TrueFISP of the pediatric pineal gland: volumetric and microstructural analysis

Structural and Volumetric Brain MRI Findings in Mild Traumatic Brain Injury

BACKGROUND AND PURPOSE

Routine MR imaging findings are frequently normal following mild traumatic brain injury and have a limited role in diagnosis and management. Advanced MR imaging can assist in detecting pathology and prognostication but is not readily available outside research settings. However, 3D isotropic sequences with ∼1-mm³ voxel size are available on community MR imaging scanners. Using such sequences, we compared radiologists' findings and quantified regional brain volumes between a mild traumatic brain injury cohort and non-brain-injured controls to describe structural imaging findings associated with mild traumatic brain injury.

MATERIALS AND METHODS

Seventy-one military personnel with persistent symptoms and 75 controls underwent 3T MR imaging. Three neuroradiologists interpreted the scans using common data elements. FreeSurfer was used to quantify regional gray and white matter volumes.

RESULTS

WM hyperintensities were seen in 81% of the brain-injured group versus 60% of healthy controls. The odds of ≥1 WM hyperintensity in the brain-injured group was about 3.5 times the odds for healthy controls (95% CI, 1.58-7.72; P = .002) after adjustment for age. A frontal lobe-only distribution of WM hyperintensities was more commonly seen in the mild traumatic brain injury cohort. Furthermore, 7 gray matter, 1 white matter, and 2 subcortical gray matter regions demonstrated decreased volumes in the brain-injured group after multiple-comparison correction. The mild traumatic brain injury cohort showed regional parenchymal volume loss.

CONCLUSIONS

White matter findings are nonspecific and therefore a clinical challenge. Our results suggest that prior trauma should be considered in the differential diagnosis of multifocal white matter abnormalities with a clinical history of mild traumatic brain injury, particularly when a frontal predilection is observed.

Pineal gland abnormality in major depressive disorder

Patients with major depressive disorder (MDD) often have circadian rhythm alteration and sleep disturbance. The pineal gland regulates the circadian rhythm and sleep by the secretion of melatonin neurohormone. However, the relationship between pineal abnormality and MDD remains elusive. 50 patients with MDD and 35 gender- and age-matched healthy controls underwent high-resolution structural MRI. Pineal parenchymal volume (PPV) was measured manually. Inter-group differences in prevalence of pineal cyst and PPV were examined. In addition, we investigated the correlations between PPV and symptom severity as well as sleep variables in the patient group. Compared to healthy controls, patients with MDD had a higher prevalence of pineal cyst. Moreover, patients had significantly decreased PPV relative to controls. However, no significant correlations were observed between PPV and symptom severity as well as sleep variables. Our findings suggest that pineal abnormality may play a critical role in depression.

Pineal gland dysfunction in Alzheimer's disease: relationship with the immune-pineal axis, sleep disturbance, and neurogenesis

Alzheimer’s disease (AD) is a globally common neurodegenerative disease, which is accompanied by alterations to various lifestyle patterns, such as sleep disturbance. The pineal gland is the primary endocrine organ that secretes hormones, such as melatonin, and controls the circadian rhythms. The decrease in pineal gland volume and pineal calcification leads to the reduction of melatonin production. Melatonin has been reported to have multiple roles in the central nervous system (CNS), including improving neurogenesis and synaptic plasticity, suppressing neuroinflammation, enhancing memory function, and protecting against oxidative stress. Recently, reduced pineal gland volume and pineal calcification, accompanied by cognitive decline and sleep disturbances have been observed in AD patients. Here, I review current significant evidence of the contribution of pineal dysfunction in AD to the progress of AD neuropathology. I suggest new insights to understanding the relationship between AD pathogenesis and pineal gland function.

Pineal volume and evening melatonin in young people with affective disorders

Affective disorders in young people have been associated with disruptions in circadian rhythms, including abnormalities in secretion of the pineal hormone melatonin. Previous research reports relationships between pineal gland volumes, melatonin secretion, and sleep-wake cycles, but the relationship between these factors has not been explored in affective disorders. This study aimed to characterize these factors and explore associations with mood symptoms and functioning in a sample of young people with affective disorders. Pineal volume from magnetic resonance imaging and melatonin assay from evening dim-light saliva collection were evaluated in 50 individuals (15-30 years old; 72 % female) with bipolar, depressive, or anxiety disorders. Actigraphy monitoring was also conducted for approximately two weeks to derive sleep-wake measures. Pineal volume was associated with melatonin secretion across the evening, replicating previous findings in psychiatrically healthy individuals. Pineal volume was smaller in participants in which melatonin onset was not detected. Timing of melatonin secretion was related to sleep timing, but amount of melatonin and pineal volume were not related to any sleep-wake measures. A shorter phase angle between onset of melatonin secretion and sleep onset was associated with longer total sleep time. Lower melatonin levels were associated with poorer social and occupational functioning. Although pineal volume is not directly related to sleep disturbances or symptoms, melatonin may influence both sleep-wake cycles and functioning in the early stages of affective disorder. Causal links remain to be established, however, treatments that target circadian rhythms may be useful in improving functioning in young people with affective disorders.

Follow-up of pineal cysts in children: is it necessary?

PURPOSE

Pineal cysts are common incidental findings in children undergoing magnetic resonance imaging (MRI). Several studies have suggested MRI follow-up if the cyst is larger than 10 mm. However, cysts do not usually change during follow-up. Prevalence, growth, and structure of the pineal cysts were analyzed to decide if follow-up MRI is necessary.

METHODS

A retrospective review between 2010 and 2015 was performed using 3851 MRI examinations of children aged 0-16 years to detect pineal cysts having a maximum diameter ≥ 10 mm. Eighty-one children with pineal cysts were identified and 79 of them had been controlled by MRI. Cysts were analyzed for the size, growth, and structure.

RESULTS

A total of 1.8% of the children had a pineal cyst with a diameter ≥ 10 mm. Cysts were present in 48 girls (59.3%) and 33 boys (40.7%). Most pineal cysts (70/79) did not significantly grow during the follow-up (median 10 months, range 3-145 months). A total of 11.4% (9/79) of the cysts grew with the biggest change measured from the outer cyst wall sagittal anteroposterior dimension (mean 3.4 mm ± 1.7 mm). Only one cyst grew more than 5 mm. We found no factors correlating with the cyst growth among 9 cysts that grew > 2 mm.

CONCLUSIONS

A majority of pineal cysts remained unchanged during the MRI follow-up. Results of this study suggest that routine MRI follow-up of pineal cysts is not necessary in the absence of unusual radiological characteristics or related clinical symptoms.

Normal neuroanatomical variants that may be misinterpreted as disease entities

Variations of normal development and benign incidental anomalies are frequently observed on diagnostic neuroimaging. It is important these are recognised for what they are, as misinterpretation may result in unnecessary further investigation, follow-up imaging and anxiety. In this article, we review benign intracranial anomalies commonly referred to our unit for specialist neuroradiology advice or multidisciplinary discussion, concerning cysts of the pineal gland and pituitary fossa, vascular anomalies, and perivascular spaces. This article outlines the embryology and development, the various imaging features as well as the clinical relevance and differential diagnoses of each normal neuroanatomical variant.

Associations of pineal volume, chronotype and symptom severity in adults with attention deficit hyperactivity disorder and healthy controls

The pineal gland, as part of the human epithalamus, is the main production site of peripheral melatonin, which promotes the modulation of sleep patterns, circadian rhythms and circadian preferences (morningness vs. eveningness). The present study analyses the pineal gland volume (PGV) and its association with circadian preferences and symptom severity in adult ADHD patients compared to healthy controls. PGV was determined manually using high-resolution 3T MRI (T1-magnetization prepared rapid gradient echo) in medication free adult ADHD patients (N=74) compared to healthy controls (N=86). Moreover, the Morningness-Eveningness Questionnaire (MEQ), the ADHD Diagnostic Checklist and the Wender-Utah Rating Scale were conducted. PGV differed between both groups (patients: 59.9±33.8mm(3); healthy controls: 71.4±27.2mm(3), P=0.04). In ADHD patients, more eveningness types were revealed (patients: 29%; healthy controls: 17%; P=0.05) and sum scores of the MEQ were lower (patients: 45.8±11.5; healthy controls 67.2±10.1; P<0.001). Multiple regression analyses indicated a positive correlation of PGV and MEQ scores in ADHD (β=0.856, P=0.003) but not in healthy controls (β=0.054, P=0.688). Patients' MEQ scores (β=-0.473, P=0.003) were negatively correlated to ADHD symptoms. The present results suggest a linkage between the PGV and circadian preference in adults with ADHD and an association of the circadian preference to symptom severity. This may facilitate the development of new chronobiological treatment approaches for the add-on treatment in ADHD.

MRI-based assessment of the pineal gland in a large population of children aged 0-5 years and comparison with pineoblastoma: part II, the cystic gland

Introduction

Pineal cysts are a common incidental finding on brain MRI with resulting difficulties in differentiation between normal glands and pineal pathologies. The aim of this study was to assess the size and morphology of the cystic pineal gland in children (0–5 years) and compare the findings with published pineoblastoma cases.

Methods

In this retrospective multicenter study, 257 MR examinations (232 children, 0–5 years) were evaluated regarding pineal gland size (width, height, planimetric area, maximal cyst(s) size) and morphology. We performed linear regression analysis with 99 % prediction intervals of gland size versus age for the size parameters. Results were compared with a recent meta-analysis of pineoblastoma by de Jong et al.

Results

Follow-up was available in 25 children showing stable cystic findings in 48 %, cyst size increase in 36 %, and decrease in 16 %. Linear regression analysis gave 99 % upper prediction bounds of 10.8 mm, 10.9 mm, 7.7 mm and 66.9 mm², respectively, for cyst size, width, height, and area. The slopes (size increase per month) of each parameter were 0.030, 0.046, 0.021, and 0.25, respectively. Most of the pineoblastomas showed a size larger than the 99 % upper prediction margin, but with considerable overlap between the groups.

Conclusion

We presented age-adapted normal values for size and morphology of the cystic pineal gland in children aged 0 to 5 years. Analysis of size is helpful in discriminating normal glands from cystic pineal pathologies such as pineoblastoma. We also presented guidelines for the approach of a solid or cystic pineal gland in hereditary retinoblastoma patients.

Electronic supplementary material

The online version of this article (doi:10.1007/s00234-016-1683-0) contains supplementary material, which is available to authorized users.

MRI-based assessment of the pineal gland in a large population of children aged 0-5 years and comparison with pineoblastoma: part I, the solid gland

Introduction

Differentiation between normal solid (non-cystic) pineal glands and pineal pathologies on brain MRI is difficult. The aim of this study was to assess the size of the solid pineal gland in children (0–5 years) and compare the findings with published pineoblastoma cases.

Methods

We retrospectively analyzed the size (width, height, planimetric area) of solid pineal glands in 184 non-retinoblastoma patients (73 female, 111 male) aged 0–5 years on MRI. The effect of age and gender on gland size was evaluated. Linear regression analysis was performed to analyze the relation between size and age. Ninety-nine percent prediction intervals around the mean were added to construct a normal size range per age, with the upper bound of the predictive interval as the parameter of interest as a cutoff for normalcy.

Results

There was no significant interaction of gender and age for all the three pineal gland parameters (width, height, and area). Linear regression analysis gave 99 % upper prediction bounds of 7.9, 4.8, and 25.4 mm², respectively, for width, height, and area. The slopes (size increase per month) of each parameter were 0.046, 0.023, and 0.202, respectively. Ninety-three percent (95 % CI 66–100 %) of asymptomatic solid pineoblastomas were larger in size than the 99 % upper bound.

Conclusion

This study establishes norms for solid pineal gland size in non-retinoblastoma children aged 0–5 years. Knowledge of the size of the normal pineal gland is helpful for detection of pineal gland abnormalities, particularly pineoblastoma.

Electronic supplementary material

The online version of this article (doi:10.1007/s00234-016-1684-z) contains supplementary material, which is available to authorized users.

The prevalence of pineal cyst in patients with cerebral palsy

PURPOSE

Pineal cysts are common incidental findings during magnetic resonance imaging (MRI) examinations. The etiology of pineal cyst development is still unclear. We aimed to determine whether there is an association between periventricular leukomalacia and pineal cyst prevalence.

METHODS

Clinical and MRI data of 201 patients with periventricular leukomalacia (110 female, 91 male; mean age, 6 years; range, 2-18 years) and 687 control patients (355 female, 332 male; mean age, 6 years¸ range, 2-18 years) who did not have any evidence of periventricular leukomalacia were independently evaluated by two radiologists for presence or absence of pineal cyst.

RESULTS

Pineal cysts were detected in 32.3% of the study group (65/201) and 8.4% of the control group (58/687) (P < 0.001). Patients with periventricular leukomalacia were more likely to have a pineal cyst. In terms of pineal cyst detection on MRI, interobserver reliability was high between the two radiologists.

CONCLUSION

The prevalence of pineal cysts is higher in patients with periventricular leukomalacia. We suggest that an ischemic process may have a role in the etiopathogenesis of pineal cyst development.

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.

Pineal gland volume in primary insomnia and healthy controls: a magnetic resonance imaging study

Little is known about the relation between pineal volume and insomnia. Melatonin promotes sleep processes and, administered as a drug, it is suitable to improve primary and secondary sleep disorders in humans. Recent magnetic resonance imaging studies suggest that human plasma and saliva melatonin levels are partially determined by the pineal gland volume. This study compares the pineal volume in a group of patients with primary insomnia to a group of healthy people without sleep disturbance. Pineal gland volume (PGV) was measured on the basis of high-resolution 3 Tesla MRI (T1-magnetization prepared rapid gradient echo) in 23 patients and 27 controls, matched for age, gender and educational status. Volume measurements were performed conventionally by manual delineation of the pineal borders in multi-planar reconstructed images. Pineal gland volume was significantly smaller (P < 0.001) in patients (48.9 ± 26.6 mm(3) ) than in controls (79 ± 30.2 mm(3) ). In patients PGV correlated negatively with age (r = -0.532; P = 0.026). Adjusting for the effect of age, PGV and rapid eye movement (REM) latency showed a significant positive correlation (rS  = 0.711, P < 0.001) in patients. Pineal volume appears to be reduced in patients with primary insomnia compared to healthy controls. Further studies are needed to clarify whether low pineal volume is the basis or the consequence of functional sleep changes to elucidate the molecular pathology for the pineal volume loss in primary insomnia.

Incidental pineal cysts in children who undergo 3-T MRI

BACKGROUND

Pineal cysts, both simple and complex, are commonly encountered in children. More cysts are being detected with MR technology; however, nearly all pineal cysts are benign and require no follow-up.

OBJECTIVE

To discover the prevalence of pineal cysts in children at our institution who have undergone high-resolution 3-T MRI.

MATERIALS AND METHODS

We retrospectively reviewed 100 consecutive 3-T brain MRIs in children ages 1 month to 17 years (mean 6.8 ± 5.1 years). We evaluated 3-D volumetric T1-W imaging, axial T2-W imaging, axial T2-W FLAIR (fluid attenuated inversion recovery) and coronal STIR (short tau inversion recovery) sequences. Pineal parenchymal and cyst volumes were measured in three planes. Cysts were analyzed for the presence and degree of complexity.

RESULTS

Pineal cysts were present in 57% of children, with a mean maximum linear dimension of 4.2 mm (range 1.5-16 mm). Of these cysts, 24.6% showed thin septations or fluid levels reflecting complexity. None of the cysts demonstrated complete T2/FLAIR signal suppression. No cyst wall thickening or nodularity was present. There was no significant difference between the ages of children with and without cysts. Cysts were more commonly encountered in girls than boys (67% vs. 52%; P = 0.043). There was a slight trend toward increasing pineal gland volume with age.

CONCLUSION

Pineal cysts are often present in children and can be incidentally detected by 3-T MRI. Characteristic-appearing pineal cysts in children are benign, incidental findings, for which follow-up is not required if there are no referable symptoms or excessive size.

Microstructural analysis of pineal volume using trueFISP imaging

AIM: To determine the spectrum of pineal microstructures (solid/cystic parts) in a large clinical population using a high-resolution 3D-T2-weighted sequence.

METHODS: A total of 347 patients enrolled for cranial magnetic resonance imaging were randomly included in this study. Written informed consent was obtained from all patients. The exclusion criteria were artifacts or mass lesions prohibiting evaluation of the pineal gland in any of the sequences. True-FISP-3D-imaging (1.5-T, isotropic voxel 0.9 mm) was performed in 347 adults (55.4 ± 18.1 years). Pineal gland volume (PGV), cystic volume, and parenchyma volume (cysts excluded) were measured manually.

RESULTS: Overall, 40.3% of pineal glands were cystic. The median PGV was 54.6 mm³ (78.33 ± 89.0 mm³), the median cystic volume was 5.4 mm³ (15.8 ± 37.2 mm³), and the median parenchyma volume was 53.6 mm³ (71.9 ± 66.7 mm³). In cystic glands, the standard deviation of the PGV was substantially higher than in solid glands (98% vs 58% of the mean). PGV declined with age (r = -0.130, P = 0.016).

CONCLUSION: The high interindividual volume variation is mainly related to cysts. Pineal parenchyma volume decreased slightly with age, whereas gender-related effects appear to be negligible.