High-frequency color flow imaging of the microcirculation

• Published in: Ultrasound in medicine & biology Vol. 26; no. 1; pp. 63 - 71
• Main Authors: Goertz, David E., Christopher, Donald A., Yu, Joanne L., Kerbel, Robert S., Burns, Peter N., Foster, F.Stuart
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 2000; Elsevier
• Subjects: Angiogenesis; Animals; Biological and medical sciences; Blood flow; Blood Flow Velocity - physiology; Blood velocity; Color Doppler imaging; Color flow mapping; Color image processing; Doppler effect; Doppler ultrasound; Ear - blood supply; High-frequency ultrasound; Investigative techniques, diagnostic techniques (general aspects); Medical imaging; Medical sciences; Mice; Mice, Inbred BALB C; Microcirculation; Microcirculation - diagnostic imaging; Microcirculation - physiology; Microvascular morphology; Miscellaneous. Technology; Morphology; Neoplasms, Experimental - diagnostic imaging; Neoplasms, Experimental - physiopathology; Neovascularization, Pathologic - diagnostic imaging; Neovascularization, Pathologic - physiopathology; Optical resolving power; Phantoms, Imaging; Ultrasonic investigative techniques; Ultrasonic transducers; Ultrasonography, Doppler, Color; Ultrasonography, Doppler, Pulsed - instrumentation; Ultrasonography, Doppler, Pulsed - methods; Microcirculation; Angiogenesis; High-frequency ultrasound; Color Doppler imaging; Color flow mapping; Blood velocity; Microvascular morphology; Doppler ultrasound; Blood flow; Doppler ultrasound study; Performance evaluation; Sonography; Animal model; Rodentia; Instrumentation; Experimental study; In vivo; Vertebrata; Mammalia; Mouse; Animal; Blood vessel; Ear; Technique; High frequency; Spatial resolution
• ISSN: 0301-5629; 1879-291X
• DOI: 10.1016/S0301-5629(99)00101-5

The extension of ultrasound (US) color flow imaging (CFI) techniques to high frequencies (> 20 MHz) has the potential to provide valuable noninvasive tools for scientific and clinical investigations of blood flow in the microcirculation. We describe the development of a slow-scan CFI system operating in the 20–100-MHz range that has been optimized to image the microcirculation. The apparatus has incorporated elements of a previously reported pulsed-wave Doppler system and is capable of operating in either CFI or pulsed-wave mode. The performance of the CFI system was evaluated at a center frequency of 50 MHz using two PVDF transducers with −6-dB beam widths of 43 and 60 μm. The −6 dB-axial resolutions were estimated to be 66 and 72 μm, respectively. In vivo validation experiments conducted using the murine ear model demonstrated the detection of flow in vessels down to 15–20 μm in diameter with flow velocities on the order of mm per s. Further experiments examining experimental murine tumors confirmed the successful detection of flow in the tumor microcirculation.