Ureterolithiasis and hydronephrosis in pregnancy on transabdominal and transvaginal ultrasound

32-year-old patient, 7 weeks pregnant, presenting with left flank pain. Longitudinal ultrasound image of the left kidney (A) shows mild hydronephrosis. Longitudinal images of the bladder show dilation of the distal left ureter with a stone (arrow, B grayscale with shadowing and arrow, C color Doppler with twinkle artifact). Transvaginal images of the distal left ureter show the stone on grayscale (D, arrow) and with color Doppler (E, arrow).