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Objectives To compare the diagnostic performance and radiation exposure of 128-slice dual-source CT coronary angiography (CTCA) protocols to detect coronary stenosis with more than 50 % lumen obstruction. Methods We prospectively included 459 symptomatic patients referred for CTCA. Patients were randomized between high-pitch spiral vs. narrow-window sequential CTCA protocols (heart rate below 65 bpm, group A), or between wide-window sequential vs. retrospective spiral protocols (heart rate above 65 bpm, group B). Diagnostic performance of CTCA was compared with quantitative coronary angiography in 267 patients. Results In group A (231 patients, 146 men, mean heart rate 58 ± 7 bpm), high-pitch spiral CTCA yielded a lower per-segment sensitivity compared to sequential CTCA (89 % vs. 97 %, P  = 0.01). Specificity, PPV and NPV were comparable (95 %, 62 %, 99 % vs. 96 %, 73 %, 100 %, P  > 0.05) but radiation dose was lower (1.16 ± 0.60 vs. 3.82 ± 1.65 mSv, P  < 0.001). In group B (228 patients, 132 men, mean heart rate 75 ± 11 bpm), per-segment sensitivity, specificity, PPV and NPV were comparable (94 %, 95 %, 67 %, 99 % vs. 92 %, 95 %, 66 %, 99 %, P  > 0.05). Radiation dose of sequential CTCA was lower compared to retrospective CTCA (6.12 ± 2.58 vs. 8.13 ± 4.52 mSv, P  < 0.001). Diagnostic performance was comparable in both groups. Conclusion Sequential CTCA should be used in patients with regular heart rates using 128-slice dual-source CT, providing optimal diagnostic accuracy with as low as reasonably achievable (ALARA) radiation dose. Key Points • 128-slice dual-source CT coronary angiography offers several different acquisition protocols. • Randomized comparison of protocols reveals an optimal protocol selection strategy. • Appropriate CTCA protocol selection lowers radiation dose, while maintaining high quality. • CTCA protocol selection should be based on individual patient characteristics. • A prospective sequential protocol is preferred for CTCA.

Objectives To investigate the diagnostic accuracy of CT coronary angiography (CTCA) in women at low to intermediate pre-test probability of coronary artery disease (CAD) compared with men. Methods In this retrospective study we included symptomatic patients with low to intermediate risk who underwent both invasive coronary angiography and CTCA. Exclusion criteria were previous revascularisation or myocardial infarction. The pre-test probability of CAD was estimated using the Duke risk score. Thresholds of less than 30 % and 30–90 % were used for determining low and intermediate risk, respectively. The diagnostic accuracy of CTCA in detecting obstructive CAD (≥50 % lumen diameter narrowing) was calculated on patient level. P  < 0.05 was considered significant. Results A total of 570 patients (46 % women [262/570]) were included and stratified as low (women 73 % [80/109]) and intermediate risk (women 39 % [182/461]). Sensitivity, specificity, PPV and NPV were not significantly different in and between women and men at low and intermediate risk. For women vs. men at low risk they were 97 % vs. 100 %, 79 % vs. 90 %, 80 % vs. 80 % and 97 % vs. 100 %, respectively. For intermediate risk they were 99 % vs. 99 %, 72 % vs. 83 %, 88 % vs. 93 % and 98 % vs. 99 %, respectively. Conclusion CTCA has similar diagnostic accuracy in women and men at low and intermediate risk. Key Points • Coronary artery disease (CAD) is increasingly investigated by computed tomography angiography (CTCA) . • CAD detection or exclusion by CTCA is not different between sexes . • CTCA diagnostic accuracy was similar between low and intermediate risk sex-specific-groups . • CTCA rarely misses obstructive CAD in low–intermediate risk women and men . • CAD yield by invasive coronary angiography after positive CTCA is similar between sex-risk-specific groups .

Objectives To determine the diagnostic performance of CT coronary angiography (CTCA) in detecting and excluding left main (LM) and/or three-vessel CAD (“high-risk” CAD) in symptomatic patients and to compare its discriminatory value with the Duke risk score and calcium score. Materials and methods Between 2004 and 2011, a total of 1,159 symptomatic patients (61 ± 11 years, 31 % women) with stable angina, without prior revascularisation underwent both invasive coronary angiography (ICA) and CTCA. All patients gave written informed consent for the additional CTCA. High-risk CAD was defined as LM and/or three-vessel obstructive CAD (≥50 % diameter stenosis). Results A total of 197 (17 %) patients had high-risk CAD as determined by ICA. The sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratios of CTCA were 95 % (95 % CI 91–97 %), 83 % (80–85 %), 53 % (48–58 %), 99 % (98–99 %), 5.47 and 0.06, respectively. CTCA provided incremental value (AUC 0.90, P  < 0.001) in the discrimination of high-risk CAD compared with the Duke risk score and calcium score. Conclusions CTCA accurately excludes high-risk CAD in symptomatic patients. The detection of high-risk CAD is suboptimal owing to the high percentage (47 %) of overestimation of high-risk CAD. CTCA provides incremental value in the discrimination of high-risk CAD compared with the Duke risk score and calcium score. Key Points • Computed tomography coronary angiography ( CTCA ) accurately excludes high - risk coronary artery disease . • CTCA overestimates high - risk coronary artery disease in 47  %. • CTCA discriminates high - risk CAD better than clinical evaluation and coronary calcification .

Objective To investigate the value of the calcium score (CaSc) plus clinical evaluation to restrict referral for CT coronary angiography (CTCA) by reducing the number of patients with an intermediate probability of coronary artery disease (CAD). Methods We retrospectively included 1,975 symptomatic stable patients who underwent clinical evaluation and CaSc calculation and CTCA or invasive coronary coronary angiography (ICA). The outcome was obstructive CAD (≥50 % diameter narrowing) assessed by ICA or CTCA in the absence of ICA. We investigated two models: (1) clinical evaluation consisting of chest pain typicality, gender, age, risk factors and ECG and (2) clinical evaluation with CaSc. Discrimination of the two models was compared. The stepwise reclassification of patients with an intermediate probability of CAD (10–90 %) after clinical evaluation followed by clinical evaluation with CaSc was assessed by clinical net reclassification improvement (NRI). Results Discrimination of CAD was significantly improved by adding CaSc to the clinical evaluation (AUC: 0.80 vs. 0.89, P  < 0.001). CaSc and CTCA could be avoided in 9 % using model 1 and an additional 29 % of CTCAs could be avoided using model 2. Clinical NRI was 57 %. Conclusion CaSc plus clinical evaluation may be useful in restricting further referral for CTCA by 38 % in symptomatic stable patients with suspected CAD. Key Points • CT calcium scores ( CaSc ) could proiritise referrals for CT coronary angiography ( CTCA ) • CaSc provides an incremental discriminatory value of CAD compared with clinical evaluation • Risk stratification is better when clinical evaluation is combined with CaSc • Appropriate use of clinical evaluation and CaSc helps avoid unnecessary CTCA referrals

Inclusive production of D∗ mesons in deep-inelastic ep scattering at HERA is studied in the range 51.25 GeV and |η(D∗)|<1.8. The data sample corresponds to an integrated luminosity of 348 pb−1 collected with the H1 detector. Single and double differential cross sections are measured and the charm contribution \\(F_2^cc\\) to the proton structure function F2 is determined. The results are compared to perturbative QCD predictions at next-to-leading order implementing different schemes for the charm mass treatment and with Monte Carlo models based on leading order matrix elements with parton showers.

The production of jets is studied in deep-inelastic e super(c)p scattering at large negative four momentum transfer squared 150