{"id":10,"date":"2013-12-28T00:18:49","date_gmt":"2013-12-28T00:18:49","guid":{"rendered":"https:\/\/www.newyorkurologyspecialists.com\/kidney-stones\/?p=10"},"modified":"2014-01-19T02:27:17","modified_gmt":"2014-01-19T02:27:17","slug":"use-hounsfield-units-optimize-care-kidney-stones-new-york-urology-specialists","status":"publish","type":"post","link":"https:\/\/www.newyorkurologyspecialists.com\/kidney-stones\/news\/kidney-stone-treatment\/use-hounsfield-units-optimize-care-kidney-stones-new-york-urology-specialists\/","title":{"rendered":"Use of Hounsfield Units to Optimize Care for Kidney Stones: New York Urology Specialists."},"content":{"rendered":"

Innovative physicians at <\/span>New York Urology Specialists<\/strong> are among the first urologists in NYC specializing in kidney stone care to use hounsfield units to optimize care for kidney stones in New York City. \u00a0 We present latest research on the topic for your reference. \u00a0<\/span><\/h3>\n
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BJU Int.<\/a>\u00a02012 Dec;110(11 Pt B):E438-42. doi: 10.1111\/j.1464-410X.2012.10964.x. Epub 2012 Feb 28.<\/h3>\n

A 970\u00a0Hounsfield\u00a0units\u00a0(HU) threshold of kidney stone density on non-contrast computed tomography (NCCT) improves patients’ selection for extracorporeal shockwave lithotripsy (ESWL): evidence from a prospective study.<\/a><\/h1>\n
Ouzaid I<\/a>,\u00a0Al-qahtani S<\/a>,\u00a0Dominique S<\/a>,\u00a0Hupertan V<\/a>,\u00a0Fernandez P<\/a>,\u00a0Hermieu JF<\/a>,\u00a0Delmas V<\/a>,\u00a0Ravery V<\/a>.<\/div>\n
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Author information<\/a><\/h3>\n
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Abstract<\/h3>\n
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What’s known on the subject? and What does the study add? Stone density on non-contrast computed tomography (NCCT) is reported to be a prognosis factor for extracorporeal shockwave lithotripsy (ESWL). In this prospective study, we determined that a 970 HU threshold of stone density is a very specific and sensitive threshold beyond which the likelihood to be rendered stone free is poor. Thus, NCCT evaluation of stone density before ESWL may useful to identify which patients should be offered alternative treatment to optimise their outcome.<\/p>\n

OBJECTIVE:<\/h4>\n

\u2022 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).<\/p>\n

PATIENTS AND METHODS:<\/h4>\n

\u2022 We prospectively evaluated 50 patients with urinary calculi of 5-22 mm undergoing ESWL. \u2022 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\u00a0units\u00a0[HU]), stone location, and presence of JJ stent were studied as potential predictors. \u2022 The outcome was evaluated 4 weeks after the ESWL session by NCCT. \u2022 ESWL success was defined as patients being stone-free (SF) or with remaining stone fragments of <4 mm, which were considered as clinically insignificant residual fragments (CIRF).<\/p>\n

RESULTS:<\/h4>\n

\u2022 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. \u2022\u00a0Stones\u00a0of patients who became SF or had CIRF had a lower density compared with\u00a0stones\u00a0in patients with residual fragments [mean (sd) 715 (260) vs 1196 (171) HU, P < 0.001]. \u2022 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. \u2022 The stone-free rate for\u00a0stones\u00a0of <970 HU was 96% vs 38% for\u00a0stones\u00a0of \u2265 970 HU (P < 0.001). A linear relationship between the calculus density and the success rate of ESWL was identified.<\/p>\n

CONCLUSION:<\/h4>\n

\u2022 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.<\/p>\n

\u00a9 2012 THE AUTHORS. BJU INTERNATIONAL \u00a9 2012 BJU INTERNATIONAL.<\/p>\n<\/div>\n<\/div>\n<\/div>\n

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J Endourol.<\/a>\u00a02012 Sep;26(9):1125-30. doi: 10.1089\/end.2012.0154. Epub 2012 Jun 12.<\/div>\n

Predictive value of attenuation coefficients measured as\u00a0Hounsfield\u00a0units\u00a0on noncontrast computed tomography during flexible ureteroscopy with holmium laser lithotripsy: a single-center experience.<\/a><\/h1>\n
Ito H<\/a>,\u00a0Kawahara T<\/a>,\u00a0Terao H<\/a>,\u00a0Ogawa T<\/a>,\u00a0Yao M<\/a>,\u00a0Kubota Y<\/a>,\u00a0Matsuzaki J<\/a>.<\/div>\n
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Abstract<\/h3>\n
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PURPOSE:<\/h4>\n

To assess the utility of attenuation coefficients as predictors of surgical outcome after a single flexible ureteroscopy (URS) with holmium laser lithotripsy. Many reports indicate that the efficacy of extracorporeal shockwave lithotripsy (SWL) can be predicted by the target’s radiofrequency attenuation, measured as\u00a0Hounsfield\u00a0units\u00a0(HUs) on noncontrast CT (NCCT). Studies of flexible URS, however, have not assessed the predictive value of attenuation coefficients on NCCT.<\/p>\n

PATIENTS AND METHODS:<\/h4>\n

Patients with renal\u00a0stones\u00a0who were treated by flexible URS with holmium laser lithotripsy between December 2009 and October 2011 at a single institute were retrospectively evaluated. Stone-free (SF) status was determined by kidneys-ureters-bladder (KUB) radiography at postoperative month 3. Correlations of possible predictors with SF status were analyzed using a logistic regression model. The comparison between groups with low and high HUs was examined using the Mann-Whitney U test.<\/p>\n

RESULTS:<\/h4>\n

There were 219 eligible procedures. According to the logistic regression model, the maximum attenuation coefficient (P=0.105) and average attenuation coefficient (P=0.175) did not significantly, independently predict SF status. Fragmentation efficiency was significantly different between cases with low and high attenuation coefficients (P=0.001). In groups with less than 20.0-mm diameter\u00a0stones, overall operative time (P<0.001 and P=0.001) and the time from starting fragmentation (P<0.001 and P=0.002) were significantly high in both attenuation groups. In groups with\u00a0stones\u00a0greater than 20.0 mm diameter, the two definitions of operative time revealed no differences between the low and high attenuation groups. The retrospective study design was the major limitation of this study.<\/p>\n

CONCLUSIONS:<\/h4>\n

We found that both the maximum and average attenuation coefficients on NCCT are significantly related to the fragmentation efficiency. In addition, this study showed that, in patient groups with stone a burden <20.0 mm in diameter, both the maximum and average attenuation coefficients were significantly predictive of operative time.<\/p>\n

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Urology.<\/a>\u00a02013 Apr;81(4):880-4. doi: 10.1016\/j.urology.2012.12.012. Epub 2013 Feb 6.<\/div>\n

Kidney stone size and\u00a0hounsfield\u00a0units\u00a0predict successful shockwave lithotripsy in children.<\/a><\/h1>\n
El-Assmy A<\/a>,\u00a0El-Nahas AR<\/a>,\u00a0Abou-El-Ghar ME<\/a>,\u00a0Awad BA<\/a>,\u00a0Sheir KZ<\/a>.<\/div>\n
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Author information<\/a><\/h3>\n
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Abstract<\/h3>\n
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OBJECTIVE:<\/h4>\n

To define the preoperative kidney and\u00a0stones\u00a0characteristics on noncontrast-enhanced computed tomography that affect the success of extracorporeal shockwave lithotripsy (SWL) for treatment of renal calculi in pediatric patients.<\/p>\n

MATERIALS AND METHODS:<\/h4>\n

From 2005 to 2011, 57 children (age\u00a0<16 years) with documented preoperative noncontrast-enhanced computed tomography scans underwent SWL for treatment of renal\u00a0stones\u00a0and were included in the present study. Stone size, site, multiplicity, average skin-to-stone distance, stone attenuation value, and kidney morphology were determined from the preoperative noncontrast-enhanced computed tomography scans. Success was defined as radiographically stone-free status at the 3-month follow-up examination after a single lithotripsy session without the need for additional sessions or ancillary procedures.<\/p>\n

RESULTS:<\/h4>\n

After a single session of SWL, 24 children (42.1%) were stone free on the 3-month follow-up imaging study without the need for additional SWL sessions. Treatment failed in 33 patients (57.9), with residual fragments in 30 children, of whom 29 required repeat SWL, and 3 with\u00a0stones\u00a0that were considered unchanged and were finally treated with percutaneous nephrolithotomy. Logistic regression analysis revealed that stone attenuation in\u00a0Hounsfield\u00a0units\u00a0(HU) and stone length were the only significant predictors of success. When the HU were stratified into 2 groups of\u00a0\u2264600 and >600 HU, the SWL success rate was 82.1% and 20%, respectively (P\u00a0=\u00a0.023). When length was stratified as\u00a0\u226412\u00a0mm and >12\u00a0mm, the stone-free rate was 58.6% and 25.1%, respectively (P\u00a0= .016).<\/p>\n

CONCLUSION:<\/h4>\n

Stone attenuation\u00a0\u2264600 HU and stone length\u00a0\u226412\u00a0mm were significant independent predictors of SWL success in children.<\/p>\n

Copyright \u00a9 2013 Elsevier Inc. All rights reserved.<\/p>\n<\/div>\n<\/div>\n

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