Hypothesis / aims of study
Primary vesicoureteral reflux (VUR) is one of the most common congenital urinary malformations in children. VUR often causes urinary tract infections and pyelonephritis, and repeated pyelonephritis can cause irreversible damage such as kidney fibrosis and kidney scar formation, eventually leading to reflux nephropathy. Therefore, early diagnosis of VUR and early control of urinary tract infections can effectively prevent the formation of renal scars and reflux nephropathy, and reduce the chance of irreversible damage to the kidneys. This article aims to further understand the value of ultrasonography in the diagnosis of VUR in children by retrospectively analyzing the ultrasound sonogram of pediatric VUR.
Study design, materials and methods
From 2010 to 2018, 80 patients with urinary tract infection diagnosed in our hospital did not have urinary tract obstruction and other congenital urinary tract malformations, and all had urinary bladder urography after the urinary tract infection was cured. Cystouregram, MCU) check. Among them, 35 males and 45 females, the ratio of male to female 1:1.2; age range of 1 month to 12 years, an average of 3 years and 11 months.
Application MINDRAY DC-8 and GE Voluson E8 color Doppler ultrasound diagnostic equipment, convex array probe (frequency is 6~8MHz) and high-frequency linear array probe (frequency 8~12MHz) combined scanning.
Ultrasound examination: Take the supine or lateral position and check in a quiet state. Children under the age of 3 crying and not cooperating with children 10% chloral hydrate 0.5ml / kg body weight and calm, parents accompany the whole process.
Ultrasound examination parameters: (1) renal sinus echo enhancement; (2) hydronephrosis, refer to the classification criteria of the American Fetal Urinary Association (SFU); (3) thickening of the renal pelvis wall (wall thickness > 2 mm for thickening); 4) Kidney atrophy (the kidney length is less than the normal mean value of 2 standard deviation for the kidney shrinkage, renal morphology irregular thinning); (5) ureteral dilatation (6) ureteral thickening (wall thickness > 2 mm for thickening) (7) Thickening of the bladder wall.
The MCU is used as the gold standard for VUR diagnosis and grading, and the reverse-flow indexing uses the five-level classification proposed by the International Countervailing Committee. All children underwent an excretory urography (MCUG) after ultrasound examination to see if there was vesicoureteral reflux. The ultrasound results were compared with the MCU results.
Statistical data were analyzed and analyzed using SPSS 13.0 software. The count data were analyzed by two independent two-class chi-square tests. The measurement data were analyzed by two independent samples t test. p < 0.05 was considered statistically significant.
1. In this study, of the 160 kidneys of 80 children with urinary tract infections, 80 kidneys were eventually diagnosed as VUR by MCU, including 14 grade I VUR kidneys, 20 grade II VUR kidneys, 30 A grade III VUR kidney and 16 grade IV VUR kidneys. .
2. Of the 80 VUR kidneys, 60 kidneys were positive for sonographic findings, 57 of which showed a combination of 2-7 different ultrasound parameters, and only 3 kidneys showed a single ultrasound parameter positive. The most common VUR ultrasound parameters of children from high to low were: renal sinus echo enhancement, hydronephrosis, thickening of the renal pelvis wall, ureteral dilatation, thickening of the ureteral wall, thickening of the bladder wall and renal atrophy.
3. Ultrasound (US) suggests that the sensitivity and specificity of the main parameters of VUR in children are as follows: the positive rate of renal sinus echo enhancement is 70% (56/80), the positive rate of hydronephrosis is 65.% (52/80), renal pelvis The positive rate of wall thickening was 60% (48/80), the positive rate of ureteral dilatation was 50% (40/80), and the positive rate of ureteral wall thickening was 40% (32/80). The positive rate of bladder wall thickening was 40% (32/80), and the positive rate of renal atrophy was 30% (24/80).
Interpretation of results
1.At present, MCU is routinely used as the gold standard for diagnosing VUR, but MCU has certain radioactivity and traumaticity. Ultrasound examination has no such damage, and can be repeated, and the advantages are obvious. However, ultrasound can not observe the direct signs of urine reflux from the bladder to the ureter, so ultrasound examination can not be used to directly diagnose VUR, we hope to explore VUR by exploring the performance of a series of pathological changes caused by VUR in ultrasound.
2.The positive rate of renal sinus echo enhancement in reflux renal is 70% (56/80); the recurrent infection rate of renal pelvis and renal pelvis is considered to be high in children with VUR, and the long duration of infection causes fibrosis or connective tissue of renal pelvis and renal pelvis wall. Hyperplasia enhances local echo. We believe that the enhancement of renal sinus echo can be used as an ultrasound symptom of VUR.
3.In the VUR kidney, the positive rate of hydronephrosis was 65% (52/80), considering the direct results of mainly severe reflux (Class III, Grade IV), and secondly related to renal inflammation caused by reflux. We believe that the signs of low tension of the renal pelvis, renal pelvis expansion and no increase in the ipsilateral kidney are unique features of VUR, which can be used as an important ultrasound sign suggesting VUR. Especially when the kidneys show renal atrophy at the same time, it is of great significance for differential diagnosis and suggesting VUR.
4.In this study, a number of ultrasound-positive signs were commonly present in the reflux kidney. When there was only one positive sign, the false positive rate of ultrasound was higher, especially the enhancement of renal sinus echo, renal pelvis and/or renal pelvis. The expansion was 22% and 14%, respectively. When two or three positive signs appeared in combination, the ultrasound suggested that the specificity of VUR was high, 97% to 100%.
Ultrasound examination is the first choice for imaging examination of urinary system diseases in children. When ultrasound is used to detect VUR in children, a number of ultrasound-positive signs are commonly present. When there is only one positive sign, the false positive rate of ultrasound is higher. When two or three positive signs appear in combination, the ultrasound prompts VUR. The specificity is very high, 97% to 100%. We believe that ultrasound suggests that the role of VUR is more meaningful when ultrasound signs appear. Ultrasound examination of infantile urinary system revealed increased renal sinus echo, renal pelvis, renal pelvic dilatation, thickening of the renal pelvis wall, and thickening and dilatation of the ureteral wall. Especially when these signs appear in combination, the possibility of VUR is high. It is highly recommended for further MCU inspections. In order to detect and diagnose VUR as early as possible, early control of urinary tract infections, reduce or reduce irreversible kidney damage and reflux nephropathy.