Comparison of myocardial T1 mapping during breath-holding and free-breathing

2021 ◽  
pp. 1-5
Author(s):  
Hideharu Oka ◽  
Kouichi Nakau ◽  
Sadahiro Nakagawa ◽  
Yuki Kobayashi ◽  
Rina Imanishi ◽  
...  
Keyword(s):  
Cross Sections ◽  
T1 Mapping ◽  
Free Breathing ◽  
Breath Holding ◽  
Basal Region ◽  
Analysis Method ◽  
Imaging Analysis ◽  
Myocardial T1 ◽  
The Mean ◽  
Almost All

Abstract Background: T1 mapping is a recently developed imaging analysis method that allows quantitative assessment of myocardial T1 values obtained using MRI. In children, MRI is performed under free-breathing. Thus, it is important to know the changes in T1 values between free-breathing and breath-holding. This study aimed to compare the myocardial T1 mapping during breath-holding and free-breathing. Methods: Thirteen patients and eight healthy volunteers underwent cardiac MRI, and T1 values obtained during breath-holding and free-breathing were examined and compared. Statistical differences were determined using the paired t-test. Results: The mean T1 values during breath-holding were 1211.1 ± 39.0 ms, 1209.7 ± 37.4 ms, and 1228.9 ± 52.5 ms in the basal, mid, and apical regions, respectively, while the mean T1 values during free-breathing were 1165.1 ± 69.0 ms, 1103.7 ± 55.8 ms, and 1112.0 ± 81.5 ms in the basal, mid, and apical regions, respectively. The T1 values were lower during free-breathing than during breath-holding in almost all segments (basal: p = 0.008, mid: p < 0.001, apical: p < 0.001). The mean T1 values in each cross section were 3.1, 7.8, and 7.7% lower during free-breathing than during breath-holding in the basal, mid, and apical regions, respectively. Conclusions: We found that myocardial T1 values during free-breathing were about 3–8% lower in all cross sections than those during breath-holding. In free-breathing, it may be difficult to assess myocardial T1 values, except in the basal region, because of underestimation; thus, the findings should be interpreted with caution, especially in children.

scholarly journals Intercomparison of slant column measurements of NO<sub>2</sub> and O<sub>4</sub> by MAX-DOAS and zenith-sky UV and visible spectrometers

2010 ◽  
Vol 3 (6) ◽  
pp. 1629-1646 ◽  
Author(s):  
H. K. Roscoe ◽  
M. Van Roozendael ◽  
C. Fayt ◽  
A. du Piesanie ◽  
N. Abuhassan ◽  
...  
Keyword(s):  
Cross Sections ◽  
Measuring Instruments ◽  
Mean Values ◽  
Straight Line ◽  
Tropospheric No2 ◽  
The Mean ◽  
Almost All ◽  
Level Of Agreement ◽  
Selection Of ◽  
Differential Spectroscopy

Abstract. In June 2009, 22 spectrometers from 14 institutes measured tropospheric and stratospheric NO2 from the ground for more than 11 days during the Cabauw Intercomparison Campaign of Nitrogen Dioxide measuring Instruments (CINDI), at Cabauw, NL (51.97° N, 4.93° E). All visible instruments used a common wavelength range and set of cross sections for the spectral analysis. Most of the instruments were of the multi-axis design with analysis by differential spectroscopy software (MAX-DOAS), whose non-zenith slant columns were compared by examining slopes of their least-squares straight line fits to mean values of a selection of instruments, after taking 30-min averages. Zenith slant columns near twilight were compared by fits to interpolated values of a reference instrument, then normalised by the mean of the slopes of the best instruments. For visible MAX-DOAS instruments, the means of the fitted slopes for NO2 and O4 of all except one instrument were within 10% of unity at almost all non-zenith elevations, and most were within 5%. Values for UV MAX-DOAS instruments were almost as good, being 12% and 7%, respectively. For visible instruments at zenith near twilight, the means of the fitted slopes of all instruments were within 5% of unity. This level of agreement is as good as that of previous intercomparisons, despite the site not being ideal for zenith twilight measurements. It bodes well for the future of measurements of tropospheric NO2, as previous intercomparisons were only for zenith instruments focussing on stratospheric NO2, with their longer heritage.

scholarly journals Free-breathing post-contrast three-dimensional T1 mapping: Volumetric assessment of myocardial T1 values

2014 ◽  
Vol 73 (1) ◽  
pp. 214-222 ◽  
Author(s):  
Sebastian Weingärtner ◽  
Mehmet Akçakaya ◽  
Sébastien Roujol ◽  
Tamer Basha ◽  
Christian Stehning ◽  
...  
Keyword(s):  
T1 Mapping ◽  
Three Dimensional ◽  
Free Breathing ◽  
Post Contrast ◽  
Volumetric Assessment ◽  
Myocardial T1

Free-breathing MOLLI: Application to myocardial T1 mapping

2012 ◽  
Vol 39 (12) ◽  
pp. 7291-7302 ◽  
Author(s):  
Jyun-Ming Tsai ◽  
Teng-Yi Huang ◽  
Yu-Shen Tseng ◽  
Yi-Ru Lin
Keyword(s):  
T1 Mapping ◽  
Free Breathing ◽  
Myocardial T1

scholarly journals Reproducibility of free-breathing multi-slice native myocardial T1 mapping using the slice-interleaved T1 (STONE) sequence

2015 ◽  
Vol 17 (S1) ◽  
Author(s):  
Jihye Jang ◽  
Sébastien Roujol ◽  
Sebastian Weingärtner ◽  
Tamer A Basha ◽  
Sophie Berg ◽  
...  
Keyword(s):  
T1 Mapping ◽  
Free Breathing ◽  
Myocardial T1

scholarly journals Intercomparison of slant column measurements of NO<sub>2</sub> and O<sub>4</sub> by MAX-DOAS and zenith-sky UV and visible spectrometers

2010 ◽  
Vol 3 (4) ◽  
pp. 3383-3423 ◽  
Author(s):  
H. K. Roscoe ◽  
M. Van Roozendael ◽  
C. Fayt ◽  
A. du Piesanie ◽  
N. Abuhassan ◽  
...  
Keyword(s):  
Cross Sections ◽  
Measuring Instruments ◽  
Mean Values ◽  
Straight Line ◽  
Tropospheric No2 ◽  
The Mean ◽  
Almost All ◽  
Level Of Agreement ◽  
Selection Of ◽  
Differential Spectroscopy

Abstract. In June 2009, 22 spectrometers from 14 institutes measured tropospheric and stratospheric NO2 from the ground for more than 11 days during the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI), at Cabauw, NL (51.97° N, 4.93° E). All visible instruments used a common wavelength range and set of cross sections for the spectral analysis. Most of the instruments were of the multi-axis design with analysis by differential spectroscopy software (MAX-DOAS), whose non-zenith slant columns were compared by examining slopes of their least-squares straight line fits to mean values of a selection of instruments, after taking 30-min averages. Zenith slant columns near twilight were compared by fits to interpolated values of a reference instrument, then normalised by the mean of the slopes of the best instruments. For visible MAX-DOAS instruments, the means of the fitted slopes for NO2 and O4 of all except one instrument were within 10% of unity at almost all non-zenith elevations, and most were within 5%. Values for UV MAX-DOAS instruments were almost as good, being 12% and 7%, respectively. For visible instruments at zenith near twilight, the means of the fitted slopes of all instruments were within 5% of unity. This level of agreement is as good as that of previous intercomparisons, despite the site not being ideal for zenith twilight measurements. It bodes well for the future of measurements of tropospheric NO2, as previous intercomparisons were only for zenith instruments focussing on stratospheric NO2, with their longer heritage.

scholarly journals Faster 3D saturation-recovery based myocardial T1 mapping using a reduced number of saturation points and denoising

2019 ◽  
Author(s):  
Giovanna Nordio ◽  
Aurélien Bustin ◽  
Freddy Odille ◽  
Torben Schneider ◽  
Markus Henningsson ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Statistical Difference ◽  
T1 Mapping ◽  
Free Breathing ◽  
High Accuracy ◽  
Saturation Recovery ◽  
Accuracy And Precision ◽  
Before And After ◽  
Myocardial T1

AbstractPurposeTo accelerate the acquisition of free-breathing 3D saturation-recovery-based (SASHA) myocardial T1 mapping by acquiring fewer saturation points in combination with a novel post-processing 3D denoising technique to maintain high accuracy and precision.Methods3D SASHA T1 mapping acquires nine T1-weighted images along the saturation recovery curve, resulting in long acquisition times. In this work, we propose to accelerate conventional cardiac T1 mapping by reducing the number of saturation points. High T1 accuracy and precision is maintained by applying a 3D denoising technique to the T1-weighted images prior to pixel-wise T1 fitting. The proposed approach was evaluated on a T1 phantom and 20 healthy subjects, by varying the number of T1-weighted images acquired between three and nine, both prospectively and retrospectively. Three patients with suspected cardiovascular disease were acquired using five T1-weighted images. T1 accuracy and precision was determined for all the acquisitions before and after denoising.ResultsIn the T1 phantom, no statistical difference was found in terms of accuracy and precision for the different number of T1-weighted images before or after denoising (P=0.99 and P=0.99 for accuracy, P=0.64 and P=0.42 for precision, respectively). In vivo, both prospectively and retrospectively, the precision improved considerably with the number of T1-weighted images employed before denoising (P<0.05) but was independent on the number of T1-weighted images after denoising.ConclusionWe demonstrate the feasibility of accelerating 3D SASHA T1 mapping by reducing the number of acquired T1-weighted images in combination with an efficient 3D denoising, without affecting accuracy and precision of T1 values.

scholarly journals Free-breathing myocardial T1 mapping using magnetization-prepared slice interleaved spoiled gradient echo imaging

2015 ◽  
Vol 17 (S1) ◽  
Author(s):  
Sébastien Roujol ◽  
Jihye Jang ◽  
Tamer A Basha ◽  
Sebastian Weingartner ◽  
Sophie Berg ◽  
...  
Keyword(s):  
T1 Mapping ◽  
Free Breathing ◽  
Gradient Echo ◽  
Myocardial T1 ◽  
Gradient Echo Imaging ◽  
Spoiled Gradient Echo

scholarly journals HYDRAULIC AND STATISTICAL GRAIN-SIZE PARAMETERS OF PINDOS TURBIDITE DEPOSITS

2018 ◽  
Vol 36 (2) ◽  
pp. 689
Author(s):  
G. Ananiadis ◽  
I. Vakalas ◽  
N. Kontopoulos ◽  
A. Zelilidis
Keyword(s):  
Grain Size ◽  
Cross Sections ◽  
Turbidity Currents ◽  
Statistical Parameters ◽  
Submarine Fans ◽  
Unidirectional Flow ◽  
Clastic Sediments ◽  
The Mean ◽  
Almost All ◽  
Grain Size Parameters

Final closure of the Pindos ocean, resulted in collision of Apulia with Pelagonian microplates, produced voluminous clastic sediments that flowed southwards as turbidity currents in the form of submarine fans, giving rise to Pindos flysch during early Tertiary. Samples coming from thinbedded sandstones were collected from five cross-sections throughout Pindos flysch in order to determine the characteristics of the turbidity current between different areas. The hydraulic and grainsize statistical parameters showed that low energy turbidity currents deposited the analyzed sediments. Almost all samples show a positive skewness due to the competency of the unidirectional flow of the transporting media, where the coarse end of the size frequency curve is "chopped off'. The kurtosis values in combination with the sorting values are plotted to the turbidity filed. A correlation between the mean palaeoflow velocity and the grain size showed that the mean palaeoflow velocities related to sandy silt samples whereas the higher velocities with sandy samples.

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