Feasibility of a New Non Invasive Method for the Evaluation of Coronary Blood Flow in the Left Anterior Descending Coronary Artery: Contrast-enhanced Transthoracic Harmonic Echo Doppler

Coronary artery disease (CAD) is considered to be a major cause of mortality and morbidity in the developing world. It has recently been shown that aortic root pathologies such as aortic stiffening and calcific aortic stenosis can contribute to the initiation and progression of this disease by affecting coronary blood flow [1,2]. Such pathologies influence the distensibility of the aortic root and therefore the hemodynamics of the entire region. As a consequence the coronary blood flow and velocity profiles will be altered [3,4,5] which could accelerate the development of an existing coronary artery disease. However, it would be very interesting to see if an occluded coronary artery would have a mutual impact on valvular dynamics and aortic root pathologies. This bi-directionality could aggravate and contribute to the progression of both the coronary and aortic root pathology.

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Calculation of coronary artery non-invasive blood flow reserve fraction based on combination of digital and analog

2021 36th Youth Academic Annual Conference of Chinese Association of Automation (YAC) ◽

10.1109/yac53711.2021.9486634 ◽

2021 ◽

Author(s):

Chenglan Wang ◽

Zirong Wang ◽

Guo Xie ◽

Haitao Duan ◽

Jing Yang

Keyword(s):

Blood Flow ◽

Coronary Artery ◽

Non Invasive ◽

Flow Reserve

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Abstract P225: Non-invasive Measurement of Renal Blood Flow (RBF) in Different Rat Models by Magnetic Resonance Imaging (MRI)

Hypertension ◽

10.1161/hyp.70.suppl_1.p225 ◽

2017 ◽

Vol 70 (suppl_1) ◽

Author(s):

Cesar A Romero ◽

Robert Knight ◽

Glauber Cabral ◽

Oscar A Carretero

Keyword(s):

Blood Flow ◽

Sham Group ◽

Motion Artifacts ◽

Arterial Stenosis ◽

7 Tesla ◽

Hypertensive Rats ◽

Rat Models ◽

Non Invasive ◽

Sd Rats ◽

Invasive Method

Quantitative measure of RBF provides important information regarding renal physiology and pathology, in different animal’s models. Arterial Spin Labelling-MRI (ASL-MRI) is a non-invasive method to measure blood flow without exogenous contrast media, using arterial water protons labeled by radiofrequency as an endogenous tracer. However, the low signal/noise radio, and the motion artifacts are a challenge for the acquisition of RBF in small animals. Our objective is evaluated the feasibility and reproducibility of the RBF measure by ASL-MRI in different hypertensive rats models. ASL-MRI images were obtained in Sprague-Dawley (SD) rats (200-300g) under inhalation anesthesia using a 7 Tesla Varian MRI system with a spin echo imaging sequence. After 4 days the MRI studies was repeated to evaluate reproducibility, using paired sample T-test and the test-retest reliability (TR) equation. RBF was also measured in in Dahl SS rats on regular chow and spontaneous hypertensive rats (SHR). Additionally we measure the RBF in a set of animals under unilateral nephrectomy (UNx) and renal arterial stenosis (RS) before and after the surgery. Table 1 shows the mean cortical RBF in different rat strains and models. Re-test analysis showed no relevant differences, being the means of differences 9.4±35 ml/min/100g tissue (p=0.58) in SD rats. The TR was 92.4±6%. UNx increase the RBF in 69.1% in comparison with sham group. (p<0.01). After the RS the blood pressure increased and the RBF decrease 56% (p<0.01) in comparison with sham group. ASL-MRI performed with navigator correction and respiratory gating is a feasible and reproducible non-invasive method to measure RBF in several rat models.

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