In vitro volume estimation of kidneys using three-dimensional ultrasonography and a position sensor

Matre, Knut; Stokke, Elisabeth M; Martens, D.; Gilja, Odd Helge

doi:10.1016/s0929-8266(99)00044-0

Cited by 40 publications

(20 citation statements)

References 16 publications

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“…Previous authors found 24% underestimation of the renal volume, estimated by US or MRI, if it was regarded as an ellipsoid. It was established that estimation of the renal volume, either adult or fetal, using three-dimensional US systems or the voxel count method assessed by MRI gives a good agreement with true volumes obtained using the Archimedes principle, as the gold standard [Bakker et al, 1999;Matre et al, 1999;Yu et al, 2000]. Results obtained from our research showed that if one used the ellipsoid formula for calculating the fetal renal volume (table 5), the underestimation would be about 32-33% on average .…”

Section: Discussionmentioning

confidence: 99%

Age-Related Changes of the Human Fetal Kidney Size

Vlajković¹,

Vasović²,

Daković-Bjelaković³

et al. 2006

Cells Tissues Organs

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Early prenatal diagnostics and the importance of genetic counseling are of great interest for echosonographic evaluation of normal fetus anatomy. Development of the human fetal kidney runs through a series of continual and mutually dependent changes during which the kidney obtains its morphological and functional maturity. This study was created to estimate the changes in kidney size during gestation in fetuses from the 4th to the 10th lunar month, to evaluate the dynamics of their growth, as well as to establish the validity of the volume calculated from these dimensions. Serial measurements of kidney dimensions (length, width, thickness) were performed in 110 fetuses. Photomicrographs of kidneys from the 4th, 6th, 8th and 10th lunar months are also presented. On the basis of the results obtained by our examination, we concluded that the period from the 14th to 16th week of intrauterine life is the fastest period of kidney growth during fetal development. Using the ellipsoid formula for calculating the fetal renal volume offers an underestimation of about 32–33% on average. The importance of this study lies in determining the average fetal kidney dimensions, which could be used as standard values in obstetrics.

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Section: Discussionmentioning

confidence: 99%

Age-Related Changes of the Human Fetal Kidney Size

Vlajković¹,

Vasović²,

Daković-Bjelaković³

et al. 2006

Cells Tissues Organs

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“…In order to test for the agreement of volumes determined using low-resolution and high-resolution scans as well as low-resolution scans and liquid displacement method the "95% limits of agreement" method from clinical measurement comparisons Altman, 1986, 2003) was applied. By calculating the mean difference (measure of the offset) and the 95% confidence interval, limits of agreement were created that depicted 95% of all differences (Matre et al, 1999). The t-factors for the 95% confidence interval were adapted to the sample size (Hayek and Buzas, 2010).…”

Section: Statistical Analysesmentioning

confidence: 99%

A novel, non-invasive and in vivo approach to determine morphometric data in starfish

Sigl

Imhof

Settles

et al. 2013

Journal of Experimental Marine Biology and Ecology

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Keywords:Acanthaster planci (Linnaeus 1758) Echinodermata Gonad index Magnetic resonance imaging Non-invasive Pyloric cecum index Starfish (Echinodermata: Asteroidea) are present in most benthic ocean habitats and play an important ecological role as keystone species or by dominating through sheer individual numbers. In order to assess nutritional and reproductive states in ecological studies on asteroids, invasive techniques to calculate organ indices are conventionally used. We present a non-invasive method that enables imaging and morphometric measurements in starfish in vivo. We used a clinical 1.5 T magnetic resonance imaging (MRI) scanner to produce sectional images of three starfish species and employed these image stacks to generate 3D models of the pyloric ceca, gonads and the endoskeleton. In comparison to pre-clinical MRI scanners, that provide higher resolutions, clinical MRI is not limited to small objects, but allows the investigation of larger samples such as the starfish used in the present study. Volume data from MRI-based 3D reconstructions were compared to conventional invasive measurement techniques as well as high resolution MRI scans and were tested for inter-observer effects. Here we show that MRI is a suitable method for precise imaging and volumetric measurements in fixed and living marine specimens. Compared to other methods, it allows not only the production of time series data on single individuals as well as populations, but also non-destructive analyses of valuable specimens, such as museum material.

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“…3D volume estimation of organs by ultrasound was originally only possible with a transducer mechanically tilted through 90° with a motor device whilst scanning continuously, with the ultrasonographic data transferred to a separate workstation for 3D reconstruction and processing Gilja et al, 1996a;Thune et al, 1996;Gilja et al, 1998). Obviously limited by the pre-determined scanning range and position of the sensor, a magnetometer based position and orientation measurement (POM) device was developed providing precision mapping of points in space and was validated as an accurate method of volume estimation Matre et al, 1999). A series of sagittal slices are acquired with a continuous sweeping motion towards the midline, beginning with the transducer at the left subcostal margin, tilted cranially, to image the most proximal part of the stomach, through to the distal stomach and ceasing at the gastroduodenal junction (Gilja et al, 1997a;Gilja et al, 2005).…”

Section: D Assessment Of Gastric Emptyingmentioning

confidence: 99%