In this volar transverse image of the carpal tunnel, the arrows represent needles, and the arrowheads represent the needle tips. In planning a carpal tunnel corticosteroid injection with ultrasound guidance, which of the arrows combines the safest path through tissues with the BEST needle visualization?

At approximately how many degrees of flexion is the MOST sensitive resting position of the knee for imaging fluid in the suprapatellar recess?

An 81-year-old male with known shoulder osteoarthritis presents to the office for an ultrasound-guided injection of the glenohumeral joint. Prior to injection, where should the needle tip be visualized?

What is the MAXIMUM normal distance between the markers in this plantar longitudinal view of the foot?

Which of the following images is MOST suggestive of sonographic features of patients with spondyloarthropathy?