MEASUREMENT OF NORMAL KIDNEY LENGTH BY SONOGRAPHY AND ITS RELATION TO AGE , SEX , AND BODY HABITUS

Address for Correspondence: Dr. Kalpana Purohit, Assistant professor, Department of Anatomy, Hind Institute of Medical Sciences, Mau, Ataria, Sitapur, Uttar Pradesh, India. E-Mail: purohit.kalpana1963@gmail.com Introduction: Normal kidney length is an important indicator of normal renal function. The length ranges from 9 to 13.5cm. Kidney sizes are roughly related to patient’s size. The assessment of renal size is an integral part of evaluation of renal diseases for both diagnostic and prognostic purposes. Normal renal longitudinal length reflects normal renal function, & it can be conveniently measured by ultrasonography. Materials and Methods: The aim of this study is to evaluate the normal range of kidney length by Ultrasonography and its correlation with Age, Sex, Height, & Weight in normal Indian population. The measurement scale was fixed to the wall to measure height. Weight was measured by a weight machine. The ultrasound image was taken in both lateral decubitus position and the renal length was measured as the maximum bipolar dimension in longitudinal plane. Observations: The mean length in all Age groups was 94.4±11.8mm of right kidney and 97.4±12mm of left kidney and correlated statistically significantly (p=0.000). The mean length of right kidney in male was 94.7±13.8mm, whereas in female it was 94±9.8mm (p=0.597) and that of left side was 98.2±14mm in male and 96.6±10mm (p=0.343) in female, which was statistically not significant. Discussion: In the present study, there was sharp increase in measurements of length till the age of 20 years and slight increase upto 30 years and thereafter, it remained stable beyond 30 years upto 50 years. In the present study the kidney length was found to be larger on left side in 63.68%, right side in 34.98% and equal in 1.35%. However the difference of length between Male and Female was not statistically significant in the present study. Conclusion: The length of kidney were smaller than previously reported, is probably a reflection of the relatively small body size of South East Asians than western population. Left kidney was larger than Right kidney. With increase in Height, Weight there was an increasing trend in the length of measurement in both the kidneys which were statistically significant.


INTRODUCTION
of extracellular volume and Acid-Base Homeostasis.It filters the plasma of the blood, & excretes metabolic waste products from the body [1].In adults, each kidney is 11cm long, 2.5cm thick and 5cm wide [2].The length ranges from 9 to 13.5cm.Kidney sizes are roughly related to patient's size.It is also known that the left kidney is larger than the right kidney [3,4].The assessment of renal size is an integral part of evaluation of renal diseases for both diagnostic and prognostic purposes [5].Presently Sonography of the kidney has replaced standard Radiography for evaluation of renal diseases [6,7].In individuals with normal renal function, an important measurement of renal size is longitudinal length & it can be conveniently measured by ultrasonography [8].Many studies have shown that the renal size measurements are influenced by many factors such as age, ethnicity, gender, weight and height [9][10][11].
renal parenchyma evenly distributed around the Central Sinus.

MATERIALS AND METHODS
The weight was taken in a weighing machine.The ultrasound image was taken in both lateral decubitus position and also instructed to hold their breath for a short while.After locating the Kidney, the transducer was rotated slightly to determine the longest renal axis and the renal length was measured as the maximum bipolar dimension in longitudinal plane which was displaying better Central Sinus Echoes, with the   1).It was found (of't' test) that male kidney were larger than female kidney in both sides.The mean length of right kidney in male was 94.7±13.8mm,whereas in female it was 94±9.8mm(p=0.597) and that of left side was 98.2±14mm in male and 96.6±10mm (p=0.343) in female, which was statistically not significant (Table 2).
There was significant difference (p=0.000) of the length of both right and left kidneys among the Weight groups.The analysis revealed that, as the weight increases the length of kidney also increases (Table 3).4.There is an increasing trend of the length of kidney with the Height, which was statistically significant (p=0.000).
yielded comparable results with kidney length ranging between 9.1-9.9cm[16,18].However, reported lengths obtained during dedicated renal ultrasound examinations were both more accurate and more precise than those reported in general abdominal ultrasound examinations.
In the present study the mean kidney length correlated with the previous studies of In the present study the kidney length was found to be larger on left side in 63.68%, right side in 34.98% and equal in 1.35%.E. Dinkel et al (1985), in their study observed that Left kidney in children were slightly greater in median length (0.9 mm) and median volume (2.5 ml) than Right kidney.The kidney was found to be longer on the Left in 51.7%, on the Right in 34.1% and of equal size in 14.2% [21].

DISCUSSION
Ultrasound is the preferred method of diagnosis in most clinical practice.Ultrasonographic renal size is one of the easily reproducible parameter and provides a rough indication of the renal function.The minimal size of a fully functional kidney is 9 cm in length [12].A difference in length of 2 cm or more between the right & left kidneys may raise the possibility of unilateral kidney disease.Many congenital and acquired diseases directly or indirectly affect renal dimensions in all age groups [3].Decrease in size and function are seen with chronic renal failure [13], renal arterial occlusion [14] and late stage renal venous thrombosis [15].Autopsy findings of renal biometry in Indian population In the present study, there was sharp increase in measurements of length till the age of 20 years and slight increase upto 30 years and thereafter, it remained stable beyond 30 years upto 50 years.A. Hekmatnia, M. Yaraghi (2004) got significant decrease in absolute and relative renal length in the age group 60-69 years old.They showed gradual decrease in renal length with increase in age and the decrease accelerates after the age of sixty years [22].However the difference of length between male and female was not statistically significant in the present study.In this present study all the length of kidney correlates well with Height, Weight and statistically significantly (p=0.000).
Higher body weight and height requires a bigger kidney [17] E. Dinkel et al (1985) found better correlation between kidney length to body height than to age or body weight [21].
The length of kidney in this study were smaller than previously reported, is probably a reflection of the relatively small body size of South East Asians than western population.Left kidney was larger than Right kidney.With increase in Height, Weight there was an increasing trend in the length of measurement in both the kidneys which were statistically significant.

International
Journal of Anatomy and Research, Int J Anat Res 2017, Vol 5(4.3):4668-73.ISSN 2321-4287 DOI: https://dx.doi.org/10.16965/ijar.2017.432 present study is conducted in the Department of Anatomy Kalinga Institute of Medical Sciences, KIIT University, Bhubaneswar, Odisha.Two Hundred (200) Ultrasonography was included of both sex & all age upto 70 years of age.Multiple Renal Cysts, Polycystic Kidney Disease, Unilateral Kidney, Chronic Kidney Disease or Malignancy, previous renal surgery or any congenital anomaly were excluded from this study.To measure height, the measurement scale was fixed to the wall.Height was measured while the subject stood without shoes or hat with heels, buttocks, shoulders and occiput touching the vertical scale & the head held upright.The standing height was measured on a stadiometer in children above 2 years & in children below 2 years the supine lengths were measured on an Infantometer.Height was measured on rounded to the nearest 0.5 cm.

Table 4 :
Descriptive Statistics and ANOVA for Parameters of Right and Left Kidney by Height (cms) by USG the basis of their Height.The groups were < 130cm, 131-150cm, 151-170cm and >170cm.The mean of length of right and left kidney along with ANOVA results according to Height has been furnished in Table Adeela Arooj et al (2011)[17], Zeb Saeed et al (2012)[18], Mujahid Raza et al (2011)[19], J.O. Carrasco etal (2009)[3], Buchholz NP et al (2000)[20].The smaller length of kidney, probably due to reflection of the relatively small body size of South East Asians[18, 20].

Table 1 :
Descriptive Statistics and ANOVA for Parameters of Right and Left Kidney by Age Group by USG.

Table 2 :
Comparison of Parameters of Right and Left Kidney by Sex by USG.

Table 3 :
Descriptive Statistics and ANOVA for Parameters of Right and Left Kidney by eight(kg) by USG.

Table 5 :
Kidney length in different studies.

Table 6 :
Percentage Distribution Of Kidney Length.Ankita Purohit, Geeta Satpathy.MEASUREMENT OF NORMAL KIDNEY LENGTH BY SONOGRAPHY AND ITS RELATION TO AGE, SEX, AND BODY HABITUS.