| 1. |
- Hansson, Nils Henrik, et al.
(författare)
-
Evaluation of ECG-gated [(11)C]acetate PET for measuring left ventricular volumes, mass, and myocardial external efficiency
- 2016
-
Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 23:4, s. 670-9
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Noninvasive estimation of myocardial external efficiency (MEE) requires measurements of left ventricular (LV) oxygen consumption with [(11)C]acetate PET in addition to LV stroke volume and mass with cardiovascular magnetic resonance (CMR). Measuring LV geometry directly from ECG-gated [(11)C]acetate PET might enable MEE evaluation from a single PET scan. Therefore, we sought to establish the accuracy of measuring LV volumes, mass, and MEE directly from ECG-gated [(11)C]acetate PET.METHODS: Thirty-five subjects with aortic valve stenosis underwent ECG-gated [(11)C]acetate PET and CMR. List mode PET data were rebinned into 16-bin ECG-gated uptake images before measuring LV volumes and mass using commercial software and compared to CMR. Dynamic datasets were used for calculation of mean LV oxygen consumption and MEE.RESULTS: LV mass, volumes, and ejection fraction measured by CMR and PET correlated strongly (r = 0.86-0.92, P < .001 for all), but were underestimated by PET (P < .001 for all except ESV P = .79). PET-based MEE, corrected for bias, correlated fairly with PET/CMR-based MEE (r = 0.60, P < .001, bias -3 ± 21%, P = .56). PET-based MEE bias was strongly associated with LV wall thickness.CONCLUSIONS: Although analysis-related improvements in accuracy are recommended, LV geometry estimated from ECG-gated [(11)C]acetate PET correlate excellently with CMR and can indeed be used to evaluate MEE.
|
|
| 2. |
- Harms, Hendrik J, et al.
(författare)
-
Automatic calculation of myocardial external efficiency using a single 11C-acetate PET scan.
- 2018
-
Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 25:6, s. 1937-1944
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Myocardial external efficiency (MEE) is defined as the ratio of kinetic energy associated with cardiac work [forward cardiac output (FCO)*mean systemic pressure] and the chemical energy from oxygen consumed (MVO2) by the left ventricular mass (LVM). We developed a fully automated method for estimating MEE based on a single 11C-acetate PET scan without ECG-gating.METHODS AND RESULTS: Ten healthy controls, 34 patients with aortic valve stenosis (AVS), and 20 patients with mitral valve regurgitation (MVR) were recruited in a dual-center study. MVO2 was calculated using washout of 11C -acetate activity. FCO and LVM were calculated automatically using dynamic PET and parametric image formation. FCO and LVM were also obtained using cardiac magnetic resonance (CMR) in all subjects. The correlation between MEEPET-CMR and MEEPET was high (r = 0.85, P < 0.001) without significant bias. MEEPET was 23.6 ± 4.2% for controls and was lowered in AVS (17.2 ± 4.3%, P < 0.001) and in MVR (18.0 ± 5.2%, P = 0.004). MEEPET was strongly associated with both NYHA class (P < 0.001) and the magnitude of valvular dysfunction (mean aortic gradient: P < 0.001, regurgitant fraction: P = 0.009).CONCLUSION: A single 11C-acetate PET yields accurate and automated MEE results on different scanners. MEE might provide an unbiased measurement of the phenotypic response to valvular disease.
|
|
| 3. |
- Kero, Tanja, et al.
(författare)
-
Accurate analysis and visualization of cardiac (11)C-PIB uptake in amyloidosis with semiautomatic software
- 2016
-
Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 23:4, s. 741-750
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: (11)C-PIB PET is a promising non-invasive diagnostic tool for cardiac amyloidosis. Semiautomatic analysis of PET data is now available but it is not known how accurate these methods are for amyloid imaging. The aim of this study was to evaluate the feasibility of one semiautomatic software tool for analysis and visualization of (11)C-PIB left ventricular retention index (RI) in cardiac amyloidosis.METHODS AND RESULTS: Patients with systemic amyloidosis and cardiac involvement (n = 10) and healthy controls (n = 5) were investigated with dynamic (11)C-PIB PET. Two observers analyzed the PET studies with semiautomatic software to calculate the left ventricular RI of (11)C-PIB and to create parametric images. The mean RI at 15-25 min from the semiautomatic analysis was compared with RI based on manual analysis and showed comparable values (0.056 vs 0.054 min(-1) for amyloidosis patients and 0.024 vs 0.025 min(-1) in healthy controls; P = .78) and the correlation was excellent (r = 0.98). Inter-reader reproducibility also was excellent (intraclass correlation coefficient, ICC > 0.98). Parametric polarmaps and histograms made visual separation of amyloidosis patients and healthy controls fast and simple.CONCLUSION: Accurate semiautomatic analysis of cardiac (11)C-PIB RI in amyloidosis patients is feasible. Parametric polarmaps and histograms make visual interpretation fast and simple.
|
|
| 4. |
- Marchesseau, Stephanie, et al.
(författare)
-
Hybrid PET/CT and PET/MRI imaging of vulnerable coronary plaque and myocardial scar tissue in acute myocardial infarction
- 2018
-
Ingår i: Journal of Nuclear Cardiology. - : SPRINGER. - 1071-3581 .- 1532-6551. ; 25:6, s. 2001-2011
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundFollowing an acute coronary syndrome, combined CT and PET with F-18-NaF can identify coronary atherosclerotic plaques that have ruptured or eroded. However, the processes behind F-18-NaF uptake in vulnerable plaques remain unclear. Methods and ResultsTen patients with STEMI were scanned after F-18-NaF injection, for 75minutes in a Siemens PET/MR scanner using delayed enhancement (LGE). They were then scanned in a Siemens PET/CT scanner for 10minutes. Tissue-to-background ratio (TBR) was compared between the culprit lesion in the IRA and remote non-culprit lesions in an effort to independently validate prior studies. Additionally, we performed a proof-of-principle study comparing TBR in scar tissue and remote myocardium using LGE images and PET/MR or PET/CT data. From the 33 coronary lesions detected on PET/CT, TBRs for culprit lesions were higher than for non-culprit lesions (TBR=2.110.45 vs 1.46 +/- 0.48; P<0.001). Interestingly, the TBR measured on the PET/CT was higher for infarcted myocardium than for remote myocardium (TBR=0.81 +/- 0.10 vs 0.71 +/- 0.05; P=0.003). These results were confirmed using the PET/MR data (TBR=0.81 +/- 0.10 for scar, TBR=0.71 +/- 0.06 for healthy myocardium, P=0.03). Conclusions We confirmed the potential of F-18-NaF PET/CT imaging to detect vulnerable coronary lesions. Moreover, we demonstrated proof-of-principle that F-18-NaF concurrently detects myocardial scar tissue.
|
|
| 5. |
- Oddstig, Jenny, et al.
(författare)
-
Differences in attenuation pattern in myocardial SPECT between CZT and conventional gamma cameras
- 2019
-
Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 26:6, s. 1984-1991
-
Tidskriftsartikel (refereegranskat)abstract
- Background: In myocardial perfusion imaging (MPI), single-photon emission tomography (SPECT) soft-tissue attenuation by the abdomen, breasts, and lateral chest wall may create artifacts that mimic true perfusion defects. This may cause misdiagnosis of myocardial perfusion. The aim of the present study was to compare the localization, extent, and depth of attenuation artifacts in MPI SPECT for a multi-pinhole cadmium zinc telluride (CZT) camera vs a conventional gamma camera. Methods: Phantom and patient measurements were performed using a CZT camera (GE NM 530c) and a conventional gamma camera (GE Ventri). All images were attenuation corrected with externally acquired low-dose computed tomography. The localization, extent, and depth of the attenuation artifact were quantified by comparing attenuation-corrected and non-attenuation-corrected images. Results: Attenuation artifacts were shifted from the inferolateral wall to the lateral wall using the CZT camera compared to a conventional camera in both the patient and the phantom. The extent of the attenuation artifact was significantly larger for the CZT camera compared to the conventional camera (23 ± 5% vs 15 ± 5%, P < .001) for patients and the result was similar for the phantom (28% vs 19%). Furthermore, the depth of the attenuation artifact (percent of maximum counts) was less pronounced for the CZT camera than for the conventional camera, both for phantom measurements (73% vs 67%) and patients (72 ± 3% vs 68 ± 4%, P < .001). Conclusions: Attenuation artifacts are found in different locations to different extents and depths when using a CZT camera vs a conventional gamma camera for MPI SPECT. This should be taken into consideration when evaluating MPI SPECT studies to avoid misinterpretation of myocardial perfusion distribution.
|
|
| 6. |
- Oddstig, Jenny, et al.
(författare)
-
The radiation dose to overweighted patients undergoing myocardial perfusion SPECT can be significantly reduced : validation of a linear weight-adjusted activity administration protocol
- 2017
-
Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 24:6, s. 1912-1921
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Large body size can cause a higher proportion of emitted photons being attenuated within the patient. Therefore, clinical myocardial perfusion SPECT (MPS) protocols often include unproportionally higher radioisotope activity to obese patients. The aim was to evaluate if a linear weight-adjusted low-dose protocol can be applied to obese patients and thereby decrease radiation exposure. Methods and result: Two hundred patients (>110 kg, BMI 18-41, [n = 69], ≤ 110 kg, BMI 31-58, [n = 131]) underwent 99mTc-tetrofosmin stress examination on a Cadmium Zinc Telluride or a conventional gamma camera using new generations of reconstruction algorithm (Resolution Recovery). Patients <110 kg were administered 2.5 MBq/kg, patients between 110 and 120 kg received 430 MBq and patients >120 kg received 570 MBq according to clinical routine. Patients >110 kg had 130% total number of counts in the images compared to patients <110 kg. Recalculating the counts to correspond to an administered activity of 2.5 MBq/kg resulted in similar number of counts across the groups. Image analyses in a subgroup with images corresponding to high activity and 2.5 MBq/kg showed no difference in image quality or ischemia quantification. Conclusion: Linear low-dose weight-adjusted protocol of 2.5 MBq/kg in MPS can be applied over a large weight span without loss of counts or image quality, resulting in a significant reduction in radiation exposure to obese patients.
|
|
| 7. |
- Pilebro, Björn, et al.
(författare)
-
Positron emission tomography (PET) utilizing Pittsburgh compound B (PIB) for detection of amyloid heart deposits in hereditary transthyretin amyloidosis (ATTR)
- 2018
-
Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 25:1, s. 240-248
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: DPD scintigraphy has been advocated for imaging cardiac amyloid in ATTR amyloidosis. PET utilizing (11)C-Pittsburgh compound B (PIB) is the gold standard for imaging brain amyloid in Alzheimer's disease. PIB was recently shown to identify cardiac amyloidosis in both AL and ATTR amyloidosis. In the ATTR population, two types of amyloid fibrils exist, one containing fragmented and full-length TTR (type A) and the other only full-length TTR (type B). The aim of this study was to further evaluate PIB-PET in patients with hereditary ATTR amyloidosis.METHODS: Ten patients with biopsy-proven V30M ATTR amyloidosis and discrete or no signs of cardiac involvement were included. Patients were grouped according to TTR-fragmentation. All underwent DPD scintigraphy, echocardiography, and PIB-PET. A left ventricular PIB-retention index (PIB-RI) was established and compared to five normal volunteers.RESULTS: PIB-RI was increased in all patients (P < 0.001), but was significantly higher in type B than in type A (0.129 ± 0.041 vs 0.040 ± 0.006 min(-1), P = 0.009). Cardiac DPD uptake was elevated in group A and absent in group B.CONCLUSION: PIB-PET, in contrast to DPD scintigraphy, has the potential to specifically identify cardiac amyloid depositions irrespective of amyloid fibril composition. The heart appears to be a target organ for amyloid deposition in ATTR amyloidosis.
|
|
| 8. |
|
|
| 9. |
- Yoneyama, H., et al.
(författare)
-
Reducing the small-heart effect in pediatric gated myocardial perfusion single-photon emission computed tomography
- 2017
-
Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 24:4, s. 1378-1388
-
Tidskriftsartikel (refereegranskat)abstract
- Background. We compared two reconstruction algorisms and two cardiac functional evaluation software programs in terms of their accuracy for estimating ejection fraction (EF) of small hearts (SH). Methods. The study group consisted of 66 pediatric patients. Data were reconstructed using a filtered back projection (FBP) method without the resolution correction (RC) and an iterative method based on an ordered subset expectation maximization (OSEM) algorithm with the RC. EF was evaluated using two software programs of quantitative gated single-photon emission computed tomography (SPECT) (QGS) and cardioREPO. We compared the EF of gated myocardial perfusion SPECT to echocardiographic measurement (Echo). Results. Forty-eight of 66 patients had an end-systolic volume < 20 mL which was used as the criterion for being included in the SH group, and the SH effect led to an overestimation of EF. While significant differences were observed between Echo (66.9 +/- 5.0%) and QGS-FBP without RC (76.9 +/- 8.4%, P < .0001), QGS-OSEM with RC (76.6 +/- 8.6%, P < .0001), and cardioREPO-FBP without RC (72.1 +/- 10.0%, P = .0011), no significant difference was observed between Echo and cardioREPO-OSEM with RC (67.4 +/- 6.1%) in SH group. Conclusions. In pediatric gated myocardial perfusion SPECT, the SH effect can be significantly reduced when an OSEM algorithm is used with RC in combination with the specific cardioREPO algorithm.
|
|
