Cisternal Volume Research Articles

Sizing a rainwater harvesting cistern by minimizing costs

Rainwater harvesting (RWH) has the potential to reduce water-related costs by providing an alternate source of water, in addition to relieving pressure on public water sources and reducing stormwater runoff. Existing methods for determining the optimal size of the cistern component of a RWH system have various drawbacks, such as specificity to a particular region, dependence on numerical optimization, and/or failure to consider the costs of the system. In this paper a formulation is developed for the optimal cistern volume which incorporates the fixed and distributed costs of a RWH system while also taking into account the random nature of the depth and timing of rainfall, with a focus on RWH to supply domestic, nonpotable uses. With rainfall inputs modeled as a marked Poisson process, and by comparing the costs associated with building a cistern with the costs of externally supplied water, an expression for the optimal cistern volume is found which minimizes the water-related costs. The volume is a function of the roof area, water use rate, climate parameters, and costs of the cistern and of the external water source. This analytically tractable expression makes clear the dependence of the optimal volume on the input parameters. An analysis of the rainfall partitioning also characterizes the efficiency of a particular RWH system configuration and its potential for runoff reduction. The results are compared to the RWH system at the Duke Smart Home in Durham, NC, USA to show how the method could be used in practice.

Relationship between external and internal udder and teat measurements of machine milked dromedary camels.

This study aims to determine the relationship between internal and external udder and teat measurements and evaluate their correlation with milk yield and milk partitioning in the udder of dromedary camels. Six Maghrebi camels reared under intensive conditions were monitored at early, middle, and late lactation. Udder measurements included udder depth, udder horizontal circumference, fore and rear teat length and diameter. Besides, scans of the left fore and rear quarters were taken in duplicate before morning milking (16h) using an oxytocin receptor blocking agent (Atosiban) to determine teat and gland distension before milk ejection. Cisternal and alveolar milk volumes were then evaluated. Correlation coefficients were calculated between the performed udder external and ultrasonographical measurements and cisternal and daily milk production on the measurement day. Significant effect of lactation stage was observed in all measured traits. All internal and external measurements decreased significantly at late lactation as well as cisternal and total milk yield. The quarter cisternal area averaged 16.3 ± 2.2cm(2) and decreased about three times at late lactation compared to early and middle lactation. All external and internal measurements were positively and highly correlated (P < 0.001). The knowledge of the relationship between udder internal and external morphological traits would permit to predict udder cisternal storage capacity and can ultimately be adopted to improve milk storage capacity of dromedary camels.

Factors Associated with Acute and Chronic Hydrocephalus in Nonaneurysmal Subarachnoid Hemorrhage.

Hydrocephalus requiring external ventricular drain (EVD) or shunt placement commonly complicates aneurysmal subarachnoid hemorrhage (SAH), but its frequency is not as well known for nonaneurysmal SAH (NA-SAH). Those with diffuse bleeding may have greater risk of hydrocephalus compared to those with a perimesencephalic pattern. We evaluated the frequency of hydrocephalus in NA-SAH and whether imaging factors could predict the need for EVD and shunting. We collected admission clinical and imaging variables for 105 NA-SAH patients, including bicaudate index (BI), Hijdra sum score (HSS), intraventricular hemorrhage (IVH) score, modified Fisher scale (mFS), and bleeding pattern. Hydrocephalus was categorized as acute (need for EVD) or chronic (shunt). We applied logistic regression to determine whether hydrocephalus risk was independently related to bleeding pattern or mediated through blood volume or ventriculomegaly. Acute hydrocephalus was seen in 26 (25%) patients but was more common with diffuse (15/28, 54%) versus perimesencephalic (10/59, 17%, p < 0.001) bleeding. Patients developing acute hydrocephalus had worse clinical grade and higher BI, HSS, and IVH scores. Adjusting the relationship between hydrocephalus and diffuse bleeding for HSS (but not BI) nullified this association. Nine (35%) patients requiring EVD eventually required shunting for chronic hydrocephalus, which was associated with greater blood burden but not poor clinical grade. Acute hydrocephalus occurs in one-quarter of NA-SAH patients. The greater risk in diffuse bleeding appears to be mediated by greater cisternal blood volume but not by greater ventriculomegaly. Imaging characteristics may aid in anticipatory management of hydrocephalus in NA-SAH.

Microglia regulate blood clearance in subarachnoid hemorrhage by heme oxygenase-1.

Subarachnoid hemorrhage (SAH) carries a 50% mortality rate. The extravasated erythrocytes that surround the brain contain heme, which, when released from damaged red blood cells, functions as a potent danger molecule that induces sterile tissue injury and organ dysfunction. Free heme is metabolized by heme oxygenase (HO), resulting in the generation of carbon monoxide (CO), a bioactive gas with potent immunomodulatory capabilities. Here, using a murine model of SAH, we demonstrated that expression of the inducible HO isoform (HO-1, encoded by Hmox1) in microglia is necessary to attenuate neuronal cell death, vasospasm, impaired cognitive function, and clearance of cerebral blood burden. Initiation of CO inhalation after SAH rescued the absence of microglial HO-1 and reduced injury by enhancing erythrophagocytosis. Evaluation of correlative human data revealed that patients with SAH have markedly higher HO-1 activity in cerebrospinal fluid (CSF) compared with that in patients with unruptured cerebral aneurysms. Furthermore, cisternal hematoma volume correlated with HO-1 activity and cytokine expression in the CSF of these patients. Collectively, we found that microglial HO-1 and the generation of CO are essential for effective elimination of blood and heme after SAH that otherwise leads to neuronal injury and cognitive dysfunction. Administration of CO may have potential as a therapeutic modality in patients with ruptured cerebral aneurysms.

Does a small posterior fossa increase nerve vascular conflict in trigeminal neuralgia?

Magnetic resonance imaging (MRI) can be helpful in visualizing neurovascular conflict (NVC) of the trigeminal nerve in patients with trigeminal neuralgia (TN), but the relationship between these two events is controversial. To investigate whether posterior fossa volume is a predisposing factor for NVC in TN. We conducted a case-control study of clinically diagnosed idiopathic TN of 30 patients aged 30-79 years and 30 age- and sex-matched controls. We compared the volume of the posterior fossa and subarachnoid space using fast-imaging employing steady-state acquisition MRI and the iPlan® programme of BrainLab. The posterior fossa volumes in controls and patients with TN were 168.97 cm(3) and 167.63 cm(3), respectively. A small pontomesencephalic cistern volume was more frequent in TN. However, neither the cisternal nor parenchymal portions of the posterior fossa were different between patients with TN and controls, and no significant volume difference was observed in this study. Although the hypothesis that small posterior fossa volume influences TN was feasible, we did not find any volumetric differences (including the cisternal and parenchymal volumes).However, small pontomesencephalic cistern volumes were more frequent in patients with TN.

Evolution of udder morphology, alveolar and cisternal milk compartment during lactation and their relationship with milk yield in Najdi sheep

A total of 30 multiparous Najdi ewes were used to study the evolution of udder morphology traits and milk fractions in the udder during suckling (3rd, 6th, 9thwk) and milking (10th, 11th, 12thwk) periods. During suckling period, daily milk yield was estimated by using the double oxytocin injections method 4-h after milking. During milking period, ewes were hand-milked once daily. Udder and teat morphology traits for all ewes were measured 4-h after milking. Udder compartments were evaluated 8-h after milking by using atosiban and oxytocin; milk samples of each fraction were collected. Najdi ewes had a medium and healthy udders (CMT&lt;1), with medium sized teats (length, 3.2±0.1 cm and width, 1.7±0.1 cm) attached at 35.7 ± 11º angle. Milk yield averaged 1.88±0.18 and 0.44±0.12 L d-1 during suckling and milking periods, respectively. A drop in milk yield (-75%, p&lt;0.01) was found in the transition from suckling to milking. Udder traits, teats angle and width, and distance between teats declined (p&lt;0.05) throughout lactation, whereas teat lengths did not show any change. Positive correlations (p&lt;0.05) were observed between milk yield and udder depth (r=0.47-0.49), width (r=0.31-0.39) and distance between teats (r=0.26-0.39). The cisternal milk volumes decreased (p&lt;0.05) after weaning, whilst the corresponding percentages increased (p&lt;0.05). Cisternal milk accounted for 55% and 67% of the total udder milk during suckling and milking periods, respectively. Cisternal milk was positively correlated (r=0.93, p&lt;0.05) with total milk yield. The percentages of protein and total solids in alveolar and cisternal milk increased significantly (p&lt;0.05) after weaning, whilst fat percentages in cisternal milk did not change. In conclusion, the evaluated Najdi ewes showed medium sized cisterns and teats, which considered adequate for machine milking. Udder morphology traits had positive correlations with milk yield and hence, can be utilized in breeding programs.

Ultrasonographic findings in the ovine udder during involution.

The objective of the study was to record, by means of ultrasonographic examination, changes occurring in the udder of ewes during involution and to compare differences between progressive or abrupt udder drying-off. In group A ewes, udder drying-off took place progressively during a period of 22 d; ewes were milked twice daily for the last time on day(D) 0; then, they were hand-milked once daily for a week (D1-D7), which was followed by another week during which ewes were hand-milked once every 2 d (D9, D11, D13), followed by a third week during which ewes were hand-milked once every 3 d (D16, D19, D22). In group B ewes, the procedure took place abruptly; ewes were milked twice daily for the last time on D0 and no milking was carried out after that. B-mode and Doppler ultrasonographic examination of the udder of all ewes was performed throughout the drying-off procedure. Appropriate data management and analysis were performed. Progressive changes of the various parameters evaluated throughout the study period were significant in both groups (P<0.005). Gray-scale results of mammary parenchyma progressively decreased during the study and differed significantly between group A and group B (P=0.049). A temporary increase in cistern volume was evident after cessation of lactation, but differences were not significant between the two groups (P>0.3). Diameter of the external pudendal artery progressively decreased during the study and differed significantly between the two groups (P=0.037). Both resistance index and pulsatility index progressively increased throughout the study period in both groups; for both parameters, differences between the two groups were significant (P<0.0005). B-mode ultrasonographic examination indicated differences in remodelling of the extracellular matrix in relation to the procedure for udder drying-off. Volume of the gland cistern did not appear to be affected by the procedure for udder drying-off. Doppler ultrasonographic examination confirmed that blood flow during initiated involution was lower than during a progressive procedure for drying-off.

Ultrastructure of cisternal synapses on outer hair cells of the mouse cochlea.

C (cisternal) synapses with a near membrane postsynaptic cistern are found on motor neurons and other central neurons, where their functional role is unknown. Similarly structured cisternal synapses mediate cholinergic inhibition of cochlear hair cells via α9α10-containing ionotropic receptors and associated calcium-activated (SK2) potassium channels, providing the opportunity to examine the ultrastructure of genetically altered cisternal synapses. Serial section electron microscopy was used to examine efferent synapses of outer hair cells (OHCs) in mice with diminished or enhanced cholinergic inhibition. The contact area of efferent terminals, the appositional area of the postsynaptic cistern, the distance of the cistern from the plasma membrane, and the average width of the cisternal lumen were recorded. The synaptic cisterns of wild-type OHCs were closely aligned (14-nm separation) with the hair cell membrane and coextensive with the micrometers-long synaptic terminals. The cisternal lumen averaged 18 nm so that the cisternal volume was approximately 30% larger than that of the cytoplasmic space between the cistern and the plasma membrane. Synaptic ultrastructure of α9L9'T knockin OHCs (acetylcholine receptor gain of function) were like those of wild-type littermates except that cisternal volumes were significantly larger. OHCs of SK2 knockout mice had few small efferent terminals. Synaptic cisterns were present, but smaller than those of wild-type littermates. Taken together, these data suggest that the cistern serves as a sink or buffer to isolate synaptic calcium signals.

Improved Sustainability of Water Supply Options in Areas with Arsenic-Impacted Groundwater

The supply of water for rural populations in developing countries continues to present enormous problems, particularly where there is arsenic contamination in the groundwater, as exists over significant parts of Bangladesh. In response, improvements in the sustainability of water supplies are feasible through the use of a combination of water sources wherein rainwater harvesting is employed for a portion of the year. This can potentially reduce the duration of the year during which arsenic-contaminated groundwater is utilized. As demonstrated, a rainwater cistern volume of 0.5 m3 in the Jessore district area of Bangladesh can provide rainwater for periods averaging 266 days of the year, which allows groundwater at 184 µg/L arsenic to be used as a water supply for the remainder of the year. This dual supply approach provides the body burden equivalent to the interim drinking water guideline of arsenic concentration of 50 µg/L for 365 days of the year (assuming the water consumption rate is 4 L/cap/day for a family of five with a rainwater collection area of 15 m2). If the water use rate is 20 L/cap/day, the same cistern can provide water for 150 days of the year; however, although this is insufficient to supply water to meet the body burden equivalent guideline of 50 µg/L. Results are provided also for different rooftop areas, sizes of cisterns and alternative arsenic guidelines [World Health Organization (WHO) and Bangladeshi]. These findings provide useful guidelines on supply options to meet sustainability targets of water supply. However, they also demonstrate that the use of cisterns cannot assist the meeting of the 10 µg/L WHO target arsenic body burden, if the arsenic contamination in the groundwater is high (e.g., at 100 µg/L).

Relationship between udder morphology traits, alveolar and cisternal milk compartments and machine milking performances of dairy camels (Camelus dromedarius)

A total of 22 dairy dromedary camels under intensive conditions in late lactation (275±24 days) were used to study the relationship between external and internal udder morphology and machine milking performances. Measurements of udder and teat morphology were obtained immediately before milking and in duplicate. Individual milk yield, lag time and total milking time were recorded during milking, and milk samples were collected and analyzed for milk composition thereafter. Cisternal and alveolar milk volumes and composition were evaluated at 9 h milking interval. Results revealed that dairy camels had well developed udders and milk veins, with medium sized teats. On average, milk yield as well as milk fat and protein contents were 4.80±0.50 L d-1, 2.61±0.16% and 3.08±0.05%, respectively. The low fat values observed indicated incomplete milk letdown during machine milking. Lag time, and total milking time were 3.0±0.3, and 120.0±8.9s, on average, respectively. Positive correlations (p&lt;0.05) were observed between milk yield and udder depth (r=0.37), distance between teats (r=0.57) and milk vein diameter (r=0.28), while a negative correlation was found with udder height (r=-0.25, p&lt;0.05). Cisternal milk accounted for 11% of the total udder milk. Positive correlations were observed between total milk yield and volume of alveolar milk (r=0.98; p&lt;0.001) as well as with volume of cisternal milk (r=0.63, p&lt;0.05). Despite the low udder milk storage capacity observed in dairy camels, our study concluded that the evaluated dromedary sample had adequate udder morphology for machine milking. Finally, positive relationships were detected between milk yield and udder morphology traits of dairy camels.

Evaluation of residential rainfall harvesting systems in Jordan

A field study was conducted to evaluate the potential of rooftop rainfall harvesting (RRH), determine the smallest tank volume and the potential contribution of RRH to the national water budget. The potential water volume from rooftops nationwide is 14.7 million cubic metres per year (MCM/year), which comprises 6% of the domestic national water budget. Public water supply rates decreased for areas practicing RRH. The number of underground tank (cisterns) increased in high rainfall areas indicating adaptation behaviours for securing water. Smallest cistern volume charts were constructed for each governorate in relation to consumption rate and rooftop area. An immediate and nationwide awareness and legislative programmes are needed to spread RRH among the whole population of Jordan.

A Spheroid Weighted‐Axis Converter of Vestibular Schwannoma Size

To evaluate spheroid models of vestibular schwannoma (VS) size for bidirectional conversion of maximum diameter in the cistern and 3-dimensional volume. Methodological study. Academic tertiary referral center. Magnetic resonance imaging studies from 91 patients with VS from 2003 to 2011 were analyzed. Linear measurements defining meatal and cisternal components were extracted. Geometrically based conformal models of tumor volume were compared with measured tumor volume using a semiautomated computerized tracing method. Models were inverted to predict maximum axial cisternal length at the level of the internal auditory canal (IAC). A spheroid-weighted axis converter (SWC) of VS size was identified by minimizing input measurement parameters while maximizing output prediction performance. Computation steps of tumor volumes were (1) meatal-measure tumor lengths along the IAC and at the porus acusticus and take the average of a cone and cylinder and (2) cisternal-measure maximum tumor length in the axial IAC plane, use the median major:minor axis ratio of 1.26:1 to estimate minor axis length, take the geometric mean of axial dimensions to estimate axis length in the coronal plane, and apply input lengths to a spheroid. Performance error of this SWC had interquartile ranges of 33% for volume and 2 to 3 mm for maximum cisternal length. Reporting variability of VS tumor size has made it difficult to reconcile outcomes studies. We propose an accessible tool for bidirectional conversion of volumetric and linear indices of tumor size to unlock potential for meta-analyses of disparate data sets.

Study on the Effective Volume Determination of Rainwater Cistern in City Districts

As a crucial part of rainwater utilization engineering, the design of the cistern size has a great influence on the project investment and efficient operation of systems. In this study, the mathematical models of relationship among the effective volume, investment and water-saving benefits are established based on the rainfall data of typical year. With the help of these models, we can calculate the effective volume of rainwater cisterns, then analyze the engineering benefits and demonstrate the feasibility of the project. So this paper offers reference for the effective volume determination of rainwater cistern in city districts.

Abstract 2456: Quantitative Analysis Of Hemorrhage Volume For Predicting Cerebral Vasospasm After Subarachnoid Hemorrhage Between Surgical Clipping And Coil Embolization

Objective: Subarachnoid clots are important in development of delayed vasospasm after subarachnoid hemorrhage (SAH). The purpose of this study was to define the association between the subarachnoid clot volume and the incidence of symptomatic vasospasm (SV) after surgical clipping and embolization with Guglielmi detachable coils (GDCs) for aneurysmal SAH. Methods: The subjects were 155 patients with aneurysmal SAHs that were detected with a CT scan at admission and were treated by surgical clipping (Clip group, n=112) or GDC embolization (Coil group, n=43) within 72 hours of ictus between January 22, 2002 and November 22, 2009. Software-based volumetric quantification of the subarachnoid clot was performed using the voxel count method (AZE Virtual Place Fujin Raijin, AZE Ltd.). Subarachnoid clot was defined as cisternal high density areas with a Hounsfield number from 43 to 90 in the CT scan. Results: SV occurred in 24.1% and 16.3% of the patients in the Clip group (age, 63.5±12.8; male, 33.9%) and the Coil group (age, 63.0±12.6; male, 18.6%), respectively. The area under the ROC curve for subarachnoid clots for SV patients was 0.588 (95% confidence interval: 0.472-0.704; Clip group) and 0.849 (95% confidence interval: 0.714-0.985; Coil group). Using subarachnoid clot volumes of 19.6 ml (Clip group) and 32.1 ml (Coil group) as the cut-off values, the sensitivity and specificity were 89 and 39% (Clip group) and 100 and 61% (Coil group), respectively. A χ 2 test also identified that subarachnoid clots (&gt;19.0 ml) were associated with the development of SV compared to lower blood volumes in the Clip group (≤19.0 ml, p=0.017) and that subarachnoid clots (&gt;32.0 ml) were associated with development of SV compared to lower blood volumes in the Coil group (≤32.0 ml, p=0.03). The hemorrhage volumes of the patients with SV in the Clip group were lower than those in the Coil group at admission (37.7±21.5 vs. 58.5±23.1 ml, p=0.034), on the day after the operation (16.5±14.6 vs. 38.3±17.4 ml, p=0.002), and on Day 3-10 after SAH (5.5±4.1 vs. 11.4±9.3 ml, p=0.017). The hemorrhage volume at admission did not differ significantly between the groups (Clip group: 32.5±22.9 ml, Coil group: 32.8±22.4 ml). Conclusions: A threshold of cisternal hemorrhage volume (&gt;19.0 ml in the Clip group and &gt;32.0 ml in the Coil group) may exist above which patients are very likely to develop SV. Aneurysm surgery itself may be harmful to the brain (brain retraction, use of a temporary clip, and mechanical manipulation of cerebral arteries) and can lead to the onset of cerebral vasospasm.

The MRI volumetry of the posterior fossa and its substructures in trigeminal neuralgia: a validated study

Our aim was to determine whether the anatomical configuration of the posterior fossa and its substructures might represent a predisposition factor for the occurrence of clinical neurovascular conflict in trigeminal neuralgia (TN). We used MRI volumetry in 18 patients with TN and 15 controls. The volume of the pontomesencephalic cistern, Meckel's cave and the trigeminal nerve on the clinical and non-affected sides was compared. The reliability has been assessed in all measurements. The posterior fossa volume was not different in the clinical and control groups; there was no difference between the affected and non-affected sides when measuring the pontomesencephalic cistern and Meckel's cave volume either. The volume of the clinically affected trigeminal nerve was significantly reduced, but with a higher error of measurement. We did not find any association between the clinical neurovascular conflict (NVC) and the size of the posterior fossa and its substructures. MRI volumetry may show the atrophy of the affected trigeminal nerve in clinical NVC.

Evaluation of Udder Cisterns and Effects on Milk Yield of Dairy Ewes

Nine Manchega (0.94 L/d) and 10 Lacaune (2.07 L/d) ewes at the same stage of lactation (90 d in milk) were used to study the interbreed differences in milk yield, mammary morphological traits, and machine-milking ability. Udder traits were measured after 6h of udder filling before the start of the experiment. Cisternal area (by ultrasonography), cisternal milk (by teat cannula drainage), and alveolar milk (by machine milking after an intravenous oxytocin injection) were randomly measured 8h after milking for 2 wk consecutively either with an intravenous injection of an oxytocin receptor blocking agent (atosiban, AT) or without (control, C) to avoid the occurrence of milk letdown before milking. Lacaune ewes had greater udder depth (22.5±0.9 vs. 19.6±0.9cm) and cistern height (27.1±3.8 vs. 15.6±3.5mm), whereas Manchega ewes had longer (42.7±1.5 vs. 32.7±1.5mm) and wider teats (17.4±0.5 vs. 13.9±0.5mm). Values per half udder for Manchega and Lacaune ewes differed in cisternal area (12.8±0.7 and 23.7±0.6cm2) and cisternal milk (120±0.6 and 269±0.5mL), but not in alveolar milk (95±0.5 and 102±0.4mL), respectively. Cisternal area and cisternal milk were positively correlated (r=0.79). Ratios between cisternal and alveolar milk were 56:44 and 73:27 for Manchega and Lacaune ewes, respectively. Cisternal milk volumes obtained with the AT or C treatment were similar in Manchega (111±10 vs. 122±8mL) but differed in Lacaune ewes (239±8 vs. 299±8mL), respectively. Consequently, alveolar milk with AT vs. C was similar in Manchega (104±8 vs. 86±7mL) but different in Lacaune ewes (115±7 vs. 89±7mL). Results of this experiment confirm the need for the use of an oxytocin-blocking agent for accurate evaluation of milk contained in the udder of dairy ewes. Moreover, despite the differences in daily milk yield, alveolar milk did not vary between breeds, emphasizing the role of the cisternal more than the alveolar compartment for maximizing daily milk secretion in dairy sheep.

Management systems with extended milking intervals in ruminants: Regulation of production and quality of milk1,2

This paper aims to compare different adaptive responses of the mammary gland of cows, ewes, and goats submitted to extended milking intervals in different systems of management. Depending on the species, these extended milking intervals can be characterized by the following milk removal approaches; 3 milkings every 2 d, elimination of 1 milking per week (i.e., 13 vs. 14 milkings per week), and once-daily milking with additional suckling (i.e., dual purpose system of suckling and milking) or without suckling (exclusive once-daily milking). All the high-yielding animals and breeds adapted without problems to being submitted to intervals between milking less than 20 to 21 h. Under these conditions, all ruminant species demonstrated only low and transitory variations in milk production and quality. Thus, management systems using such an interval are good tools for the dairy producer who wants to save time without important adverse economic impact. When animals have good mammary gland health, these management systems can be applied without preliminary adaptation. However, goats and some breeds of dairy ewes seem to adapt to once-daily milking better than cows. Additionally, goats and ewes with higher production levels demonstrate a lower reduction in milk yield. With goats, there is only a limited variation in milk quality and cheese-making capacity of the milk produced, but ewes and cows show a significant enrichment of milk constituents, especially in fat. This indicates some differences in the regulation of lactose, protein, and fat synthesis depending on the duration of the milking interval and provides interesting models for physiological studies on milk secretion and synthesis regulation. Anatomical and physiological characteristics of lactating cows and ewes, in terms of cisternal vs. alveolar volumes within the mammary glands, could contribute to different abilities in adaptation to different milking systems. In goats, however, other mechanisms, such as compliancy of the mammary gland and regulation of tight junction impermeability, could be involved in milk secretion regulation and, thus, could become new targets for genetic selection of animals better adapted to accept extended milking intervals.

Chiari I anatomy after ventriculoperitoneal shunting: posterior fossa volumetric evaluation with MRI

Cephalocranial disproportion was said to be responsible for Chiari I malformation after ventriculoperitoneal shunt. We aimed to evaluate if the volumetric characteristics of Chiari I after a ventriculoperitoneal shunt was due to a general volumetric reduction and if it is restricted to the posterior fossa. Our results show that the posterior fossa volume, cisternal, clival length, and posterior cranial fossa volume ratio were reduced in the shunted group compared to the controls (p<0.05). Cerebellar and supratentorial volumes were similar between both groups. Craniocaudal extent, inferior, and superior tonsillar herniations were greater in the shunted group than control (p<0.05). The frontal occipital horn ratio in both groups was within normal range. Chiari I anatomy after a ventriculoperitoneal shunt could develop in children and we propose a "posterior cranial fossa disproportion" rather than a "cephalocranial disproportion."

Chiari 1 anatomy following ventriculoperitoneal shunting:Posterior fossa volumetric evaluation with MRI

Cephalocranial disproportion has been said to be responsible for Chiari 1 malformation following ventriculo-peritoneal shunt. We aimed to evaluate if the volumetric characteristics of Chiari 1 following a ventriculo-peritoneal shunt was due to a general volumetric reduction or restricted to the Posterior fossa. Our results show that the posterior fossa volume, cisternal, clival length and posterior cranial fossa volume ratio were reduced in the shunted group compared to the controls. p<0.05. Cerebellar and Supratentorial volumes were similar between both groups. Craniocaudal extent, inferior and superior tonsilar herniations were more in the shunted group than controls. p<0.05 . The frontal occipital horn ratio in both groups was within normal range. Chiari 1 anatomy following a ventriculo-peritoneal shunt could develop in children and we propose a ‘Posterior cranial fossa disproportion’ rather than a ‘Cephalocranial disproportion’.

Changes in Cisternal Compartment Based on Stage of Lactation and Time Since Milk Ejection in the Udder of Dairy Cows

Two experiments were conducted to study changes induced by stage of lactation and milk ejection in the cisternal compartment of the udder in dairy cows. In experiment 1, 18 cows grouped according to stage of lactation were used 12h after milking for measuring alveolar and cisternal milk volumes (by cannula) and cisternal area (by ultrasonography) in the front quarters. Cisternal milk and cisternal area were correlated (r=0.74 to 0.82) for all stages of lactation. As lactation advanced, volumes of alveolar and cisternal milk and cisternal area decreased. Proportion of cisternal milk varied between stages (early, 33.2%; mid, 23.1%; and late, 42.6%). In experiment 2, 7 cows were used to show return of milk from cisternal to alveolar compartments when milk ejection was induced without milking. Cisternal area was measured before (0min) and after (3, 15, 30, and 60min) an i.v. oxytocin (OT) injection administered immediately before normal a.m. and p.m. milking times. Cisternal area increased dramatically from 0 to 3min (98%) and decreased slowly thereafter. The 0- and 3-min data provide clear evidence of milk ejection, and their difference indicated cistern elasticity. Maximum cisternal area in each cow was similar for the 8- and 16-h milking intervals, indicating that in both cases the cistern was completely full of milk. Decrease in cisternal area after 3min was significant at 15, 30, and 60min. Decreased cisternal area was interpreted as the reflux of cisternal milk to the alveolar compartment. We termed this ‘cisternal recoil.’ In conclusion, ultrasonography was a useful method to evaluate dynamic changes in cisternal milk throughout lactation and after udder stimulation in dairy cows. Evidence exists that udder cisterns decrease when lactation advances and milk returns to the alveolar compartment when cows remain unmilked after milk ejection.