Uric acid stones, clinical manifestations and therapeutic considerations

2018 ◽  
Vol 94 (1114) ◽  
pp. 458-462 ◽  
Author(s):  
Qi Ma ◽  
Li Fang ◽  
Rui Su ◽  
Liang Ma ◽  
Guohai Xie ◽  
...  
Keyword(s):  
Uric Acid ◽  
Dietary Habits ◽  
Urinary Tract Obstruction ◽  
Stone Formation ◽  
Clinical Manifestations ◽  
Urinary Stones ◽  
Dual Energy Ct ◽  
Composition Analysis ◽  
Extracorporeal Shock Wave ◽  
Uric Acid Stones

Uric acid stones account for 10%–15% of all urinary stones. Changes in dietary habits, environment or both can result in the increase of uric acid stones. The formation of uric acid stones is related to hyperuricosuria, low urinary volume and persistently low urinary pH. Diabetes and obesity also significantly increase the risk of stone formation. Dual-energy CT provides a convenient and reliable method for diagnosis. Stone composition analysis and 24-hour urine metabolic evaluations should be considered for further evaluation. Most small uric acid stones (diameter <2 cm) can be treated by pharmacotherapy or extracorporeal shock wave lithotripsy. However, ureteroscopy and other minimally invasive procedures should be reserved for larger stones (diameter ≥2 cm), or patients with concomitant urinary tract obstruction and/or infections. Additionally, adjustment of potential pathophysiologic defects by pharmacotherapy and dietary modification is strongly recommended for the prevention of uric stone recurrence.

scholarly journals Single-energy CT predicts uric acid stones with accuracy comparable to dual-energy CT—prospective validation of a quantitative method

2021 ◽  
Author(s):  
Johan Jendeberg ◽  
Per Thunberg ◽  
Marcin Popiolek ◽  
Mats Lidén
Keyword(s):  
Uric Acid ◽  
Ct Scan ◽  
Prediction Models ◽  
Urinary Stone ◽  
Dual Energy ◽  
Urinary Stones ◽  
Dual Energy Ct ◽  
K Nearest Neighbors ◽  
Uric Acid Stones

Abstract Objectives To prospectively validate three quantitative single-energy CT (SE-CT) methods for classifying uric acid (UA) and non-uric acid (non-UA) stones. Methods Between September 2018 and September 2019, 116 study participants were prospectively included in the study if they had at least one 3–20-mm urinary stone on an initial urinary tract SE-CT scan. An additional dual-energy CT (DE-CT) scan was performed, limited to the stone of interest. Additionally, to include a sufficient number of UA stones, eight participants with confirmed UA stone on DE-CT were retrospectively included. The SE-CT stone features used in the prediction models were (1) maximum attenuation (maxHU) and (2) the peak point Laplacian (ppLapl) calculated at the position in the stone with maxHU. Two prediction models were previously published methods (ppLapl-maxHU and maxHU) and the third was derived from the previous results based on the k-nearest neighbors (kNN) algorithm (kNN-ppLapl-maxHU). The three methods were evaluated on this new independent stone dataset. The reference standard was the CT vendor’s DE-CT application for kidney stones. Results Altogether 124 participants (59 ± 14 years, 91 men) with 106 non-UA and 37 UA stones were evaluated. For classification of UA and non-UA stones, the sensitivity, specificity, and accuracy were 100% (37/37), 97% (103/106), and 98% (140/143), respectively, for kNN-ppLapl-maxHU; 95% (35/37), 98% (104/106), and 97% (139/143) for ppLapl-maxHU; and 92% (34/37), 94% (100/106), and 94% (134/143) for maxHU. Conclusion A quantitative SE-CT method (kNN-ppLapl-maxHU) can classify UA stones with accuracy comparable to DE-CT. Key Points • Single-energy CT is the first-line diagnostic tool for suspected renal colic. • A single-energy CT method based on the internal urinary stone attenuation distribution can classify urinary stones into uric acid and non-uric acid stones with high accuracy. • This immensely increases the availability of in vivo stone analysis.

scholarly journals Urinary stone composition analysis of 3684 patients in the eastern Shandong region of China

2019 ◽  
Author(s):  
Xuebao Zhang ◽  
Jiajia Ma ◽  
Ning Wang ◽  
Chunhua Lin
Keyword(s):  
Uric Acid ◽  
Infrared Spectrum ◽  
Calcium Oxalate ◽  
Spectrum Analysis ◽  
Urinary Stones ◽  
Composition Analysis ◽  
Carbonate Apatite ◽  
Uric Acid Stones ◽  
Analysis System ◽  
Spectrum Analysis System

Abstract Objective To explore the composition of urinary stones in the eastern Shandong region of China and discuss its clinical significance. Methods A total of 3684 specimens of urinary calculi from the eastern Shandong region were collected in our study. Compositions of stones were analyzed by Automatic Infrared Spectrum Analysis System (type LIIR-20). The results were verified through manual analysis of the spectrogram which is accompanied by polarizing microscopy and chemical analysis if necessary. Results Among the 3684 specimens, there were 1767 single-component stones and 1917 mixed-component stones. According to the difference of the main components of the stones, the stones can be divided into the following types: calcium oxalate monohydrate stones (1779, 48.29%), anhydrous uric acid stones (1105, 29.99%), carbonate apatite stones (590, 16.02%), ammonium magnesium phosphate hexahydrate stones (143, 3.88%), calcium oxalate dehydrate stones (36, 0.98%), and cystine stones (31, 0.84%). Conclusion There are relatively many uric acid stones in the eastern Shandong region of China. The automatic infrared spectrum analysis system for calculus has the advantages of accuracy and convenience.

Evaluation of split-filter dual-energy CT for characterization of urinary stones

2021 ◽  
pp. 20210084
Author(s):  
Elisabeth Appel ◽  
Christoph Thomas ◽  
Andrea Steuwe ◽  
Benedikt M Schaarschmidt ◽  
Olga R Brook ◽  
...  
Keyword(s):  
Uric Acid ◽  
Urinary Stone ◽  
Dual Energy ◽  
Urinary Stones ◽  
Dual Energy Ct ◽  
Ct Scanner ◽  
Stone Composition ◽  
Calcium Stones ◽  
Uric Acid Stones ◽  
Dual Source

Objective: To assess accuracy of dual-energy computed tomography (DECT) to differentiate uric acid from calcium urinary stones in dual-energy split filter vs sequential-spiral vs dual-source acquisition. Methods: Thirty-four urinary stones (volume 89.0 ± 77.4 mm³; 17 calcium stones, 17 uric acid stones) were scanned in a water-filled phantom using a split-filter equipped CT scanner (SOMATOM Definition Edge, Siemens Healthineers, Forchheim, Germany) in split-filter mode at 120kVp and sequential-spiral mode at 80 and 140kVp. Additional DE scans were acquired at 80 and 140kVp (tin filter) with a dual-source CT scanner (SOMATOM Definition FLASH, Siemens Healthineers). Scans were performed with a CTDIvol of 7.3mGy in all protocols. Urinary stone categorization was based on dual energy ratio (DER) using an automated 3D segmentation. As reference standard, infrared spectroscopy was used to determine urinary stone composition. Results: All three DECT techniques significantly differentiated between uric acid and calcium stones by attenuation values and DERs (p < 0.001 for all). Split-filter DECT provided higher DERs for uric acid stones, when compared with dual-source and sequential-spiral DECT, and lower DERs for calcified stones when compared with dual-source DECT (p < 0.001 for both), leading to a decreased accuracy for material differentiation. Conclusion: Split-filter DECT, sequential-spiral DECT and dual-source DECT all allow for the acquisition of DER to classify urinary stones. Advances in knowledge: Split-filter DECT enables the differentiation between uric acid and calcium stones despite decreased spectral separation when compared with dual-source and dual-spiral DECT.

scholarly journals Urinary stone composition analysis of 3684 patients in the eastern Shandong region of China

2019 ◽  
Vol 48 (3) ◽  
pp. 030006051988726
Author(s):  
Xuebao Zhang ◽  
Jiajia Ma ◽  
Ning Wang ◽  
Chunhua Lin
Keyword(s):  
Uric Acid ◽  
Calcium Oxalate ◽  
Urinary Calculi ◽  
High Rate ◽  
Urinary Stones ◽  
Composition Analysis ◽  
Carbonate Apatite ◽  
Stone Composition ◽  
Calcium Oxalate Dihydrate ◽  
Uric Acid Stones

Objective There has not been a study that analyzed the composition of urinary stones from patients in the eastern Shandong region of China. Thus, we explored the composition of urinary stones in the eastern Shandong region of China and discuss the clinical significance of the findings. Methods A total of 3684 urinary calculi from the eastern Shandong region were collected in our study. Compositions of the stones were analyzed using an Automatic Infrared Spectrum Analysis System (type LIIR-20). The results were verified through manual analysis of the spectrograms, which was accompanied by polarizing microscopy and chemical analysis if necessary. Results Among the 3684 specimens, there were 1767 single-component stones and 1917 mixed-component stones. According to the main components of the stones, the stones were divided into the following types: calcium oxalate monohydrate stones (1779, 48.3%), anhydrous uric acid stones (1105, 30.0%), carbonate apatite stones (590, 16.0%), ammonium magnesium phosphate hexahydrate stones (143, 3.9%), calcium oxalate dihydrate stones (36, 1.0%), and cystine stones (31, 0.8%). Conclusions There was a relatively high rate of uric acid stones in patients from the eastern Shandong region of China.

scholarly journals In vivo identification of uric acid stones with dual-energy CT: diagnostic performance evaluation in patients

2009 ◽  
Vol 35 (5) ◽  
pp. 629-635 ◽  
Author(s):  
Paul Stolzmann ◽  
Marko Kozomara ◽  
Natalie Chuck ◽  
Michael Müntener ◽  
Sebastian Leschka ◽  
...  
Keyword(s):  
Uric Acid ◽  
Performance Evaluation ◽  
Diagnostic Performance ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Uric Acid Stones

Nephrolithiasis

2018 ◽  
Author(s):  
José Luiz Nishiura ◽  
Ita Pfeferman Heilberg
Keyword(s):  
Uric Acid ◽  
Calcium Oxalate ◽  
Dietary Habits ◽  
Stone Formation ◽  
Urine Volume ◽  
First Episode ◽  
Dietary Advice ◽  
Dietary Recommendations ◽  
Genetic Traits ◽  
Oxalate Precipitation

Nephrolithiasis is a highly prevalent condition, but its incidence varies depending on race, gender, and geographic location. Approximately half of patients form at least one recurrent stone within 10 years of the first episode. Renal stones are usually composed of calcium salts (calcium oxalate monohydrate or dihydrate, calcium phosphate), uric acid, or, less frequently, cystine and struvite (magnesium, ammonium, and phosphate). Calcium oxalate stones, the most commonly encountered ones, may result from urinary calcium oxalate precipitation on the Randall plaque, which is a hydroxyapatite deposit in the interstitium of the kidney medulla. Uric acid nephrolithiasis, which is common among patients with metabolic syndrome or diabetes mellitus, is caused by an excessively acidic urinary pH as a renal manifestation of insulin resistance. The medical evaluation of the kidney stone patient must be focused on identifying anatomic abnormalities of the urinary tract, associated systemic diseases, use of lithogenic drugs or supplements, and, mostly, urinary risk factors such as low urine volume, hypercalciuria, hyperuricosuria, hypocitraturia, hyperoxaluria, and abnormalities in urine pH that can be affected by dietary habits, environmental factors, and genetic traits. Metabolic evaluation requires a urinalysis, stone analysis (if available), serum chemistry, and urinary parameters, preferably obtained by two nonconsecutive 24-hour urine collections under a random diet. Targeted medication and dietary advice are effective to reduce the risk of recurrence. Clinical, radiologic, and laboratory follow-ups are needed to prevent stone growth and new stone formation, to assess treatment adherence or effectiveness to dietary recommendations, and to allow adjustment of pharmacologic treatment. This review contains 5 highly rendered figure, 3 tables, and 105 references.

Nephrolithiasis

2017 ◽  
Author(s):  
José Luiz Nishiura ◽  
Ita Pfeferman Heilberg
Keyword(s):  
Uric Acid ◽  
Calcium Oxalate ◽  
Dietary Habits ◽  
Stone Formation ◽  
Urine Volume ◽  
First Episode ◽  
Dietary Advice ◽  
Dietary Recommendations ◽  
Genetic Traits ◽  
Oxalate Precipitation

Nephrolithiasis is a highly prevalent condition, but its incidence varies depending on race, gender, and geographic location. Approximately half of patients form at least one recurrent stone within 10 years of the first episode. Renal stones are usually composed of calcium salts (calcium oxalate monohydrate or dihydrate, calcium phosphate), uric acid, or, less frequently, cystine and struvite (magnesium, ammonium, and phosphate). Calcium oxalate stones, the most commonly encountered ones, may result from urinary calcium oxalate precipitation on the Randall plaque, which is a hydroxyapatite deposit in the interstitium of the kidney medulla. Uric acid nephrolithiasis, which is common among patients with metabolic syndrome or diabetes mellitus, is caused by an excessively acidic urinary pH as a renal manifestation of insulin resistance. The medical evaluation of the kidney stone patient must be focused on identifying anatomic abnormalities of the urinary tract, associated systemic diseases, use of lithogenic drugs or supplements, and, mostly, urinary risk factors such as low urine volume, hypercalciuria, hyperuricosuria, hypocitraturia, hyperoxaluria, and abnormalities in urine pH that can be affected by dietary habits, environmental factors, and genetic traits. Metabolic evaluation requires a urinalysis, stone analysis (if available), serum chemistry, and urinary parameters, preferably obtained by two nonconsecutive 24-hour urine collections under a random diet. Targeted medication and dietary advice are effective to reduce the risk of recurrence. Clinical, radiologic, and laboratory follow-ups are needed to prevent stone growth and new stone formation, to assess treatment adherence or effectiveness to dietary recommendations, and to allow adjustment of pharmacologic treatment. This review contains 5 highly rendered figure, 3 tables, and 105 references.

scholarly journals Urolithiasis in male patients: A pilot study on the ethnic differences and clinical profile

2014 ◽  
Vol 4 (4) ◽  
pp. 393-98
Author(s):  
Jayadevan Sreedharan ◽  
LJ John ◽  
HAM Aly Freeg ◽  
J Muttappallymyalil
Keyword(s):  
Uric Acid ◽  
Calcium Oxalate ◽  
Calcium Oxalate Monohydrate ◽  
Dietary Factors ◽  
Clinical Profile ◽  
Urinary Stones ◽  
Ureteral Stones ◽  
Stone Size ◽  
Uric Acid Stones ◽  
Male Patients

Background   Ethnicity play a role in the occurrence of urinary stones, probably related to climatic, environmental and dietary factors in ethnic groups. The association between ethnicity, age, clinical profile, stone size with type of ureteric stones among males with urolithiasis was studied.   Materials and Methods Male patients (>18 years) with lower ureteral stones size <10mm attending outpatient department of Urology, at a private hospital, Ajman over a period of one year were included. Ethics approval was obtained from Institutional Ethics Committee. Data was retrieved from the case records which included socio-demographic variables (age, ethnicity), clinical profile (ureteric colic, duration of pain, other complaints), and laboratory investigations (type of stone, stone size). Descriptive and inferential statistics were performed with SPSS-20 and p values <0.05 considered significant. Results 185 male patients were included. Mean age was 41.5 (7.3) years, range (22-71) years. Out of the total, 81 (43.8%) patients were Asians, 81(43.8%) Arabs and 23 (12.4%) were of other ethnicity. Most patients (95.1%) presented with ureteric pain. 49 (26.5%) had family history of stone disease where calcium oxalate monohydrate and uric acid stones were common, with majority being first degree relation. Data on stone type was available for 90 patients; of which, 21 were calcium oxalate monohydrate, 33-calcium oxalate dehydrate, 24-uric acid and remaining 12 other form of stones. Average age for different types of stone was 38.3, 41.6, 39.4 and 42.8 years for calcium oxalate monohydrate, calcium oxalate dehydrate, uric acid and other types respectively. Conclusion Uric acid stones were more prevalent among Asians and calcium oxalate-dehydrate stones among Arabs. Future studies can be conducted among multiethnic population focusing on dietary pattern and stone analysis.DOI: http://dx.doi.org/10.3126/nje.v4i4.11359 Nepal Journal of Epidemiology 2014; 4(4):393-98

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