Cine-MRI for adhesion detection is a promising novel modality that can help the large group of patients developing pain after abdominal surgery. Few studies into its diagnostic accuracy are ...available, and none address observer variability. This retrospective study explores the inter- and intra-observer variability, diagnostic accuracy, and the effect of experience. A total of 15 observers with a variety of experience reviewed 61 sagittal cine-MRI slices, placing box annotations with a confidence score at locations suspect for adhesions. Five observers reviewed the slices again one year later. Inter- and intra-observer variability are quantified using Fleiss' (inter) and Cohen's (intra) κ and percentage agreement. Diagnostic accuracy is quantified with receiver operating characteristic (ROC) analysis based on a consensus standard. Inter-observer Fleiss' κ values range from 0.04 to 0.34, showing poor to fair agreement. High general and cine-MRI experience led to significantly (
< 0.001) better agreement among observers. The intra-observer results show Cohen's κ values between 0.37 and 0.53 for all observers, except one with a low κ of -0.11. Group AUC scores lie between 0.66 and 0.72, with individual observers reaching 0.78. This study confirms that cine-MRI can diagnose adhesions, with respect to a radiologist consensus panel and shows that experience improves reading cine-MRI. Observers without specific experience adapt to this modality quickly after a short online tutorial. Observer agreement is fair at best and area under the receiver operating characteristic curve (AUC) scores leave room for improvement. Consistently interpreting this novel modality needs further research, for instance, by developing reporting guidelines or artificial intelligence-based methods.
Abstract
Funding Acknowledgements
Type of funding sources: Public hospital(s). Main funding source(s): HUS diagnostic imaging center
Aims
Subclinical myocardial disease is common in patients with ...rheumatoid arthritis (RA). Impaired cardiac function, myocardial fibrosis and inflammation have previously correlated with RA disease activity. Our aim was to study whether myocardial changes are detectable by cardiac magnetic resonance (CMR) at the time of RA diagnosis.
Material and methods: We recruited 21 untreated early RA patients without history of heart disease in Helsinki University Hospital and Lohja Hospital (Finland) between 10/2018 and 2/2020, and nine healthy volunteers. The patients underwent a clinical examination, laboratory tests, and CMR including mapping of extracellular volume fraction (ECV), and T1 and T2 relaxation times. The healthy controls underwent non-contrast CMR.
Results
The RA patients were older than the controls (median 58.1 years vs. 41.6 years, respectively, table 1.). T1 was slightly higher in RA patients compared with healthy controls in anteroseptal segments (1015 ms vs. 982 ms, P = 0.017) (table 2). No difference in T2 was detected and the ECV values were considered normal. Segmental T1, T2 or ECV showed no significant correlations with age, duration of the symptoms or with RA disease activity (DAS28-CRP score).
Conclusions
The minor, but statistically significant, elevation of T1 relaxation time in the anteroseptal segments suggests that myocardial changes may occur already in the early phase of RA, the anteroseptal segments being most vulnerable. The elevation of T1 relaxation time can be caused by mild myocardial inflammation or fibrosis. Although no significant correlation with DAS28-CRP was observed, subclinical systemic inflammation may have contributed to the myocardial abnormalities.
Table 1. Pre-contrast T1 relaxation time (ms) T2 relaxation time (ms) ECV (%) Mean RA patients Controls P-value RA patients Controls P-value RA patients Global myocardial mean 996 (978-1011) 982 (964-1000) 0.304 48.0 (44.6-49.7) 46.3 (44.1-48.7) 0.295 26.6 (25.7-28.5) Anterior segments 954 (919-1000) 951 (921-998) 0.929 47.7 (46.4-49.8) 47.9 (43.5-50.1) 0.871 26.7 (25.3-28.8) Anteroseptal segments 1015 (987-1041) 982 (947-996) 0.017 48.3 (45.5-49.9) 45.7 (43.8-48.4) 0.150 28.3 (26.8-29.2) Inferoseptal segments 1012 (992-1023) 998 (967-1003) 0.077 48.0 (43.5-49.4) 44.9 (43.5-46.2) 0.533 26.7 (26.0-27.9) Inferior segments 1016 (987-1064) 1003 (992-1025) 0.625 47.5 (45.1-50.3) 46.1 (44.2-48.4) 0.304 27.3 (25.6-29.0) Inferolateral segments 997 (974-1043) 992 (980-1016) >0.999 46.6 (42.6-49.1) 45.1 (42.4-49.1) 0.689 25.8 (25.3-28.2) Anterolateral segments 973 (945-973) 981 (954-1010) 0.563 47.0 (45.1-48.5) 46.6 (43.5-49.6) 0.625 26.4 (24.7-28.0) T1 and T2 relaxation time mapping and ECV results. Abstract Figure. ECV mapping
Abstract
Funding Acknowledgements
Type of funding sources: Public hospital(s). Main funding source(s): Helsinki University Hospital, Finland
Background
Aortic stenosis (AS) is the most prevalent ...valvular disease in the developed countries. 4D flow is an emerging cardiac magnetic resonance (CMR) imaging technique, which has been suggested to improve the evaluation of AS severity. The accuracy of peak flow measurement by 4D flow CMR in patients with severe AS has, however, remained unvalidated.
Purpose
We investigated the reliability of the novel 4D flow CMR technique in measuring transvalvular peak systolic flow in patients with severe aortic valve stenosis.
Methods
The study included 63 patients clinically evaluated for valve replacement due to severe symptomatic AS. All the patients underwent echocardiography, 2D phase-contrast and 4D flow CMR. CMR was performed on consecutive patients according to international guidelines. Mean age of the patients was 73.8 ± 11.5 years, mean aortic valve area 0.7 ± 0.2 cm², and 40 of the valves were tricuspid and 23 bicuspid. QFlow and QFlow 4D software were used for flow analyses. Bland-Altman analyses and Wilcoxon signed rank sum tests were performed using SPSS software.
Results
CMR 4D flow analyses underestimated peak flow values when compared with echocardiography (bias -1.1 m/s, limits of agreement ± 1.5 m/s) and with 2D flow analyses (bias -1.2 m/s, limits of agreement ± 1.7 m/s). The difference between values obtained by 4D flow (median 3.1 m/s, range 1.5 – 4.9 m/s) and echocardiography (median 4.3 m/s, range 2.1 – 6.1 m/s) as well as by 2D flow (median 4.3 m/s, range 2.0 – 8.4 m/s) were statistically significant (p < 0,001). The difference between 2D flow analyses and echocardiography remained statistically insignificant (bias 0.05 m/s, limits of agreement ± 1.6 m/s).
Conclusions
We found that 4D flow analysis significantly underestimates systolic peak flow values in patients with severe AS. This may be due to intra-voxel averaging of the narrow jets. In contrast to previous assumptions, traditional 2D flow technique may therefore outperform 4D flow in measuring valvular peak flow by CMR in patients with severe AS. This should be taken into consideration when assessing disease severity by CMR.
Abstract Figure. Peak systolic flow in AS patients (n = 63)
Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
Global longitudinal strain (GLS) by echocardiography is a sensitive method for measuring left ventricular (LV) function, ...and of better prognostic value in valvular heart disease than ejection fraction (EF). Cardiac magnetic resonance imaging (CMR) is the most accurate method for measuring LV volume and EF, but GLS has not been possible to measure by CMR until recently.
Purpose
This study compares GLS obtained by CMR and echocardiography in patients with severe aortic valve stenosis. Normal values for GLS by CMR are reported as well.
Methods
GLS was measured in 32 patients with severe aortic valve stenosis with speckle tracking echocardiography, using GE Vivid E95 (n = 15) and Philips EPIQ (n = 17) ultrasound machines, as well as with CMR (Avanto 1.5T FIT, Siemens Medical Solutions). For normal values, GLS was measured by CMR in 9 healthy controls. Endo- and epicardial borders of two, three and four chamber cine images were traced for CMR GLS using dedicated software (Qstrain 2.0, Medis, NL). Both CMR and Vivid E95 measured midmyocardial strain, whereas the EPIQ AutoStrain method measures endomyocardial strain. Absolute values of GLS are reported. Pearson correlation coefficient was calculated and paired Student’s t-test was used for comparisons.
Results
A significant correlation (r = 0.45, p = 0.01) was found between echocardiographic and CMR GLS (Figure). GLS by Vivid E95 had a very good correlation with CMR GLS (r = 0.84, p = 0.0001), whereas GLS by Philips EPIQ did not correlate significantly (r = 0.14, p = 0.01). In patients with aortic stenosis and healthy controls, the average GLS by CMR was 18.3 ± 3% and 20.9 ± 2% respectively. The average GLS by CMR was comparable to that obtained by GE Vivid E95 (17.3 ± 4% vs. 17.2 ± 3%, p = 0.92), and higher than by Philips EPIQ (19.2 ± 2% vs. 15.4 ± 2%, p < 0.0001).
Conclusion
This study shows that GLS by CMR is feasible and correlates with GLS obtained by echocardiography, especially when quantifying midmyocardial strain. Echocardiographic GLS values based on endomyocardial strain were lower.
Patient characteristics Age 75 ± 14 y NYHA 1 1 (3 %) NYHA 2 20 (67 %) NYHA 3 8 (27 %) NYHA 4 1 (3 %) CMR EF 66 ± 8 % AVA 0.7 ± 0.2 cm² NYHA = NYHA class of symptoms, EF = ejection fraction by CMR, AVA = aortic valve area by echocardiography Abstract Figure. GLS by CMR vs. Echocardiography
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