Ultrasonographic Methods And Assessment Of Hypoplastic Kidney For Medical Selection Of Flight Cadets

Objective:To explore the feasibility of ultrasound marker renal body projection method to measure renal mobility for the diagnosis of renal prolapse in medical selection of flight cadets,to develop ultrasound diagnostic criteria for renal prolapse in medical selection of flight cadets,and to provide a reference basis for further revision and improvement of relevant criteria for flight recruitment,and to improve the efficiency of flight recruitment.Methods:The 338 conscripted students who participated in the medical selection stage of the 2021 Air Force flight cadet recruitment were included in the body projections of the upper and lower poles of both kidneys,the lower edge of the costal arch and the anterior superior iliac spine by ultrasound positioning in the supine and upright positions,and the length of both kidneys and the direct and indirect mobility of the kidneys were measured.The intra-class correlation coefficient(ICC)was used to evaluate the agreement between the body projection method and the conventional ultrasound method for measuring the length of the kidney,and the agreement between the indirect kidney mobility measured by the body projection method with the lower border of the rib arch and the anterior superior iliac spine as the reference;the Wilcoxon signed rank sum test was used to compare the difference between the upper and lower pole of the kidney and the direct mobility.The Wilcoxon signed rank sum test was used to compare the differences between indirect and direct renal mobility;the normal range of indirect renal mobility measured by ultrasound was established using the percentile method(90%,95%,99%);and the correlation betweenmobility and clinical physical indicators was analyzed.To comprehensively evaluate the characteristics of kidney mobility of flight cadets and to establish ultrasonic diagnostic criteria of renal prolapse suitable for medical selection of flight cadets by combining the current recruitment work.Results:(1)Feasibility analysis of a new method for ultrasound measurement of renal mobility(1)The ICC coefficients between the conventional method of measuring kidney length and the body projection method of measuring kidney length were 0.758,0.780,0.728,and 0.766,respectively,with good agreement,and the results were statistically significant;(2)indirect kidney mobility of both kidneys was greater than direct mobility,and the difference was statistically significant,P<0.05;(3)indirect mobility of the upper pole of both kidneys relative to the lower edge of the costal arch(AB-ab)and the indirect mobility of the lower pole of both kidneys relative to the lower edge of the rib arch(bc-BC)had the largest ICC coefficients,0.923 and0.911,respectively,and the results were statistically significant.(2)Normal range of kidney mobility and factors affecting it(1)The upper lateral boundary values of 90%,95%,and 99% reference range of mobility of both kidneys were as follows:(right kidney)5.0cm,5.5 cm,and 7.3 cm,and(left kidney)5.4cm,5.7 cm,and 7.0cm;(2)The correlation between the mobility of the kidneys and clinical physical measurement indexes Correlation analysis showed that the weight,abdominal circumference,chest circumference,BMI,and BSA of 338 subjects were negatively correlated with the degree of kidney mobility(P<0.05).(3)Establishment of ultrasound diagnostic criteria for renal prolapse suitable for medical selection for flight cadet recruitment(1)the subcostal ratio of the left kidney in the upright position was smaller than that of the right kidney;(2)the greater the subcostal ratio of the kidney in the upright position,the greater the renal mobility;(3)the ROC curve of the subcostal ratio of the kidney was drawn using the upper boundary of the95% reference range of the renal mobility as the standard,and the threshold value,sensitivity,specificity and area under the curve of the "subcostal ratio of the kidney" for the diagnosis of renal prolapse were obtained.The threshold value,sensitivity,specificity,and area under the curve of "renal subcostal ratio" were 0.66,100%,82.7%,and 0.937 for the right kidney and 0.46,93.8%,69.3%,and 0.872 for the left kidney,respectively.Conclusions:(1)In this study,we analyzed the measurement of renal ultrasound projection localization and renal mobility in 338 cadets recruited for medical selection of flight trainees,and concluded that the method of measuring renal mobility under ultrasound localization is feasible,in which the lower pole of the kidney and the lower edge of the rib arch are used as the standard localization point to measure the indirect renal mobility more accurately and reasonably.(2)In this study,the normal range of renal mobility was initially established by ultrasound measurement and assessment of renal mobility in students recruited for flight.The analysis of clinical data showed that weight,abdominal circumference,chest circumference,BMI,and BSA were negatively correlated with the degree of renal mobility in 338 subjects(P<0.05)..(3)Analyzing the pattern of changes in indicators such as the proportion of the kidney under the rib cage and kidney mobility,we recommend that the diagnostic ultrasound criteria for the recruitment of flight cadets for medical selection of renal prolapse be considered unqualified if any of the following are met:(1)right kidney whole kidney or(and)left kidney whole kidney below the rib arch;(2)right kidney indirect mobility greater than or equal to 7.3cm or(and)left kidney indirect mobility greater than or equal to 7.0cm;(3)right kidney subcostal arch proportion greater than 2/3 and mobility greater than or equal to 5.5cm,or left kidney kidney subcostal arch proportion greater than 1/2 and mobility greater than or equal to 5.7cm.