PURPOSE: This study aimed to characterize the urinary tract stones in phantom and patients using single-source dual-energy computed tomography. MATERIALS AND METHODS: Twenty stones of pure crystalline composition (uric acid [UA], struvite, cystine, and calcium oxalate monohydrate) were assessed in a phantom and 11 patients (age 39-67 years) with urinary tract stones were evaluated. An initial low-dose unenhanced CT (tube potential, 120 kilovolts [peak]; milliampere range, 150-450; noise index, 26; section thickness, 5 mm) followed by a targeted dual-energy computed tomography acquisition on a single-source dual-energy computed tomography (Discovery CT 750 HDCT, GE) was performed. Uric acid and non-UA stones were defined using a 2-material decomposition (material density-iodine/water) algorithm. The stone effective atomic number (Zeff) was used to subclassify non-UA stones. The stone attenuation (Hounsfield unit) was also studied to determine its performance in predicting the composition. Ex vivo chemical analysis of the stone served as a criterion standard. RESULTS: Of the 59 verified stones (phantom, 20; patients, 39; mean size, 6 mm), there were 16 UA and 43 non-UA type. The material density images were 100% sensitive and accurate in detecting UA and non-UA stones. The Zeff accurately stratified struvite, cystine, and calcium (calcium oxalate monohydrate) stones in the phantom. In patients, Zeff identified 83% of calcium stones (n = 24), and in stones of mixed type, it resembled dominant composition. The Hounsfield unit measurements alone were 71% sensitive and 69% accurate in detecting the UA stones. CONCLUSIONS: Single-source dual-energy computed tomography can accurately predict UA and non-UA stone composition in vitro and in vivo. Substratification of non-UA stones of pure composition can be made in vitro and in vivo. In stones of mixed composition, the Zeff values reflect the dominant composition.
PURPOSE: This study aimed to characterize the urinary tract stones in phantom and patients using single-source dual-energy computed tomography. MATERIALS AND METHODS: Twenty stones of pure crystalline composition (uric acid [UA], struvite, cystine, and calcium oxalate monohydrate) were assessed in a phantom and 11 patients (age 39-67 years) with urinary tract stones were evaluated. An initial low-dose unenhanced CT (tube potential, 120 kilovolts [peak]; milliampere range, 150-450; noise index, 26; section thickness, 5 mm) followed by a targeted dual-energy computed tomography acquisition on a single-source dual-energy computed tomography (Discovery CT 750 HDCT, GE) was performed. Uric acid and non-UA stones were defined using a 2-material decomposition (material density-iodine/water) algorithm. The stone effective atomic number (Zeff) was used to subclassify non-UA stones. The stone attenuation (Hounsfield unit) was also studied to determine its performance in predicting the composition. Ex vivo chemical analysis of the stone served as a criterion standard. RESULTS: Of the 59 verified stones (phantom, 20; patients, 39; mean size, 6 mm), there were 16 UA and 43 non-UA type. The material density images were 100% sensitive and accurate in detecting UA and non-UA stones. The Zeff accurately stratified struvite, cystine, and calcium (calcium oxalate monohydrate) stones in the phantom. In patients, Zeff identified 83% of calcium stones (n = 24), and in stones of mixed type, it resembled dominant composition. The Hounsfield unit measurements alone were 71% sensitive and 69% accurate in detecting the UA stones. CONCLUSIONS: Single-source dual-energy computed tomography can accurately predict UA and non-UA stone composition in vitro and in vivo. Substratification of non-UA stones of pure composition can be made in vitro and in vivo. In stones of mixed composition, the Zeff values reflect the dominant composition.
Authors: Raphaële Renard-Penna; Aurélie Martin; Pierre Conort; Pierre Mozer; Philippe Grenier Journal: World J Urol Date: 2014-10-26 Impact factor: 4.226
Authors: Shuai Leng; Maria Shiung; Songtao Ai; Mingliang Qu; Terri J Vrtiska; Katharine L Grant; Bernhard Krauss; Bernhard Schmidt; John C Lieske; Cynthia H McCollough Journal: AJR Am J Roentgenol Date: 2015-01 Impact factor: 3.959
Authors: Murat Akand; Mustafa Koplay; Necat Islamoglu; Murat Gul; Ozcan Kilic; Merter Bora Erdogdu Journal: Int Urol Nephrol Date: 2016-05-20 Impact factor: 2.370
Authors: Shuai Leng; Alice Huang; Juan Montoya Cardona; Xinhui Duan; James C Williams; Cynthia H McCollough Journal: AJR Am J Roentgenol Date: 2016-05-25 Impact factor: 3.959