OBJECTIVE: To establish a method for measuring the photoelectric performance index (luminance response characteristic and luminance tolerance) of medical electronic endoscope. METHODS: Based on the clinical application and product features of medical electronic endoscope, the umbrella grayscale test chart and the adjustable gray scale test chart are designed and made from two aspects of distribution and density differential. RESULTS: The influence of gray scale arrangement, background illumination intensity and illumination spectrum on photoelectric performance measurement of electronic endoscope is verified by test. CONCLUSIONS It is a reference for the design analysis, evaluation and modification of electronic endoscope product photoelectric part, whether it is suitable for fast detection of umbels and more accurate gray scale test chart.
Electronics, Medical ; Endoscopes ; Light ; Quality Control

Objective To evaluate the clinical value of CT urography (CTU) in quantitative analysis of single?kidney renal glomerular filtration rate (GFR) in patients with renal tumor and hydronephrosis.Methods A total of 49 patients with renal tumor or hydronephrosis from January 2018 to September 2018 in the Second Hospital of Tianjin Medical University were prospectively collected. In all cases, the CT urography and 99mTc?DTPA renal dynamic imaging data and related clinical data were collected. All patients were divided into two groups: the experimental group (39 patients with a total of 78 kidneys) and the validation group (10 patients with a total of 20 kidneys). According to the presence or absence of renal diseases, the kidneys of the experimental group and the validation group were further divided into four groups, namely, the single kidney group, the tumor group, the stagnant water group and the healthy group. The CT urography protocol consisted of noncontrast, arterial phase, nephrographic, and excretory phase imaging. The total renal GFR was determined by CT measurement of renal clearance of contrast media (CM), and the total CT?GFR was then split into single?kidney CT?GFR by a left and right kidney proportionality factor. Differences between CT?GFR and SPECT?GFR measurements in each group of the experimental group was compared by paired?sample t test. Correlations between CT?GFR and SPECT?GFR in the experimental group and their correlations with RPV was analyzed by Pearson method. The Bland?Altman mapping method was used to evaluate the consistency between CT?GFR and SPECT?GFR in the experimental group. Results Paired difference between single?kidney CT?GFR (48.76 ± 18.50) ml·min-1·1.73 m-2 and single?kidney SPECT?GFR (45.68±17.95) ml·min-1·1.73 m-2 in the experimental group, P<0.05, demonstrating 6.8% systemic overestimation. A good correlation(r=0.80, P<0.01) and consistency (± 22.50 ml·min-1·1.73 m-2, ± 49.2% measurement deviations) was revealed between both measurements. There were positive correlations between CT?GFR and SPECT?GFR in the renal tumor group, hydronephrosis group, and healthy kidney group (r=0.67, 0.92, 0.80; P<0.01) respectively, and with good agreement (95% CI measurement deviation<30 ml·min-1·1.73 m-2). In all validation groups, there was no statistical difference between the estimated and true values of the Gates?GFR (all P>0.05). Pearson Correlation analysis showed that the correlations between CT?GFR and RPV in all experimental groups were better than the correlation between Gates?GFR and RPV (P<0.05). Conclusions This study demonstrated the feasibility of using CT urography to measure single?kidney GFR, verifying its application value in diseases such as kidney tumors and obstructive hydronephrosis, and proved that the proposed single?kidney CT?GFR correlates better than the SPECT?GFR with RPV.