This study describes the morphometry of spleen dimensions; compare the presence of a significant difference between sex and age as well as dimensional correlations with anthropometric measurements. The mean of spleen dimensions was also compared with other studies and consistency and the difference was noted in the current study. The sonography assessment of spleen dimensions provides essential inputs for clinicians in daily clinical practice for proper diagnosis of splenomegaly (32, 44, 53–55). The result of this study gives reference values which helps radiologist for appropriate diagnosis of diseases associated to splenomegaly and splenic atrophy, for the surgeons to appropriately design surgical cases associated to spleen, for hematologist and immunologist for proper diagnosis of various gastrointestinal and hematological diseases and forensic studies (56–59).
The mean of spleen length at 95% CI with SD was 10.24 ± 1.45 cm which is consistent with studies conducted in Russia and Kashmir (60, 61). But, less than from study conducted in Turkey(42), Bangladesh, Jordan and North India (8, 41, 62, 63) and greater than from study conducted in Nepal, Nigeria, Sudan and Northern Ethiopia (29, 33, 42, 64).
The mean of spleen width was 4.79 ± 0.998 cm which is less than from study conducted in Bangladesh, Nepal, Kashmir, North India and Nigeria (8, 42, 44, 61, 63, 64) and greater than from study conducted in Sudan and Northern Ethiopia (29, 33).
The mean of spleen thickness in the current study was 3.93 ± 1.054 cm which is consistent with the study conducted in Ethiopia (33). But less than from studies conducted in Russia, Bangladesh, Jordan, Nepal, north India, and Nigeria (8, 41, 42, 44, 60, 63, 64) and is greater than from a study conducted in Sudan (29).
The mean spleen volume was 109.34 ± 61.68 cm³ which is less than from studies conducted in Saud Arabia, Russia, Jordan and Nepal (41, 53, 60, 64, 65) but greater than from the study conducted in Sudan and Ethiopia (33, 40).
The overall dimensional difference of the current study from studies conducted in other areas may be due to age group difference, sample size difference, anthropometric measurements, geographical differences, nutritional status, physical exercise, and race difference which were stated in different literature (32, 44, 59, 66–69).
The fact that fewer average total red cell mass among females and due to genetic factor splenic dimensions was lower in females (31, 70). This is supported by our findings where all dimensions were significantly larger in males than females. This is consistent with the study conducted in Turkey, Saudi, Nigeria and Sudan (40, 53, 59, 71, 72). But, a non-significant difference in spleen volume was observed in a study conducted in Nepal (64) which is due to the small sample size and age range difference where 1–90 years were included in the study of Nepal. Also, the length was higher among females than males in the study conducted in Egypt (73) which is maybe due to nutritional status where Egyptian culture accepts excess weight gain among women than men due to fertility considerations (74, 75).
The spleen dimensions decrease in older age due to a decrease in the number and size of B cell follicles of the white pulp of the spleen which decreases with a decrease of germinal center in older age groups (76–78). This is supported by our finding where the lengths, width, thickness, and volumes were significantly increased up to the age of 40 years then decrease in older ages. This is consistent with the study conducted in Iraq, western Nepal, and India (32, 45, 54, 55, 79, 80). But, this different from the study conducted in Pakistan, Jordan, and Nigeria (41, 42, 68, 72). The difference is maybe due to nutritional status where larger anthropometric measurements and obesity were observed in the study of Pakistan (68), Jordan (41) and Nigeria (42, 72).
From a physiological perspective as individuals' body parameters (height, weight, BMI, and BSA) increase, the blood volume increase and requiring larger spleens for filtration (41). This is supported by our finding where all dimensions were positively correlated with height, weight, BMI, and BSA (p < 0.05). This is consistent with the study conducted in Jordan, USA, India, Sudan (29, 31, 37, 41, 61, 63, 79). But, different from the study conducted in Turkey, Nigeria and Egypt (42, 62, 68, 73). This may be due to nutritional status where the study participants in the study of Turkey, Nigeria and Egypt were overweight than ours. The non-significant correlations observed between spleen width and BMI in the current study (P = 0.080) is consistent with the study conducted in Sudan (40).
Limitation Of The Study