodsA total of 114 consecutive patients received an ECG-triggered or ECG-gated helical scan on a 3rd-generation dual-source CT with 70-120kV (ATVS) and 330mAsqual.ref. CM was adapted to BV, scan time (s) and kV. Image quality (IQ) was assessed in a 17-segment coronary model using attenuation values (HU), contrast-to-noise (CNR), signal-to-noise ratio (SNR) (objective IQ) and a Likert scale (subjective IQ: 1 = poor/2 = sufficient/3 = good/4 = excellent). igResultsPatient distribution was: n = 60 for 70kV, n = 37 80kV and n = 17 90kV. Mean BV was 5.4±0.6L for men and 4.1±0.6L for women. Mean CM volume (300 mg I/mL) and flow rate were: 30.9±6.4mL and 3.3±0.5mL/s (70kV); 40.8±7.1mL and 4.5±0.6mL/s (80kV); 53.6±8.6mL and 5.7±0.6mL/s (90kV). Overall mean HU was >300HU in 98.2% (112/114) of patients. Overall mean attenuation was below 300HU in two scans (70kV) due to late scan timing. Of 1.661 segments, 95.4% was assessable. Mean CNR was 14±4(70kV), 13±3(80kV) and 14±4(90kV); mean SNR was 10±2(both 70kV+80kV) and 9±2(90kV). Objective IQ was comparable between kV settings, protocols and sex. Subjective IQ was diagnostic in all scans and excellent-sufficient in 95.4% of segments.ConclusionsPersonalisation of CCTA CM injection protocols to BV and ATVS is a promising technique to tailor CM administration to the individual patient, while maintaining diagnostic IQ.

Personalization of CM Injection Protocols in Coronary Computed Tomographic Angiography (People CT Trial)

“…Patients were randomized and enrolled in one of three CM injection protocols (Group 1: group BW; Group 2: group LBW; Group 3: group CO) with tailored flow rates and consequtively tailored IDRs. e injection protocols were defined with help of a formula, which has been explained extensively elsewhere [20] and can be found in Appendix 1. Besides personalization to these patient characteristics, the injection protocol was adapted to the tube voltage, as described in previous studies [21][22][23][24][25].…”

Contrast medium administration with a body surface area protocol in step-and-shoot coronary computed tomography angiography with dual-source scanners

“…Step-and-shoot acquisition has advantages over high-pitch scanning, due to the more relaxed heart rate limits 9,16,22 . as well as over retrospective ECG-gated scanning, due to its lower radiation dose [37][38][39] .…”

“…The use of iodinated contrast medium (CM) provides sufficient vessel attenuation to allow proper evaluation of blood vessel lesions 6,7 . However, with the increase in the number of examinations, the use of iodinated CM for CCTA has become a concern, as it may lead to contrast-induced nephropathy (CIN) [8][9][10][11] , and CM remaining in the right cardiac cavity after the scan is not useful. Although the relationship between CCTA and the development of CIN is under debate, elderly patients with cardiac disease are considered at risk of developing CIN 9,12 .…”

“…However, with the increase in the number of examinations, the use of iodinated CM for CCTA has become a concern, as it may lead to contrast-induced nephropathy (CIN) 8 – 11 , and CM remaining in the right cardiac cavity after the scan is not useful. Although the relationship between CCTA and the development of CIN is under debate, elderly patients with cardiac disease are considered at risk of developing CIN 9 , 12 . With the appearance of CT scanners with faster gantry rotation (≤ 350 ms) and wider coverage, scan duration is now shorter, which allows adjustment of the protocol for CM administration 9 , 10 , 13 – 16 .…”

“…Although the relationship between CCTA and the development of CIN is under debate, elderly patients with cardiac disease are considered at risk of developing CIN 9 , 12 . With the appearance of CT scanners with faster gantry rotation (≤ 350 ms) and wider coverage, scan duration is now shorter, which allows adjustment of the protocol for CM administration 9 , 10 , 13 – 16 .…”