Niyazi Acer

Comparison of Three Methods for the Estimation of Total Intracranial Volume Stereologic, Planimetric, and Anthropometric Approaches

There is a well-known close relationship between the total intracranial volume (TIV) and the brain size. Several studies in different countries have estimated the cranial capacity, which indirectly reflects the brain volume. However, we have not seen a study evaluating the results of the methodologies for the assessment of TIV. This study was carried out on 30 normal subjects whose ages ranged between 19 and 77 years old (males, 18; females, 12). Three different methods were used to assess the TIV. The mean (±SD) estimated TIV using linear dimensions method in males and females were 1416.8 ± 64 cm3 and 1291.9 ± 152 cm3, respectively. The mean estimated TIV using point counting method in males and females was 1474 ± 93 cm3 and 1252 ± 72 cm3, respectively. By using the planimetric method of the mean and SD of TIV, male and females were 1492.1 ± 74 cm3 and 1319.6 ± 100 cm3, respectively. There were no statistical difference between TIV measurements obtained using the optimized stereologic technique and planimetry (P > 0.05). TIV between males and females was statistically significant (P < 0.001). This study showed that there are minor differences among the given 3 distinct methods. With the disadvantage of requiring more time to apply, the planimetry and point counting methods provide more assumption-free results than the anthropometric approach. However, the anthropometric method can be applied to assess TIV without needing sophisticated tools.

Stereological Estimation of the Orbital Volume: A Criterion Standard Study

Several methodologies have been proposed to assess the orbital volume (OV). However, we have not seen a criterion standard study evaluating the results of the methodologies for the assessment of OV. In the current study, the actual OV of 9 dry skulls was measured using the water filling method as the criterion standard. Consecutive computed tomographic sections at a thickness of 1.5 mm were used to estimate the OV by means of the point counting method. The mean (SD) of the OV measured by the water filling method was 17.84 (1.56) cm3. By using the point counting method, it was 17.05 (1.69) cm3. There was no statistically significant difference between sides (P > 0.001). The results of the OV values obtained by the two methods were compared statistically. The agreements between the two methods were also evaluated using the Bland-Altman plots. There was no statistically significant difference between the OV measurements obtained by the stereological technique and water filling method. The described method could be used for the assessment of OV in vivo.

Estimation of Cranial Capacity in 17-26 Years Old University Students

Es natural que exista una relacion entre la capacidad craneana y el tamano del cerebro. Numerosos estudios realizados, han estimado la capacidad craneana con lo cual han determinado indirectamente el volumen del cerebro. El estudio fue realizado en 366 individuos (226 hombres y 140 mujeres), normales, entre 17-26 de edad, pertenecientes a grupos del Mugia Universidad de Mugia, Turquia. Para la estimacion de la capacidad craneana se utilizaron las dimensiones lineales de la cabeza. La media y SD de la capacidad craneana en hombres y mujeres, fue de 1411,64+118,9 cm3 y 1306,95+162,9 cm3, respectivamente. Las diferencias fueron estadisticamente significativas (p<0.05). La investigacion demostro que la capacidad craneana es mayor en los hombres que en las mujeres. Tambien propusimos una formula de regresion que podria ser usada para predecir la capacidad craneana

Analysis of the Volumes of the Posterior Cranial Fossa, Cerebellum, and Herniated Tonsils Using the Stereological Methods in Patients with Chiari Type I Malformation

Objective. The aim of this study was to determine the posterior cranial fossa volume, cerebellar volume, and herniated tonsillar volume in patients with chiari type I malformation and control subjects using stereological methods. Material and Methods. These volumes were estimated retrospectively using the Cavalieri principle as a point-counting technique. We used magnetic resonance images taken from 25 control subjects and 30 patients with chiari type I malformation. Results. The posterior cranial fossa volume in patients with chiari type I malformation was significantly smaller than the volume in the control subjects (P < 0.05). In the chiari type I malformation group, the cerebellar volume was smaller than the control group, but this difference was not statistically significant (P > 0.05). In the chiari type I malformation group, the ratio of cerebellar volume to posterior cranial fossa volume was higher than in the control group. We also found a positive correlation between the posterior cranial fossa volume and cerebellar volume for each of the groups (r = 0.865, P < 0.001). The mean (±SD) herniated tonsillar volume and length were 0.89 ± 0.50 cm3 and 9.63 ± 3.37 mm in the chiari type I malformation group, respectively. Conclusion. This study has shown that posterior cranial fossa and cerebellum volumes can be measured by stereological methods, and the ratio of these measurements can contribute to the evaluation of chiari type I malformation cases.

Sella turcica: an anatomical, endocrinological, and historical perspective

IntroductionThe sphenoid bone has a superior depression called the sella turcica, Latin for “Turkish saddle,” where the pituitary gland is found. The availability of modern radiological imaging techniques has replaced plain radiography of the sella turcica in the investigation of hypothalamo–pituitary abnormalities. However, the size of the sella turcica, and smaller sella turcica size in particular, may cause pituitary dysfunction because of the changes in the structure of pituitary gland or may be associated with some genetic or acquired endocrine disorders. The name “sella turcica” is one of the most commonly used terms in everyday endocrine practice.MethodsIn this review, after a brief explanation of the anatomical and endocrinological features of the sella turcica had been given, a historical perspective of sella turcica nomenclature was presented for the first time.Findings and conclusionsAfter Andreas Vesalius’s description of it as a suitable cavity for the gland that receives the “phlegm of the brain” in DeHumani Corporis Fabrica (1543), medical scholars began to use seat/saddle-related terms such as the ephippium, pars sellaris, sella equina, sella ossis, and sella sphenoidalis. The real designation of the sella turcica, however, was introduced to the anatomical nomenclature by the anatomist Adrianus Spigelius (1578–1625) in his famous work De Corpora Humanis Fabrica (1627).

Estimation of cerebral surface area using vertical sectioning and magnetic resonance imaging: a stereological study.

Stereological techniques using isotropic uniform random and vertical uniform random sections have been used for surface area estimation. However, there are a few studies in which the surface area of the brain is estimated using the vertical section technique in a stereological approach. The objective of the current study was to apply the vertical section technique using cycloid test probes for estimation of cerebral surface area in magnetic resonance imaging (MRI). In this study, cerebral surface areas were estimated in a total of 13 young subjects (6 males, 7 females) who were free of any neurological symptoms and signs. The means (+/-S.D.) of the surface areas were 1619.92+/-140. 97 cm (2), 1625.69+/-147. 58 cm(2) and 1674.69+/-160. 60 cm(2) for 36, 18 and 12 vertical sections, respectively. The mean coefficient of error obtained by applying cycloid test lines that use a 2. 8-cm ratio of area associated with each cycloid was estimated at <7% for the three models. No significant difference was found for each of the 36, 18 and 12 vertical sections (p>0.05). In addition, the three models correlated well with each other. From these results, it is concluded that the vertical section technique is an unbiased, efficient and reliable method and is ideally suited to in vivo examination of MRI data for estimating the surface area of the brain. Hence, we suggest that estimation of surface area using MRI and stereology may be clinically relevant for assessing cortical atrophy as well as for investigating the structure and function of cerebral hemispheres.

Unbiased Estimation of the Eyeball Volume Using the Cavalieri Principle on Computed Tomography Images

The size of the eyeball has been the subject of a few studies. None of them used stereological methods to estimate the volume. In the current study, we estimated the volume of eyeball in normal men and women using the stereological methods. Eyeball volume (EV) was estimated using the Cavalieri principle as a combination of point-counting and planimetry techniques. We used computed tomography scans taken from 36 participants (15 men and 21 women) to estimate the EV. The mean (SD) EV values obtained by planimetry method were 7.49 (0.79) and 7.06 (0.85) cm3 in men and women, respectively. By using point-counting method, the mean (SD) values were 7.48 (0.85) and 7.21 (0.84) cm3 in men and women, respectively. There was no statistically significant difference between the findings from the 2 methods (P > 0.05). A weak correlation was found between the axial length of eyeball and the EV estimated by point counting and planimetry (P < 0.05, r = 0.494 and r = 0.523, respectively). The findings of the current study using the stereological methods could provide data for the evaluation of normal and pathologic volumes of the eyeball.

The Age-related Development of Maxillary Sinus in Children

Introduction:Paranasal sinuses are complex structures and show individual variation. Providing normative values for paranasal sinus size and their changes related to age could be helpful in evaluating the presence of some diseases related to sinonasal region. The purpose of the current study was to investigate the development of maxillary sinuses and evaluate the volume changes according to age and sex by using stereological and ellipsoidal formula methods after that to compare these approaches with each other in children. Materials and Methods:This retrospective volumetric computed tomography (CT) study was carried out on 361 individuals (180 females, 181 males) between 0 and 18 years old (10 females, 10 males in each group, only 14 age group includes 11 males) with no signs of sinus pathology volumetric estimations determined on CT images using point-counting approach of stereological methods and ellipsoid formula by using morphometric data. Results:Maxillary sinus volume measurements that were obtained using 2 methods were increased with age in both sexes until 16 years old. There was a significant correlation determined between 2 methods (ICC 0.894–1.000 for right and 0.862–0.999 for left maxillary sinus measurements). According to the sex, the right and left mean maxillary sinuses volumes were determined at 8.30 ± 5.19 and 8.57 ± 5.53 cm3 in male and at 7.60 ± 4.57 and 7.99 ± 4.73 cm3 in female by using ellipsoid formula respectively. By the stereological method these values were 8.28 ± 5.26, 8.44 ± 5.35 cm3 and 7.64 ± 4.55, 7.85 ± 4.73 cm3 respectively. There was no statistically significant difference between the volume of maxillary sinuses with sex and side using both methods. Conclusions:This study presents the basic data for studies relative to the development of the maxillary sinus in children according to 2 methods. The current study demonstrated that the point-counting method and ellipsoid formula are both effective in determining volume estimation of maxillary sinuses and are well suited for CT studies.

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

Pineal gland is a very important neuroendocrine organ with many physiological functions such as regulating circadian rhythm. Radiologically, the pineal gland volume is clinically important because it is usually difficult to distinguish small pineal tumors via magnetic resonance imaging (MRI). Although many studies have estimated the pineal gland volume using different techniques, to the best of our knowledge, there has so far been no stereological work done on this subject. The objective of the current paper was to determine the pineal gland volume using stereological methods and by the region of interest (ROI) on MRI. In this paper, the pineal gland volumes were calculated in a total of 62 subjects (36 females, 26 males) who were free of any pineal lesions or tumors. The mean ± SD pineal gland volumes of the point-counting, planimetry, and ROI groups were 99.55 ± 51.34, 102.69 ± 40.39, and 104.33 ± 40.45 mm3, respectively. No significant difference was found among the methods of calculating pineal gland volume (P > 0.05). From these results, it can be concluded that each technique is an unbiased, efficient, and reliable method, ideally suitable for in vivo examination of MRI data for pineal gland volume estimation.

Macrocerebellum: Volumetric and Diffusion Tensor Imaging Analysis.

Macrocerebellum is a rare entity characterized by an enlarged cerebellum. We describe a case of a 48-month-old child with macrocerebellum. We performed serial volumetric analysis [total brain volume (TBV) and cerebellar volume] over a period of 4 years. We analyzed the white matter microstructure in the cerebellum using diffusion tensor imaging (DTI). In our patient, we found higher fractional anisotropy (FA) and lower mean diffusivity (MD) in the cerebellar white matter compared to age-matched controls. Our results may represent accelerated myelination secondary to the abnormal cerebellar development.