U SIGN

Upside Down Stomach organoaxial rotation of stomach in gastric volvulus resulting in reversed positions of lesser and greater curvatures

V SIGN

Vanishing Tumor-AKA Pseudo tumor-fluid in a fissure, usually minor, mostly seen in CHF-vanishes with reversal of failure

Vacuum Disk Sign-abnormal gas in the disk in degenerative disk disease; vacuum joint sign is normal

Vacuum Joint Sign-normal appearance of gasses (nitrogen) that come out of solution in a large joint from traction

W SIGN

Westermark's Sign-focal or regional pulmonary oligemia seen occasionally distal to occlusive thromboembolic disease in the lung

Whiskering-irregular bone growth at sites of tendinous insertions; enthesophytes, seen in DJD, DISH and spondyloarthropathies

Waterbottle Heart-globular shape of heart from a Artificial Intelligence

Waterbottle Heart-globular shape of heart from a large pericardial effusion

Wimberger's Ring Sign-denser white line of calcification encircling the osteoporotic epiphyses in scurvy

Wimberger's Sign-bilateral focal destruction of the medial aspect, proximal tibial metaphyses; pathognomonic for congenital syphilis

Water Lily Sign-collapse of inner wall of hydatid cyst into a partially air-filled, partially fluid-filled cavity

Whirlpool Sign-clockwise swirling of Sup. Mesenteric V. around Sup. Mesenteric A. on transverse abdominal US in infants with midgut volvulus

Y SIGN

Yin Yang Sign-swirling blood flow in a pseudoaneurysm on US or partly thrombosed aneurysm on contrast CT, resembling ancient Chinese symbol

Y Sign-characteristic shape of thecal sac compression in lumbar epidural lipomatosis producing a stellate shape like a "Y"