Cavalieri Method Research Articles

Influence of substitutive ovarian steroids in the nuclear and cell body volumes of neurons in the posterodorsal medial amygdala of adult ovariectomized female rats

The volumes of the neuronal nucleus and the cell body in the left posterodorsal medial amygdala (MePD) of adult ovariectomized (OVX) female rats submitted to different hormonal therapies were studied here, aiming to reveal possible influence of substitutive sex steroids in these morphological parameters. One week following ovariectomy and at the end of treatments, brains were cut to semi-thin sections (1μm) and stained with 1% toluidine blue for stereological estimations, carried out using the Cavalieri method and the technique of point counting. Both the volume of the neuronal nucleus and the soma showed a statistically significant difference when comparing the data among OVX females treated with vehicle (V), estradiol (EB) alone, EB plus progesterone (EB+P) or P alone [n=5 rats in each group; one-way ANOVA test, P<0.01 in both cases]. The Tukey test showed that OVX and EB+P treated females had higher mean neuronal nucleus and somatic volumes when compared to V (P<0.01) or EB alone (P<0.01). Also, OVX females treated with P alone showed larger mean neuronal nucleus and somatic volumes when compared to V (P<0.05). These results suggest that the neuronal nucleus and the somatic volumes can be modulated by substitutive ovarian hormones administered to OVX females, for which P can lead to higher results. These findings reveal additional epigenetic actions of the sex steroids in the MePD and new neuronal morphological features in adult female rats.

Comparison of methods to assess quadriceps muscle volume using magnetic resonance imaging

To compare the precision of four methods to estimate the volume of quadriceps muscles using axial MRI. Entire legs of 10 healthy young subjects were scanned using a 1.5 Tesla magnetic resonance imaging scanner and 4-mm-thick sections without any gaps. Quadriceps muscles were outlined on all of the slices to obtain the MRI reference standard measure of quadriceps muscle volume. This MRI reference standard was compared with the volume estimated using (i) the truncated cone formula, (ii) the Cavalieri method, (iii) a cubic spline interpolation of missing cross sectional areas, and, (iv) the deformation of a parametric specific object. For each method, 3 to 21 slices were used. The average volume error was significantly (P < 0.001) different in comparing the four methods (4.4%, 2.3%, 1.1%, and 1.2%, respectively). In addition, the number of slices required to reach a given volume error was significantly (P < 0.001) different across all methods (respectively, 12, 9, 5, and 7 slices required to reach a volume error of 1.1%). While methods based on interpolation and deformation of a parametric specific object have not been used in literature, these two methods are the most precise approaches to reach a given level of precision.

PROGNOSTIC VALUES OF LESION VOLUME AND BIOCHEMICAL MARKERS IN ISCHEMIC AND HEMORRHAGIC STROKE: A STEREOLOGICAL AND CLINICAL STUDY

Purpose: Our aim was to evaluate the relationship between lesion volume, serum level of biochemical markers, and clinical situation in ischemic and hemorrhagic stroke. Methods: MRI was obtained on 33 ischemic and 28 hemorrhagic strokes. The Cavalieri method was used to measure the volume. To evaluate neurological situation of the patients, we used the National Institutes of Health Stroke Scale (NIHSS) and Rankin Disability Scores at the first, third, seventh, and thirtieth days. We measured the level of leptin, high sensitivity C-reactive protein (hs-CRP), insulin, cortisol, fibrinogen, protein C, protein S, von Willebrand factor, D-dimer, Antitrombin III, and Factor VIII (F VIII) at the same time intervals. Results: In ischemic events, cortisol level at third and seventh days, and fibrinogen level at the first day were correlated with lesion volumes (r = 0.5, p = .02; r = 0.4, p = .02; r = 0.5, p = .005, respectively). In hemorrhagic events, only fibrinogen level was correlated with lesion volumes at third day (r = 0.6, p = .04). No significant differences were found among all these biochemical parameters, neurological situation (p > .05), and lesion volumes at all times. Conclusion: In the prediction of stroke prognosis, lesion volume and all of the evaluated biochemical parameters are not deterministic factors.

Stereological Evaluation of Laryngeal Cancers Using Computed Tomography Via the Cavalieri Method

Tumor volume is accepted to be a significant prognostic factor for cancers arising in the head and neck regions. There were few studies on laryngeal tumor volume calculations. The purposes of this study were (1) to describe and adapt the relevant methods of computed tomography and stereology to estimate laryngeal tumor volume measured by the Cavalieri method; (2) to examine the possible correlation between tumor size and the number of involved neck lymph nodes in patients with laryngeal malignancies; and (3) to investigate if there is left-right asymmetry for this correlation and the number of involved lymph nodes in bilateral laryngeal malignancies. Fifty-two patients with bilateral laryngeal cancer only from a total of 137 patients with laryngeal cancer who underwent neck dissection during the study period were included in the study. In all cases, neck dissection was part of the treatment of laryngeal cancer. The Cavalieri estimator was used to estimate the tumor volumes on computed tomographic images. The tumor volume increased with the number of involved lymph nodes in the bilateral laryngeal malignancies in both the right and left neck regions. In addition, the volume of the primary lesion and the number of lymph node metastases in the cancer cells in the right neck region were well correlated in patients with laryngeal cancer but not the number of lymph node metastases in the left neck region. Correct, unbiased, reliable volume measurements for staging and therapeutic decision making of laryngeal cancers via the Cavalieri method may be possible.

Pyramidal neuron number in layer 3 of primary auditory cortex of subjects with schizophrenia

Individuals with schizophrenia demonstrate impairments of sensory processing within primary auditory cortex. We have previously identified lower densities of dendritic spines and axon boutons, and smaller mean pyramidal neuron somal volume, in layer 3 of the primary auditory cortex in subjects with schizophrenia, all of which might reflect fewer layer 3 pyramidal neurons in schizophrenia. To examine this hypothesis, we developed a robust stereological method based upon unbiased principles for estimation of total volume and pyramidal neuron numbers for each layer of a cortical area. Our method generates both a systematic, uniformly random set of mapping sections as well as a set of randomly rotated sections cut orthogonal to the pial surface, within the region of interest. We applied our approach in twelve subjects with schizophrenia, each matched to a normal comparison subject. Primary auditory cortex volume was assessed using Cavalieri's method. The relative and absolute volume of each cortical layer and, within layer 3, the number and density of pyramidal neurons were estimated using our novel approach. Subject groups did not differ in regional volume, layer volumes, or pyramidal neuron number, although pyramidal neuron density was significantly greater in subjects with schizophrenia. These findings suggest that previously observed lower densities of dendritic spines and axon boutons reflect fewer numbers per neuron, and contribute to greater neuronal density via a reduced neuropil. Our approach represents a powerful new method for stereologic estimation of features of interest within individual layers of cerebral cortex, with applications beyond the current study.

Three-dimensional reconstruction of postovulatory follicles from histological sections

The postovulatory follicle (POF) resorption process is classified in daily phases by examination of their 2-D histomorphological structure and characteristics to indicate the elapsed time since spawning. These characteristics were used to investigate the associated reduction in volume by three-dimensional (3-D) reconstruction of POFs in ovary samples of European hake ( Merluccius merluccius) and Atlantic cod ( Gadus morhua). Ovaries were serially sectioned and POFs were analysed to collect the sequence of profiles to generate a 3-D model. The volume of POFs determined from 3-D reconstruction was also compared to results following Cavalieri and Geometrical Best-Fitting methods. The data of POF volumes obtained were shown to be typical characteristic of four and three different POF histomorphological stages defined for hake and cod, respectively. In both species, POFs shrank sharply in the first hours, and then decreased more gradually until their complete resorption. There was no statistical difference in volume measurement of POFs determined by the three methods listed above, and therefore, the volume of POFs may, be used to validate the reliability of 2-D histomorphological staging to age POFs.

Confidence intervals for the volume of brain structures in Cavalieri sampling with local errors

The identification and quantification of morphological alterations that occur in the brain due to neurological disease, development and ageing, is of special interest in brain research. Design-based stereological methods have been widely applied in combination with magnetic resonance (MR) imaging to estimate the volume of brain structures. In the Cavalieri method, the volume V is directly estimated from equidistant and parallel MR images of the brain with a uniform random starting position. A second level of sampling is usually required to estimate the section area from each image (e.g., by applying point counting). The mathematical justification and implementation of the methodology is simple and it can be applied to structures of arbitrary shape. However, due to the spatial dependence in the data sample, how to predict the precision of the estimator of V becomes a difficult task. In this paper, we develop a method to construct a confidence interval for V by analysing the variability produced by each level of sampling (i.e., between and within sections’ variability). Simulation from two known analytical measurement functions is carried out to show its validity. Finally, the new approach is applied to investigate the significance of hippocampus volume change in a patient with epilepsy after 2 years of disease.

Lipid Content of Non‐cultured and Cultured Pig Embryo

The objectives of the study were: (i) to work out a precise and efficient method for quantitative analysis of lipid content and (ii) to quantitatively determine the lipid content in non-cultured and cultured pig embryos. The experiment was carried out on pig embryos from zygote to late blastocyst stages produced in vivo and embryos collected at the zygote stage and then cultured in vitro up to blastocyst stage. Embryos were fixed, dehydrated, embedded in epoxy resin and cut into semi-thin sections to analyse the quantity of lipids in fat droplets. Stained sections were then analysed with Cavalieri and point counting methods to evaluate the following stereological parameters of the embryo: total embryo volume - V(e), volume density of cytoplasm per unit volume of embryo - Vv(c,e), volume density of lipid droplets per unit volume of embryo cytoplasm - Vv(fat,c) and total volume of lipid droplets per whole embryo - V(fat). Values of Vv(fat,c) and V(fat) remained unchanged up to the morula stage, but decreased significantly at blastocyst and late blastocyst stages both in cultured and non-cultured embryos. Volume density of lipid droplets per unit volume of embryo cytoplasm and total volume of lipid droplets for cultured embryos showed statistically significant differences between late blastocyst and almost all other stages. Comparisons of Vv(fat,c) in embryos at the same stages of development but differing in origin of embryos (non-cultured or cultured) show that statistically significant differences exist for all analysed stages. In conclusion, differences in lipid content observed in pig embryos were dependent on the developmental stage of the embryo as well as the culture conditions (i.e. cultured and non-cultured embryos at the same stage of development).

Influence of different bonding systems and soft start polymerisation on marginal gap formation: stereological approach

The aim of the present paper was to investigate the effects of soft start polymerisation and the influence of the different adhesive systems on marginal gap formation using a stereological approach. Three adhesive systems [Single Bond (SB), Scotchbond Multi-Purpose (SM) and Clearfil SE Bond (SE)] and two curing techniques (standard cure and soft cure) were studied. For every curing technique, 24 cylindrical class V dentin cavities, 3 mm in diameter and 2 mm thick, were prepared and restorated with 3M Valux Plus composite resin using three different dentin bonding agents. Marginal gap formation was investigated under scanning electron microscope (SEM). On the micrographs, the surface areas of the gaps were measured according to the modified Cavalieri method. Data were analysed by ANOVA and Duncan multi-comparison tests (α=0˙05). Statistical analysis of variance (ANOVA) presented statistical significance for two factors: curing techniques and adhesives (p<0˙05). Interactions between adhesives and curing technique was not found significantly important (p>0˙05). With the relation averages, The Duncan test was carried out at the 5% level of significance. Soft cure has showed significantly less marginal gap formation in all adhesive systems. Clearfil SE Bond with soft cure has showed significantly less marginal gap formation, whereas Scotchbond MP with standard cure had higher values in all test groups (p<0˙05).

Magnetic resonance imaging versus histological assessment for estimation of lesion volume after experimental spinal cord injury

The purpose of this study was to compare measures of lesion volume obtained by means of 1.5-T MR imaging to those obtained by the Cavalieri method, 6 weeks after experimental spinal cord injury. Nine male Wistar rats were subjected to spinal cord injury by clip compression (50 g) at the T-4 level. Six weeks postinjury, the rats were sacrificed, and spinal cords were analyzed ex vivo for lesion volume by means of 1.5-T MR imaging and subsequently, by the Cavalieri method. In the latter method, cords were cut longitudinally in 25-microm sections and stained with solochrome cyanin for myelin. The area of the lesion was determined for each serial section, and the distance-weighted sum of all area measures was then calculated to estimate the total lesion volume. Bland-Altman analysis showed that the 2 methods had an acceptable level of agreement for lesion volume estimation, but the Cavalieri method was prone to an overestimation bias. The MR imaging estimates of lesion volume were greater than the Cavalieri method estimates in 3 spinal cords, but the difference between measures was within 1 standard deviation of perfect agreement in these 3 lesions, and the mean difference between measures was 18.3%. In contrast, in those lesions in which the Cavalieri method yielded larger lesion volumes (5 lesions), the difference between measures was 2 standard deviations away from perfect agreement for 2 animals and the mean difference between measures was 72.4%. The results illustrate that the overestimation bias of the Cavalieri method is due, in part, to artifacts produced during processing of the spinal cord tissue.

Penicillin-induced epilepsy model in rats: Dose-dependant effect on hippocampal volume and neuron number

This study was designed to evaluate the penicillin-induced epilepsy model in terms of dose-response relationship of penicillin used to induce epilepsy seizure on hippocampal neuron number and hippocampal volume in Sprague–Dawley rats. Seizures were induced with 300, 500, 1500 and 2000 IU of penicillin-G injected intracortically in rats divided in four experimental groups, respectively. Control group was injected intracortically with saline. Animals were decapitated on day 7 of treatment and brains were removed. The total neuron number of pyramidal cell layer from rat hippocampus was estimated using the optical fractionator method. The volume of same hippocampal areas was estimated using the Cavalieri method. Dose-dependent decrease in hippocampal neuron number was observed in three experimental groups (300, 500 and 1500 IU of penicillin-G), and the effects were statistically significant when compared to the control group ( P < 0.009). Dose-dependent decrease in hippocampal volume, on the other hand, was observed in all three of these groups; however, the difference compared to the control group was only statistically significant in 1500 IU of penicillin-G injected group ( P < 0.009). At the dose of 2000 IU penicillin-G, all animals died due to status seizures. These results suggest that the appropriate dose of penicillin has to be selected for a given experimental epilepsy study in order to demonstrate the relevant epileptic seizure and its effects. Intracortical 1500 IU penicillin-induced epilepsy model may be a good choice to practice studies that investigate neuroprotective mechanisms of the anti-epileptic drugs.

Correlation between the surface area of synovial membrane and the surface area of articular cartilage in synovial joints of the mouse and human

Articular cartilage is avascular. Evidence suggests that in mature animals synovial fluid is the dominant source of nutrition for articular cartilage. If so, there might be a direct correlation between the surface area of synovial membrane and the surface area of articular cartilage in synovial joints. The hindlimb joints of young adult Swiss Webster mice were prepared for histology and sagitally sectioned at regular intervals. The surface area of synovial membrane and the surface area and volume of articular cartilage were calculated from serial photomicrographs of knee, ankle, and first metatarsophalangeal (MTP) joints using ImageJ software and Cavalieri's method. Sagittal E12 slices from numerous synovial joints in a single human cadaver were similarly analysed. There was a strong statistically significant positive linear correlation between the surface area of synovial membrane and articular cartilage in the hindlimb joints of the mouse (r = 0.96, 95% CI 0.90-0.98, P < 0.0001). A similarly strong highly statistically significant corelation was observed between the surface area of synovial membrane and volume of articular cartilage. This relationship was also observed across a wider range of synovial joints in the human (r = 0.83, 95% CI 0.48-0.95, P = 0.0009). All analyses remained highly statistically significant after adjusting the standard errors and consequent P values for the linear models based on multiple observations in the same subject. This study demonstrates for the first time that there is a direct positive linear correlation between the surface area of synovial membrane and the surface area of articular cartilage in synovial joints in the mouse and human. These novel findings support the concept that the nutrition of mature articular cartilage is dependent on synovial fluid and may also explain why some joints communicate with surrounding bursae. Perhaps more consideration should be given to synovial membrane when studying the pathology of articular cartilage.

The effects of high‐fat diet on the renal structure and morphometric parametric of kidneys in rats

To characterize the kidney in a high-fat-induced obesity model, we examined the renal structure of adult Sprague-Dawley rats fed a control diet or a high-fat diet for 3 months. Ten adult female Sprague-Dawley rats were fed a diet consisting highly of fat (30%) for a period of 3 months. Ten control rats were maintained with standard rat chow. All animals were weighed every 10 days for 3 months. At the end of the experiment, the naso-anal length of the anaesthetized rats was measured to calculate body mass index, and subsequently whole kidneys of intracardially formalin-perfused animals were removed. Quantitative features of the kidney were analysed with the Cavalieri and physical dissector methods applied to serial paraffin sections. Kidney samples were also examined histologically. The body mass indices of the control and treatment groups were 4.528 +/- 0.242 and 5.876 +/- 0.318 kg m(-2), respectively. The difference between the body mass indices of the two groups was statistically significant (P < 0.01, Mann-Whitney U-test), suggesting that the animals fed with a high-fat diet may be overweight. Stereological examination of the kidneys revealed differences in kidney weight, total kidney volume, volume of cortex, medulla, glomeruli, proximal and distal tubules, and numerical density of glomeruli and glomerular height in the treatment group compared with the control group. Light microscopic investigation showed a dilatation in blood vessels and Bowman's space, mononuclear cell infiltration, degeneration in nephrons, including glomerulosclerosis and tubular defects, and an increase in the connective tissue in the kidneys in the treatment group. We concluded that a fatty diet is responsible for the rats' obesity and may lead to renal deformities as a result of histopathological changes such as dilatation, tubular defects, inflammation and connective tissue enlargement of the kidney.

Volumetric analysis of the posterior cranial fossa in a family with four generations of the Chiari malformation Type I

Many authors have concluded that the Chiari malformation Type I (CM-I) is due to a smaller than normal posterior cranial fossa. In order to establish this smaller geometry as the cause of hindbrain herniation in a family, the authors of this paper performed volumetric analysis in a family found to have this malformation documented in 4 generations. Members from this family found to have a CM-I by imaging underwent volumetric analysis of their posterior cranial fossa using the Cavalieri method. No member of this family found to have CM-I on preoperative imaging had a posterior fossa that was significantly smaller than that of age-matched controls. The results of this study demonstrate that not all patients with a CM-I will have a reduced posterior cranial fossa volume. Although the mechanism for the development of hindbrain herniation in this cohort is unknown, this manifestation can be seen in multiple generations of a familial aggregation with normal posterior fossa capacity.

Expression of protein gene product 9.5, tyrosine hydroxylase and serotonin in the pineal gland of rats with streptozotocin-induced diabetes

Hyperglycemia is a well-known factor in reducing nocturnal pineal melatonin production. However, the mechanism underlying diabetes-induced insufficiency of pineal melatonin has remained uncertain. This study was undertaken to examine the structure, innervation and functional activity of the pineal gland in streptozotocin (STZ)-induced diabetes in rats by immunohistochemistry, Western blotting and image analysis. The number of the pinealocytes and the volume of pineal were also estimated using stereologic quantification including the optical fractionator and Cavalieri's method. It has also shown a progressive reduction of the total area of the pineal gland and the nuclear size of pinealocytes beginning at 4 weeks of induced diabetes. Surprisingly, the immunoreactive intensities and protein amounts of serotonin (5-HT) and protein gene product (PGP) 9.5 in the pineal gland were progressively increased from 4 weeks of diabetes. Meanwhile, nerve fibers immunoreactive for PGP 9.5 had disappeared. Diabetes-induced neuropathy was observed in nerve fibers containing tyrosine hydroxylase (TH). The affected nerve fibers appeared swollen and smooth in outline but they showed a distribution pattern, packing density and protein levels comparable to those of the age-matched control animals. Ultrastructural observations have revealed diabetes-induced deformity of Schwann cells and basal lamina, accumulation of synaptic vesicles and deprivation of the dense-core vesicles in the axon terminals and varicosities. The increase in immunoreactivities in 5-HT and PGP 9.5 and shrinkage of pineal gland in the diabetic rats suggest an inefficient enzyme activity of the pinealocytes. This coupled with the occurrence of anomalous TH nerve fibers, may lead to an ineffective sympathetic innervation of the pinealocytes resulting in reduced melatonin production in STZ-induced diabetes.

Morphology, and Muscle- and Papilla-Volume Ratios, of the Tongue of Laudakia stellio (Agamidae, Squamata): A Histological and Stereological Study

We examined the histological structure of the tongue of Laudakia stellio, the starred agama lizard (Agamidae, Squamata), under light microscopy. We also investigated the muscle and papilla volume ratios, with volumes of each aspect of interest estimated according to the Cavalieri method. The macroscopically short, thick and muscle-rich front tip of the tongue of L. stellio does not show any bifurcation, and under light microscopy, the oval-shaped papilla-free front tip was seen to be covered by keratinized stratified epithelium. The dorsal and ventral parts were different, with the former partially covered by keratinized stratified epithelium and rich in secretory glands and secretory cells. The ventral part, which contained keratinized stratified cells, had a flat surface with no papillae. The dorsal surface of the anterior and posterior parts contained fungiform papillae, with the apical parts of these papillae containing minimal keratin; the interpapillar space was covered by keratin-free squamous stratified epithelium. The middle section of the tongue contained cylindrical-type papillae, with serous and mucous secretory glands and ducts at their base. Finally, the frontal and middle parts of the ventral and dorsal surfaces did not contain any taste buds, although there were some in the hind part of the dorsal surface. As morphometric estimates of volumes of the muscles and papillae, the mean volume ratios (relative to total tongue volume)+/-standard deviation were 0.66+/-0.03 and 0.33+/-0.03, with mean coefficients of error of 0.02 and 0.03, respectively.

Sulcal variability, stereological measurement and asymmetry of Broca's area on MR images

Leftward volume asymmetry of the pars opercularis and pars triangularis may exist in the human brain, frequently referred to as Broca's area, given the functional asymmetries observed in this region with regard to language expression. However, post-mortem and magnetic resonance imaging (MRI) studies have failed to consistently identify such a volumetric asymmetry. In the present study, an analysis of the asymmetry of sulco-gyral anatomy and volume of this anterior speech region was performed in combination with an analysis of the morphology and volume asymmetry of the planum temporale, located within the posterior speech region, in 50 healthy subjects using MRI. Variations in sulcal anatomy were documented according to strict classification schemes and volume estimation of the grey matter within the brain structures was performed using the Cavalieri method of stereology. Results indicated great variation in the morphology of and connectivity between the inferior frontal, inferior precentral and diagonal sulci. There were significant inter-hemispheric differences in the presence of (1) the diagonal sulcus within the pars opercularis, and (2) horizontal termination of the posterior Sylvian fissure (relative to upward oblique termination), both with an increased leftward incidence. Double parallel inferior precentral sulci and absent anterior rami of the Sylvian fissure prevented stereological measurements in five subjects. Therefore volumes were obtained from 45 subjects. There was a significant leftward volume asymmetry of the pars opercularis (P = 0.02), which was significantly related to the asymmetrical presence of the diagonal sulcus (P < 0.01). Group-wise pars opercularis volume asymmetry did not exist when a diagonal sulcus was present in both or neither hemispheres. There was no significant volume asymmetry of the pars triangularis. There was a significant leftward volume asymmetry of the planum temporale (P < 0.001), which was significantly associated with the shape of the posterior Sylvian fissure as a unilateral right or left upward oblique termination was always associated with leftward or rightward volume asymmetry respectively (P < 0.01). There was no relationship between volume asymmetries of the anterior and posterior speech regions. Our findings illustrate the extent of morphological variability of the anterior speech region and demonstrate the difficulties encountered when determining volumetric asymmetries of the inferior frontal gyrus, particularly when sulci are discontinuous, absent or bifid. When the intrasulcal grey matter of this region is exhaustively sampled according to strict anatomical landmarks, the volume of the pars opercularis is leftward asymmetrical. This manuscript illustrates the importance of simultaneous consideration of brain morphology and morphometry in studies of cerebral asymmetry.

Posterior fossa dimension and volume estimates in pediatric patients with Chiari I malformations

Chiari I malformations (CMI) involve pathological hindbrain abnormalities reported to be correlated with a hypoplastic posterior fossa. CMI was traditionally characterized by the downward herniation of the cerebellar tonsils with a descent of 5 mm or more below the foramen magnum. The fullness of the cisterna magna and CSF flow at the level of the cervicomedullary junction have been shown to be more useful in selecting symptomatic patients for surgical decompression. The present study calculates posterior fossa dimension and volume estimates in pediatric patients using magnetic resonance imaging. The combination of neuroradiological and clinical findings is used to re-examine the criteria used for diagnosis and treatment of pediatric CMI patients. A retrospective chart review was conducted on patients who were admitted to the Division of Neurosurgery of the Children's hospital of Eastern Ontario between 1990 and 2007. Clinical and radiological assessments were performed on all patients. Posterior fossa volumes (PFV) and intracranial volumes (ICV) were measured from sagittal head magnetic resonance imaging scans using the Cavalieri method. Sixty-one CMI patients were identified. There were 32 male and 29 female patients with a mean age of 10 years (range: 8 weeks-18 years). Thirty-four (55%) of these patients were symptomatic with scoliosis (38%), suboccipital headaches (29%), and motor/sensory deficits (26%) being the most prominent symptoms. The mean PFV/ICV ratio for all the CMI patients (0.110) was found to be statistically smaller than that of the control patients (0.127, p=0.022). Mean PFV/ICV ratios for asymptomatic and symptomatic CMI patients were found to be similar for children aged 0-9 years (p=0.783) but different for children aged 10-18 years (p=0.018). Mean PFV values were found to be smaller in pediatric CMI patients than control patients; this complements earlier studies in adults and supports the present theory concerning the pathophysiological mechanism of CMI. Subtle morphometric differences among asymptomatic and symptomatic patients aged 0-9 years stress the importance of monitoring asymptomatic patients for the onset of symptoms in their adult years. Symptom development in CMI is likely multifactorial and is much more extensive than the degree of cerebellar tonsillar herniation.

Histological characteristics and stereological volume assessment of the ovine tonsils

Tonsils form a first line of defence against foreign antigens and therefore play a key role in immunity. Since documented information about ovine tonsils is limited, a study was performed in which the morphological characteristics and the volume of lymphoid tissue present in each ovine tonsil were determined. The tonsils of five adult healthy sheep were examined histologically and the volumes were estimated using the Cavalieri method. The pharyngeal tonsil had a mean volume of 1296.1 ± 205.9 mm 3 and was by far the largest ovine tonsil, followed by the paired palatine tonsil with a mean volume of 715.0 ± 110.5 mm 3. The tonsil of the soft palate, the paired tubal and paraepiglottic tonsils and the lingual tonsil were much smaller with a mean volume of, respectively, 90.3 ± 24.9 mm 3, 80.1 ± 24.3 mm 3, 29.7 ± 11.8 mm 3 and 10.1 ± 2.8 mm 3. The folds and crypts of the pharyngeal and palatine tonsils were covered by a reticular and a non-reticular epithelium. Both tonsils were mainly composed of primary and secondary lymph follicles. The palatine tonsils contained 1–3 crypts with a few secondary infoldings. Lymphoid tissue in the tonsil of the soft palate was located at the nasopharyngeal (dorsal) side of the soft palate. The tubal tonsil was lined with a pseudostratified columnar ciliated epithelium and consisted of scattered lymphoid cells and lymph follicles. The paraepiglottic tonsil consisted of lymph follicles and aggregated lymphoid cells. Its overlying keratinized stratified squamous epithelium was folded and often heavily infiltrated by lymphocytes. The ovine lingual tonsil was not macroscopically visible and did not contain clearly distinguishable lymph follicles. It consisted of aggregations of lymphoid cells that were mainly located within the vallate lingual papillae.

Magnetic resonance imaging based volumetry: a primary approach to unravelling the brain

Abstract Magnetic resonance (MR) imaging based volumetry is recognized as an important technique for studying the brain. In this review, two principle volumetric methods using high resolution MR Images were introduced, namely the Cavalieri method and the voxel based morphometry (VBM). The Cavalieri method represents a manual technique that allows the volume of brain structures to be estimated efficiently with no systematic error or sampling bias, whereby the VBM represents an automated image analysis which involves the use of statistical parametric mapping of the MR imaging data. Both methods have been refined and applied extensively in recent neuroscience research. The present paper aims to describe the development of methodologies and also to update the knowledge of their applications in studying the normal and diseased brain. *Supported by National Natural Science 'Foundation of China (Grant Nos. 30625024, 30530300), the programs for NCET in University (Grant No. 04-0866), SRFDP (Grant No.20060610073) ...