Summary Background Myocardial native T1 and T2 mapping are promising techniques for quantitative assessment of diffuse myocardial pathologies; however, due to conflicting data regarding normal values, routine clinical implementation of this method is still challenging. Methods To evaluate this situation during daily clinical practice the characteristics of normal values obtained in 60 healthy volunteers who underwent magnetic resonance imaging (MRI) scans on 1.5T and 3T scanners were studied. The T1 modified look-locker inversion recovery (MOLLI; 5(3)3; modified for higher heart rates) and T2 navigator gated black-blood prepared gradient-spin-echo (GraSE) sequences were used. Results While age and body mass index did not affect relaxation times, a gender and heart rate dependency was found showing higher T1 and T2 values in females, whereas at higher heart rates a prolongation of T1 and a shortening of T2 relaxation times was found. Particularly prone to artifacts were T2 measurements at 3T and the inferolateral wall. In the individual setting mean relaxation times for T1 were 995.8 ± 30.9 ms at 1.5T and 1183.8 ± 37.5 ms at 3T and 55.8 ± 2.8 ms at 1.5T and 51.6 ± 3 ms at 3T for T2 indicating a high dependency of reference values on MRI protocol when compared to the literature. Furthermore, as presumed mean T1 and T2 values correlated in the same individual. Conclusions The T1 and T2 relaxation times depend on physiological factors and especially on MRI protocols. Therefore, reference values should be validated individually in every radiological institution before implementing mapping protocols in daily clinical practice. Correlation of mean T1 and T2 values in the same proband at both field strengths indicates intraindividual reproducibility.

BackgroundEvidence on PD-1/PD-L1-directed immune checkpoint inhibitor (ICI) therapy for advanced non-small-cell lung cancer (NSCLC) is mainly based on clinical trials in first- or second-line settings.ObjectiveWe aimed to investigate response and prognostic factors with special regard to third- or later-line therapy.Patients and MethodsWe retrospectively analyzed all patients who had received ICI monotherapy with nivolumab, pembrolizumab, or atezolizumab for advanced NSCLC. Computed tomography evaluations were analyzed using response evaluation criteria in solid tumors (RECIST, version 1.1). Kaplan–Meier analyses were conducted to calculate progression-free (PFS) and overall (OS) survival; the impact of influencing variables was evaluated using uni- and multivariate Cox-regression analyses.ResultsAmong 153 patients (59% men, mean age 66 years), median PFS was 4 months [mo; 95% confidence interval (95% CI) 3–5], OS was 13 mo (10–17), and objective response rate (ORR) was 22%. Therapy line ≥ 3 was associated with significantly inferior PFS (p = 0.003) and OS (p = 0.001). In first-line therapy PFS, OS, and ORR were 7 mo (3–11), 17 mo [9–not evaluable (n.e.)], and 36%; in second-line 4 mo (3–7), 18 mo (13–n.e.) and 19%, and in ≥ third-line 2 mo (1–3), 9 mo (4–12), and 13%. PFS was significantly influenced by PD-L1 expression in first-line therapy (p = 0.006). In ≥ third-line patients, Eastern Cooperative Oncology Group (ECOG) performance status significantly affected PFS and OS (both p < 0.001).ConclusionsThird- or later-line single-agent anti-PD-1/PD-L1 therapy is less efficacious as compared to first- and second-line treatment. In that setting, ECOG performance status predominates known predictors like PD-L1 expression or presence of an alteration in EGFR or ALK.

SummaryBackgroundLeadless pacemaker systems are an important upcoming device in clinical rhythmology. Currently two different products are available with the Micra system (Medtronic) being the most used in the clinical setting to date. The possibility to perform magnetic resonance imaging (MRI) is an important feature of modern pacemaker devices. Even though the Micra system is suitable for MRI, little is yet known about its impact on artifacts within the images.ObjectiveThe aim of our ex vivo study was to perform cardiac MRI to quantify the artifacts and to evaluate if artifacts limit or inhibit the assessment of the surrounding myocardium.MethodsAfter ex vivo implantation of the leadless pacemaker (LP) in a porcine model, hearts were filled with saline solution and fixed on wooden sticks on a plastic container. The model was examined at 1.5 T and at 3 T using conventional sequences and T2 mapping sequences. In addition, conventional X‑rays and computed tomography (CT) scans were performed.ResultsCorrect implantation of the LP could be performed in all hearts. In almost all MRI sequences the right ventricle and the septal region surrounding the (LP) were altered by an artifact and therefore would sustain limited assessment; however, the rest of the myocardium remained free of artifacts and evaluable for common radiologic diagnoses. A characteristic shamrock-shaped artifact was generated which appeared to be even more intense in magnitude and brightness when using 3 T compared to 1.5 T.ConclusionThe use of the Micra system in cardiac MRI appeared to be feasible. In our opinion, it will still be possible to make important clinical cardiac MRI diagnoses (the detection of major ischemic areas or inflammatory processes) in patients using the Micra system. We suggest the use of 1.5 T as the preferred method in clinical practice.

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Assuming that atrial fibrillation (AF) is associated with left atrial remodeling and dysfunction, we hypothesize that left atrial and left atrial appendage ejection fractions (LAEF and LAAEF) are useful and may be more sensitive outcome predictors of pulmonary vein isolation (PVI). Fifty patients who underwent PVI at our institution with available pre-interventional cardiac computed tomography (CT) for procedure planning were included in this retrospective study. The patients were separated into two groups by recurrence and non-recurrence of AF and subgroups of paroxysmal and persistent AF. Semiautomatic volumetric analysis of the left atrium was used to calculate morphological and functional parameters and optimal cut-offs were calculated using the Youden index. LAEF (accuracy 94%, sensitivity 67%) and LAAEF (accuracy 90%, sensitivity 67%) were significantly reduced in patients with AF recurrence (16% vs. 36%, p = 0.00002; 16% vs. 42%, p = 0.000002), and in the subgroup analysis, the functional parameters were independent from AF type (paroxysmal and persistent). With a cut-off of <23% for both LAEF and LAAEF (area under the curve (AUC) 0.94, 95%CI 0.84–0.99 and AUC 0.96, 95%CI 0.86-0.99, respectively), AF recurrence occurred in 77.8%, within a mean follow-up period of 229 days. In conclusion, left atrial function on prior cardiac CT offers useful parameters for predicting AF recurrence after PVI.