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- Sörensen, Jens, et al.
(författare)
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Myocardial External Efficiency in Asymptomatic Severe Primary Mitral Regurgitation Using 11C-Acetate PET
- 2023
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 64:4, s. 645-651
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Tidskriftsartikel (refereegranskat)abstract
- Subjects with asymptomatic moderate-severe or severe primary mitral regurgitation (MR) are closely observed for signs of progression or symptoms requiring surgical intervention. The role of myocardial metabolic function in progression of MR is poorly understood. We used 11C-acetate positron emission tomography (PET) to non-invasively measure myocardial external efficiency (MEE), which is the energetic ratio of external cardiac work and left ventricular oxygen consumption.Methods and Results: 47 patients in surveillance with MR and no or minimal symptoms prospectively underwent PET, echocardiography and cardiac magnetic resonance imaging (CMR) on the same day. PET was used to simultaneously measure cardiac output, LV mass and oxygen consumption to establish MEE. PET in patients were compared to healthy volunteers (n = 9). MEE and standard imaging indicators of regurgitation severity, LV volumes and function were studied as predictors of time to surgical intervention. Patients were followed median 3.0 years (interquartile range 2.0-3.8) and the endpoint was reached in 22 subjects (47%). MEE in patients reaching the endpoint (23.8±5.0%) was lower than in censored patients (28.5±4.5%, P = 0.002) and in healthy volunteers (30.1±4.9%, 0.001). MEE with a cut-off lower than 25.7% was significantly associated with the outcome (hazard ratio of 7.5 (95%CI: 2.7-20.6, p<0.0001) and retained independent significance when compared to standard imaging parameters.Conclusion: MEE independently predicted time to progression requiring valve surgery in patients with asymptomatic moderate-severe or severe primary MR. The study suggests that inefficient myocardial oxidative metabolism precedes clinically observed progression in MR.
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| 3. |
- Gustafsson, Agneta, et al.
(författare)
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A multicentre simulation study of planar whole-body bone scintigraphy in Sweden
- 2022
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Ingår i: EJNMMI Physics. - : Springer Science and Business Media LLC. - 2197-7364. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Whole-body bone scintigraphy is a clinically useful non-invasive and highly sensitive imaging method enabling detection of metabolic changes at an early stage of disease, often earlier than with conventional radiologic procedures. Bone scintigraphy is one of the most common nuclear medicine methods used worldwide. Therefore, it is important that the examination is implemented and performed in an optimal manner giving the patient added value in the subsequent care process. The aim of this national multicentre survey was to investigate Swedish nuclear medicine departments compliance with European practice guidelines for bone scintigraphy. In addition, the effect of image acquisition parameters on the ability to detect metabolic lesions was investigated. Methods: Twenty-five hospital sites participated in the study. The SIMIND Monte Carlo (MC) simulation and the XCAT phantom were used to simulate ten fictive patient cases with increased metabolic activity distributed at ten different locations in the skeleton. The intensity of the metabolic activity was set into six different levels. Individual simulations were performed for each site, corresponding to their specific camera system and acquisition parameters. Simulated image data sets were then sent to each site and were visually evaluated in terms of if there was one or several locations with increased metabolic activity relative to normal activity. Result: There is a high compliance in Sweden with the EANM guidelines regarding image acquisition parameters for whole-body bone scintigraphy. However, up to 40% of the participating sites acquire lower count density in the images than recommended. Despite this, the image quality was adequate to maintain a stable detection level. None of the hospital sites or individual responders deviated according to the statistical analysis. There is a need for at least 2.5 times metabolic activity compared to normal for a lesion to be detected. Conclusion: The imaging process is well harmonized throughout the country and there is a high compliance with the EANM guidelines. There is a need for at least 2.5 times the normal metabolic activity for a lesion to be detected as abnormal.
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| 4. |
- Trägårdh, Elin, et al.
(författare)
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Evaluation of inter-departmental variability of ejection fraction and cardiac volumes in myocardial perfusion scintigraphy using simulated data
- 2015
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Ingår i: EJNMMI Physics. - : Springer Science and Business Media LLC. - 2197-7364. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Myocardial perfusion scintigraphy (MPS) is a clinically useful noninvasive imaging modality for diagnosing patients with suspected coronary artery disease. By utilizing gated MPS, the end diastolic volume (EDV) and end systolic volume (ESV) can be measured and the ejection fraction (EF) calculated, which gives incremental prognostic value compared with assessment of perfusion only. The aim of this study was to evaluate the inter-departmental variability of EF, ESV, and EDV during gated MPS in Sweden.Methods: Seventeen departments were included in the study. The SIMIND Monte Carlo (MC) program together with the XCAT phantom was used to simulate three patient cases with different EDV, ESV, and EF. Individual simulations were performed for each department, corresponding to their specific method of performing MPS. Images were then sent to each department and were evaluated according to clinical routine. EDV, ESV, and EF were reported back.Results: There was a large underestimation of EDV and ESV for all three cases. Mean underestimation for EDV varied between 26% and 52% and for ESV between 15% and 60%. EF was more accurately measured, but mean bias still varied between an underestimation of 24% to an overestimation of 14%. In general, the intra-departmental variability for EDV, ESV, and EF was small, whereas inter-departmental variability was larger.Conclusions: Left ventricular volumes were generally underestimated, whereas EF was more accurately estimated. There was, however, large inter-departmental variability.
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