Comparison of three methods for the estimation of pineal gland volume using magnetic resonance imaging

Pineal gland volume loss in females with multiple sclerosis

Introduction

Multiple sclerosis has a complex pathophysiology, and numerous risk factors can contribute to its development, like exposure to sunlight that is associated with serum levels of melatonin. The aim of this study was to determine whether the volume of the pineal gland, assessed by magnetic resonance imaging (MRI), correlated with the presence of multiple sclerosis.

Methods

This retrospective study included a total of 394 patients. Subjects were divided into two groups: the first group consisted of 188 patients with a definite diagnosis of multiple sclerosis (based on revised McDonald criteria) and the second group consisted of 206 healthy controls. To examine the influence of age on pineal gland volume, we stratified the whole sample into three age groups: first involved patients under 20 years, second patients between 20 and 40 years, and third group included patients over 40 years. The maximum length (L) and height (H) of the pineal gland were measured on the T1-weighted sagittal images, and the width (W) was measured on the T2-weighted coronal or axial images. The volume of the gland was calculated as an approximation to an ellipse, according to the formula V = (L × H × W)/2.

Results

Pineal gland volume of female multiple sclerosis (MS) patients (N = 129) was significantly lower than in healthy females (N = 123) (p = 0.013; p < 0.05), unlike in males where there is not such difference. Also, pineal gland volume is not age-dependent, and the observed smaller pineal gland in MS patients can reliably be attributed to the disease itself. Additionally, large pineal gland size, especially over 62.83 mm3 when compared to pineal gland volume below 31.85 mm3 is associated with more than double reduced risk of multiple sclerosis (OR 0.42; p = 0.003).

Discussion

Our results suggest that women with multiple sclerosis have smaller pineal glands that can theoretically be explained by a lack of input stimuli and the resultant decrease in gland volume. Additionally, the risk of multiple sclerosis is reduced in larger pineal gland volumes.

Prevalence of pineal gland calcification: systematic review and meta-analysis

BACKGROUND

Pineal gland calcification is the formation of corpora arenacea predominantly composed of calcium and phosphorus. It plays an important role in regulating the light/dark circadian changes to synchronize their daily physiological activities like feeding, metabolism, reproduction, and sleep through the secretion of melatonin. Therefore, this study aimed to assess the pooled prevalence of pineal gland calcification.

METHODS

A systematic review was done using published research articles from different electronic databases. Cross-sectional studies were included for systematic review and only studies conducted on the human population were included for quantitative analysis. Published articles were selected by assessing the title and abstract for relevance to the review objectives. Finally, the full text was retrieved for further assessment.

RESULTS

The pooled prevalence of pineal gland calcification was 61.65% [95% CI: 52.81, 70.49], with a heterogeneity of I² = 97.7%, P ≤ 0.001. According to the qualitative analysis, an increase in age, male sex, and white ethnicity are the major socio-demographic characteristics that increase the prevalence of pineal gland calcification.

CONCLUSION

The pooled prevalence of pineal gland calcification was higher compared with reports from previous studies. Different studies reported pineal gland calcification was most prevalent in the adult population compared with the pediatric age groups. According to the qualitative analysis, an increase in age, male sex, and white ethnicity are the major socio-demographic characteristics that increase the prevalence of pineal gland calcification.

A Probabilistic Atlas of the Pineal Gland in the Standard Space

Pineal gland (PG) is a structure located in the midline of the brain, and is considered as a main part of the epithalamus. There are numerous reports on the facilitatory role of this area for brain function; hormone secretion and its role in sleep cycle are the major reports. However, reports are rarely available on the direct role of this structure in brain cognition and in information processing. A suggestion for the limited number of such studies is the lack of a standard atlas for the PG; none of the available MRI templates and atlases has provided parcellations for this structure. In this study, we used the three-dimensional (3D) T1-weighted MRI data of 152 healthy young volunteers, and provided a probabilistic map of the PG in the standard Montreal Neurologic Institute (MNI) space. The methods included collecting the data using a 64-channel head coil on a 3-Tesla Prisma MRI Scanner, manual delineation of the PG by two experts, and robust template and atlas construction algorithms. This atlas is freely accessible, and we hope importing this atlas in the well-known neuroimaging software packages would help to identify other probable roles of the PG in brain function. It could also be used to study pineal cysts, for volumetric analyses, and to test any associations between the cognitive abilities of the human and the structure of the PG.

Reduced pineal gland volume across the stages of schizophrenia

A few magnetic resonance imaging (MRI) studies reported reduced pineal gland volume in chronic schizophrenia (Sz), implicating the involvement of melatonin in the pathophysiology of the illness. However, it is not known whether this abnormality, if present, exists at the early illness stages and/or develops progressively over the course of the illness. This MRI study examined pineal gland volume in 64 patients with first-episode schizophrenia (FESz), 40 patients with chronic Sz, 22 individuals with at-risk mental state (ARMS), and 84 healthy controls. Longitudinal changes in pineal volume (mean inter-scan interval = 2.5 ± 0.7 years) were also examined in a subsample of 23 FESz, 16 chronic Sz, and 21 healthy subjects. In the cross-sectional comparison, the ARMS, FESz, and chronic Sz groups had significantly smaller pineal volume to the same degree as compared with healthy controls. A longitudinal comparison demonstrated that pineal volume did not change over time in any group. There was no association between pineal volume and clinical variables (e.g., symptom severity, medication) in the ARMS and Sz groups. The results suggest that a smaller pineal gland may be a static vulnerability marker of Sz, which probably reflects an early neurodevelopmental abnormality.

Sex Difference in the Morphology of Pineal Gland in Adults Based on Brain Magnetic Resonance Imaging

PURPOSE

We aimed to figure out the anatomical features of pineal gland region on magnetic resonance imaging (MRI) and to explore the sex difference in pineal gland-related parameters with increasing age.

METHODS

We measured the pineal gland on MRI images from 198 healthy adults (96 males and 102 females). Included subjects were divided into 4 age groups. After 3-dimensional reconstruction, the anatomic features of pineal gland and its distances to superior colliculus and splenium of corpus callosum were analyzed in each group. The prevalence of cystic pineal gland was calculated. Moreover, we calculated the volume of pineal gland (PGV) and explored the differences of PGV in males and females across different age groups. Linear regression analysis was performed to detect the relationship between age and pineal gland-related parameters.

RESULTS

In 198 subjects, the mean length, width, and height of pineal gland were 7.58 ± 0.45 mm, 4.92 ± 0.40 mm, and 2.90 ± 0.20 mm. The distances between pineal gland and superior colliculus as well as splenium of corpus callosum were 3.96 ± 0.92 mm and 4.3 ± 1.89 mm, respectively. The PGV was 54.1 ± 7.02 mm. Significant sex differences were found in pineal gland length (P < 0.001), cranial cavity diameter (P < 0.001), pineal gland index (P < 0.001) and PGV values (P = 0.02). The prevalence of cystic pineal gland was 36.4% in total subjects, 41.7% in males and 32.4% in females. No linear relationship was found between age and pineal gland parameters.

CONCLUSION

We measured the pineal gland morphology based on MRI images. Significant influences on pineal gland parameters were found in subjects with different sex, whereas no effect was observed from age.

Brain Volume Estimation Enhancement by Morphological Image Processing Tools

BACKGROUND

Volume estimation of brain is important for many neurological applications. It is necessary in measuring brain growth and changes in brain in normal/abnormal patients. Thus, accurate brain volume measurement is very important. Magnetic resonance imaging (MRI) is the method of choice for volume quantification due to excellent levels of image resolution and between-tissue contrast. Stereology method is a good method for estimating volume but it requires to segment enough MRI slices and have a good resolution. In this study, it is desired to enhance stereology method for volume estimation of brain using less MRI slices with less resolution.

METHODS

In this study, a program for calculating volume using stereology method has been introduced. After morphologic method, dilation was applied and the stereology method enhanced. For the evaluation of this method, we used T1-wighted MR images from digital phantom in BrainWeb which had ground truth.

RESULTS

The volume of 20 normal brain extracted from BrainWeb, was calculated. The volumes of white matter, gray matter and cerebrospinal fluid with given dimension were estimated correctly. Volume calculation from Stereology method in different cases was made. In three cases, Root Mean Square Error (RMSE) was measured. Case I with T=5, d=5, Case II with T=10, D=10 and Case III with T=20, d=20 (T=slice thickness, d=resolution as stereology parameters). By comparing these results of two methods, it is obvious that RMSE values for our proposed method are smaller than Stereology method.

CONCLUSION

Using morphological operation, dilation allows to enhance the estimation volume method, Stereology. In the case with less MRI slices and less test points, this method works much better compared to Stereology method.

Assessment of Pineal Gland Volume and Calcification in Healthy Subjects: Is it Related to Aging?

Purpose:

The human pineal gland is a small neuroendocrine organ which produces melatonin. The main goal of this study was to provide a reference range for pineal volume in all age groups and to determine calcified and noncalcified tissue and their proportions, which may be a reflection of melatonin production in all age groups, by using very thin computerized tomography (CT) slices.

Materials and methods:

A total of 167 outpatients had undergone cranial CT. Each of the subject’s total pineal volume (TPV), calcified pineal volume (CPV) and noncalcified pineal volume (NPV) according to age groups were calculated in cubic millimeters. Also, proportion of calcification (POC) was noted.

Results:

The median values were 88.5 mm³ (12.3 mm³–411mm³) for TPV, 74.3 mm³ (12.3 mm³–298 mm³) for NPV, and 3.9 mm³ (0 mm³–141 mm³) for CPV. POC showed a gradual increase from 0–49 years. In the ≥70 group, when compared with the 60–69 age group, CPV and POC values were significantly lower (P: 0.036, P: 0.034, respectively).

Conclusion:

This study brings a radiological point of view to the distribution of pineal calcification according to age that has a link with melatonin secretion.