Purpose: To evaluate the prevalence of coronary artery disease (CAD) in middle-aged, male marathon runners using coronary dual source CT angiography (DSCTA). Materials and Methods: 50 male marathon runners older than 45 years (mean age: 52.7, standard deviation: 5.9 years, range: 45 to 67 years) received DSCTA including calcium scoring (CS) in addition to standard pre-participation screening. Based on standard risk factors, the risk for coronary events was calculated using the PROCAM score. Coronary status was defined using the following system: 1. absence of CAD (CS zero, no coronary plaques) 2. mild coronary atherosclerosis (CS > 0, coronary plaques with luminal narrowing < 50 %), 3. moderate coronary atherosclerosis (CS > 0, luminal narrowing > 50 %), 4. significant CAD (CS > 0, luminal narrowing > 75 %). Results: The mean PROCAM score was 1.85 % (standard deviation = 1.56, range 0.39 to 8.47 %). 26/50 marathon runners had no atherosclerosis. 1 of the remaining 24 participants had significant CAD, 3 had moderate coronary atherosclerosis and 20 had mild coronary atherosclerosis. Treadmill exercise testing was unremarkable in terms of myocardial ischemia in all participants. Age, systolic blood pressure, personal minimum time, family history of cardiovascular disease and PROCAM score were factors associated with an increased risk for coronary atherosclerosis. Conclusion: Coronary atherosclerosis can be detected in almost 50 % of male marathon runners aged older than 45 years. In 24 % of the participants plaques were located in the proximal coronary system. However, only a minority of these persons have obstructive CAD. As expected, treadmill exercise testing failed to detect these persons that possibly have a higher risk for coronary events. Key points: • Coronary atherosclerosis can be detected in ~50 % of male marathon runners > 45 years • Only a minority of these persons have obstructive CAD • Treadmill exercise testing failed to detect these persons • Cardiac CT might help to identify athletes with elevated risk for coronary events, especially in persons with a family history of coronary artery disease Citation Format: • Tsiflikas I, Thomas C, Fallmann C et al. Prevalence of Subclinical Coronary Artery Disease in Middle-Aged, Male Marathon Runners Detected by Cardiac CT. Fortschr Röntgenstr 2015; 187: 561 – 568 Ziel: Ziel der Studie war die Evaluierung der Prävalenz der KHK bei männlichen Marathonläufern mittleren Alters mittels Dual Source cCTA (DSCTA). Material und Methoden: 50 Marathonläufer (52,7 ± 5,9 Jahre) wurden zusätzlich zur sportmedizinischen Routinediagnostik mittels DSCTA einschließlich Calcium-Scoring (CS) untersucht. Das CS wurde bei allen Personen im high-pitch-Modus (hpDSCTA), die CTA bei 21 Personen im hpDSCTA und 29 Personen im sequentiellen „step-and-shot“-Modus (sDSCTA) durchgeführt. Die effektive Dosis (ED) wurde für beide Scanverfahren bestimmt. Der Risikofaktor für koronare Ereignisse wurde basierend auf Standardrisikofaktoren mittels des PROCAM-Scores berechnet. Der Koronarstatus wurde wie folgt klassifiziert: 1. keine KHK (CS = 0, keine Koronarplaques), 2. milde Koronarsklerose (CS> 0, Stenose < 50 %), 3. moderate Koronarsklerose (CS > 0, Stenose > 50 %) 4. signifikante KHK (CS > 0, Stenose > 75 %). Ergebnisse: Der mediane PROCAM-Score betrug 1,85 ± 1,56 %. 26 von 50 Marathonläufern hatten keine KHK. 1 Person hatte eine signifikante KHK, 3 Personen eine moderate sowie 20 eine milde Koronarsklerose. Die Laufband-Ergometrie konnte bei keinem Sportler Koronarischämien nachweisen. Als Faktoren für ein erhöhtes KHK-Risiko konnten Alter, Blutdruck, persönliche Mindestzeit, familiäre Anamnese und der PROCAM-Score identifiziert werden. Die mediane ED für die DSCTA lag bei 1,259 ± 0,542 mSv. Bei der hpDSCTA war die ED im Vergleich zur sDSCTA signifikant niedriger (0,762 vs. 1,618 mSv, p < 0,0001). Schlussfolgerung: Bei fast 50 % der asymptomatischen Marathonläufer über 45 Jahren kann mittels cCTA eine Koronarsklerose nachgewiesen werden. Bei 24 % dieser Probanden waren die Plaques in den proximalen Abschnitten der Koronararterien lokalisiert. Tatsächlich leidet jedoch nur ein kleiner Anteil dieser Personen an einer obstruktiven KHK.Die Laufband-Ergometrie kann wie erwartet diese Risikopersonen für koronare Ereignisse nicht erkennen. Kernaussagen: • Koronarsklerose bei ~50 % männlicher Marathonläufer > 45 Jahre • Nur ein kleiner Teil dieser Personen leidet an einer obstruktiven KHK • Auf dem Laufbandergometer können diese Risikopersonen nicht erkannt werden • Kardio-CT mögliche Hilfe bei der Detektion der Athleten mit erhöhtem koronaren Risiko, insbesondere bei familiärem Risikoprofil

(1) Background: To evaluate the effects of an AI-based denoising post-processing software solution in low-dose whole-body computer tomography (WBCT) stagings; (2) Methods: From 1 January 2019 to 1 January 2021, we retrospectively included biometrically matching melanoma patients with clinically indicated WBCT staging from two scanners. The scans were reconstructed using weighted filtered back-projection (wFBP) and Advanced Modeled Iterative Reconstruction strength 2 (ADMIRE 2) at 100% and simulated 50%, 40%, and 30% radiation doses. Each dataset was post-processed using a novel denoising software solution. Five blinded radiologists independently scored subjective image quality twice with 6 weeks between readings. Inter-rater agreement and intra-rater reliability were determined with an intraclass correlation coefficient (ICC). An adequately corrected mixed-effects analysis was used to compare objective and subjective image quality. Multiple linear regression measured the contribution of “Radiation Dose”, “Scanner”, “Mode”, “Rater”, and “Timepoint” to image quality. Consistent regions of interest (ROI) measured noise for objective image quality; (3) Results: With good–excellent inter-rater agreement and intra-rater reliability (Timepoint 1: ICC ≥ 0.82, 95% CI 0.74–0.88; Timepoint 2: ICC ≥ 0.86, 95% CI 0.80–0.91; Timepoint 1 vs. 2: ICC ≥ 0.84, 95% CI 0.78–0.90; all p ≤ 0.001), subjective image quality deteriorated significantly below 100% for wFBP and ADMIRE 2 but remained good–excellent for the post-processed images, regardless of input (p ≤ 0.002). In regression analysis, significant increases in subjective image quality were only observed for higher radiation doses (≥0.78, 95%CI 0.63–0.93; p < 0.001), as well as for the post-processed images (≥2.88, 95%CI 2.72–3.03, p < 0.001). All post-processed images had significantly lower image noise than their standard counterparts (p < 0.001), with no differences between the post-processed images themselves. (4) Conclusions: The investigated AI post-processing software solution produces diagnostic images as low as 30% of the initial radiation dose (3.13 ± 0.75 mSv), regardless of scanner type or reconstruction method. Therefore, it might help limit patient radiation exposure, especially in the setting of repeated whole-body staging examinations.

(1) This study evaluates the impact of an AI denoising algorithm on image quality, diagnostic accuracy, and radiological workflows in pediatric chest ultra-low-dose CT (ULDCT). (2) Methods: 100 consecutive pediatric thorax ULDCT were included and reconstructed using weighted filtered back projection (wFBP), iterative reconstruction (ADMIRE 2), and AI denoising (PixelShine). Place-consistent noise measurements were used to compare objective image quality. Eight blinded readers independently rated the subjective image quality on a Likert scale (1 = worst to 5 = best). Each reader wrote a semiquantitative report to evaluate disease severity using a severity score with six common pathologies. The time to diagnosis was measured for each reader to compare the possible workflow benefits. Properly corrected mixed-effects analysis with post-hoc subgroup tests were used. Spearman’s correlation coefficient measured inter-reader agreement for the subjective image quality analysis and the severity score sheets. (3) Results: The highest noise was measured for wFBP, followed by ADMIRE 2, and PixelShine (76.9 ± 9.62 vs. 43.4 ± 4.45 vs. 34.8 ± 3.27 HU; each p < 0.001). The highest subjective image quality was measured for PixelShine, followed by ADMIRE 2, and wFBP (4 (4–5) vs. 3 (4–5) vs. 3 (2–4), each p < 0.001) with good inter-rater agreement (r ≥ 0.790; p ≤ 0.001). In diagnostic accuracy analysis, there was a good inter-rater agreement between the severity scores (r ≥ 0.764; p < 0.001) without significant differences between severity score items per reconstruction mode (F (5.71; 566) = 0.792; p = 0.570). The shortest time to diagnosis was measured for the PixelShine datasets, followed by ADMIRE 2, and wFBP (2.28 ± 1.56 vs. 2.45 ± 1.90 vs. 2.66 ± 2.31 min; F (1.000; 99.00) = 268.1; p < 0.001). (4) Conclusions: AI denoising significantly improves image quality in pediatric thorax ULDCT without compromising the diagnostic confidence and reduces the time to diagnosis substantially.

Objectives: Computed tomography (CT) imaging of the clavicula displays the reference standard for forensic bone age diagnostics in adolescents and young adults. Consequently, highest efforts on radiation reduction are warranted. Therefore, the aim of this study was to investigate the feasibility of low-dose (LD) CT imaging of the clavicula for age estimation in living adolescents. Methods: A total of 207 non-contrast chest CT of 144 patients born between 1988 and 2012, performed in 2018 due to various clinical indications, were included in this retrospective study. The mean patient age was 16.9 ± 6.6 years. Patients were divided into a LD (n = 146) and standard-dose (SD; n = 61) group. Image quality, confidence levels, and ossification stages (using the 5-stage classification including the subgroups 2a–3c) were assessed by two radiologists independently. Radiation dose was determined via dosimetry software. Results: Dose simulation with z-axis reduction to depict the clavicula only resulted in a median exposure of 0.1 mSv (IQR: 0.0) in LD compared with 0.9 mSv (IQR: 0.6) in SD (p < 0.001). The median image quality was rated by both readers significantly worse in LD compared with SD on a Likert scale ranging from 1 to 4 with a median of 3 (IQR: 1) versus 4 (IQR: 0; p < 0.001 for both readers). There was an almost perfect agreement for the ossification stages between both readers with a Cohen’s kappa of 0.83 (p < 0.001). Median confidence levels of both readers were not significantly different between LD and SD in the decisive subgroups 2a–3c. Conclusions: Low-dose CT imaging of the clavicula for age estimation in living adolescents is possible without loss of readers’ confidence. Key Points: • Radiological bone age diagnostics in young delinquents with unknown exact chronological age is important as the judicial systems differentiate between youths and adults. • Low-dose computed tomography scanning of the medial clavicular joint for forensic age estimation is feasible in living adolescents without loss of readers’ confidence. • Sufficient image quality of the medial clavicular joint for forensic bone age diagnostics in living adolescents is achievable using a median dose of 0.1 mSv.