Low-dose dobutamine cardiovascular magnetic resonance segmental strain study of early phase of intramyocardial hemorrhage rats

Background This study investigates the segmental myocardial strain of the early phase of intramyocardial hemorrhage (IMH) caused by reperfused myocardial infarction (MI) in rats by low-dose dobutamine (LDD) cardiovascular magnetic resonance (CMR) feature-tracking. Methods Nine sham rats and nine rats with 60-min myocardial ischemia followed by 48-h reperfusion were investigated using CMR, including T2*-mapping sequence and fast imaging with steady-state precession (FISP)–cine sequence. Another FISP–cine sequence was acquired after 2 min of dobutamine injection; the MI, IMH, and Non-MI (NMI) areas were identified. The values of peak radial strains (PRS) and peak circumferential strains (PCS) of the MI, IMH and NMI segments were acquired. The efficiency of PRS and PCS (EPRS and EPCS, respectively) were calculated on the basis of the time of every single heartbeat. Results The PRS, PCS, EPRS, and EPCS of the sham group increased after LDD injection. However, the PRS, PCS, EPRS, and EPCS of the IMH segment did not increase. Moreover, the PRS and PCS of the MI and NMI segments did not increase, but the EPRS and EPCS of these segments increased. The PRS, PCS, EPRS, and EPCS of the IMH segment were lower than those of the MI and NMI segments before and after LDD injection, but without a significant difference between MI segment and NMI segment before and after LDD injection. Conclusions LDD could help assess dysfunctions in segments with IMH, especially using the efficiency of strain. IMH was a crucial factor that decreased segmental movement and reserved function.

CMMCSegNet: Cross-Modality Multicascade Indirect LGE Segmentation on Multimodal Cardiac MR

Since Late-Gadolinium Enhancement (LGE) of cardiac magnetic resonance (CMR) visualizes myocardial infarction, and the balanced-Steady State Free Precession (bSSFP) cine sequence can capture cardiac motions and present clear boundaries; multimodal CMR segmentation has played an important role in the assessment of myocardial viability and clinical diagnosis, while automatic and accurate CMR segmentation still remains challenging due to a very small amount of labeled LGE data and the relatively low contrasts of LGE. The main purpose of our work is to learn the real/fake bSSFP modality with ground truths to indirectly segment the LGE modality of cardiac MR by using a proposed cross-modality multicascade framework: cross-modality translation network and automatic segmentation network, respectively. In the segmentation stage, a novel multicascade pix2pix network is designed to segment the fake bSSFP sequence obtained from a cross-modality translation network. Moreover, we propose perceptual loss measuring features between ground truth and prediction, which are extracted from the pretrained vgg network in the segmentation stage. We evaluate the performance of the proposed method on the multimodal CMR dataset and verify its superiority over other state-of-the-art approaches under different network structures and different types of adversarial losses in terms of dice accuracy in testing. Therefore, the proposed network is promising for Indirect Cardiac LGE Segmentation in clinical applications.

60-S Retrogated Compressed Sensing 2D Cine of the Heart: Sharper Borders and Accurate Quantification

Background and objective: Real-time compressed sensing cine (CSrt) provides reliable quantification for both ventricles but may alter image quality. The aim of this study was to assess image quality and the accuracy of left (LV) and right ventricular (RV) volumes, ejection fraction and mass quantifications based on a retrogated segmented compressed sensing 2D cine sequence (CSrg). Methods: Thirty patients were enrolled. Each patient underwent the reference retrogated segmented steady-state free precession cine sequence (SSFPref), the real-time CSrt cine and the segmented retrogated prototype CSrg sequence providing the same slices. Functional parameters quantification and image quality rating were performed on SSFPref and CSrg images sets. The edge sharpness, which is an estimate of the edge spread function, was assessed for the three sequences. Results: The mean scan time was: SSFPref = 485.4 ± 83.3 (SD) s (95% CI: 454.3–516.5) and CSrg = 58.3 ± 15.1 (SD) s (95% CI: 53.7–64.2) (p < 0.0001). CSrg subjective image quality score (median: 4; range: 2–4) was higher than the one provided by CSrt (median: 3; range: 2–4; p = 0.0008) and not different from SSFPref overall quality score (median: 4; range: 2–4; p = 0.31). CSrg provided similar LV and RV functional parameters to those assessed with SSFPref (p > 0.05). Edge sharpness was significantly better with CSrg (0.083 ± 0.013 (SD) pixel−1; 95% CI: 0.078–0.087) than with CSrt (0.070 ± 0.011 (SD) pixel−1; 95% CI: 0.066–0.074; p = 0.0004) and not different from the reference technique (0.075 ± 0.016 (SD) pixel−1; 95% CI: 0.069–0.081; p = 0.0516). Conclusions: CSrg cine provides in one minute an accurate quantification of LV and RV functional parameters without compromising subjective and objective image quality.

Low-Dose Dobutamine Cardiovascular Magnetic Resonance Segmental Strain Study of Early Phase of Intramyocardial Hemorrhage Rats

Background: This study investigates the segmental myocardial strain of the early phase of intramyocardial hemorrhage (IMH) caused by reperfused myocardial infarction (MI) in rats by low-dose dobutamine (LDD) cardiovascular magnetic resonance (CMR) feature-tracking. Methods: Nine sham rats and nine rats with 60-min myocardial ischemia followed by 48-h reperfusion were investigated using CMR, including T2*-mapping sequence and fast imaging with steady-state precession (FISP)–cine sequence. Another FISP–cine sequence was acquired after 2 min of dobutamine injection; the MI, IMH, and Non-MI (NMI) areas were identified. The values of peak radial strains (PRS) and peak circumferential strains (PCS) of the MI, IMH and NMI segments were acquired. The efficiency of PRS and PCS (EPRS and EPCS, respectively) were calculated on the basis of the time of every single heartbeat. Results: The PRS, PCS, EPRS, and EPCS of the sham group increased after LDD injection. However, the PRS, PCS, EPRS, and EPCS of the IMH segment did not increase. Moreover, the PRS and PCS of the MI and NMI segments did not increase, but the EPRS and EPCS of these segments increased. The PRS, PCS, EPRS, and EPCS of the IMH segment were lower than those of the MI and NMI segments before and after LDD injection, but without a significant difference between MI segment and NMI segment before and after LDD injection. Conclusions: LDD could help assess dysfunctions in segments with IMH, especially using the efficiency of strain. IMH was a crucial factor that decreased segmental movement and reserved function.

Retrogated compressed sensing cine in one minute

Funding Acknowledgements Type of funding sources: None. PURPOSE Real-time compressed sensing cine (CSrt) provides reliable quantifications for both ventricles but impairs image quality . This aim of this study was to assess the accuracy of left (LV) and right ventricular (RV) volumes, ejection fraction and mass quantifications based on a retrogated segmented compressed sensing-fashioned accelerated 2D cine sequence (CSrg). Image quality was also evaluated. METHOD AND MATERIALS Thirty patients were enrolled. Each patient underwent the reference retrogated segmented steady-state free precession cine sequence (SSFPref), the first generation real-time CSrt cine and the segmented retrogated prototype CSrg sequence providing the same numbers and positions of slices. Functional parameters quantification was performed on SSFPref and CSrg images sets. Image quality was assessed for the three sequences by using edge sharpness which is an estimate of the edge spread function. RESULTS Mean scan times were SSFPref = 512 ± 15 s, CSrt = 24 ± 5 s and CSrg = 58 ± 15 s. CSrg provided LV and RV functional parameters (end-systolic, end-diastolic, ejection fraction and LV mass) which were not significantly different from the one assessed with SSFPref (p &gt; 0.05). Edge sharpness was significantly better with CSrg (0.083 ± 0.013 pixel-1) than with CSrt (0.070 ± 0.011 pixel-1; p = 0.0004) and not different from the reference techniques (0.075 ± 0.016 pixel-1; p = 0.0516). Inter and intrarater variabilities demonstrated intraclass correlation coefficients over 0.96. CONCLUSION CSrg cine provides in one minute an accurate quantification of LV and RV functional parameters without compromising the sharpness of myocardial boarders which was impaired by the first-generation real-time compressed sensing sequence. Abstract Figure. Image quality and volumes assessment

Changes in carotid artery intima-media thickness during the cardiac cycle – a comparative study in early childhood, mid-childhood, and adulthood

Background: Carotid intima-media thickness (CIMT), an ultrasonographic marker of cardiovascular risk, is increasingly used in adults and children. The choice of specific images used to quantify CIMT from a cine sequence is often based on image quality rather than on a consistent point in the cardiac cycle. This methodological study quantified the imprecision that may be introduced by variation of CIMT during the cardiac cycle. Probands and methods: Data from four-year-olds, 11 to 12-year-olds, and adults (n=30 each age group) were selected retrospectively from two population-derived studies. Far wall CIMT of the right common carotid artery was measured at end-diastole and peak systole using standardized protocols. All images were analysed using semi-automated edge-detection software. Results: In all age groups CIMT varied significantly during the cardiac cycle and was largest at end-diastole. The mean difference in CIMT between end-diastole and peak systole was greater in four-year-olds (38 μm; 95 % confidence interval (CI) 33 to 43 μm) and 11 to 12-year-olds (31 μm; CI 26 to 36 μm) than in adults (18 μm; CI 16 to 22 μm). Carotid IMT increased by 8.8 % (CI 7.7 to 9.8 %), 6.9 % (CI 5.8 to 8.1 %), and 3.8 % (CI 3.1 to 4.5 %) between minimum and maximum arterial diameter in four-year-olds, 11 to 12-year-olds, and adults, respectively. The greatest variation in CIMT during the cardiac cycle was observed in children (up to 14 %). Conclusions: Inconsistent timing of CIMT measurement during the cardiac cycle is an avoidable source of imprecision, especially in children, in whom inter-individual differences are smallest. As CIMT is largest at end-diastole, this is the most appropriate time point for consistent and comparable measurements to be made.

4D Fetal Echocardiography in Clinical Practice

ABSTRACT Spatiotemporal image correlation (STIC) is a technique that acquires the fetal cardiac volumes, and then analyzes it offline in both multiplanar and rendered modes, using both static and moving images from a four-dimensional (4D) cine sequence simulating a full cardiac cycle. Spatiotemporal image correlation makes it possible to evaluate cardiac structures and their vascular connections, is less operator dependent, and allows cardiac volumes to be sent to specialists in tertiary centers for examination. Spatiotemporal image correlation can be combined with other software techniques, such as virtual organ computer-aided analysis (VOCAL) and automatic volume calculation (SonoAVC), to calculate cardiac function parameters. It can also be used in association with Omniview® in order to obtain standard echocardiographic planes using simple targets arterial rendering (STAR) and four-chamber view and swing technique (FAST). Recently, fetal intelligent navigation echocardiography (FINE), acquired from 3D STIC volumes, has made it possible to automatically obtain nine standard echocardiographic planes. In this article, we review the chief applications of 4D echocardiography using STIC technique in clinical practice. How to cite this article Araujo Júnior E, Tedesco GD, Carrilho MC, Peixoto AB, Carvalho FHC. 4D Fetal Echocardiography in Clinical Practice. Donald School J Ultrasound Obstet Gynecol 2015;9(4): 382-396.