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Background: This study highlighted the differences between the biochemical compositions of urinary stones from patients with type 1 diabetes versus those with type 2 diabetes. Materials and Methods: This study included patients diagnosed with kidney stones and diabetes who were referred to the Urological Clinic of the Dr. C. I. Parhon Hospital in Iasi from April 2017 to April 2024. We analyzed the spectroscopic stone composition from 128 lithiasis patients treated in our Clinic. In the current study, the distribution of the biochemical composition of stones varied significantly between diabetic patients with type 2 diabetes, who formed primarily mixed uric acid stones, and diabetic patients with type 1 diabetes, who mainly developed pure uric acid stones (p < 0.001). Patients with uric acid stones had significantly higher mean creatinine values than the other stone types (p < 0.001). Urinary pH levels were abnormal for all biochemical subtypes of stones, indicating acidic urine. However, patients with uric acid stones had lower pH values than the group average. From the Kaplan–Mayer analysis, patients with pure uric acid stones had a shorter time to stone recurrence compared to patients with other biochemical types identified. Conclusions: These findings, which highlight the prevalence of pure uric acid stones in patients with type 1 diabetes and the impact of this on the strategy for dissolving pure stones, represent a significant advancement in understanding urinary lithiasis in diabetic patients. [ABSTRACT FROM AUTHOR]

Objectives: Urosepsis currently accounts for half of all post flexible ureterorenoscopy (F-URS) complications, with an incidence of up to 4.3%. It represents a quarter of all septic episodes in adults and 2% of hospital spendings. The primary objective of this study was to define the predictive clinical parameters that increase the risk of urosepsis after F-URS. Subjects/patients (or materials) and methods: This prospective multicentric study evaluated patients who underwent F-URS for calculus between June 2016 and June 2018 in eleven French centers. Clinical, bacteriological, morpho-constitutional stone data, intraoperative information and complications were compared. Risk factors for postoperative urosepsis were identified and analyzed. Results: We included 486 F-URS in 432 patients. The ureter was prepared using a double J stent in 51% of cases, a digital endoscope was used in 56% of patients with a median operative time of 120 min IQR (90–125) and using a sheath in 90% of cases. Postoperative urosepsis was observed in 18 patients (4%) with a median time to onset of 2 days IQR (1–5). The presence of coronary insufficiency: 3 (17%) vs 14 (3%) p = 0.005, a larger stone diameter: 11 cm [9–17] vs 10 cm [8–13] p = 0.02, a positive preoperative urine culture even when treated: 3 (17%) vs 56 (12%) p = 0.04, as well as the final composition of the type IV calculus (carbapatite or struvite) 5 (28%) vs 20 (4%) p < 0.001, were significantly associated with the occurrence of urosepsis. In multivariate analysis, only the presence of a type IV stone (OR = 14.0; p = 0.025) remained significant. Conclusion: Ureteroscopic treatment of a type IV stone (carbapatite or struvite) in a patient should raise concerns about the risk of post-operative urosepsis. When recognized intraoperatively, they should lead to a pyelic urinary sample and prolonged clinical surveillance. [ABSTRACT FROM AUTHOR]

Purpose: Preventative strategies and surgical treatments for urolithiasis depend on stone composition. However, stone composition is often unknown until the stone is passed or surgically managed. Given that stone composition likely reflects the physiological parameters during its formation, we used clinical data from stone formers to predict stone composition. Materials and Methods: Data on stone composition, 24-hour urine, serum biochemistry, patient demographics, and medical history were prospectively collected from 777 kidney stone patients. Data were used to train gradient boosted machine and logistic regression models to distinguish calcium vs noncalcium, calcium oxalate monohydrate vs dihydrate, and calcium oxalate vs calcium phosphate vs uric acid stone types. Model performance was evaluated using the kappa score, and the influence of each predictor variable was assessed. Results: The calcium vs noncalcium model differentiated stone types with a kappa of 0.5231. The most influential predictors were 24-hour urine calcium, blood urate, and phosphate. The calcium oxalate monohydrate vs dihydrate model is the first of its kind and could discriminate stone types with a kappa of 0.2042. The key predictors were 24-hour urine urea, calcium, and oxalate. The multiclass model had a kappa of 0.3023 and the top predictors were age and 24-hour urine calcium and creatinine. Conclusions: Clinical data can be leveraged with machine learning algorithms to predict stone composition, which may help urologists determine stone type and guide their management plan before stone treatment. Investigating the most influential predictors of each classifier may improve the understanding of key clinical features of urolithiasis and shed light on pathophysiology. [ABSTRACT FROM AUTHOR]

An increased prevalence of vascular calcification (VC) has been reported in kidney stone formers (KSFs), along with an elevated cardiovascular risk. The aim of the current study is to assess whether VC in these patients develops at a younger age and is influenced by stone composition. This single-center, matched case-control study included KSFs with uric acid or calcium oxalate stones (diagnosed based on stone analysis) and age- and sex-matched controls without a history of nephrolithiasis. The prevalence and severity of abdominal aortic calcification (AAC) and bone mineral density (BMD) were compared between KSFs and non-KSFs. In total, 335 patients were investigated: 134 with calcium oxalate stones, 67 with uric acid stones, and 134 controls. Overall, the prevalence of AAC was significantly higher among calcium stone formers than among the controls (67.9% vs. 47%, p = 0.002). In patients under 60 years of age, those with calcium oxalate stones exhibited both a significantly elevated AAC prevalence (61.9% vs. 31.3%, p = 0.016) and severity (94.8 ± 15.4 vs. 30.3 ± 15.95, p = 0.001) compared to the controls. Within the age group of 40–49, osteoporosis was identified only in the KSFs. Multivariate analysis identified age, smoking, and the presence of calcium stones as independent predictors of AAC. This study highlights that VC and osteoporosis occur in KSFs at a younger age than in non-stone-formers, suggesting potential premature VC. Its pathogenesis is intriguing and needs to be elucidated. Early evaluation and intervention may be crucial for mitigating the cardiovascular risk in this population. [ABSTRACT FROM AUTHOR]

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Objectives: The aim of this study is to analyze the compositions of urinary stones and investigate their distributions in different ages, genders, seasons, and clinical features of Northern Vietnamese patients. Methods: A total of 231 patients with urinary stones from Northern Vietnam were collected and analyzed composition from 1/2021-12/2022. For all patients, age, sex, stone location, stone side, urine pH, and hospitalized date (month) were collected. Results: Kidney stones are more frequently found in men than women with the male: female urinary stones ratio in this study being 1.96:1. The highest stone prevalence appeared between 60 and 69 years old. The most common stone composition was calcium oxalate, followed by calcium phosphate, uric acid, struvite, and cysteine. Mix stones of CaOx and CaP were more prevalent than pure stones. Males submitted more CaOx, CaP, and UA stones, whereas females were susceptible to infectious stones. Stones were more frequently found on the left side of the upper urinary tract (51.9%) than on the right side (27.3%) and lower urinary tract (7.8%). Cultural tendency leads to a smaller number of stones during the Lunar new year (February), and Ghost month (August). [ABSTRACT FROM AUTHOR]

Proper analysis of urinary stone composition is a cornerstone for diagnosis, targeted treatment and recurrence prevention of urolithiasis. The aim of this study was to determine the composition, frequency and distribution of mixed stones according to gender and age of patients. A total of 42,519 urinary stones from 30,311 men and 12,208 women submitted between January 2007 and December 2020 were studied. Most urinary calculi consisted of two components (50.9%), followed by stones of a single constituent (27.1%) and three-component stones (21.9%), while four-component stones were only rarely identified (0.1%). Among all stones, 49.8% consisted of whewellite (COM), weddellite (COD), and mixtures of COM and COD, 33.8% were pure carbonate apatite (CA) and mixtures of CA with COM and/or COD, while 7.6% were composed of uric acid anhydrous (UAA), uric acid dihydrate (UAD), and mixed UAA and UAD. The remaining 8.8% of calculi were rare single-component stones and rare mixtures of various constituents. The number of stone components was inversely associated with age (p < 0.001). The proportion of men decreased significantly with the number of stone constituents, from 3.01:1 for single-component stones to 1.0:1 for four-component urinary calculi (p < 0.001). The vast majority of urinary calculi consisted of two or more components in varying proportions. While age was inversely associated with the number of stone constituents, the proportion of women increased significantly from single-component to four-component urinary calculi. A significant proportion of mixed stones could present a challenge for diagnosis and targeted recurrence prevention. [ABSTRACT FROM AUTHOR]

Purpose: Bone loss has been found to occur frequently in patients with particular metabolic disorders that are likely associated with certain kidney stone composition. Thus, we compared the bone mineral density (BMD) of patients with different kidney stone compositions. Patients and methods: A total of 204 consecutive patients who exhibited stone formation with calcium oxalate (CaOx), calcium phosphate (CaP), uric acid (UA), and magnesium ammonium phosphate (MAP) underwent 24 h urine test and BMD measurement. BMD was measured by dual X-ray absorptiometry at the lumbar spine (LS) and femoral neck (FN). The Z-score was used to express BMD. A BMD Z-score ≤ − 2 was defined as a diagnostic threshold for bone loss. Results: Amongst the patients, 38 had an LS BMD Z-score of ≤ − 2, but only 2 had FN BMD Z-score of ≤ − 2. The group with an LS BMD Z-score of ≤ − 2 exhibited significantly larger male − female ratio, higher frequency of hypercalciuria and CaP, and lower frequency of MAP than the group with an LS BMD Z-score of > − 2. Reduced LS BMD was most remarkable in the CaP group, followed by the CaOx, UA, and MAP groups. The LS BMD Z-score of hypercalciuric patients was significantly lower than that of normocalciuric patients only in the CaP group. Conclusion: Patients with different kidney stone compositions presented different BMD status. Using this information may facilitate medical decision-making in patients with kidney stone who should undergone BMD earlier. [ABSTRACT FROM AUTHOR]

Objective To explore the application value of CT Hounsfield unit (HU) of urinary calculi in the determination of stone composition in children. Methods For this retrospective study, between April 2009 and April 2022, 422 children of urinary tract calculi were recruited as research subjects. Based upon the results of postoperative stone composition analysis, they were assigned into 4 groups of calcium oxalate calculus, uric acid calculus, struvite and cystine calculus. Urinary pH value, HU value in stone core, HU value in stone periphery, average HU value and Hounsfield unit density (HUD) of stone were statistically examined. Results The HU value in the periphery of uric acid calculus group (399±158), calcium oxalate calculus group (529±223), struvite group (556±312), cystine calculus group (566±154), uric acid calculus group was lower than calcium oxalate calculus group, struvite group and cystine calculus group, the differences were statistically significant (P < 0.05). The average HU value of uric acid calculus group (425±166), calcium oxalate calculus group (585±251), struvite group (597±326), cystine calculus group (589±155), uric acid calculus group was lower than calcium oxalate calculus group, struvite group and cystine calculus group, the differences were statistically significant (P < 0.05). The HU value in the core of the uric acid calculus group was (476±201), the calcium oxalate calculus group was (697±324), and the struvite group was (681±371). The HU value in the core of the uric acid calculus group was lower than that of the calcium oxalate calculus group and the struvite group, and the differences were statistically significant (P < 0.05). The HUD of the calcium oxalate calculus group (65±27), uric acid calculus group (39±16), struvite group (54±25), cystine calculus group (41±17), calcium oxalate calculus group was higher than uric acid calculus group, struvite group and cystine calculus group, the differences were statistically significant (P < 0.05). The HUD of uric acid calculus group was lower than that of struvite group, and the difference was statistically significant (P < 0.05). The urine pH value of cystine calculus group was 6.5 (6.0, 7.13), calcium oxalate calculus group was 6.0 (6.0, 6.5), and uric acid calculus group was 6.0 (6.0, 6.5). The urine pH value of cystine calculus group was higher than that of calcium oxalate calculus group and uric acid calculus group, and the differences were statistically significant (P < 0.001). The area under curve (AUC) of HUD of calcium oxalate calculus and non-calcium oxalate calculus groups was 0.755 with a sensitivity of 0.722, a specificity of 0.705 and an optimal cut-off value of 48. Non-uric acid core calculus in uric acid calculus group had an AUC of 0.700 with a sensitivity of 0.607, a specificity of 0.764 and an optimal cutoff value of 566. AUC of median urinary pH value in cystine calculus and non-cystine calculus groups was 0.704 with a sensitivity of 0.682, a specificity of 0.657 and an optimal cutoff value of 6.25. Conclusions Measurement of CT HU value may provide references for determining the composition of calcium oxalate and uric acid calculi. When HU value of stone core is below 566, it hints at uric acid calculus. Calcium oxalate calculus is suggested when HUD is 48 or above. [ABSTRACT FROM AUTHOR]

Objective To study the characteristics of gallstone composition in Tibetans. Methods Gallstone/gallbladder stone(GS) specimens were collected from 106 Tibetan patients in the Department of General Surgery of Tibet Autonomous Region People′s Hospital from January to June 2021. The contents of cholesterol, bilirubin, cholic acid and calcium, sulfur, iron and zinc in gallstone were determined by ultraviolet spectrophotometer and by inductively coupled plasma spectrometer. Results Among 106 cases of cholecystolithiasis, 8.49% (9 cases) were cholesterol gallstones with cholesterol content of 534(528,725)μg/mg; 19.81% (21 cases) were pigment stones, and the content of bile pigment was 320(311,413)μg/mg; 71.69% (76 cases) were other types of stones; At the same time, bile acid with different contents was detected in three types of stones, and the content of bile acid in other types of stones was 22(12,33)μg/mg; The content of calcium, zinc and sulfur in pigment stone was relatively high(P＜0.05), but the content of iron didn′t show had significant difference. Conclusions Gallstone ofTibetan people is mainlycomposed of other stones and pigment stones. Cholesterol stones only account for a small proportion, which is quite different from the composition profile from other parts of China. The content of calcium, sulfur and zinc in pigment stone is relatively high, and the content of calcium is the highest element.

Urolithiasis is a major public health issue due to its increasing prevalence. The objective of this study was to describe the spectrophotometric profile of upper urinary tract stones (UTS) in Senegal. We conducted a multicenter retrospective study of all patients treated for upper UTS whose chemical composition was analyzed from January 2014 to January 2020 in eight regions of Senegal. Socio-demographic, clinical, paraclinical, and prognosis data were collected and analyzed. Three hundred and thirty-four patients were included in this study with a mean age of 46.3 ± 18.4 years and a sex ratio of 1.38. About one-third of patients (31.1%) had a body mass index > 25 kg/m2 and 74.2% presented with lumbar pain was the main clinical symptom. Calcium oxalate and calcium phosphate stones were the predominant types found, respectively, in 37.7% and 24.5% of patients. Uric acid was the main stone constituent in 18.6% of patients and struvites represented 14.7% of cases. Stones were located in the renal calyces and pelvis in 71.2% of cases. Surgical lithotomy was performed in 62.7% of patients for UTS extraction. Upper UTS are frequent condition in Senegalese with predominance of males and young adults. Calcium and uric acid stones are the main types. Preventive dietary and lifestyle measures are needed to reduce their burden. [ABSTRACT FROM AUTHOR]

Objective To study the characteristics of gallstone composition in Tibetans. Methods Gallstone/gallbladder stone(GS) specimens were collected from 106 Tibetan patients in the Department of General Surgery of Tibet Autonomous Region People′s Hospital from January to June 2021. The contents of cholesterol, bilirubin, cholic acid and calcium, sulfur, iron and zinc in gallstone were determined by ultraviolet spectrophotometer and by inductively coupled plasma spectrometer. Results Among 106 cases of cholecystolithiasis, 8.49% (9 cases) were cholesterol gallstones with cholesterol content of 534(528,725)μg/mg; 19.81% (21 cases) were pigment stones, and the content of bile pigment was 320(311,413)μg/mg; 71.69% (76 cases) were other types of stones; At the same time, bile acid with different contents was detected in three types of stones, and the content of bile acid in other types of stones was 22(12,33)μg/mg; The content of calcium, zinc and sulfur in pigment stone was relatively high(P＜0.05), but the content of iron didn′t show had significant difference. Conclusions Gallstone of Tibetan people is mainly composed of other stones and pigment stones. Cholesterol stones only account for a small proportion, which is quite different from the composition profile from other parts of China. The content of calcium, sulfur and zinc in pigment stone is relatively high, and the content of calcium is the highest element. [ABSTRACT FROM AUTHOR]

The objective: to study the peculiarities of changes in the activity levels of the renal specific enzymes N-acetyl-β-Dglucosaminidase (NAG) and β-galactosidase (β-Gal) as indicators of the functional state of the kidney parenchyma in the urine of patients with ureterolithiasis, depending on the mineral composition of the calculi and their localization in the ureter Materials and methods. 81 patients were examined for unilateral ureterolithiasis (45 men, 36 women), the average age of the patients was 43.2±9.7 years. In the studied patients, the stone sizes were on average 1.1±0.38 cm. The activity of NAG and β-Gal was determined in the urine before the stone was removed. All patients were divided into groups: 1st group - 33 patients with calcium oxalate stones, 2nd group - 18 persons with uric acid stones, 4th group - 12 patients with phosphate stones. The control group included 28 practically healthy people. Depending on the location of the calculus, the patients were divided into subgroups: localization of stones in the upper third of the ureter - subgroup 1a (n=17), in the middle third - subgroup 2a (n=23), in the lower third of the ureter - subgroup 3a (n=41). Urine for analysis was obtained during catheterization of the ureter from the side affected by the stone, before the use of medical agents and after physiological urination. Results. The activity levels of NAG and β-Gal in the urine from the side affected by the calculus (renal pеlvis) in 81 patients were statistically significantly different from similar indicators in the urine from the bladder after physiological urination in the same patients (р<0.001-0.02). In the urine of patients with unilateral ureterolithiasis, there were no significant changes in the activity levels of NAG and β-Gal depending on the mineral composition of the calculi, with the exception of patients with phosphate urolithiasis. The intensity of activity levels (both NAG and β-Gal) in the urine of these patients was most high in the upper third of the ureter (group 1a), the less high - in the lower third of the ureter (group 3a), the difference was statistically significant (р<0.001-0.02). Conclusions. The analysis of changes in the levels of urinary activity of NAG and β-Gal allows to objectively assess the functional state of the tubular nephrothelium in patients with ureterolithiasis before surgical intervention, and in the post-treatment period will help to monitor the effectiveness of treatment. [ABSTRACT FROM AUTHOR]

Purpose: As part of the management of nephrolithiasis, determination of chemical composition of stones is important. Our objective in this study is to assess urologists' accuracy in making visual, intraoperative determinations of stone composition. Materials and methods: We conducted a REDCap survey asking urologists to predict stone composition based on intraoperative images of 10 different pure-composition kidney stones of 7 different types: calcium oxalate monohydrate (COM), calcium oxalate dihydrate (COD), calcium phosphate (CP) apatite, CP brushite, uric acid (UA), struvite (ST) and cystine (CY). To evaluate experience, we examined specific endourologic training, years of experience, and number of ureteroscopy (URS) cases/week. A self-assessment of ability to identify stone composition was also required. Results: With a response rate of 26% (366 completed surveys out of 1,370 deliveries), the overall accuracy of our cohort was 44%. COM, ST, and COD obtained the most successful identification rates (65.9%, 55.7%, and 52.0%, respectively). The most frequent misidentified stones were CP apatite (10.7%) and CY (14.2%). Predictors of increased overall accuracy included self-perceived ability to determine composition and number of ureteroscopies per week, while years of experience did not show a positive correlation. Conclusions: Although endoscopic stone recognition can be an important tool for surgeons, it is not reliable enough to be utilized as a single method for stone identification, suggesting that urologists need to refine their ability to successfully recognize specific stone compositions intraoperatively. [ABSTRACT FROM AUTHOR]

Several studies have reported a worldwide increase in incidence and prevalence of nephrolithiasis, with some specificities across countries and regions. A retrospective review was performed on all urinary calculi submitted between 2009 and 2019 from a large part of the western Switzerland to our laboratory. A total of 10,437 stones were analysed and the presence of 18,804 compounds revealed. The median age of patients was 51 years and the global male-to-female ratio was 2.49:1. From 2009 to 2019, calcium oxalates containing calculi were the most frequent, followed by calcium phosphate and uric acids, the latter being more common in men, whereas carbapatite was the second most frequent component in women. Infection stone frequency remained unchanged and low, with a higher rate for women. Finally, while Randall’s plaque frequency was relatively small (7.4%), patients experiencing them were significantly younger. In this review, we identified an age and gender relationship of stone composition and Randall’s plaque formation in our Swiss region, which paves the way for future investigations.

The development of new modalities for kidney stone prevention rests upon understanding the progression of mineralization within the renal pyramid. The progression from small foci of mineralized volumes within the renal pyramid to larger interstitial plaques that ultimately lead into clinically detectable calcium-based stones on calcium phosphate stems will be presented through correlative microscopy approach. High resolution X-ray computed tomography (micro-XCT), electron microscopy, and energy dispersive X-ray (EDX) compositional analyses of interstitial plaques, stems, and attached stones were performed. Increase in mineral density progressed with mineralization severity, with the highest mineral densities detected within mature Randall's plaque and stems to which kidney stones were attached. EDX analyses revealed variable elemental composition within interstitial plaque, stems, and stones. Micro-XCT reconstructions of stones with stems enabled visualization of unoccluded tubules within stems, with average tubule diameters corresponding to thin limbs of Henle, blood vessels, and collecting ducts. Correlative microscopy confirmed that the progression of mineralization leading to calcium-based nephrolithiasis occurs through a continuum involving four anatomically and structurally distinct biomineralization regions: 1) proximal intratubular mineralization within the renal pyramid; 2) interstitial Randall's plaque near the tip of the papilla; 3) emerging plaque (stems); and, 4) the body of heterogeneous stones.Statement of significanceNephrolithiasis is a common condition affecting nearly 1 in 11 Americans. The most common type of stone, calcium oxalate is known to form on a calcium phosphate deposit on the renal papilla known as Randall's plaque. Novel imaging techniques have identified distinct regions of biomineralization not just at the tip, but throughout the renal papilla. The classic understanding of Randall's plaque formation is reformulated using correlative imaging techniques. This study establishes a stepwise progression of anatomically-specific biomineralization events including, 1) proximal intratubular mineralization within the renal pyramid; 2) interstitial Randall's plaque near the tip of the papilla; 3) emerging plaque (stems); and, 4) the body of heterogeneous stones, and provides insights into the need for plausible site-specific therapeutic intervention.

Background: Urolithiasis is a growing issue globally, but it is heterogeneous, with a different epidemiology and pathophysiology for each different stone composition. Objective: The purpose of this study is to describe the incidence of urinary stones in the USA from 2016 to 2019 by chemical composition and to investigate the influence of age and geography on these stone types. Design, setting, and participants: We obtained compositional analyses for all urinary stones submitted to a national laboratory over an approximately 3-yr period. Outcome measurements and statistical analysis: Data collected included the chemical constituents of a stone, patient age, and geographical origin. We describe the incidence of each stone type by frequency. Statistical testing was performed to determine the influence of age and geographical region on overall incidence of each stone composition. Results and limitations: In total, 99 908 specimens were analyzed. When pure stones were ordered by frequency, we found that the most common stone type was calcium oxalate (CaOx) (79.2%), followed by uric acid (UA; 14.3%), calcium phosphate (CaPO4; 3.7%), cystine (0.51%), drug induced (0.12%), and magnesium ammonium phosphate (0.04%). CaOx, UA, and CaPO4 were often mixed with one another. Among CaOx stones, the plurality (28.0%) was made of pure calcium oxalate monohydrate (COM), and only 0.002% was pure calcium oxalate dihydrate. There was an overall association between stone composition and both geographical distribution and age (p < 0.001). Conclusions: CaOx stones comprise the majority of urinary stones in the USA, of which almost 28% were pure COM. Additionally, age and geographical region are significantly associated with variations in stone composition. Patient summary: We evaluated the incidence of urinary stones in the USA based on their chemical composition. The most common stone type was calcium oxalate, the majority of which was pure calcium oxalate monohydrate. We also found age and geographical region to be significantly associated with variations in stone composition.

Objective: To assess the diagnostic accuracy and intra-observer agreement of endoscopic stone recognition (ESR) compared with formal stone analysis. Introduction: Stone analysis is a corner stone in the prevention of stone recurrence. Although X-ray diffraction (XRD) and infrared spectroscopy are the recommended techniques for reliable formal stone analysis, this is not always possible, and the process takes time and is costly. ESR could be an alternative, as it would give immediate information on stone composition. Materials and Methods: Fifteen endourologists predicted stone composition based on 100 videos from ureterorenoscopy. Diagnostic accuracy was evaluated by comparing the prediction from visual assessment with stone analysis by XRD. After 30 days, the videos were reviewed again in a random order to assess intra-observer agreement. Results: The median diagnostic accuracy for calcium oxalate monohydrate was 54% in questionnaire 1 (Q1) and 59% in questionnaire 2 (Q2), whereas calcium oxalate dihydrate had a median diagnostic accuracy of 75% in Q1 and 50% in Q2. The diagnostic accuracy for calcium hydroxyphosphate was 10% in Q1 and 13% in Q2. The median diagnostic accuracy for calcium hydrogen phosphate dihydrate and calcium magnesium phosphate was 0% in both questionnaires. The median diagnostic accuracy for magnesium ammonium phosphate was 20% in Q1 and 40% in Q2. The median diagnostic accuracy for uric acid was 22% in both questionnaires. Finally, there was a diagnostic accuracy of 60% in Q1 and 80% in Q2 for cystine. The intra-observer agreement ranged between 45% and 72%. Conclusion: Diagnostic accuracy of ESR is limited and intra-observer agreement is below the threshold of acceptable agreement. [ABSTRACT FROM AUTHOR]

Based on mean Hounsfield Unit (HuMean), we aimed to evaluate the additional use of standard deviation of Hounsfield Unit (HuStd), minimum Hounsfield Unit (HuMin), and maximum Hounsfield Unit (HuMax) in noncontrast computed tomography (NCCT) to evaluate uric acid (UA) stones more accurately. The data of patients who underwent the NCCT examination and infrared spectroscopy in our hospital from August 2017 to December 2021 were analyzed retrospectively. Based on CT scans, the HuMean, HuStd, HuMin, and HuMax of all patients were measured. The patients were divided into groups according to the stone composition. The attenuation value of mixed stones was in the middle of their pure stones. Except for Str, statistically significant differences between UA stones and other pure stones were observed for HuMean, HuStd, HuMin, and HuMax. A moderate correlation was found between HuMean, HuStd, HuMin, and HuMax and UA stones (rs showed −0.585, −0.409, −0.492, and −0.577, respectively). Receiver operator characteristic (ROC) curve showed that the area under the curve (AUC) of HuMean and HuMax were higher than those of HuStd and HuMin (AUC = 0.896, AUC = 0.891 vs. AUC = 0.777, AUC = 0.833). Higher AUC (0.904), specificity (0.899) and positive predictive value (PPV) (0.712) can be obtained by combining HuMean and HuMax in the diagnosis of UA stones. In conclusion, HuMean and HuMax can better predict UA stones than HuStd and HuMin. The combined use of HuMean and HuMax can lead to higher accuracy. [ABSTRACT FROM AUTHOR]

Introduction Urinary tract calculi are commonly treated with ureteroscopy and laser stone fragmentation (URSL). The composition of calculi depends on underlying patient factors. Stones associated with metabolic or infectious conditions are sometimes thought to be more difficult to treat. This analysis explores whether the composition of calculi impacts on stone-free and complication rates. Material and methods A prospectively maintained database of patients undergoing URSL between 2012-2021 was used to explore records for patients with uric acid (Group A), infection (Group B) and calcium oxalate monohydrate (Group C) calculi. Patients who had undergone URSL to treat ureteric or renal calculi were included. Patient demographics, stone parameters and operative details were collected, with the principal outcomes being stone-free rate (SFR) and associated complications. Results A total of 352 patients were included (58 Group A, 71 Group B and 223 Group C patients) and had their data analysed. SFR was >90% for all three groups and a single Clavien-Dindo grade III complication was noted. No significant differences were found between the groups for complications, SFR and day case rates. Conclusions This cohort of patients demonstrated that outcomes were similar for three different types of urinary tract calculi, which form for differing reasons. URSL appears to be an effective, safe treatment for all stone types with comparable results. [ABSTRACT FROM AUTHOR]

Background and objective Urinary stones are a prevalent medical condition entailing significant health burdens and substantial financial ramifications. Its global prevalence is expected to rise notably, particularly in low-middle-income nations. Understanding the spectrum of diverse urinary stone types is crucial for effective management and prevention. This study aims to elucidate the demographic profiles, clinical types, and recurrence of urinary stone cases at a tertiary care hospital in Eastern India. Methods and materials The clinical data from the electronic medical record of 1,231 patients with urolithiasis who underwent surgery in a tertiary care center in eastern India from January 2015 to November 2022 were retrospectively analyzed. Patient data, including demographic information, clinical records, dietary habits, water intake, and stone recurrence history, were collected. A thorough statistical analysis was conducted to elucidate the associations between patient characteristics, urinary stone composition, and recurrence. Results Among the 1,231 participants, the majority of cases (343 (27.9%)) were in the 31-40 age group, with a higher prevalence in males (876 (71.2%)) than in females (355 (28.8%)). Flank pain or abdominal pain (593 (48.1%)) was the primary complaint, followed by nausea/vomiting (227 (18.5%)). Most stones (922 (74.9%)) were located in the kidney, and calcium oxalate was the predominant stone component (773 (62.8%)). The highest stone recurrence rates were in patients aged between 21-30 years (21 (36.8%)) and 31-40 years (16 (28.0%)). A low non-vegetarian diet and adequate hydration may reduce the likelihood of stone recurrences. Conclusion This study provides insights into the compositional analysis of urinary stones in the eastern Indian population, addressing the causes of their recurrence and management strategies, which are crucial for prevention and effective management. The findings indicate that the early middle-aged group exhibited the highest incidence of urinary stones. We also observed that strict adherence to a low animal protein, along with proper hydration and lifestyle changes, significantly reduced urinary stone recurrence., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Ranchi Urology Centre's Institutional Ethics Committee issued approval (RUC IEC 04/23). The committee has reviewed the submitted proposal for stone analysis involving human participants and found no harm to the patients during the course of the study. Therefore, the study is approved in its current state. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Kumar et al.)

Purpose: Stone composition can provide valuable information for the diagnosis, treatment and recurrence prevention of urolithiasis. The aim of this study was to evaluate the distribution of urinary stone components and the impact of different crystal forms according to gender and age of patients in Germany. Methods: A total of 45,783 urinary stones submitted from 32,512 men and 13,271 women between January 2007 and December 2020 were analyzed by infrared spectroscopy. Only the first calculus obtained per patient was included in the analysis. Results: The most common main stone component was calcium oxalate (CaOx) (71.4%), followed by carbonate apatite (CA) (10.2%) and uric acid (UA) (8.3%). Struvite (2.1%), brushite (1.3%), protein (0.5%) and cystine (0.4%) stones were only rarely diagnosed. CaOx (75%) and UA stones (81%) were more frequently obtained from men than women (p < 0.001). Weddellite (COD) and uric acid dihydrate (UAD) were more common in younger ages than whewellite (COM) and anhydrous uric acid (UAA), respectively, in both men and women. The ratios of COM-to-COD and UAA-to-UAD calculi were approximately 4:1 and 8:1, respectively. The peak of stone occurrence was between the ages of 40 and 59 years. Conclusion: Stone composition is strongly associated with gender and age. The peak incidence of calculi in both women and men was in the most active phase of their working life. The distinction between different crystal forms could provide clues to the activity and mechanisms of lithogenesis. Further research is needed in understanding the causative factors and the process of stone formation. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the epidemiological characteristics of stone components in patients with urolithiasis and analyze the associations between stone components with patients' clinical characteristics. A total of 7126 patients with urolithiasis between July 2005 and June 2020 were retrospectively analyzed. In this research, calcium oxalate stones (74.6%) accounted for the highest proportion, followed by infection stones (11.8%), uric acid (10.6%), brushite (2.0%), and others (1.1%). The change in trend in the composition of urinary stones revealed that the proportion of uric acid declined steadily, while the content of infection stones increased gradually over 15 years. The results also suggested that stone composition was significantly associated with PM2.5, gender, age, BMI, diabetes, hypertension, CCVD, alcohol consumption, albumin, creatinine, WBCHP, leukocyte, urine pH, nitrite and urine culture (P < 0.05). However, there was no significant correlation between stone composition with smoking, WBC and NEU% (P > 0.05). Our study concluded that calcium oxalate represented the highest proportion, followed by infection stones, uric acid, brushite, and others. The proportion of uric acid declined steadily, while the infection stones increased gradually. Furthermore, the factors influencing the formation of urinary calculi are PM2.5, gender, age, BMI, diabetes, hypertension, CCVD, alcohol consumption, albumin, creatinine, WBCHP, leukocyte, urine pH, nitrite and urine culture. Collectively, these results may provide clues to establish effective prevention and management strategies for urinary calculi. [ABSTRACT FROM AUTHOR]

Abstract Introduction: Large variations in demographic, economic and environmental factors might influence the worldwide distribution of urolithiasis, but scarce data are available concerning their associations with stone composition. We aimed to evaluate the frequency and composition of kidney stones and their associations with temperature, humidity, and human development index (HDI). Materials and Methods: A total of 1,158 stones from distinct patients (47±14 years old, male/female 2:1) were included. The mean annual temperature and relative humidity of each town were considered separately. Results: Calcium oxalate monohydrate (COM) was disclosed in 38.8% of patients, calcium oxalate dihydrate (COD) in 22.1%, mixed COD/apatite in 9.4%, pure apatite in 1.9%, brushite in 1.8%, struvite in 8.3%, pure uric acid in 11.1%, mixed uric acid/COM in 5.6%, and cystine/rare types in 0.8%. Mean HDI of all pooled cities was 0.780±0.03. However, people living in HDI0.800 (OR=2.14, 95% CI 1.11-4.11). Furthermore, a progressive increase in the struvite stones frequency from 4.5 to 22.8% was detected from HDI>0.800 through HDI

Purpose: To evaluate the distribution and dynamic trends in constituents of urinary stones in China. Materials and methods: The composition of 23,182 stones were analyzed and then recorded between January 2011 and December 2019. The characteristics in terms of stone patient's gender, age and calendar year were analyzed. Results: Most stones (22,172, 95.64%) had several crystal components, among which 40.25% (8925/22,172) were mixtures with infection components. Calcium oxalate (CaOx) and uric acid (UA) stones were more commonly encountered in men, but calcium phosphate (CaP), magnesium ammonium phosphate (MAP) and carbonate apatite (CA) stones were more prevalent in women (p < 0.05). In males, the proportion of CaOx stones increased up to the age of 40, but subsequently decreased (p < 0.001). Interestingly, females showed an inverse trend regarding CaOx stones (p < 0.001). The proportion of UA stones increased with age (p < 0.001), and CA stones most frequently were recorded at age 20–49. Over the past 9 years, UA, CA, and MAP stones increased over time, whereas there was a tendency for CaOx stones to decrease (p < 0.05). Conclusions: The scarcity of pure stones and a certain proportion of mixtures with infection stone components (e.g., mixtures of CaOx and CA) suggest that treatment directed against a single stone component is insufficient for effective recurrence prevention. Age and gender were significant determinants of stone composition, and according to the observed chronological trends, it seems that in the future, more UA, CA and MAP stones and fewer CaOx stones may be encountered in the studied population. [ABSTRACT FROM AUTHOR]

Introduction: Relative supersaturation (SS) for calcium oxalate (CaOx), calcium phosphate (CaP), and uric acid (UA) has been used for assessing urinary crystallization and estimated by programs, including EQUIL, Joint Expert Speciation System (JESS), and Lithorisk. We compared outputs from these programs and their correspondence with stone composition. Materials and Methods: SS of CaOx, CaP, and UA, using EQUIL, JESS, and Lithorisk were calculated from stone-forming patients. Pearson correlation coefficients were used to ascertain the correspondence between the outputs. Fractional regression models evaluated the relationship between SS and the percentage of each compound in the stones. Results: Two hundred eleven patients were included. Pearson correlation coefficients for CaOx (r ≥ 0.96), CaP (r ≥ 0.99), and UA SS (r ≥ 0.99) showed a high correspondence between all programs. We observed a significant correspondence between CaOx SS and the percentage of CaOx dihydrate in the stone (p < 0.001), as well as between the percentage of brushite and apatite and CaP SS. UA SS showed the strongest correspondence with the percentage of UA in the stones (p < 0.001). Conclusions: Good correlation between EQUIL, JESS, and Lithorisk was observed and good correspondence with stone composition. The magnitude of the association demonstrated by fractional regression models supports evidence for applying SS in clinical practice. [ABSTRACT FROM AUTHOR]

Purpose: To propose a size-related definition of stone dust produced by lithotripsy of urinary stones. Methods: Stone dust was defined as particles small enough to adhere to the following criteria: (1) spontaneous floating under 40 cm H2O irrigation pressure; (2) mean sedimentation time of > 2 s through 10 cm saline solution; (3) fully suitable for aspiration through a 3.6 F working channel. Irrigation, sedimentation, and aspiration tests were set up to evaluate each criterion. Primary outcome was particle size limit agreeing with all three criteria. Stone particles with a given size limit (≤ 2 mm, ≤ 1 mm, ≤ 500 µm, ≤ 250 µm, ≤ 125 µm and ≤ 63 µm) were obtained from laser lithotripsy, including samples from prevailing stone types: calcium oxalate monohydrate, calcium oxalate dihydrate, uric acid, carbapatite, struvite, brushite, and cystine. Results: All particles ≤ 250 µm from all stone types were in agreement with all three criteria defining stone dust, except for struvite where size limit for a positive irrigation and sedimentation test was ≤ 125 µm. Conclusion: A size limit of ≤ 250 µm seems to generally adhere to our definition of stone dust, which is based on floating and sedimentation proprieties of stone particles, as well as on the ability to be fully aspirated through the working channel of a flexible ureteroscope. [ABSTRACT FROM AUTHOR]

Purpose of Review: Conventional CT imaging is an excellent tool for the diagnosis of nephrolithiasis however is limited in its ability to detect stone composition. Dual-energy CT (DECT) scans have demonstrated promise in overcoming this limitation. We review the current utility of DECT in nephrolithiasis. Recent Findings: DECT is superior to conventional CT in differentiating uric acid stones from non-uric acid stones, with numerous studies reporting sensitivities and specificities approaching > 95%. Dose reduction protocols incorporating low-dose CT scans are commonly used, providing significantly lower effective radiation doses compared to conventional CT. DECT remains an effective diagnostic tool in patients with large body habitus. Summary: DECT can accurately detect uric acid stones, which can help guide which stones may be suitable to medical dissolution. Further studies evaluating the effectiveness of DECT in guiding management of patients with nephrolithiasis can help to promote its widespread use. [ABSTRACT FROM AUTHOR]

Urolithiasis is one of the most frequent urological diseases. Identifying the causes of stone formation forms the basis for successful prevention of recurrence. Metabolic diagnostics and measures for prevention of recurrence are based on the assignment of the patient to a low-risk or high-risk group. Analysis of the urinary calculi is an essential prerequisite for identifying patients at risk. The general recommendations on diet and lifestyle are considered to be the basis of treatment. Depending on the type of stone and the individual biochemical risk profile of a patient, these general measures should be supplemented by targeted medical nutrition therapy and pharmacological treatment. Mixed stones can pose a challenge for the treatment and prevention of recurrence. A personalized treatment decision that takes the various components of mixed stones into account could further improve the prevention of recurrence of urolithiasis., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

To investigate the outcomes of transurethral seminal vesiculoscopy (TSV) for the treatment of seminal vesicle calculi (SVC), prostatic utricle calculi (PUC) and combination of them, a retrospective review on 27 patients with SVC and/or PUC who complained of intractable haematospermia was conducted. Patient demographics, disease duration, operation time, stone location and complications were recorded. The calculi in the seminal vesicle and/or prostatic utricle were removed by holmium laser lithotripsy and/or basket extraction. The stone composition was determined in 19 of 27 patients using Infrared spectroscopy. The average age and disease duration of patients were 39.4 years and 23.1 months respectively. The mean operative time was 78.5 min. We detected SVC, SVC and PUC, and PUC in 59.3% (16/27), 33.3% (9/27) and 7.4% (2/27) patients respectively. The stones were mainly composed of calcium oxalate dehydrate (COD), carbonate apatite (CA), COD and calcium oxalate monohydrate (COM), CA and magnesium ammonium phosphate, CA and COM, and COD and uric acid in 42.1% (8/19), 21.1% (4/19), 15.8% (3/19), 15.8% (3/19), 5.3% (1/19) and 5.3% (1/19) cases respectively. No intraoperative and post‐operative complications were noted. These results suggested that SVC and PUC can be diagnosed and treated using TSVs. [ABSTRACT FROM AUTHOR]

Background: Nephrolithiasis is a common condition that has various classifications according to stone composition. Stone formation can affect renal function; it can be a strong risk factor for chronic kidney disease (CKD). The main objective of this study is to explore the association between creatinine clearance and different stone compositions. Methods: This is a retrospective cohort study conducted in a tertiary center in Jeddah, Saudi Arabia, between 2005 and 2014. Renal function was assessed by the estimating glomerular filtration rate (eGFR) by the Cockcroft-Gault equation. Stone composition was determined by urinary calculi analysis with infrared spectrometry. Results: Stones of 365 patients, with a mean age of 48.2 ± 13.6 years and a male to female ratio of 3.2:1, were analyzed. Stage 2 CKD has been documented. It involved oxalate, struvite, cystine, and uric acid stones. The worst eGFR was reported for stones containing uric acid. The eGFR was least affected with apatite stones followed by brushite stones. Conclusion: Stone disease can affect renal function. Different stone compositions show factor for renal impairment, and this should be considered in patient management. A special precaution should be considered for higher risk groups. Multidisciplinary patient care and immediate referral to a nephrologist are strongly advised.

Purpose: To assess migration of urinary stones with ureteral stents in place.Materials and Methods: We performed a retrospective analysis of stone characteristics and locations in patients treated with secondary retrograde intrarenal surgery for symptomatic urinary stones at our institution. We analyzed 393 patients with a median age of 53 years and a median stone size of 7 mm. Stone location was assessed at ureteral stent insertion and four weeks later prior to stent removal and retrograde intrarenal surgery (RIRS).Results: Migration of urinary stones was seen in 33.1% of the patients with an indwelling ureteral stent. Stones with caudal migration were smaller for any given initial position. 7.1% of the stones were located at one of the three sites of narrowing at initial presentation, this percentage increased to 18.8% at the time of stone extraction. Stone composition did not affect stone migration.Conclusion: Radiographic imaging prior to retrograde intrarenal surgery is recommended due to the migration of urinary stones with indwelling ureteral stents. The most appropriate surgical approach can be devised depending on stone localization. [ABSTRACT FROM AUTHOR]

Purpose: To assess the efficacy of dual-energy CT (DECT) in predicting the composition of urinary stones with a single index (dual energy ratio [DER]) and five indices. Methods: Patients undergoing DECT before active urolithiasis treatment were prospectively enrolled in the study. Predictions of stone composition were made based on discriminant analysis with a single index (DER) and five indices (stone density at 80 and 135 kV, Zeff [the effective atomic number of the absorbent material] of the stone, DER, dual-energy index [DEI] and dual-energy difference [DED]). After extraction, stone composition was evaluated by means of physicochemical analyses (X-ray phase analysis, electron microscopy, wet chemistry techniques, and infrared spectroscopy). Results: A total of 91 patients were included. For calcium oxalate monohydrate (COM) stones, the sensitivity, specificity, and overall accuracy of DECT with one index (DER) were 83.3%, 89.8%, and 86.8%, respectively; for calcium oxalate dihydrate (COD) and calcium phosphate stones—88.2%, 92.9%, and 91.2%, respectively; for uric acid stones—0%, 98.8% and 97.8%, respectively; for struvite stones—60%, 95.3%, and 93.4%, respectively. Discriminant analysis with five indices yielded the following sensitivity, specificity, and overall accuracy: 95.2%, 89.8%, and 92.3% for COM stones, 85.3%, 96.4%, and 92.3% for COD stones, and 100% in all three categories for both uric acid and struvite stones. Conclusions: DECT is a promising tool for stone composition assessment. It allowed for evaluation of chemical composition of all stone types with specificity and accuracy ranging from 85% to 100%. Five DECT indices have shown much better diagnostic accuracy compared to a single DECT index. [ABSTRACT FROM AUTHOR]

Aims: To evaluate the stone composition and the distribution of the stone types in the geographical regions of Turkey according to where patients were born and where patients live. Methods: The patients who were treated for urinary system stone disease in our hospital between January 2011 and March 2019 were included in the study. Stone samples were collected by endoscopic stone surgery methods or shock wave lithotripsy. Stone analyses were made with manual chemical analysis methods. Stone types and distribution were recorded according to geographical regions of Turkey. Results: A total of 706 patients who were treated for urolithiasis were included in the study. Calcium oxalate (CO) stones were at the highest rates for both genders [127 (68.6%) and 359 (68.9%), for females and males, respectively]. There were no statistically significant differences in terms of stone types between genders (p=0.323). There were statistically significant more CO (297), uric acid (17), mixed stones (78) in the Anatolian (central) region than the other regions according to the geographical region where patients were born (p<0.001, for each). Additionally, there were significantly more calcium phosphate stone formers (25) in the Anatolian region according to the geographical region where patients lived (p<0.001). Conclusions: CO is the most common stone type in Turkey independently of where patients were born or where patients live. Higher prevalence rates of stone disease and CO stones were seen in Central Anatolia. Both geographic origin and dietary habits affect the incidence of urinary system stone disease. [ABSTRACT FROM AUTHOR]

Objectives: To explore characteristics of urinary stone composition in China, and determine the effects of gender, age, body mass index (BMI), stone location, and geographical region on stone composition. Patients and methods: We prospectively used Fourier‐transform infrared spectroscopy to analyse stones from consecutive patients presenting with new‐onset urolithiasis at 46 hospitals in seven geographical areas of China, between 1 June 2010 and 31 May 2015. Chi‐squared tests and logistic regression analyses were used to determine associations between stone composition and gender, age, BMI, stone location, and geographical region. Results: The most common stone constituents were: calcium oxalate (CaOx; 65.9%), carbapatite (15.6%), urate (12.4%), struvite (2.7%), and brushite (1.7%). CaOx and urate stones occurred more frequently in males, whereas carbapatite and struvite were more common in females (P < 0.01). CaOx and carbapatite were more common in those aged 30–50 and 20–40 years than in other groups. Brushite and struvite were most common amongst those aged <20 and >70 years. The detection rate of urate increased with age, whilst cystine decreased with age. Obese patients were more likely to have urate stones than carbapatite or brushite stones (P < 0.01). CaOx, carbapatite, brushite, and cystine stones were more frequently found in the kidney than other types, whereas urate and struvite were more frequent in the bladder (P < 0.01). Stone composition varied by geographical region. Conclusions: The most common stone composition was CaOx, followed by carbapatite, urate, struvite, and brushite. Stone composition differed significantly in patients grouped by gender, age, BMI, stone location, and geographical region. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the accuracy of rapid kV-switching single-source dual-energy computed tomography (rsDECT) for prediction of classes of non-uric-acid stones. Materials and methods: Non-uric-acid renal stones retrieved via percutaneous nephrolithotomy were prospectively collected between January 2017 and February 2018 in a single institution. Only stones ≥ 5 mm and with pure composition (i.e., ≥ 80% composed of one component) were included. Stone composition was determined using Fourier Transform Infrared Spectroscopy. The stones were scanned in 32-cm-wide anthropomorphic whole-body phantom using rsDECT. The effective atomic number (Zeff), the attenuation at 40 keV (HU40), 70 keV (HU70), and 140 keV (HU140) virtual monochromatic sets of images as well as the ratios between the attenuations were calculated. Values of stone classes were compared using ANOVA and Mann–Whitney U test. Receiver operating curves and area under curve (AUC) were calculated. A p value < 0.05 was considered statistically significant. Results: The final study sample included 31 stones from 31 patients consisting of 25 (81%) calcium-based, 4 (13%) cystine, and 2 (6%) struvite pure stones. The mean size of the stones was 9.9 ± 2.4 mm. The mean Zeff of the stones was 12.01 ± 0.54 for calcium-based, 11.10 ± 0.68 for struvite, and 10.23 ± 0.75 for cystine stones (p < 0.001). Zeff had the best efficacy to separate different classes of stones. The calculated AUC was 0.947 for Zeff; 0.833 for HU40; 0.880 for HU70; and 0.893 for HU140. Conclusion: Zeff derived from rsDECT has superior performance to HU and attenuation ratios for separation of different classes of non-uric-acid stones. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate whether the size of spontaneously passed stones (SPS) may be associated with clinical parameters. Methods: A search for SPS was conducted in our electronic stone database, comprising data on stones analyzed over the last 33 years at our institution. Adults with upper urinary tract stones were included. Cases with stenotic urinary tract disease or past history of anastomotic urinary tract surgery were excluded. Stone size expressed as maximal stone diameter (MSD) and stone volume (SV) was compared between groups by one-way ANOVA. Logistic regression analyses were performed to identify predictors of MSD ≥ 6 mm. Results: Overall mean MSD and SV for 18,029 SPS was 4.1 mm and 11.5 mm3, respectively, and significantly differed between stone composition groups (p < 0.001). The lowest mean MSD and SV were found for calcium oxalate monohydrate (3.6 mm and 9.0 mm3, respectively) and the highest mean MSD and SV were found for struvite (7.9 mm and 61.0 mm3, respectively). Stone composition and increasing age were found to be independent predictors of MSD ≥ 6 mm (both p < 0.001). Sex differentiation did not contribute as a predictor of MSD ≥ 6 mm. Conclusions: Stone composition and—to a lesser extent—age serve as independent predictors of size of spontaneously passed stones. Of particular importance, large spontaneously passed stones of ≥ 6 mm may be frequently found in cystine, brushite or struvite stone formers, whereas a minority of all calcium oxalate stones exceed that cutoff. Future studies shall evaluate these parameters as possible predictors of spontaneous stone passage. [ABSTRACT FROM AUTHOR]

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The article compared the effectiveness of reduced dose computed tomography (RdCT) against the standard dose computed tomography (sCT), focusing on the effects of voltage reduction on density measurements of urolithiasis to determine whether there exists a correlation between stone composition. The study involved 201 patients being tested for renal colic who were subjected to both tests. A discussion of RdCT and sCT on Hounsfield unit levels is presented.

The aim of the study was to report the characteristics of urolithiasis in Uyghur patients from Xinjiang, China. The composition of stones collected from 1863 patients in the Uyghur region of Xinjiang was analyzed. The median age of patients was 17 years [25th and 75th percentiles: 2, 36]. The stones were delivered by 1299 males (69.7%) and 564 females (30.3%). Calcium oxalate was the predominant stone component in 42.1% of the patients, followed by ammonium urate in 20.6%. Females had formed more stones of magnesium ammonium phosphate 8.9 vs. 5.6% (p = 0.010) and carbonate apatite 6.2 vs. 3.3% (p = 0.004). In contrast uric acid was more common in males than in females; 21.6 vs. 15.1% (p = 0.001). In this series, pediatric patients (age range 0–18) were more likely to present with a stone (51.5%, p < 0.001). Moreover, the largest number of pediatric stones was recorded in children 1–2 years old (37.9%, p < 0.001). The occurrence of ammonium urate stones was extremely high (52.4%) in children with an age below 1 year. There was a downward trend for ammonium urate with age in both children and adults (p for trend < 0.001, respectively). In contrast the frequency of uric acid declined with age in pediatric patients, but increased in adults (p for trend < 0.001, respectively). This study provides a basis for further considerations on the management of Xinjiang Uyghur patients and emphasize the severity of pediatric stone problems. [ABSTRACT FROM AUTHOR]

Copyright of CT Theory & Applications is the property of Editorial Department of CT Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)