MORPHOMETRIC STUDY OF PITUITARY GLAND WITH CORRELATION OF AGE AND GENDER USING MAGNETIC RESONANCE IMAGING

1* 2 3 4 1 5 Sunima Maskey , Dil Islam Mansur , Subindra Karki , Pragya Shrestha , Sheprala Shrestha , Mukta Singh Bhandari Maskey S et al


Introduc on
The pituitary gland is the master gland of the body. It's size varies with age and gender. MRI is the safest and effec ve diagnos c tool for pituitary gland examina on.

Objec ves
This study was aim to determine the anteroposterior, height and transverse dimensions of normal pituitary gland in different age groups of both sex with MRI.

Methodology
It was a descrip ve cross-sec onal study. It consisted of 567 images of individuals (242 males and 325 females) of various age from 20 to 70 years from the Department of Radiodiagnosis, Dhulikhel Hospital.

Result
The mean anteroposterior, height and transverse dimension of pituitary gland is 9.74±1.18 mm, 5.95±1.11 mm and 11.65±2.15 mm respec vely in which females have higher value. Independent sample t test showed highly significant differences (p< 0.05) between the mean anteroposterior dimension in males and females. The present study showed the mean value of anteroposterior dimension is maximum at age group 50-59. The mean value of height, transverse dimension and volume of males and females is maximum at 20-29 age group and minimum at 70-79 age group. One way ANOVA shows that there is significant difference between in height, transverse dimension and volume at different age group (p< 0.05).

Conclusion
It was concluded that the height and volume of pituitary gland is maximum at second decade of life then it gradually decreases with age. The mean value of anteroposterior, height and transverse dimension showed greater value of females than males.

INTRODUCTION
The pituitary gland is the master gland which controls 1 almost all the ac vi es of other gland in the body. It is a reddish gray in color, ovoid in shape and measures about 8 mm in anteroposterior, 12 mm in transverse dimension and 2,3 5.9 mm height. It is located within the hypophyseal fossa of 1,2 sphenoid bone and covered by a diaphragm sellae. Magne c resonance imaging (MRI) generate image using the nuclei of atoms inside the body which is specifically 4 useful for so ssues visualiza on. It is considered safe for studies since it does not use any harmful ionizing radia ons 5 and provides high resolu on images. Likewise It is the most accurate and preferable diagnos c technique for pituitary 6,7 gland. Studies have claimed the varia on size of pituitary gland 8,9 associated with age, gender and pathological condi on. As the size varies with age, it is very important to find the morphological dimension and correla on with age and gender. There are several disorders of pituitary gland such as pituitary adenomas, inflamma on, hypertrophyetc which 6,10 may affect size and shape of gland. Due to varia ons in size and shape of pituitary with age, pituitary volume is 11 taken as the best predictor of pituitary gland size. Morphometric analysis of pituitary gland has been studied by many researchers worldwide because of its importance. Knowledge of accurate anatomical measurements of it is important for clinician for be er prognosis of the diseases. The data is not sufficiently available for Nepalese popula on. Thus, the present study was aimed to evaluate pituitary morphometry by using MRI images.

METHODOLOGY
A descrip ve cross-sec onal study was conducted in the Department of Anatomy and data was collected from the Department of Radio-diagnosis, Dhulikhel Hospital/ Kathmandu University Hospital, Dhulikhel, Nepal by using images of MRI scan. MRI was performed with a 1.5 Tesla Ingenia Philips machine. The ethical clearance was obtained from IRC-KUSMS (Ref. no. 50/19).The convenient sampling technique was used for data collec on. Total number of 567 images of individuals (242 males and 325 females) of various age from 20 to 70 years were taken from June 2019 to December 2020. The obtained data were studied under different age groups and each ten years were grouped as an age group. Hence, the present study consisted of 20-29, 30- transverse dimension x 0.52. Data was collected and entered in Microso excel and analyzed using the Sta s cal Package for the Social Sciences version 16.0 for descrip ve sta s cal analysis. P-value was calculated to find the level of significance and P value <0.05 was considered as significant.

RESULTS
The mean anteroposterior, height and transverse dimension of pituitary gland in which all values of females were found to be more than males is described in Table 1. Independent sample t test showed highly significant differences (p< 0.05) between the mean anteroposterior dimension in males and females.
Furthermore, the mean value of anteroposterior, height and transverse dimension of pituitary gland in different age group is shown in Table 2. The present study showed the mean value of anteroposterior dimension is maximum at age group 50-59 yrs. It was found that the height, transverse dimension and volume is highest at 20-29 yrs age group. One way ANOVA shows that there is significant difference between in height, transverse dimension and volume at different age group (p< 0.05). The mean value of anteroposterior, height, transverse dimension and volume of pituitary gland in different age group and in both sex is described in Table 3. Anteroposterior dimension: The mean value of  (Table 3). This study coated that the mean value of height of females is greater than males in all age group except at 60-69 yrs age group. Transverse dimension: The mean value of transverse dimension of males and females is maximum at 20-29 yrs age group 12.18±1.95 mm and 12.07±1.89 mm respec vely and minimum at 70-79 yrs age group 9.24±2.95 mm and 10.87±1.75 mm respec vely ( Table 3). The present study showed that the mean value of transverse dimension of males at 20-29 yrs and 50-59 yrs age group is greater than females. Volume: The mean value of volume of males and females is 3 maximum at 20-29 yrs age group (377.5 ± 94.94 mm and anteroposterior dimension of males is maximum (10.05±0.97 mm) at 50-59yrs age group and minimum (9.32±1.15 mm)at 70-79 yrs age group. Similarly, the mean value of anteroposterior dimension of females is maximum (10.01±1.31 mm) at 20-29 yrs age group and minimum (9.40±1.05 mm) at 60-69 yrs age group. The mean values of females is larger in all group except 50-59 yrs and 60-69yrs age group (Table 3). Height: The mean value of height of males and females is highest at 20-29 yrs age group i.e. 6.19±0.99 mm and 6.38±1.13 mm respec vely and lowest at 70-79 yrs age 3 401.42 ± 115.16 mm respec vely) and minimum at 70-79 3 yrs age group (236.95 ± 96.08 mm and 305.58 ± 110.18 3 mm respec vely). The differences between the mean volume in males and females at all groups were found to be insignificant except at 20-29 yrs age group where it is highly significant (p<0.05) ( Table 3). The conducted study showed that the mean value of volume at 50-59 yrs age group had higher value for males than females. The mean volume of gland shows significant associa on with puberty age with maximum value at 20-29 yrs age group which is gradually decreasing with the age.

DISCUSSION
Pituitary gland is very important neuro endocrine organ 2 which secrete hormones that is essen al for life. MRI is most preferable diagnos c technique for the examina on of so 6,7 ssues. It is therefore important to get normal pituitary gland value of MRI images. Pituitary gland varia ons are 8,9 noted among individuals from different part of the world. Change in the shape and size o en affected by age and gender. The varia ons in size also reflects hormonal func on 10 imbalance. In our study the overall mean height was 5.95±1.11 mm which is lesser than the study done by Yadav et al., 3,8,12 Lamichhane et al. and Kumar. In contrast, the finding of 9 Suzuki et al. has lower mean value than our study. Fewer study done by Mohammad  popula on showed the lower mean value than ours. Generally, the volume were higher at the early puberty age than in the declining years. The present study revealed the maximum mean value is for the age group 20-29 yrs 3 (751.47±205.75 mm ) then it gradually decrease with age. Similar the study done among Sudanese, Indian, Nepali, Nigerian and Kashmiri popula on showed maximum volume at 20-29 yrs age group which supported our 3,8,12,15,19 study. A study done in India revealed the value of mean volume of 3 females (360.96±110.33 mm ) is greater than that of males 11 (341.17±103.29 mm3) which is similar to our study. In 19 contrast, Ibinaiye et al. reported larger values in male.

CONCLUSION
The present study showed the height and volume of pituitary gland is maximum at second decade of life then it gradually decreases with age. The mean value of anteroposterior, height and transverse dimension showed greater value of females than male. It could also establish normal reference values for MRI of pituitary gland which may be used in diagnosis and treatment of diseases.

RECOMMENDATIONS
It is highly recommended to conduct similar study including large popula on to see the sexual dimorphism in Nepalese popula on.

LIMITATIONS OF THE STUDY
Study could not include the popula on from other part of the country so the result obtained from this study could not be generalized to other popula on.