Prostate volume normal radiology, MULTIPARAMETRIC MR IMAGING OF PROSTATE TUMORS: PI-RADS V.2.1

Following the MR examination the brains of the animals were analyzed for EM. There was a shift from the slow to the fast component at min time point.

The water signal was increasing by 4. The results of the E. Conclusion: The unexpected volume fraction changes i.

A biexponential DWI study in rat brain intracellular oedema

It may suggest that ADC decrease in stroke, in contrast to general presumptions, cannot be explained only by water shift from extra to intracellular space i. All rights reserved. It was pointed out that even without compartmentation the biexponential signal decay is still present [4] and it can also be observed in a single cell [5].

Many speculations have been put forward about the two components: sol and gel state of water [6], bulk water and membrane bound water [7], prostate volume normal radiology water and bound water in the hydration shells of the macromolecules [4]. E-mail address: roy.

Because these speculations could not be proven so far, the biexponential model itself was questioned [8] arguing about a continuous, broad distribution of ADC values [9]. Thus other mathematical models have been proposed to describe the diffusion and the consequent signal decay in Diffusion weighted imaging DWI : diffusional kurtosis imaging Taylor expansion of the logarithm of signal decay [8,10,11], inverse Laplace transformation [9], and stretched exponential [12] etc.

The aim of this study is to examine the changes in MR parameters derived from DWI biexponential analysis in an in vivo intracellular brain oedema model. Electron microscopy was also applied in order to shed more light on the morphological background of MR related observations.

Biexponential DWI analysis may help to understand water movements in brain oedema. The DWI results of pure intracellular oedema were compared to those obtained in stroke, in which intracellular oedema i.

Steier et al. Prostate volume normal radiology and methods 2. Experimental protocol Ten male Wistar rats Charls Rivers, local distributor weighing — g were used. All procedures were done according to the University research ethical guidelines.

A prosztatadaganatos betegek sugárterápiájának mikroköltség-számítása

The animals were endotrachelly intubated and anaesthesia was maintained at 1. Following establishment of a base-line measurement, the water loading took place.

Correct IP injection site was visualized with an MR measurement. Blood was acquired by way of cardiac puncture for serum analysis of sodium and potassium ion selective electrode as well as plasma osmolarity vapour pressure osmometer.

Following 24 h, the brains of the animals were removed and analyzed for electron microscopy EM. The exact method of EM analysis is described previously [14]. Magnetic resonance imaging 3. The body coil was used for excitation and a commercially available loop of RF coil, having an inner diameter of 40 mm was used for the signal acquisition Siemens Medical Solutions, Erlangen, Germany.

For base-line establishment, 3 diffusion-weighted and spectroscopy measurements were done. The voxel was adjusted to each animal in order to cover the brain as much as possible The average voxel size was 13 mm × 10 mm × 5 mm. In this way only the unsuppressed water signal was recorded. Freehand regions of interests ROIs were drawn on diffusion weighted images covering both sides of the cortex. Parameters were calculated according to the selected region.

For the water signal evaluation standard spectroscopy prostate volume normal radiology was used on a Siemens Leonardo workstation. For signal processing only Fourier transformation was applied. The changes in ADC and water signal are referenced to the average of the initial three base line measurements [15]. Values are expressed as means ± standard deviation.

Statistical analysis was done using two-tailed equal distribution paired Student t-tests. Results 3. Changes in serum osmolarity and sodium The IP injection of the dextrose solution caused a severe hyponatraemia reaching a serum sodium level of This hyponatremia was accompanied with a decrease of serum osmolarity to levels of Following the R.

By evaluating the volume fraction contributions of the slow Pslow and fast P-fast components to the ADC-mono we realize that while the P-fast exhibits a tendency to increase, the P-slow shows the opposite tendency to decline. The changes in the Pfast and P-slow of Changes in water signal The results of the spectroscopy measurements showed that the water signal was increasing.

MULTIPARAMETRIC MR IMAGING OF PROSTATE TUMORS: PI-RADS V.2.1

It had increased by 2. The water signal continued to elevate up until the min time point. Reaching an increase of 4. Electron microscope observations In the examined areas of both the temporal cortex and the caudo-putamen, with negligible exceptions, the excess water was found in astrocytes i.

The bulk of excess water was present around arterioles Fig. In several places, molecular remnants of the disintegrated organelles of swollen astrocytes selfe-assembled into regular Fig. Discussion The biexponential approach is a robust model that gives consistent ADCs and volume fraction values in the brain tissue and appears to be insensitive to an inversion pulse T1magnetization transfer, extension of echo time T2 [1,3].

However, a recent paper suggests that ADC-slow increases by Fig. The ADC values were normalized to the average of the initial three base-line measurements.

Average values of the fast component of ADC in the rat cerebral cortex throughout the MR measurement protocol.

The predominance of the fast volume fraction i. These characteristics of the bi-exponential approach may substantiate that it will have diagnostic value in the daily clinical practice [16—18] similar to the mono-exponential approach in the low b-value range.

The intracellular oedema created in this study resulted in volume fractions that are unexpected. In contrast to stroke [1,4,17], P-fast increased.

However there are substantial differences that can explain the discrepancy.

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In intracellular oedema i. There is no tissue necrosis that might result in degradation of macromolecules and dysfunction of membrane pumps and channels. Therefore, based on our experiments it can be deduced that the intracellular oedema alone i. Our results also contradict in vitro studies in which cells were swollen i.

Average values of the slow component of ADC in the rat cerebral cortex throughout the MR measurement protocol. Percentages of the fast and slow components of ADC.