Testicular Ultrasound Analysis as a Predictive Tool of Ram Sperm Quality

Abstract

Testicular ultrasound is a non-invasive technique that could be very useful for predicting ram seminal quality. Recent software developments allow macroscopic and microscopic evaluation of testicular parenchyma. Thus, the aim of this study was to evaluate the testicular echotexture using ultrasound-video analysis and investigate its possible correlation with semen quality. Nine rams were evaluated for one year using a portable ultrasound scanner and the echotexture was analyzed with ECOTEXT® software. The number of black (Ec1), white (Ec2), and grey pixels (Ec3), tubular density (TD), lumen area (LA), and lumen diameter (LD) were analyzed. Semen was collected by an artificial vagina the same day and the sperm concentration, morphology, motility, viability, phosphatidylserine (PS) translocation, reactive-oxygen-species (ROS) levels, DNA damage and capacitation state were evaluated. Ec2 and Ec3 correlated positively with “bad quality” sperm parameters (the percentage of spermatozoa with high ROS levels, with PS translocation and proximal cytoplasmic droplets), and negatively with motility. In contrast, TD and LA showed a positive correlation with “good quality” parameters (motility or normal morphology) and a negative correlation with spermatozoa with high ROS levels, with DNA fragmentation, and proximal or distal cytoplasmic droplets. Thus, echotexture analysis by ultrasound-video analysis could be a valuable tool for assessing ram fertility.

Ultrasound-Based Technologies for the Evaluation of Testicles in the Dog: Keystones and Breakthroughs

“…Acoustic impedance is, in turn, related to the tissue density crossed by the acoustic beam, resulting in a larger (shift toward white in the sonogram) or lesser (shift toward black in the sonogram) echo. Assuming a relationship between pixel intensity and a specific point’s ability to reflect the acoustic beam as a sign of tissue density, several studies have investigated the relationship between the pixel intensity of testicular sonograms, quantified by image-analysis software, and semen quality in domestic animals [ 17 , 18 , 19 , 20 , 21 , 22 ] and humans [ 23 , 24 , 25 , 26 ]. These studies revealed that changes in testicular pixel intensity were correlated with the percentage of morphologically normal live spermatozoa.…”

“…In veterinary medicine, the study of testicular vascularization has been conducted in various animal species, including stallions [ 8 , 81 , 82 , 83 , 84 ], jackasses [ 85 ], tomcats [ 86 , 87 ], bulls [ 17 , 88 , 89 ], rams [ 20 , 90 , 91 ], bucks [ 62 , 92 ], and dogs [ 52 , 65 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 ]. The results of these studies essentially confirm a relationship between testicular arterial blood flow and seminal quality in both normal and pathological conditions.…”

Understanding Sperm Quality for Improved Reproductive Performance

“…Recent ultrasound-video analysis and software developments have allowed the visualization of tissue at the microscopic level. Carvajal-Serna et al [8] revealed that echotexture analysis via ultrasound video could be a valuable tool for assessing the breeding soundness of rams. An increase in the number of white and grey pixels could indicate a decrease in seminal quality, and tubular density and lumen area could be predictors of good seminal quality.…”

Ultrasonography of Testicular Maturation and Correlation with Body Growth and Semen Evaluation in Beagle Dog Model

“…Acoustic impedance is connected to the density of the tissue penetrated by the acoustic beam, leading to a stronger or weaker echo. Multiple studies have explored the correlation between the grayscale intensity values of testicular parenchyma and the quality of semen in domestic animals [ 4 , 22 , 30 , 31 , 32 , 33 ], and humans [ 34 , 35 , 36 , 37 ]. These studies found a correlation between alterations in testicular pixel intensity and the proportion of morphologically normal viable sperm cells.…”