A Test And Clinical Application Research Of Single-Source Single-Energy CT Dual Energy Imaging Method For Urinary Calculi Ingredient Analysis

Objective:(1) The aim of this study is to explore the feasibility of detecting the composition of urinary calculi in vitro by using the single-source single-energy CT dual energy imaging method, with urinary calculi Fourier transformation infrared spectrum analysis results as the golden standard.(2) This study is aim to investigate the applicable feasibility for the stones ingredient analysis in vivo by using the single-source single-energy CT dual energy imaging method, with urinary calculi Fourier transformation infrared spectrum analysis results as the golden standard. Materials and Methods:(1) In vitro, 36 stones specimens were scanned by single-source single-energy 64 row CT dual energy imaging. CT scans were assessed in terms of CT values in 80 k Vp and 140 k Vp datasets independently. The stones samples were divided into 5 groups(uric acid、mixed uric acid、calcified stones、struvite stones、cysteine stones) according to the results of Fourier transform infrared spectrum analysis which was seen as a gold standards for stone ingredient analysis. Then DEI values were calculated according to a certain formula. These data were statistical analysis by SPSS19.0 software. One-way analysis of variance was used to test all the DEI data and the DEI data were compared among different groups which the means were differ or not all differ by Student-Newman-Keuls test. P<0.05 indicated a statistical significance.(2) In vivo, 49 patients with symptoms of urinary stones were caned using dual-energy imaging method. CT values of each stone were recorded for the 80 and 140 k Vp datasets. Then DEI values were calculated according to the certain formula. Fourier transform infrared spectrum analysis was carried out on the stone samples acquired from these patients. Then the values were taken as the standard values that concluded from the Fourier transform infrared spectrum analysis. The stones were divided into different groups by the results of Fourier transform infrared spectrum analysis. SPSS19.0 software was used for data analysis, one-way analysis of variance was used to test the DEI data among different groups. Student-Newman-Keuls test was used to pairwise comparison of the different subgroups. P<0.05 indicated a statistical significance. Radiation doses were recorded. Results:(1) The DEIs were 0.0123±0.0041 for uric acid(UA), 0.0361±0.0126 for mixed UA, 0.0990±0.0155 for calcified stones, 0.0618±0.0065 for struvite stones and 0.0583±0.0077 for cysteine stones in vitro. There were significant differences among UA mixed UA, calcium, struvite and cysteine stones(P=0.024、P<0.001、P<0.001、P<0.001). Statistical differences were noted between mixed UA and calcium, struvite stones(P<0.001、P=0.029). There were significant differences between calcium and struvite, cysteine stones(P<0.001、P<0.001). There were no significant differences among other groups of DEI values.(2) In the clinical research, the DEIs were 0.0125±0.0104 for UA, 0.0495±0.0274 for mixed UA, 0.1013±0.0422 for calcified stones, 0.0807±0.0095 for struvite stones and 0.0854±0.0356 for cysteine stones in vivo. There were significant differences among UA mixed UA, calcium, struvite and cysteine stones(P=0.036、P<0.001、P<0.001、P<0.001). Statistical differences were noted between mixed UA and calcium stones(P<0.001). There were significant differences between calcium and struvite stones(P=0.022). There were no significant differences among other groups of DEI values. Conclusions:(1) Comparied with merely single energy imaging of 80 KVP and 140 KVP, single-source single-energy CT dual-energy imaging is a better method in distinguishing the composition of urinary calculi in vitro. It has obvious advantages of identification uric acid and non-uric acid stones, calcium and uric acid stones in vitro.(2) Single-source single-energy CT dual-energy imaging method shows fairly high ability in identifing uric acid and other stones types, calcium and non-calcium stones, and it may approach or even reach the diagnosis level of dual-source CT dual- energy method, and has a good clinical value.