Evaluation of the applicability of musculoskeletal ultrasonography of the thoracolumbar and lumbar spine segment of healthy dogs

Ultrasonographic Imaging Protocol and Sonoanatomy of the Lumbar Spine in Healthy Dogs

Ultrasound is an imaging technique commonly used in veterinary medicine. Ultrasound devices are widely available, their means of examination are relatively short and cheap, and they do not generate ionizing radiation. In addition, ultrasound generally does not need to be performed under general anesthesia. This study was performed on 23 canine cadavers with full clinical histories and with no confirmed pathological changes in the spine region. The imaging modalities were established in dogs in lateral recumbency, with the selected side being the uppermost angle, in a neutral position. All dogs were examined in the transverse and longitudinal planes. Sacral crest, intertransverse ligament, vertebral canal floor, vertebral body, and intervertebral discs were only visible in the longitudinal plane. Vertebral arch, supraspinal ligament, dorsal wall of the vertebral canal and muscles were visualized only in the transverse plane. This article provides a brief and relatively easy-to-perform protocol for ultrasound imaging of the lumbar spine of dogs. In addition, it presents a detailed description of the sonoanatomy of the area under investigation.

Evaluator effect on the ultrasound measurement of subcutaneous fat deposition and loin eye area from weaning to slaughter lambs

Background and Aim:

Ultrasound is a non-invasive technique that enables animal evaluation and body condition classification of animals. Although it is not difficult to obtain an image, the analysis of this image can influence results quality. This study aimed to evaluate the repeatability and reproducibility of the technician trained in image interpretation obtained using different ultrasound frequencies.

Materials and Methods:

Ninety-six lambs were used, ranging in weight from 15 to 40 kg. The images were captured using a linear probe of 13 cm, with a 3.5 megahertz (MHz) frequency and an acoustic couplant aid “standoff” or using a multifrequency transducer (6 and 8 MHz), on B mode, with a linear probe and 8.0 MHz frequency. All measurements were performed by the same technician, on the left side, between the 12^th and 13^th rib. Five different evaluators, at two different times, with aid of Image J software measured the loin eye area (LEA; only for images obtained with 3.5 MHz), Longissimus thoracis et lumborum depth (DLM), subcutaneous fat thickness (SFT), subcutaneous fat thickness plus skin (SFST), and skin thickness (ST).

Results:

For LEA, DLM, SFT, SFST, and ST, variation was observed (p<0.01) between evaluators; however, there was no difference (p>0.05) between the 2 times of evaluation. Images measurements obtained with a frequency of 8.0 MHz had better repeatability indices and reproducibility indices. Accordingly, the identity test demonstrated that measurements performed on images obtained using 3.5 or 8.0 MHz were not equivalent.

Conclusion:

Ultrasound image measurements obtained using an 8.0 MHz frequency were more accurate and precise. It is important to use only one evaluator or providing the simultaneous training for all evaluators.