Influence of cardiac phase on myocardial native T1 values by a segmental approach

Abstract Funding Acknowledgements Type of funding sources: None. Background. Native T1 values are usually assessed in the end-diastole to minimize motion artifacts while the systolic data acquisition offers the advantage of a thicker myocardium, with reduced partial-volume effects. Higher myocardial T1 values have been detected in diastole at both 1.5T and 3T but the dependence of this difference on myocardial segments or gender has not been fully explored. Aim. We provided a systematic comparison of myocardial native T1 values in diastole and systole, by considering separately myocardial segments and dividing males and females. Methods. Sixty-one healthy subjects (46.0 ± 14.1 years, 32 males) underwent CMR at 1.5T (Signa Artist; GE Healthcare). Three short-axis slices of the left ventricle acquired in diastole and systole using a Modified Look–Locker Inversion Recovery sequence. Image analysis was performed with a commercially available software package. T1 value was assessed in all 16 myocardial segments and global value was the mean. Results. Table 1 shows the comparison between T1 values calculated from maps obtained in diastole and systole. Systolic T1 values were significantly lower in the basal anterolateral segment, in all medium segments except for the medium inferior segment, and in all apical segments. The percentage difference between diastolic and systolic T1 values was considered to compensate for the higher T1 values in females, and a significantly higher value was detected in females for the majority of medium segments, for all apical segments, and for the global value. Conclusion. The diastolic-systolic discrepancy was more pronounced for the females and at the apical level, supporting the hypothesis that, besides the physiologic variations in myocardial blood volume during the cardiac cycle, the partial volume-effect may be a strong additional contributing factor. Native T1 values should be obtained always in the same cardiac phase to avoid a potential bias in the discrimination between healthy and pathologically affected myocardium.

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Correction for the Partial Volume Effects (PVE) in Nuclear Medicine Imaging: A Post-Reconstruction Analytic Method

Applied Sciences ◽

10.3390/app11146460 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6460

Author(s):

Fabio Di Martino ◽

Patrizio Barca ◽

Eleonora Bortoli ◽

Alessia Giuliano ◽

Duccio Volterrani

Keyword(s):

Nuclear Medicine ◽

Imaging System ◽

Tomographic Reconstruction ◽

Mathematical Expression ◽

Reconstruction Algorithm ◽

Volume Effect ◽

Nuclear Medicine Imaging ◽

Theoretical Derivation ◽

Reconstruction Process ◽

Partial Volume

Quantitative analyses in nuclear medicine are increasingly used, both for diagnostic and therapeutic purposes. The Partial Volume Effect (PVE) is the most important factor of loss of quantification in Nuclear Medicine, especially for evaluation in Region of Interest (ROI) smaller than the Full Width at Half Maximum (FWHM) of the PSF. The aim of this work is to present a new approach for the correction of PVE, using a post-reconstruction process starting from a mathematical expression, which only requires the knowledge of the FWHM of the final PSF of the imaging system used. After the presentation of the theoretical derivation, the experimental evaluation of this method is performed using a PET/CT hybrid system and acquiring the IEC NEMA phantom with six spherical “hot” ROIs (with diameters of 10, 13, 17, 22, 28, and 37 mm) and a homogeneous “colder” background. In order to evaluate the recovery of quantitative data, the effect of statistical noise (different acquisition times), tomographic reconstruction algorithm with and without time-of-flight (TOF) and different signal-to-background activity concentration ratio (3:1 and 10:1) was studied. The application of the corrective method allows recovering the loss of quantification due to PVE for all sizes of spheres acquired, with a final accuracy less than 17%, for lesion dimensions larger than two FWHM and for acquisition times equal to or greater than two minutes.

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Evolution of biventricular T1 values in patients with right-sided congenital heart disease

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeaa356.405 ◽

2021 ◽

Vol 22 (Supplement_1) ◽

Author(s):

O Burdet ◽

AG Pavon ◽

J Bouchardy ◽

C Blanche ◽

P Monney ◽

...

Keyword(s):

Congenital Heart Disease ◽

Heart Disease ◽

Congenital Heart ◽

Interstitial Fibrosis ◽

Pulmonary Stenosis ◽

Pulmonary Regurgitation ◽

Native T1 ◽

Funding Sources ◽

Basal Slice ◽

Relationship Of

Abstract Funding Acknowledgements Type of funding sources: None. Background Conflicting reports exist on the prevalence and clinical impact of interstitial fibrosis in right ventricular (RV) congenital heart disease (CHD). This study evaluates the longitudinal evolution of native myocardial T1 relaxation time (T1) in RV CHD. Methods On a 1.5T scanner, an ECG-triggered modified Look-Locker inversion recovery sequence (scheme 3(3)3(3)5) was acquired on a short-axis basal slice covering the RV and left ventricle (LV) on two consecutive CMR exams. Global and segmental (LV = 6, RV = 4) RV and LV T1 values were calculated (Figure). Results Mean time between CMR exams for 36 included patients (age 34 ± 2y) was 22 ± 2 months. All LV segments and 81/88% of RV segments of first and second CMR could be analyzed, respectively. T1 increased mildly but not significantly (table). There was no relationship of T1 to pulmonary regurgitation fraction, pulmonary stenosis or RV enddiastolic volume (p > 0.05). Global RV T1 of the second CMR was related to RV ejection fraction (RVEF): r = 0.353, 3.0 ± 1.4, p = 0.038. T1 of the infero-septal LV segment of first and second CMR, global LV T1 of second CMR and increase of T1 of global LV, anterior, antero-lateral and –septal LV segments, were related to age at CMR: r = 0.333 - 0.463, p < 0.05, respectively. Conclusions Native T1 values increased mildly in patients with stable RV CHD, which was not statistically significant probably due to the short to median follow-up. Global RV T1 appears to be related to RVEF which could be sign of increasing interstitial fibrosis whereas the relationship of LV T1 to age might be a physiological finding. First CMR native T1 (ms) Second CMR native T1 (ms) p LV Global 1007 ± 37 1014 ± 39 0.413 LV Anterior 994 ± 53 999 ± 54 0.710 LV Antero-lateral 965 ± 63 981 ± 58 0.186 LV Infero-lateral 1000 ± 52 1004 ± 63 0.695 LV Inferior 1035 42 1037 ± 50 0.744 LV Infero-septal 1028 ± 35 1036 ± 43 0.282 LV Antero-septal 1016 ± 38 1024 ± 48 0.347 RV Global 1091 ± 90 1096 ± 85 0.410 RV Inferior 1112 ± 104 1115 ± 118 0.696 RV Infero-lateral 1061 ± 130 1077 ± 115 0.425 RV Antero-lateral 1046 ± 127 1080 ± 109 0.088 RV Anterior 1088 ± 156 1108 ± 154 0.410 Abstract Figure. Determination of biventricular T1 values

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Partial volume effect of SPECT images in PRRT with 177Lu labelled somatostatin analogues: A practical solution

Physica Medica ◽

10.1016/j.ejmp.2018.12.029 ◽

2019 ◽

Vol 57 ◽

pp. 153-159 ◽

Cited By ~ 2

Author(s):

Domenico Finocchiaro ◽

Salvatore Berenato ◽

Elisa Grassi ◽

Valentina Bertolini ◽

Gastone Castellani ◽

...

Keyword(s):

Somatostatin Analogues ◽

Volume Effect ◽

Partial Volume Effect ◽

Practical Solution ◽

Partial Volume ◽

Spect Images

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Spectrum separation resolves partial-volume effect of MRSI as demonstrated on brain tumor scans

NMR in Biomedicine ◽

10.1002/nbm.1271 ◽

2008 ◽

Vol 21 (10) ◽

pp. 1030-1042 ◽

Cited By ~ 15

Author(s):

Yuzhuo Su ◽

Sunitha B. Thakur ◽

Karimi Sasan ◽

Shuyan Du ◽

Paul Sajda ◽

...

Keyword(s):

Brain Tumor ◽

Volume Effect ◽

Partial Volume Effect ◽

Partial Volume

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Effect of voxel size and partial volume effect on accuracy of tooth volumetric measurements with cone beam CT: Author response

Dentomaxillofacial Radiology ◽

10.1259/dmfr.20130095 ◽

2013 ◽

Vol 42 (5) ◽

pp. 20130095

Author(s):

O Peters ◽

D Maret

Keyword(s):

Cone Beam Ct ◽

Volume Effect ◽

Partial Volume Effect ◽

Author Response ◽

Cone Beam ◽

Voxel Size ◽

Partial Volume ◽

Volumetric Measurements

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Segmentation of the skull in MRI volumes using a deformable model and taking the partial volume effect into account

10.1117/12.348584 ◽

1999 ◽

Cited By ~ 1

Author(s):

Hilmi Rifai ◽

Isabelle Bloch ◽

Seth A. Hutchinson ◽

Joe Wiart ◽

Line Garnero

Keyword(s):

Volume Effect ◽

Partial Volume Effect ◽

Deformable Model ◽

Partial Volume

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Ventricle Boundary in CT: Partial Volume Effect and Local Thresholds

International Journal of Biomedical Imaging ◽

10.1155/2010/674582 ◽

2010 ◽

Vol 2010 ◽

pp. 1-6 ◽

Cited By ~ 5

Author(s):

Ihar Volkau ◽

Fiftarina Puspitasari ◽

Wieslaw L. Nowinski

Keyword(s):

Computed Tomography ◽

Cerebrospinal Fluid ◽

Grey Matter ◽

Ground Truth ◽

Gaussian Mixture ◽

Volume Effect ◽

Partial Volume Effect ◽

Partial Volume ◽

Image Histogram ◽

Global Threshold

We present a mathematical frame to carry out segmentation of cerebrospinal fluid (CSF) of ventricular region in computed tomography (CT) images in the presence of partial volume effect (PVE). First, the image histogram is fitted using the Gaussian mixture model (GMM). Analyzing the GMM, we find global threshold based on parameters of distributions for CSF, and for the combined white and grey matter (WGM). The parameters of distribution of PVE pixels on the boundary of ventricles are estimated by using a convolution operator. These parameters are used to calculate local thresholds for boundary pixels by the analysis of contribution of the neighbor pixels intensities into a PVE pixel. The method works even in the case of an almost unimodal histogram; it can be useful to analyze the parameters of PVE in the ground truth provided by the expert.

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