EVALUATION OF ROOT CANAL OBTURATION RESULTS WITH THE CANAL SHAPING SYSTEM WAVE ONE AND GUTTA THERMAFIL

Objective: To evaluate the results of root canal obturation with Wave One (WO) canal shaping system and Gutta Thermafil obturation system. Design: Nonrandomized prospective experimental trial between December 2020 and March 2021. Setting: Central Military Hospital 108. Subject: 30 lower incisors extracted teeth without stem rupture, without root damage such as fracture, stray, fissure. Results: The number of slices with the biggest gaps accounting for 16.7%. The number of slices with the smallest gaps accounting for 10%. The number of slices with gaps over the total slices accounted for 14.4%. The void area in the apical slice was 1,413 ± 519.5 µm2 and the largest void area was 38,654.2 ± 3,939.8 µm2. Conclusion: Thermafil Gutta Percha has a good fit to the canal wall, which can seal the canal more easily and accurately.

Myocardial T2 values by a segmental approach with healthy ageing and gender

Funding Acknowledgements Type of funding sources: None. Introduction. No data are available in literature about normal ranges for T2 in human myocardium using GE scanners. Aims. Our aims were to obtain myocardial regional and global T2 values as a reference for normality for the first time using a GE scanner and to assess their association with physiological variables. Methods. A stratified approach was adopted for healthy volunteers recruitment, ensuring the presence of 10 participants for both genders in each age decile: 20–30, 30–40, 40-50, 50-60, 60-70 years. Basal, medium, and apical short-axis slices of the left ventricle were acquired by a multi-echo fast-spin-echo (MEFSE) sequence. Image analysis was performed with a commercially available software package. T2 value was assessed in all 16 myocardial segments and global value was the mean. Results. The global T2 value averaged across all subjects was 52.2 ± 2.5 ms (range: 47.0-59.9 ms). Inter-study, intra-observer, and inter-observer reproducibility was good (coefficient of variation < 5%). The 3.6% of segments was excluded because of artifacts and/or partial-volume effects. Segmental T2 values differed significantly (P < 0.0001), with the lowest value in the basal anterolateral segment (50.0 ± 3.5 ms) and the highest in the apical lateral segment (54.9 ± 5.1 ms). Mean T2 was significantly lower in the basal slice compared to both medium (51.0 ± 2.4 vs 51.8 ± 2.6 ms; P < 0.0001) and apical slices (51.0 ± 2.4 vs 54.2 ± 3.7 ms; P < 0.0001), and in the medium slice than in the apical slice (51.8 ± 2.6 vs 54.2 ± 3.7 ms; P < 0.0001). Aging was associated with increased segmental and global T2 values. Females showed higher T2 values than males. T2 values were not correlated to heart rate. Mean T2 values, standard deviation, and lower and upper limits of normal for all 16 myocardial segments are shown in Figure 1 for males and in Figure 2 for females, considering separately each age group. Conclusion. The optimized MEFSE sequence allows for robust, reliable, and reproducible quantification of segmental T2 values. T2 values differ among myocardial slices and are influenced by age and gender, making mandatory to define gender- and age-specific segmental reference values for distinguishing between healthy and diseased myocardium. The normal ranges defined in this study on a large cohort of healthy subjects could be used as reference by other sites using the same sequence, allowing them to recruit a smaller population and accelerating the spread of myocardial T2 mapping in the clinical arena.

Left Ventricular Deformation in Patients with Connective Tissue Disease: Evaluated by 3.0T Cardiac Magnetic Resonance Tissue Tracking

The aim of this study was to assess left ventricular (LV) myocardial strain in patients with connective tissue disease (CTD) and compare LV deformation between subgroups of idiopathic inflammatory myopathy (IIM) and non-IIM. Ninety-eight patients with CTD, comprising 56 with IIM and 42 with non-IIM, and 30 healthy subjects were enrolled and underwent 3.0T cardiac magnetic resonance imaging (MRI) scanning. The LV function and strain parameters were measured and assessed. Our result revealed that CTD patients had preserved LV ejection fraction (60.85%) and had significantly decreased global and regional peak strain (PS) in radial, circumferential, and longitudinal directions (all p < 0.05). IIM patients showed significantly reduced global longitudinal PS (GLPS) and longitudinal PS at apical slice, whereas all strain parameters decreased in non-IIM patients. Except GLPS and longitudinal PS at apical slice, all strain parameters in non-IIM patients were lower than those in IIM patients. By Pearson’s correlation analysis, the LV global radial and circumferential PS were correlated to N-terminal pro-brain natriuretic peptide level and LV ejection fraction in both IIM and non-IIM patients. This study indicated that CTD patients showed abnormal LV deformation despite with preserved LVEF. The impairment of LV deformation differed between IIM and non-IIM patients.

Abstract 2574: Accuracy of Apical Rotation by Two-dimensional Speckle Tracking Echocardiography is Influenced by Apical Slice Location.

Background : During the cardiac cycle, there is a systolic twist and an early diastolic untwist about LV long axis, because of opposite rotation of the basal and apical segments. Previous studies showed that speckle tracking echocardiography (STE) allows to measure the rotation of these segments and thereby to assess global LV torsion. Unfortunately, STE does not always allow visualization of the real apex, thus raising concerns about the reliability of LV torsion data using this approach. Methods : We compared LV apical rotation by tagged magnetic resonance (cMR) and STE in 30 patients with normal regional and global systolic function. With cMR, rotation was measured on serial contiguous 10 mm thick short-axis (SAX) sections, whereas with STE, it was only obtained on the most apical available SAX section. cMR and STE were compared using either the most apical cMR SAX slice or the cMR slice that best matched the end-diastolic internal dimensions of the available STE slice. Results : LV rotation measured by cMR decreased from apex to base (Fig 1 ). When using the best matched cMR SAX slice, cMR and STE were well correlated (r=0.7, Fig 2 , black dots). By contrast, when using the most apical cMR SAX slice, the correlation between cMR and STE was lost (Fig 2 , white dots). By comparing end-diastolic internal dimensions, the level of the STE slice was found to be at the real apex in 10% of pts, and at 10, 20 and 30 mm below the apex in 27%, 50% and 13% of pts, respectively. Conclusion : Although STE allows to measure LV apical rotation, it rarely does so at the level of the real apex. This results in an almost systematic and mostly unpredictable underestimation of apical rotation.

Simultaneous regional myocardial blood flows by tritiated water and microspheres

Regional myocardial blood flow (RMF) was measured simultaneously by use of labeled 8-mum microspheres and the constant-rate infusion of 3H2O in 22 open-chest dogs (Na pentobarbital anesthesia) under markedly different hemodynamic conditions. Following cardiac excision, three adjacent 80-mg tissue samples were taken from the subendocardial, mid-wall, and subepicardial layers of quadrantal left ventricular (LV) segments of the basal and midventricular cardiac slices, and from one segment of the apical slice, totaling 81 samples per LV. RMF was calculated by the microsphere reference-flow technique and by two 3H2O tissue-uptake models. Good agreement between techniques (r=0.9-0.96) was found in comparing flows to the myocardial layers. Using Kety's "single-mixer" model of 3H2O tissue uptake, fairly good agreement was found between techniques in the 80-mg tissue samples; the cofficient of variation from regression was 18.5% which improved markedly to 12.3% when the flow values for each technique were averaged in the three adjacent samples. Analysis of variance showed that flow to the various LV subdivisions (layer, segment, slice) of control animals was heterogeneous.