Changes

File:CT measurement of kidney stone in soft tissue and bone window.jpg|Measurement of a 5.6 mm large kidney stone in soft tissue window (at left, with width of 400 HU, and center at 50 HU) versus skeletal [[CT_scan#Processwindow (right, W1800,C400). 145 HU is regarded as an appropriate cutoff to distinguish a stone from surrounding tissue.<ref name="LidénThunberg2015">{{cite journal|last1=Lidén|first1=Mats|last2=Thunberg|first2=Per|last3=Broxvall|first3=Mathias|last4=Geijer|first4=Håkan|title=Two- and three-dimensional CT window]]measurements of urinary calculi length and width: a comparative study|journal=Acta Radiologica|volume=56|issue=4|year=2015|pages=487–492|issn=0284-1851|doi=10.1177/0284185114528490}}</ref>

*Measure the size of stones. Stones Proper sizing of a stone is important at around 5 mm and above, since smaller stones generally pass spontaneously.<ref group="notes">Ureteric stones less than 5 mm (0.2 in) in diameter pass spontaneously in up to 98% of cases, while those measuring 5 to 10 mm (0.2 to 0.4 in) in diameter pass spontaneously in less than 53% of cases.<ref name=Gettman2005br>- {{cite journal|last=Gettman|first=MT|last2=Segura|first2=JW|title=Management of ureteric stones: Issues and controversies|journal=British Journal of Urology International|volume=95|issue=Supplement 2|pages=85–93|year=2005|pmid=15720341|doi=10.1111/j.1464-410X.2005.05206.x}}</ref> Sizing of larger stones is also important in order to decide which treatment to choose.<ref group="notes">Small proximal ureteral calculi of less than 10 mm are best treated with shock wave lithotripsy and ureteroscopy, while those larger than 10 mm are best treated with flexible ureteroscopy combined with holmium laser lithotripsy.<br> - {{cite web|url=https://www.uptodate.com/contents/management-of-ureteral-calculi|title=Management of ureteral calculi|author=Glenn M Preminger, Section Editors:Stanley Goldfarb, Michael P O'Leary. Deputy Editor:Albert Q Lam|date=2018-01-19|website=UpToDate}}</ref>