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

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.

Dual Energy Computed Tomography (DECT) for Determination of Renal Calculi Composition - In-Vivo Analysis and In-Vitro Comparison with Qualitative Chemical Analysis - A Prospective Comparative Study at a Single Centre at SDM Medical College and Hospital – Dharwad, Karnataka

2021 ◽  
Vol 8 (41) ◽  
pp. 3534-3540
Author(s):  
Srinivas Kalabhavi ◽  
Pramod Makannavar ◽  
Revanasiddappa Kanagali ◽  
Prabhath A.N. ◽  
Narendrakumar Shah
Keyword(s):  
Uric Acid ◽  
Chemical Analysis ◽  
Renal Stones ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Stone Composition ◽  
Uric Acid Stones ◽  
In Vivo Analysis

BACKGROUND Dual energy computed tomography (DECT) is a new method of computed tomography (CT) imaging which allows to determine stone composition in addition to assessing stone morphology. The purpose of this study was to evaluate the role of dual energy CT (DECT) preoperatively to assess the composition of urinary stones and to compare it with post-operative in vitro qualitative chemical analysis as reference standard. METHODS Forty patients (18 male and 22 female) who presented with symptoms of renal stones in the department of urology were included in the study. All 40 patients who were diagnosed to have renal stones clinically and by ultrasonography (USG) kidney, ureter and bladder (KUB) region were subjected to dual energy CT. The stone composition assessed in vivo using DECT preoperatively and in vitro by chemical analysis post operatively after stone extraction by surgical procedure. The results were compared by statistical analysis. Sensitivity, specificity and positive predictive value (PPV) were calculated and descriptive study done using Statistical Package for Social Sciences (SPSS) 20.00 version. Data was analysed by comparing it with correlative qualitative chemical analysis. RESULTS In our study, in vivo analysis using DECT showed most common type of stone was calcium oxalate seen in 20 cases compromising 50 % of total cases. Next common stone type was uric acid stone (22.5 %) followed by cysteine (17.5 %) and calcium hydroxyapatite (10 %) respectively. When the same stones were subjected to ex vivo chemical analysis, one of the calcium oxalate stone came out to be calcium phosphate and one of the cysteine stone came out to be mixed stone. Thus, out of 40 stones, 38 stones were found to have the same result in ex vivo chemical analysis as that of in vivo analysis by dual energy CT. Hence, accuracy of dual energy CT in diagnosis of renal stones was found to be 100 % with CI 91.19 % - 100 %. CONCLUSIONS With dual energy CT, it is possible to determine the composition of renal calculi in vivo non-invasively (with specificity of 100 % in our present study). Therefore, this helps in deciding the modality of treatment pre-operatively whether the stone is amenable to medical management (e.g., Uric acid stones) or requires extracorporeal shock wave lithotripsy (ESWL) or surgical intervention can be determined preoperatively. This helps to reduce the unnecessary financial burden and is found to be time saving. KEYWORDS Renal Calculus, Dual Energy CT, Stone Composition, Uric Acid Stones, Non-Uric Acid Stones, Attenuation, Hounsfield Units HU, Chemical Analysis of Stones.

scholarly journals Dual-energy computed tomography for the differentiation of uric acid stones: ex vivo performance evaluation

2008 ◽  
Vol 36 (3-4) ◽  
pp. 133-138 ◽  
Author(s):  
Paul Stolzmann ◽  
Hans Scheffel ◽  
Katharina Rentsch ◽  
Thomas Schertler ◽  
Thomas Frauenfelder ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Uric Acid ◽  
Performance Evaluation ◽  
Ex Vivo ◽  
Dual Energy ◽  
Dual Energy Computed Tomography ◽  
Uric Acid Stones

In Vivo Differentiation of Uric Acid Versus Non-Uric Acid Urinary Calculi With Third-Generation Dual-Source Dual-Energy CT at Reduced Radiation Dose

2018 ◽  
Vol 210 (2) ◽  
pp. 358-363 ◽  
Author(s):  
Axelle Franken ◽  
Pierre Alain Gevenois ◽  
Alain Van Muylem ◽  
Nigel Howarth ◽  
Caroline Keyzer
Keyword(s):  
Uric Acid ◽  
Radiation Dose ◽  
Urinary Calculi ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Third Generation ◽  
Acid Versus ◽  
Dual Source ◽  
In Vivo Differentiation

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 COMPARATIVE ANALYSIS OF DATA FROM A DUAL-ENERGY COMPUTER TOMOGRAPH AND THE RESULTS OF A MINERALOGICAL RESEARCH OF URINARY STONES

2018 ◽  
pp. 54-58 ◽  
Author(s):  
T. Kh. Nazarov ◽  
I. V. Rychkov ◽  
D. G. Lebedev ◽  
K. E. Trubnikova
Keyword(s):  
Computed Tomography ◽  
Uric Acid ◽  
High Sensitivity ◽  
Dual Energy ◽  
Average Density ◽  
Urinary Stones ◽  
Infrared Spectrometry ◽  
Dual Energy Ct

Introduction. The idea of using dual-energy computed tomography (DECT) originated in the early development of computed tomography (CT). However, only recently, advances in radiation diagnosis have made it possible to use dual-energy CT for routine clinical use. We describes the characteristic features of dual-energy CT scanners, as well as the results of a study of 245 patients with urolithiasis, the identification of urinary stones in vivo and the subsequent comparative characteristics with mineralogical studies of uroliths. Purpose. Evaluate the possibility of using DECT in the diagnosis of urolithiasis with the determination of the chemical composition of urinary stones in vivo. Materials and methods. A group of patients (n=245) aged 18 to 84 years was examined. All patients with the established diagnosis-urolithiasis-were treated with DECT (Somatom Definition, Siemens, Forchheim, Germany) with data processing, then in-vitro infrared spectrometry (IR-Alpha-P spectrometer) to determine the true composition of the calcu lus. Results. After conducting the DECT and then ROC analysis and comparing the results with the IR-spectrometry data, it was established that stones with an average density of less than 500 HU according to DECT can be attributed to urate, with a uric acid content of more than 50% with a sensitivity of 91,1% (34 stones of 35) and specificity of 100% — the content of uric acid is also determined in polymineral calculi with a content of less than 50%. The knowledge gained on the composition and structure of the stone in vivo can subsequently be used in pathogenetic treatment and prevention of complications in patients with urolithiasis, and influence the choice of the tactics of removing the uroliths. Conclusions. The obtained results give the right to apply DECT in the diagnosis of urolithiasis, and with high sensitivity to identify urate stones in vivo, thereby influencing the choice of the tactics of removal of uroliths and pathogenetic treatment, as well as the prevention of complications in patients with urolithiasis.

Efficacy of single-source rapid kV-switching dual-energy CT for characterization of non-uric acid renal stones: a prospective ex vivo study using anthropomorphic phantom

2019 ◽  
Vol 45 (4) ◽  
pp. 1092-1099
Author(s):  
Roberto Cannella ◽  
Mohammed Shahait ◽  
Alessandro Furlan ◽  
Feng Zhang ◽  
Joel D. Bigley ◽  
...  
Keyword(s):  
Uric Acid ◽  
Ex Vivo ◽  
Renal Stones ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Single Source ◽  
Anthropomorphic Phantom ◽  
Ex Vivo Study

In Vivo Comparison of Radiation Exposure in Third Generation versus Second Generation Dual-Source Dual-Energy CT for Imaging Urinary Calculi

2021 ◽  
Author(s):  
Jonathan P Lam ◽  
Lauren F Alexander ◽  
William E Haley ◽  
David O Hodge ◽  
James M Kofler ◽  
...  
Keyword(s):  
Radiation Exposure ◽  
Second Generation ◽  
Urinary Calculi ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Third Generation ◽  
Dual Source

Dual-energy CT for the characterization of urinary calculi: In vitro and in vivo evaluation of a low-dose scanning protocol

2009 ◽  
Vol 19 (6) ◽  
pp. 1553-1559 ◽  
Author(s):  
C. Thomas ◽  
O. Patschan ◽  
D. Ketelsen ◽  
I. Tsiflikas ◽  
A. Reimann ◽  
...  
Keyword(s):  
Low Dose ◽  
Urinary Calculi ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
In Vivo Evaluation ◽  
Scanning Protocol
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