Validation of multi‐detector computed tomography as a non‐invasive method for measuring ovarian volume in macaques (Macaca fascicularis)

Abstract

The purpose of this study was to validate low radiation dose, contrast-enhanced, multi-detector computed tomography (MDCT) as a non-invasive method for measuring ovarian volume in macaques. Computed tomography scans of four known-volume phantoms and nine mature female cynomolgus macaques were acquired using a previously described, low radiation dose scanning protocol, intravenous contrast enhancement, and a 32-slice MDCT scanner. Immediately following MDCT, ovaries were surgically removed and the ovarian weights were measured. The ovarian volumes were determined using water displacement. A veterinary radiologist who was unaware of actual volumes measured ovarian CT volumes three times, using a laptop computer, pen display tablet, hand-traced regions of interest, and free image analysis software. A statistician selected and performed all tests comparing the actual and CT data. Ovaries were successfully located in all MDCT scans. The iliac arteries and veins, uterus, fallopian tubes, cervix, ureters, urinary bladder, rectum, and colon were also consistently visualized. Large antral follicles were detected in six ovaries. Phantom mean CT volume was 0.702±SD 0.504 cc and the mean actual volume was 0.743±SD 0.526 cc. Ovary mean CT volume was 0.258±SD 0.159 cc and mean water displacement volume was 0.257±SD 0.145 cc. For phantoms, the mean coefficient of variation for CT volumes was 2.5%. For ovaries, the least squares mean coefficient of variation for CT volumes was 5.4%. The ovarian CT volume was significantly associated with actual ovarian volume (ICC coefficient 0.79, regression coefficient 0.5, P = 0.0006) and the actual ovarian weight (ICC coefficient 0.62, regression coefficient 0.6, P = 0.015). There was no association between the CT volume accuracy and mean ovarian CT density (degree of intravenous contrast enhancement), and there was no proportional or fixed bias in the CT volume measurements. Findings from this study indicate that MDCT is a valid non-invasive technique for measuring the ovarian volume in macaques.

Association Between Left and Right Atrial Remodeling With Atrial Fibrillation Recurrence After Pulmonary Vein Catheter Ablation in Patients With Paroxysmal Atrial Fibrillation

“…22 Helms et al 12 demonstrated in a 12-month follow-up study of the both paroxysmal and permanent AF patients, using 3-dimensional MDCT that the sensitivity of large LA volumes Ͼ135 mL for predicting the recurrence of AF was 36%, and the specificity of such volumes was 96%. In the present study, the higher diagnostic accuracy of each atrial enlargement for predicting AF recurrence was obtained by quantitative 3-dimensional measurements in combination with a computer-and navigation-aided technique (OsiriX software), [17][18][19] and the value of combined atrial volumes had the highest diagnostic accuracy. The combined LA and RA enlargements may better express more remarkable, overall structural remodeling than examination of individual atrial remodeling.…”

“…OsiriX software allows the quantitative measurement of volume from 3-dimensional MDCT data. [17][18][19] Each short-axis 0.7-mm interval CT image was examined, and the region of interest was defined on the LA and RA areas ( Figure 2). Thus, RA and LA volumes were quantitatively calculated from 3-dimensional images, using OsiriX software.…”

Magnetic Resonance Imaging Volumetry for Noninvasive Measures of Phenotypic Flexibility during Digestion in Burmese Pythons

“…MRI-based organ volumes were measured with the freeware imaging software OsiriX (http://www.osirix -viewer.com; Rosset et al 2004). Organ volumes were determined by outlining a region of interest (ROI) around the organ with the "pencil ROI-tool" in OsiriX on a pressure-sensitive monitor (Cintiq 21UX, Wacom) in the 2-D viewer window of OsiriX (e.g., Jones et al 2010).…”

Review on Ovarian Cryopreservation in Large Animals and Non-Human Primates

“…The benefit of these experimental animals is that the physiology and anatomy are similar to the human (Stevens, 1997;Weinbauer et al, 2008), although the ovarian size of the most studied cynomolgus monkey is considerably smaller (0.258+/-0.159 cm 3 ) (Jones et al, 2010) as compared to the human. Even if a lot of procedures are introduced in the human without appropriate tests in non-human primate species, it is advisable to include these animal models in preclinical research.…”