Sex- and age-related composition of 10 617 calculi analyzed by infrared spectroscopy

Daudon, Michel; Donsimoni, R; Hennequin, Carole; Fellahi, Soraya; G, Le Moel; Pâris, M.; Troupel, S; Lacour, Bernard

doi:10.1007/bf00300021

Cited by 183 publications

(113 citation statements)

References 21 publications

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“…Urinary calculi made of calcium oxalate monohydrate (COM) are among the most common stones affecting the populations of industrialized countries [1,2], and can be especially resistant to shock wave (SW) lithotripsy [3,4]. However, study of stone breakage in vitro has shown that COM stones vary dramatically in their fragility to SW's, with some stones being very resistant, and others quite fragile [5,6], and this variability is consistent with clinical experience [4].…”

Section: Introductionsupporting

confidence: 52%

CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro

et al. 2007

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COM stones are often resistant to breakage using shock wave (SW) lithotripsy. It would be useful to identify by computed tomography (CT) those COM stones that are susceptible to SW's. For this study, 47 COM stones (4-10 mm in diameter) were scanned with micro CT to verify composition and also for assessment of heterogeneity (presence of pronounced lobulation, voids, or apatite inclusions) by blinded observers. Stones were then placed in water and scanned using 64-channel helical CT. As with micro CT, heterogeneity was assessed by blinded observers, using high-bone viewing windows. Then stones were broken in a lithotripter (Dornier Doli-50) over 2 mm mesh, and SW's counted. Results showed that classification of stones using micro CT was highly repeatable among observers (κ=0.81), and also predictive of stone fragility. Stones graded as homogeneous required 1874±821 SW/g for comminution, while stones with visible structure required half as many SW/g, 912±678. Similarly, when stones were graded by appearance on helical CT, classification was repeatable (κ=0.40), and homogeneous stones required more SW's for comminution than did heterogeneous stones (1702±993 SW/g, compared to 907±773). Stone fragility normalized to stone size did not correlate with Hounsfield units (p=0.85). In conclusion, COM stones of homogeneous structure require almost twice as many SW's to comminute than stones of similar mineral composition that exhibit internal structural features that are visible by CT. This suggests that stone fragility in patients could be predicted using pre-treatment CT imaging. The findings also show that Hounsfield unit values of COM stones did not correlate with stone fragility. Thus, it is stone

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Section: Introductionsupporting

confidence: 52%

CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro

et al. 2007

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“…However, micro-CT revealed visible content of other minerals in many of the stones; this is expected, because most stones contain more than one mineral component (18). In particular, micro-CT revealed calcium salt content in 13 of the 16 uric acid stones.…”

Section: Resultsmentioning

confidence: 84%

Noninvasive Differentiation of Uric Acid versus Non–Uric Acid Kidney Stones Using Dual-Energy CT

et al. 2007

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Rationale and Objectives-To determine the accuracy and sensitivity for dual-energy computed tomography (DECT) discrimination of uric acid (UA) stones from other (non-UA) renal stones in a commercially implemented product.Materials and Methods-Forty human renal stones comprising uric acid (n = 16), hydroxyapatite (n = 8), calcium ox-alate (n = 8), and cystine (n = 8) were inserted in four porcine kidneys (10 each) and placed inside a 32-cm water tank anterior to a cadaver spine. Spiral dual-energy scans were obtained on a dual-source, 64-slice computed tomography (CT) system using a clinical protocol and automatic exposure control. Scanning was performed at two different collimations (0.6 mm and 1.2 mm) and within three phantom sizes (medium, large, and extra large) resulting in a total of six image datasets. These datasets were analyzed using the dual-energy software tool available on the CT system for both accuracy (number of stones correctly classified as either UA or non-UA) and sensitivity (for UA stones). Stone characterization was correlated with micro-CT.Results-For the medium and large phantom sizes, the DECT technique demonstrated 100% accuracy (40/40), regardless of collimation. For the extra large phantom size and the 0.6-mm collimation (resulting in the noisiest dataset), three (two cystine and one small UA) stones could not be classified (93% accuracy and 94% sensitivity). For the extra large phantom size and the 1.2-mm collimation, the dual-energy tool failed to identify two small UA stones (95% accuracy and 88% sensitivity). Conclusions-In an anthropomorphic phantom model, dual-energy CT can accurately discriminate uric acid stones from other stone types. KeywordsKidney stones; renal calculi; dual-energy computed tomography; uric acid; urolithiasis Symptomatic urinary stone disease affects approximately 900,000 persons in the United States each year, resulting in annual medical cost of $5.3 billion. Nephrolithiasis has traditionally been evaluated using plain film radiographic techniques with or without tomography or administration of intravenous contrast for excretory urography. Over recent years, however, computed tomography (CT) has supplanted these traditional techniques because of increased sensitivity, speed, and the lack of intravenous contrast (1 Although state-of-the-art CT provides accurate submillimeter details of the size and location of renal stones (4,5), current routine clinical image analysis does not differentiate stone composition. This is particularly important in the case of uric acid (UA) stones (~10% of cases), because urinary alkalinization can be prescribed to dissolve UA stones and could thereby be initiated at presentation rather than following lengthy metabolic workup. Therefore simple and reliable differentiation of UA versus non-UA stone composition could potentially allow patients with UA stones to avoid invasive interventional urinary procedures for stone removal or external shock wave lithotripsy, both of which are expensive and might result in renal hemorrh...

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“…Few stones are composed of a single material. 17 Given the variability of stone densities within the same stone, 18 we determined the mean stone density of three separate readings within the same stone. The results of our study show that a mean stone density ≥800 HU is a predictor of ESWL failure.…”

Section: Discussionmentioning

confidence: 99%

The usefulness of stone density and patient stoutness in predicting extracorporeal shock wave efficiency: Results in a North African ethnic group

Abdelaziz¹,

Elabiad

Aderrouj

et al. 2014

CUAJ

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Cite as: Can Urol Assoc J 2014;8(7-8):e567-9. http://dx.doi.org/10.5489/cuaj.1849 Published online August 11, 2014. Abstract Introduction:We determine the role of stone density and skin-tostone distance (SSD) by non-contrast computed tomography of the kidneys, ureters and bladder (CT-KUB) in predicting the success of extracorporeal shock wave lithotripsy (ESWL). Methods: We evaluated 89 patients who received ESWL for renal and upper ureteric calculi measuring 5 to 20 mm, over a 12-month period. The mean stone density in Hounsfield units (HU) and mean SSD in mm was determined on pre-treatment CT-KUB at the CT workstation. ESWL was successful if post-treatment residual stone fragments were ≤3 mm. Results: ESWL success was observed in 68.5% of patients. Mean stone densities were 505 ± 153 and 803 ± 93 HU in the ESWL successful and failure groups, respectively (p < 0.001, student's t-test). The mean SSD were 10.6 ± 2.0 and 11.2 ± 2.6 cm in ESWL successful and failure groups, respectively; this was not statistically significant. Conclusions: This study shows that stone density can help to predict the outcome of ESWL. We propose that stone density <500 HU are highly likely to result in successful ESWL. Conversely, stone densities >800 HU are less likely to be successful.

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Sex- and age-related composition of 10 617 calculi analyzed by infrared spectroscopy

Cited by 183 publications

References 21 publications

CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro

CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro

Noninvasive Differentiation of Uric Acid versus Non–Uric Acid Kidney Stones Using Dual-Energy CT

The usefulness of stone density and patient stoutness in predicting extracorporeal shock wave efficiency: Results in a North African ethnic group

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