MO118ROLE OF DUAL ENERGY COMPUTED TOMOGRAPHY IN PREDICTING THE CHEMICAL COMPOSITION OF STONES

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Dr Sanjay Bhat ◽  
Anupma Kaul

Abstract Background and Aims Dual-energy CT (DECT) has shown excellent outcomes in differentiating the chemical composition of the urinary stones with a great accuracy. A reliable determination of the chemical type of the stone help the clinician to better satisfy treatment options for the patient- medical versus surgery We used the DECT in our study to assess the accuracy of non-invasive differentiation of renal stones using the 3rd generation dual-source computed tomography (CT) scanner in determining the chemical composition of renal stones and to determine appropriate management based on DECT determined chemical composition of stones. Method This prospective study was conducted in the Department of surgery and radiodiagnosis and Imaging, Era Medical College and RML institute of Medical Sciences , Lucknow over the study period, i.e., November 2016 to May 2018 . The patients were those referred for non-contrast/contrast CT for the diagnosis/evaluation of urolithiasis from the department of Surgery admitted for PCNL/ESWL/therapeutic ureterorenoscopy. DECT ratios of the various stones were noted and compared with the post extraction analysis of stones for composition. A total of 100 patients were included in the study, and their DECT results were compared with the post-extraction analysis (by infrared spectroscopy as the standard comparative method). Results Mean age of patients was 41.15+/- 10.08 years with 64% being males. DECT was highly sensitive and specific in the diagnosis of various types of calculi based on their dual-energy ratio. It was found to be 100% sensitivity and 97.2% specificity for differentiating UA stones with level of agreement between chemical and DECT was almost perfect (k= .951) .However for hydroxyapatite stones was substantial (k=.889). Most of the stones belonged to non-UA category (72%), and only 28% were UA calculi. The sensitivity and specificity in differentiating a calcium oxalate from non-calcium oxalate calculus was 94.1% and 95.5%, respectively. Conclusion DECT highly sensitive and effective in characterizing chemical composition of the urinary stones and can help in determining the management plan and reduce the unnecessary burden of surgical interventions.

2011 ◽  
Vol 197 (1) ◽  
pp. W76-W83 ◽  
Author(s):  
Giuseppina Manglaviti ◽  
Silvia Tresoldi ◽  
Chiara Stefania Guerrer ◽  
Giovanni Di Leo ◽  
Emanuele Montanari ◽  
...  

Urologiia ◽  
2017 ◽  
Vol 3_2017 ◽  
pp. 98-103 ◽  
Author(s):  
A.G. Martov Martov ◽  
D.A. Mazurenko Mazurenko ◽  
M.M. Klimkova Klimkova ◽  
V.E. Sinitsyn Sinitsyn ◽  
L.A. Nersisyan Nersisyan ◽  
...  

2009 ◽  
Vol 76 (2) ◽  
pp. 107-111
Author(s):  
D. Tiscione ◽  
L. Ruggera ◽  
P. Beltrami ◽  
M.A. Cerruto ◽  
A. Cielo ◽  
...  

Objectives Several authors hypothesized the usefulness of the non-contrast helical computed tomography (NCHCT) with the determination of stone Hounsfield Unit (HU) values in order to predict urinary stone compositions. Preoperative knowledge of stone composition might be interesting in pre-operative decision-making process. The aim of this study was to evaluate the possible correlation between stone chemical composition and correspondent stone HU value in an in-vivo experience. Methods Forty patients with urinary stones were preoperatively studied with abdominal NCHCT, where stone HU values were reported. Stone chemical composition was obtained in each patient, using the colorimetric method. The HU value of each stone was compared with the correspondent chemical analysis. Results The median HU values of calcium oxalate (n=10), mixed calcium oxalate and phosphate (n=19), calcium phosphate (n=2), uric acid (n=6) and mixed uric acid and calcium oxalate (n=3) stones were 1060 HU [interquartile range (IQR) 743.75–1222.5]; 900 HU (IQR 588.5–1108.5); 774 HU (range 720–828); 371 HU (IQR 361.25–436.25) and 532 HU (range 476–626), respectively. Conclusions Our results confirmed a statistically significant difference of the HU values between calcium and pure uric acid calculi, suggesting a correlation between stone chemical composition and CT-density. Hounsfield unit


Author(s):  
Sachin Khanduri ◽  
Umar Faizan Sagar ◽  
Nazia Khan ◽  
Nitin Chahar ◽  
Shreshtha Jain ◽  
...  

Author(s):  
T. Kh. Nazarov ◽  
I. V. Rychkov ◽  
D. G. Lebedev ◽  
K. E. Trubnikova

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.


2021 ◽  
Vol 28 (3) ◽  
pp. E202134
Author(s):  
Shafqat Shabir Bhawani ◽  
Majid Jehangir ◽  
Mohammad Masood ◽  
Sajjad Ahmad Dar ◽  
Sajad Nazir Syed

Introduction. Computed tomography is more accurate than excretory urography in evaluation of renal stones due to its high sensitivity and temporal resolution; it permits sub-millimetric evaluation of the size and site of calculi but cannot evaluate their chemical composition. Dual-energy computed tomography allows evaluating the chemical composition of urinary calculi using simultaneous image acquisition at two different energy levels. The objective of the research was to determine renal stone composition using dual-energy multidetector computed tomography, and its correlation with post-extraction chemical analysis of stones. Materials and Methods. This prospective study was conducted in the Department of Radiodiagnosis and Imaging from September 2017 to March 2019. A total of 50 patients with urolithiasis at the age of 18-70 years were included in the study. Dual-energy computed tomography ratios of various stones were noted, and preoperative composition of calculi was given based on their colour and dual-energy computed tomography ratio. These results were compared with the post-extraction chemical analysis of stones (using Fourier infrared transform spectroscopy as the standard comparative method.) Results. The most common type of calculi in our study population was calcium oxalate stones (78%) followed by uric acid stones (12%), cystine stones (6%) and hydroxyapatite stones (4%). The dual-energy ratio of calcium oxalate, uric acid, cystine and hydroxyapatite stones ranged from 1.38-1.59, 0.94-1.08, and 1.20-1.28 and 1.52-1.57, respectively, with the mean dual-energy ratio of 1.43, 1.01, 1.25 and 1.55, respectively. Dual-energy computed tomography was found to be 100% sensitive and specific for differentiating uric acid stones from non‑uric acid stones. The sensitivity and specificity in differentiating calcium oxalate calculus from non‑calcium oxalate calculus was 97.5% and 90.9%, respectively, with 96% accuracy and kappa value of 0.883 suggesting strong agreement. Conclusions. Dual-energy computed tomography is highly sensitive and accurate in distinguishing between various types of renal calculi. It has vital role in management as uric acid calculi are amenable to drug treatment, while most of non-uric acid calculi require surgical intervention.


2019 ◽  
Vol 45 (4) ◽  
pp. 1092-1099
Author(s):  
Roberto Cannella ◽  
Mohammed Shahait ◽  
Alessandro Furlan ◽  
Feng Zhang ◽  
Joel D. Bigley ◽  
...  

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Celsus Ukelina Undie ◽  
Ewomazino Ibanga Nnana ◽  
Kalenebari Raymond Torporo

Abstract Background Uroliths are stones formed in the urinary tract. Analysis of stones helps to identify risk factors for their development and prevention of recurrence. Standard stone analysis using modern technology is not routinely done in Nigeria. This study sought to determine the chemical composition of urinary stones seen in Abuja, Nigeria. Methods This was a retrospective study on composition of uroliths. Urinary stones surgically removed from 155 patients through minimal access surgical procedures between January 2015 and August 2019 were analysed. Optical crystallography and infrared spectroscopy were used to determine the chemical composition of the urinary stones. Results A total of 155 urinary stones were assembled from the patients. More stones were removed from male patients and the male to female ratio was 1.9:1. Stones were rare in the extremes of age. The predominant location (89.7%) of stones was in the upper urinary tract. All stones were of mixed composition with calcium oxalate accounting for 93.55%. Calcium oxalate, calcium phosphate and uric acid stones were more common in the upper tract, while 2 of the 3 struvite stones were found in the lower tract. Conclusion Stones found in this study were of mixed composition with the most common constituent being Calcium oxalate and the least common, struvite.


QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Ahmed Salah Mahmoud Ahmed Shehata ◽  
Mohamed Rafik El-Halaby ◽  
Ahmed Mohamed Saafan

Abstract Objectives to make a reliable correlation between the chemical composition of the urinary calculi and its Hounsfield unit on CT scan, upon which we can depend on it for prediction of the type of the urinary calculi. The prediction of the chemical structure of the stone would help us to reach a more efficient therapeutic and prophylactic plan. Methods A retrospective study was performed by interpretation of the preoperative CT scans for patients who were presented by urinary stones. Identification of the chemical structure of the calculi was implemented using Fourier Transform Infrared Spectroscopy (FT-IR spectroscopy). The laboratory report revealed multiple types of stones either of pure or mixed composition. Afterwards, a comparison was done between Hounsfield units of the stones and the chemical structure. Results The chemical structure of the urinary stones revealed four pure types of stones (Uric acid, Calcium Oxalate, Struvite and Cystine) and two types of mixed stones (mixed calcium oxalate+ Uric, and mixed calcium oxalate+ calcium phosphate). Uric acid stone had a mean Hounsfield Unit (HU) density of428 ± 81, which was quite less than the other stones, followed by struvite stones with density ranging about 714 ± 38. Mixed calcium oxalate stones could be differentiated from other types of stones like uric acid, pure calcium oxalate and struvite stones by the Hounsfield unit of Computed Tomography (the mean Hounsfield Unit was 886 ± 139 and 1427 ± 152 for mixed calcium oxalate + uric stone and mixed calcium oxalate + calcium phosphate stones respectively). Moreover, pure calcium oxalate stones were easily differentiated from all other stones using the mean Hounsfield density as it was 1158 ± 83. It was challenging only when it was compared to cystine stones, as they were quiet similar to HU value (997 ± 14). The variation of Hounsfield values among the previously mentioned stones, was statistically significant (p < 0.001). Conclusion The study proved that the Hounsfield Unit of CT scanning is a convenient measure to predict the chemical structure of urinary calculi.


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