Relationship between the thickness of the renal cortex and age:study with CT measurement / 中华放射学杂志

ABSTRACT

Objective To study the relationship between the renal cortical thickness and age,and to establish the range of the normal renal cortex thickness by using CT measurement in different age groups so as to obtain a best age-related and practicable method for clinical measurement. Methods (1) the accuracy of measuring renal cortical thickness by CT was evaluated; 18 kidneys resected due to renal neoplasm were studied and the cortical thickness of the normal part of these specimens was assessed. The difference between the renal cortical thickness of specimens and preoperative measurements of renal cortex of the same patient by contrast enhanced CT was analyzed statistically. (2) 120 patients without history of renal disease or long term usage of potentially renal toxic drugs or history of hypertention were examined by CT with indication(s) other than renal disease. All the patients were divided into 20-40, 41-60, and 61-80 year-old groups. The renal cortical and parenchymal thickness and renal size were measured in three CT sections. The difference of the measurements among the three groups and their relationship to age was analyzed statistically. Results There was no significant difference between the renal cortical thickness measured by enhanced spiral CT and measured in renal specimens(t =0. 80,P =0. 43). The renal cortical thickness in three groups was 0. 73 cm, 0. 65 cm, and 0. 53 cm, respectively, and the differences among the three groups were significant ( F = 93.430, P 0. 05). Conclusion The measurement of the renal cortical thickness with enhanced spiral CT was reliable and was a sensitive method in investigating the morphologic changes of the kidney. The renal cortical thickness of normal kidney diminishes with age, but the change of the ratio of thickness of renal cortex to renal parenchyma with age was not significant.