CT measurement of prostate volume using OsiriX^® viewer is reliable, repeatable, and not dependent on observer, CT protocol, or contrast enhancement in dogs

Abstract

Computed tomography (CT) is an established method for evaluating dogs with suspected prostatic disease; however, publications assessing the effects of varying factors on prostate volume measurements are lacking. The objectives of this two-part, observer agreement, methods comparison study were to assess observer agreement and the effects of varying CT technical parameters for volume measurements of canine prostate glands on CT images using OsiriX ® DICOM viewer software. In the first retrospective study, two observers measured prostate volumes of 13 client-owned dogs thrice on noncontrast and contrast CT images. In the second prospective study, two observers measured the prostate volume of 10 cadavers using five different CT protocols and eight cadavers using three slice thicknesses. Observer agreement analyses were performed, and prostatic CT volume measurements were compared with water displacement volume measurements. Intra-and interobserver variability and the effect of contrast enhancement were found to be minimal when a one-way analysis of variance model and intraclass correlation coefficients were used. No significant differences emerged between different protocols and slice thicknesses using a linear mixed effects model. When the prostate CT volume was compared using a Bland-Altman plot with the reference volume acquired by the water displacement method, agreement without consistent bias between the methods was shown, and over 90% of measurements were located within the 95% limits of agreement. The findings supported using OsiriX ® software for CT prostatic volume measurements in dogs.

Anatomical and Three-Dimensional Study of the Female Feline Abdominal and Pelvic Vascular System Using Dissections, Computed Tomography Angiography and Magnetic Resonance Angiography

“…Thus, we chose OsiriX as it is one of the commercially available programs and is claimed to be the most widely used DICOM viewer in the world [ 43 ], especially among certified radiologists in veterinary referral centers and those doing teleradiology. In this project, OsiriX MD 13.0.2 software provided the best views of the vascular structures; however, we agree with [ 44 ] which highlights a disadvantage of OsiriX ® in that it is only compatible with the Mac ® operating system. The second software used was Amira 5.6, usually used in research institutions and universities.…”

Dimensional and spatial computed tomographic abnormalities of the rectum and prostate are only partly reversible after surgical repair of perineal hernia in dogs

“…The volume of the prostate was measured with a previously described and validated method 8,16 . Prostate margins were drawn manually on every sequential transverse image, and prostatic volume was then calculated using the software tool.…”

“…This study is part of a larger project on PH in dogs. 8,15,16 Privately owned male dogs undergoing investigation of PH at the Veterinary Teaching Hospital of the University of Helsinki (VTHUH) were CT scanned before and 3 months after PH repair between 2017 and 2021. Power analysis was conducted to compare the clinical outcomes of two surgical techniques.…”

“…The volume of the prostate was measured with a previously described and validated method. 8,16 Prostate margins were drawn manually on every sequential transverse image, and prostatic volume was then calculated using the software tool. To proportion the prostate volume to the size of the dog, the ratio between the cubic root of the volume to the length of the sixth lumbar vertebra was determined and recorded as ratio volume (RV).…”