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Subject-specific parameters in lumped hemodynamic models of the cardiovascular system can be estimated using data from experimental measurements, but the parameter estimation may be hampered by the variability in the input data. In this study, we investigate the influence of inter-sequence, intra-observer, and inter-observer variability in input parameters on estimation of subject-specific model parameters using a previously developed approach for model-based analysis of data from 4D Flow MRI acquisitions and cuff pressure measurements. The investigated parameters describe left ventricular time-varying elastance and aortic compliance. Parameter reproducibility with respect to variability in the MRI input measurements was assessed in a group of ten healthy subjects. The subject-specific parameters had coefficient of variations between 2.6 and 35% in the intra- and inter-observer analysis. In comparing parameters estimated using data from the two MRI sequences, the coefficients of variation ranged between 3.3 and 41%. The diastolic time constant of the left ventricle and the compliance of the ascending aorta were the parameters with the lowest and the highest variability, respectively. In conclusion, the modeling approach allows for estimating left ventricular elastance parameters and aortic compliance from non-invasive measurements with good to moderate reproducibility concerning intra-user, inter-user, and inter-sequence variability in healthy subjects., Competing Interests: Declarations. Competing interests: The authors declare that they have no competing financial interests. Ethical approval: This study was carried out in accordance with the recommendations of the Regional Ethical Review Board in Linköping, with written informed consent from all subjects. All subjects gave written informed consent in accordance with the Declaration of Helsinki. The protocol was approved by the Regional Ethical Review Board in Linköping (Dnr 2015/396-31)., (© 2025. The Author(s).)

Purpose: To report the clinical course and the retinal imaging features of a case of cytology-proven primary vitreoretinal lymphoma (PVRL) presenting with a transient bacillary layer detachment (BALAD) during the disease course., Methods: Observational case report., Results: A 50 year-old woman was referred to us with a 2-month history of vitritis in both eyes, poorly responding to oral prednisolone. After discontinuation of oral prednisolone, worsening of vitritis and the appearance of multiple creamy-like subretinal infiltrates in the mid-peripheral retina of both eyes, along with the exclusion of common causes of intermediate/posterior uveitis, made us consider PVRL. Aqueous humor sampling detected MYD88 L265P mutation, and subsequent diagnostic pars plana vitrectomy in the left eye yielded a positive cytology for large B cell lymphoma consistent with PVRL. During the disease course, optical coherence tomography of the macula showed a BALAD in the right eye, which resolved during follow-up., Conclusion: Our case indicates that BALAD is a possible rare manifestation of PVRL, and this should be considered in the differential diagnosis process in order to avoid diagnostic delays.