Mouse Inguinal Lymph Node Volume Analysis: An Ultra-high-frequency Ultrasound Imaging Technique to Determine the Volume of Inguinal Lymph Node in Mouse Model

Ultra-high-frequency ultrasound, or UHFUS, facilitates high spatial resolution imaging of superficial structures in a live animal.

To begin, place an anesthetized mouse in the supine position on the heated platform of an imaging station to regulate its body temperature. Insert a probe to monitor the body temperature.

Next, coat the limbs with conductive paste and secure them to the electrocardiogram electrodes embedded in the platform to monitor the physiological parameters. Remove the hair from the mouse inguinal region. Apply the acoustic coupling medium to provide an efficient path for ultrasound propagation. Position the UHFUS transducer over the inguinal region.

During the scan, the transducer emits ultra-high-frequency ultrasound pulses with reduced penetration depth into the superficial inguinal lymph node. Based on the lymph node density and size, a fraction of the ultrasound pulses with varying amplitudes is reflected and received by the transducer, converting these signals into electrical signals.

Further, the computer reconstructs them to obtain a two-dimensional high-resolution ultrasound image, wherein the brightness of each dot is determined by the amplitude of the reflected signals. Scan the entire region of the lymph node by linear movement of the transducer to obtain a sequence of short-axis images.

Using suitable software, post process the acquired ultrasound images to create a 3D ultrasound image of the inguinal lymph node and measure its volume.