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Objective Preoperative chest radiograph screening is widely used before cardiac surgery. The objective of this study was to investigate the frequency of abnormal findings on a routine chest radiograph before cardiac surgery. Methods In this retrospective cohort study, 1136 patients were included. Patients were scheduled for cardiac surgery and underwent a preoperative chest radiograph. The primary outcome was the frequency of abnormalities on the chest radiograph. Secondary outcome was the effect of those abnormalities on surgery. Results One half of the patients (570/1136; 50%) had 1 or more abnormalities on the chest radiograph. Most frequent abnormalities were cardiomegaly, aortic elongation, signs of chronic obstructive pulmonary disease, vertebral fractures or height loss, possible pulmonary or mediastinal mass, pleural effusion, and atelectasis. In 2 patients (2/1136; 0.2%), the chest radiograph led to postponement of surgery, whereas in none of the patients the surgery was cancelled. In 1 patient (1/1136; 0.1%) the surgical approach was altered and in 15 patients (15/1136; 1.3%) further analysis was performed without having an impact on the planned surgical approach. Conclusions Although abnormalities are frequently found on preoperative chest radiographs before cardiac surgery, change in clinical management with regard to planned surgery or surgical approach occurs infrequently. [ABSTRACT FROM AUTHOR]

Background Stroke after cardiac surgery is a severe complication with a persistently high incidence of 1.4 – 9.7%. Postoperative strokes are mainly embolic and can be provoked by manipulation and clamping of the aorta during cardiac surgery, resulting in the mobilization of atherothrombotic material and calcifications from the aortic wall. Computed tomography (CT) can offer preoperative visualization of aortic calcifications with low radiation exposure. We hypothesize that preoperative knowledge regarding the location and extent of aortic calcifications can be used to optimize surgical strategy and decrease postoperative stroke rate. Methods/design The CRICKET study (ultra low-dose chest CT with iterative reconstructions as an alternative to conventional chest x-ray prior to heart surgery) is a prospective multicenter randomized clinical trial to evaluate whether non-contrast chest CT before cardiac surgery can decrease postoperative stroke rate by optimizing surgical strategy. Patients scheduled to undergo cardiac surgery aged 18 years and older are eligible for inclusion. Exclusion criteria are pregnancy, a chest/cardiac CT in the past three months, emergency surgery, concomitant or prior participation in a study with ionizing radiation and unwillingness to be informed about incidental findings. Subjects (n = 1.724) are randomized between routine care, including a chest x-ray, or routine care with an additional low dose chest CT. The primary objective is to investigate whether the postoperative in-hospital stroke rate is reduced in the CT arm compared to the routine care arm of the randomized trial. The secondary outcome measures are altered surgical approach based on CT findings and cost-effectiveness. [ABSTRACT FROM AUTHOR]

Objective To assess the maximally achievable computed tomography (CT) dose reduction for coronary artery calcium (CAC) scoring with iterative reconstruction (IR) by using phantom-experiments and a systematical within-patient study. Methods Our local institutional review-board approved this study and informed consent was obtained from all participants. A phantom and patient study were conducted with 30 patients (23 men, median age 55.0 (52.0–56.0) years) who underwent 256-slice electrocardiogram-triggered CAC-scoring at four dose levels (routine, 60%, 40%, and 20%-dose) in a single session. Tube-voltage was 120 kVp, tube-current was lowered to achieve stated dose levels. Data were reconstructed with filtered back-projection (FBP) and three IR levels. Agatston, volume and mass scores were determined with validated software and compared using Wilcoxon signed ranks-tests. Subsequently, patient reclassification was analyzed. Results The phantom study showed that Agatston scores remained nearly stable with FBP between routine-dose and 40%-dose and increased substantially at lower dose. Twenty-three patients (77%) had coronary calcifications. For Agatston scoring, one 40%-dose and six 20%-dose FBP reconstructions were not interpretable due to noise. In contrast, with IR all reconstructions were interpretable. Median Agatston scores increased with FBP from 26.1 (5.2–192.2) at routine-dose to 60.5 (11.6–251.7) at 20% dose. However, IR lowered Agatston scores to 22.9 (5.9–195.5) at 20%-dose and strong IR (level 7) with Agatston reclassifications in 15%. Conclusion IR allows for CAC-scoring radiation dose reductions of up to 80% resulting in effective doses between 0.15 and 0.18 mSv. At these dose-levels, reclassification-rates remain within 15% if the highest IR-level is applied. [ABSTRACT FROM AUTHOR]

Objective To evaluate the effect of chest size on coronary calcium score (CCS) as assessed with new-generation CT systems from 4 major vendors. Methods An anthropomorphic, small-sized (300 × 200 mm) chest phantom containing 100 small calcifications (diameters, 0.5–2.0 mm) was evaluated with and without an extension ring on state-of-the-art CT systems from 4 vendors. The extension ring was used to mimic a patient with a large chest size (400 × 300 mm). Image acquisition was repeated 5 times with small translations and/or rotations. Routine clinical acquisition and reconstruction protocols for small and large patients were used. CCS was quantified as Agatston and mass scores with vendor software. Results The small-sized phantom resulted in median (interquartiles) Agatston scores of 10 (9–35), 136 (123–146), 34 (30–37), and 87 (85–89) for Philips, GE, Siemens, and Toshiba, respectively. Mass scores were 4 mg (3–9 mg), 23 mg (21–27 mg), 8 mg (8–9 mg), and 20 mg (20–20 mg), respectively. Adding the extension ring resulted in reduced Agatston scores for all vendors (17%–48%) and mass scores for 2 vendors (11%–49%). Median Agatston scores decreased to 9 (5–10), 79 (60–80), 27 (24–32), and 45 (29–53) units, and median mass scores remained similar for Philips at 4 mg (4–6 mg) and Siemens at 8 mg (7–8 mg) and decreased for the other vendors to 13 mg (11–14 mg) and 10 mg (8–13 mg), respectively. Conclusion This multivendor phantom study showed that CCS can be underestimated up to 50% (49%–66%) for Agatston scores and 49% (36%–59%) for mass scores at a larger chest size, which may be relevant for women and large patients. However, CCS underestimation by chest size differs considerably by vendor. [ABSTRACT FROM AUTHOR]