Spectral Analysis of Tissue Displacement for Cardiac Activation Mapping: Ex-vivo Working Heart and In-vivo Study

AbstractFirst in vivo brain conductivity reconstructions using Helmholtz MR-Electrical Properties Tomography (MR-EPT) have been published. However, a large variation in the reconstructed conductivity values is reported and these values differ from ex vivo conductivity measurements. Given this lack of agreement, we performed an in vivo study on eight healthy subjects to provide reference in vivo brain conductivity values. MR-EPT reconstructions were performed at 3 T for eight healthy subjects. Mean conductivity and standard deviation values in the white matter, gray matter and cerebrospinal fluid (σWM, σGM, and σCSF) were computed for each subject before and after erosion of regions at tissue boundaries, which are affected by typical MR-EPT reconstruction errors. The obtained values were compared to the reported ex vivo literature values. To benchmark the accuracy of in vivo conductivity reconstructions, the same pipeline was applied to simulated data, which allow knowledge of ground truth conductivity. Provided sufficient boundary erosion, the in vivo σWM and σGM values obtained in this study agree for the first time with literature values measured ex vivo. This could not be verified for the CSF due to its limited spatial extension. Conductivity reconstructions from simulated data verified conductivity reconstructions from in vivo data and demonstrated the importance of discarding voxels at tissue boundaries. The presented σWM and σGM values can therefore be used for comparison in future studies employing different MR-EPT techniques.

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751 Prediction of Colonic Neoplasia Through Spectral Marker Analysis from the Endoscopically Normal Rectum: An Ex Vivo and In Vivo Study

Gastroenterology ◽

10.1016/s0016-5085(08)60510-7 ◽

2008 ◽

Vol 134 (4) ◽

pp. A-109

Author(s):

Hemant K. Roy ◽

Vladimir Turzhitsky ◽

Andrew Gomes ◽

Michael J. Goldberg ◽

Jeremy D. Rogers ◽

...

Keyword(s):

Ex Vivo ◽

In Vivo Study ◽

Marker Analysis ◽

Colonic Neoplasia

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In vivo study and thermodynamic investigation of two lanthanum complexes, La(dpp)3 and La(XT), for the treatment of bone resorption disorders

Chemical Science ◽

10.1039/c5sc01767j ◽

2015 ◽

Vol 6 (11) ◽

pp. 6439-6447 ◽

Cited By ~ 15

Author(s):

J. F. Cawthray ◽

D. M. Weekes ◽

O. Sivak ◽

A. L. Creagh ◽

F. Ibrahim ◽

...

Keyword(s):

Bone Resorption ◽

Ex Vivo ◽

In Vivo Study ◽

Oral Drug ◽

Thermodynamic Investigation ◽

Preventative Measure ◽

Drug Candidates

Lanthanum could act as a preventative measure against bone resorption disorders; two compounds are thoroughly investigated both in vivo and ex vivo as potential oral drug candidates.

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Ex vivo and in vivo study of Kowa HA-2 applanation tonometer in the measurement of intraocular pressure in cats

Semina Ciências Agrárias ◽

10.5433/1679-0359.2017v38n6p3647 ◽

2017 ◽

Vol 38 (6) ◽

pp. 3647

Author(s):

Claudia Lizandra Ricci ◽

Rogério Giuffrida ◽

Glaucia Prada Kanashiro ◽

Hilidia Stephania Rufino Belezzi ◽

Carolina De Carvalho Bacarin ◽

...

Keyword(s):

Intraocular Pressure ◽

Ex Vivo ◽

Clinical Signs ◽

In Vivo Study ◽

Eye Drops ◽

Significant Difference ◽

Applanation Tonometer ◽

Ex Vivo Study ◽

Healthy Eyes

The objective of this study was to evaluate the use of the Kowa HA-2 applanation tonometer in measuring intraocular pressure (IOP) in cats. Ten healthy eyes were used in an ex vivo study in which the calibration curve for manometry vs. tonometry was determined by artificially raising the IOP in 5 mmHg increments up to 60 mmHg (10-60 mmHg). Both eyes of 10 anesthetized cats were studiedin vivo to compare manometry vs. tonometry. In the ambulatory study, 78 healthy eyes, 7 eyes with glaucoma and 20 eyes with uveitis were evaluated by tonometry, which was performed with topical anesthesia and 1% fluorescein eye drops for the formation of fluorescein semicircles. The correlation coefficient (r²) between the manometer and the Kowa HA-2 tonometer was 0.993 and the linear regression equation was y = 0.0915x + 0.0878 in the ex-vivo study. In the in vivo study, the IOP values (mean±SD, in mmHg) in manometry were 15.6 ± 1.1(14.0 – 17.5) and in tonometry were 15.5 ± 1.2(13.5 – 17.2), with no significant difference (P > 0.05) between manometry and tonometry. In ambulatory study, using the Kowa HA-2 tonometer, the IOP values (mean±SD, in mmHg) were 15.0 ± 1.5 (11.8 – 18.3) for the healthy eyes, 38.4 ± 8.1(29.6 – 53.7) for glaucomatous eyes and 10.4 ± 2.0(5.3 – 12.2) for eyes with uveitis. There was a strong correlation and accuracy between the IOP values with the manometry and the Kowa HA-2 tonometer. In the ambulatorystudy the IOP values obtained with the tonometer were compatible for animals with healthy eyes and with clinical signs of glaucoma and uveitis. We conclude that the Kowa HA-2 tonometer can be used in the measurement of IOP in cats, since it is a practical and accurate method in this species.

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