مقاله انگلیسی رایگان در مورد تصویر سازی جریان خون با اشعه فراصوتی آپتو آکوستیک – الزویر 2018

Simultaneous measurement of multiple hemodynamic parameters is of high importance for the understanding of tissue function and disease progression. Hemodynamic responses are normally produced in response to physical or organ activity, environmental changes as well as neural activity to guarantee proper oxygen delivery to tissues [1,2]. Majority of cardiac and vascular disorders are similarly related to systemic hemodynamic dysfunction, so that hemodynamic measurements are essential in their timely diagnosis and treatment monitoring [3]. Color Doppler ultrasound (US) has arguably become the gold standard for mapping the distribution of blood flow. Handheld US scanners are extensively employed in the clinics for diagnosing blood clots, defects in heart valves, blockage in arteries and numerous other conditions [4]. Owing to its unique capability for non-invasive label-free mapping of the distribution of oxy- and deoxyhemoglobin deep in living tissues, multi-spectral optoacoustic tomography (MSOT) has recently found widespread use in preclinical imaging applications [5,6] and is undergoing rapid clinical translation in various point-of-care diagnostic applications, such as melanomas [7,8], inflammatory bowel (Crohn’s) disease [9], breast abnormalities [10], thyroid cancer [11,12] or peripheral vascular diseases [13]. Efficient integration between MSOT and US in a hybrid handheld scanner is expected to further accelerate clinical translation of MSOT and significantly enhance imaging performance of the stand-alone systems by simultaneously delivering their highly complementary contrasts. While a number of possible hybridization approaches have been previously suggested [14–18], such an efficient combination is inherently challenged by the fundamentally different excitation and image formation strategies behind the two modalities. Recently, a hand-held probe based on a multi-segment detector array combining linear and concave segments with different inter-element pitch has been reported [19,20]. The different parts of the array provide optimized performance for each modality, hence enabling accurate multi-modal optoacoustic and pulse-echo US imaging. The linear segment may additionally be exploited for other US modes, such as Doppler US. Here we adopted the multi-segment array approach in order to achieve multi-modal MSOT, pulse-echo US and color Doppler imaging in a hand-held mode. The experimental performance of the multi-modal approach is further showcased by imaging the carotid artery region of a healthy volunteer, where Doppler US is commonly used for the detection of vascular abnormalities, such as stenosis or intraluminal turbulence [21].