A 970 Hounsfield units (HU) threshold of kidney stone density on non-contrast computed tomography (NCCT) improves patients%26apos; selection for extracorporeal shockwave lithotripsy (ESWL): evidence from a prospective study

作者：Ouzaid Idir^*; Al qahtani Said; Dominique Sebastien; Hupertan Vincent; Fernandez Pedro; Hermieu Jean Francois; Delmas Vincent; Ravery Vincent

来源：BJU International, 2012, 110(11B): E438-E442.

DOI：10.1111/j.1464-410X.2012.10964.x

• shockwave lithotripsy
• non-contrast computed tomography
• urolithiasis

OBJECTIVE %26lt;br%26gt;To evaluate the usefulness of measuring urinary calculi attenuation values by non-contrast computed tomography (NCCT) for predicting the outcome of treatment by extracorporeal shockwave lithotripsy (ESWL). %26lt;br%26gt;PATIENTS AND METHODS %26lt;br%26gt;We prospectively evaluated 50 patients with urinary calculi of 5-22 mm undergoing ESWL. %26lt;br%26gt;All patients had NCCT at 120 kV and 100 mA on a spiral CT scanner. Patient age, sex, body mass index, stone laterality, stone size, stone attenuation values (Hounsfield units [HU]), stone location, and presence of JJ stent were studied as potential predictors. %26lt;br%26gt;The outcome was evaluated 4 weeks after the ESWL session by NCCT. %26lt;br%26gt;ESWL success was defined as patients being stone-free (SF) or with remaining stone fragments of %26lt;4 mm, which were considered as clinically insignificant residual fragments (CIRF). %26lt;br%26gt;RESULTS %26lt;br%26gt;Our survey concluded that 26 patients (52%) were SF, 12 (24%) had CIRF and 12 (24%) had residual fragment on NCCT after a one ESWL treatment. %26lt;br%26gt;Stones of patients who became SF or had CIRF had a lower density compared with stones in patients with residual fragments [mean (SD) 715 (260) vs 1196 (171) HU, P %26lt; 0.001]. %26lt;br%26gt;The Youden Index showed that a stone density of 970 HU represented the most sensitive (100%) and specific (81%) point on the receiver-operating characteristic curve. %26lt;br%26gt;The stone-free rate for stones of %26lt;970 HU was 96% vs 38% for stones of %26gt;= 970 HU (P %26lt; 0.001). A linear relationship between the calculus density and the success rate of ESWL was identified. %26lt;br%26gt;CONCLUSION %26lt;br%26gt;The use of NCCT to determine the attenuation values of urinary calculi before ESWL helps to predict treatment outcome, and, consequently, could be helpful in planning alternative treatment for patients with a likelihood of a poor outcome from ESWL.

• 出版日期2012-12