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Summary

Sonographic observations were made of the image mean gray scale (mgs) of the flexor tendons and ligaments in the left and right metacarpal regions of each of 10 clinically normal horses. In images made in the dorsal and sagittal planes, the mgs was measured at multiple sites in the superficial digital flexor tendon (sdft), deep digital flexor tendon (ddft), accessory ligament (al), and suspensory ligament (sl), and at single sites in the medial and lateral limbs of the sl, and the palmar ligament. Relative sonographic brightness of each tendon and ligament was calculated by dividing the value of its mgs by the mean value for the mgs of images of 3 soft tissue equivalent phantoms. When a multivariate repeated-measures of anova of the relative brightness values was statistically significant (P ≤ 0.05), Tukey's method of multiple comparisons was used to determine which values were significantly different from each other. In the dorsal plane, the sl was significantly brighter than the ddft, sdft, and al; relative brightnesses of the ddft and sdft were similar, as were those of the sdft and al. In the sagittal plane, the sl again was the significantly brightest structure, followed by the al, and similar brightnesses of the ddft and sdft. In dorsal images made 25 cm distal to the accessory carpal bone, relative brightnesses of the sdft, ddft, and the medial and lateral limbs of the sl were similar. In images made 30 cm distal to the accessory carpal bone, relative brightness of the palmar ligament was significantly (P < 0.05) less than that of the sdft and ddft in the dorsal plane, but not in the sagittal plane, where it was significantly greater. Relative brightness values represented a unique sonographic characteristic of each structure and, in the future, may provide further insights into tendon and ligament structure and function.

Free access
in American Journal of Veterinary Research

SUMMARY

Ultrasonographic or anatomic observations or both were made of the kidneys of 26 dogs. The anatomic studies established precise correlations between the gross anatomic features of the organ and its ultrasonographic images obtained in transverse, sagittal, dorsal, and 2 oblique planes. Uniformily mottled echogenicity of the renal cortex could be clearly differentiated from the less echogenic renal medulla. In the middorsal plane, the papillae of the renal pyramids were directed towards the renal sinus. The bases of the pyramids were almost circular in outline in the midsagittal images and the renal crest was seen as an echogenic line. Although the renal sinus was highly echogenic, neither the renal pelvis nor its recesses were detected. The walls of each of the interlobar arteries provided echogenic parallel lines, passing in the renal recesses between the renal pyramids. Arcuate arteries were demonstrated at the corticomedullary junction and interlobular arteries were detected within the renal cortex.

For the right kidney, transverse images were obtained with the ultrasonographic transducer at the last 2 intercostal spaces; images in the dorsal, sagittal, and oblique planes were obtained with the transducer placed over the caudal extremity of the kidney. In the left kidney, transverse images were made with the transducers at, and caudal to, the last intercostal space; images in the dorsal, sagittal, and oblique planes were obtained with the transducer placed over the lateral border of the kidney. The use of such a protocol ensures that the entire organ is inspected and a diagnosis of either a normal or pathologic kidney is made.

Free access
in American Journal of Veterinary Research

Abstract

Objectives

To obtain Doppler ultrasonographic images of renal arteries in horses and to establish reference range values for systolic and diastolic renal arterial blood flow and resistive indices. Also to determine whether Doppler ultrasonography could be used in horses to detect changes in renal blood flow after IV administration of furosemide.

Animals

11 clinically normal adult horses.

Procedures

Pulsed-wave Doppler examinations were performed on arcuate arteries of 5 sedated horses. Continuous-wave Doppler examinations were performed on pyelorenal arteries in 7 nonsedated horses and were repeated in 6 horses after furosemide administration. Peak-systolic velocity (SV) and end-diastolic velocity (EDV) were measured and the resistive indices (RI) were calculated.

Results

Using pulse-wave Doppler ultrasonography in sedated horses, arcuate arteries were determined to have a SV of 0.406 ± 0.116 m/s (mean ± SD), EDV of 0.184 ± 0.057 m/s, and Rl of 0.549 ± 0.044. Using continuous-wave Doppler ultrasonography in nonsedated horses, pyelorenal arteries were determined to have SV of 1.047 ± 0.009 m/s, EDV of 0.510 ± 0.006 m/s, and Rl of 0.512 ± 0.004. Doppler waveforms from the arcuate and pyelorenal arteries had a low resistance flow pattern, characterized by a systolic peak followed by a continuous antegrade diastolic flow. After furosemide administration, the pyelorenal arterial velocities increased, but the RI remained unchanged.

Conclusions

Doppler ultrasonography may be used to record renal blood flow in horses and to detect changes following furosemide administration.

Clinical Relevance

Doppler ultrasonographic images may assist in the diagnosis of renal diseases that affect either blood flow or Doppler waveform. (Am J Vet Res 1997;58:697–701)

Free access
in American Journal of Veterinary Research

Abstract

Objectives

To determine the sonographic dimensions and an imaging protocol for the pyloric region of the normal canine stomach, and whether sonography could be used to demonstrate antroduodenal motility.

Animals

20 clinically normal, mixed-breed dogs (mean ± SD, 15.1 ± 7.1 kg).

Procedure

In vitro sonographic observations of the gastroduodenal junction were made after each had been mounted on an acrylic rack placed in an organ bath. The in vivo studies were performed in anesthetized dogs.

Results

The wall of the pyloric antrum was 4 to 5 mm thick, that of the pylorus was 3 to 4 mm thick, and that of the cranial part of the duodenum was 2 to 3 mm thick. The pyloric canal had a length of 16 to 17 mm and overall in vivo diameter of 22 mm, and the muscular part of its wall was 2 to 3 mm thick. In vivo sonographic images were best made with the dog in dorsal recumbency, tilted 30° to the right-the feasibility study clearly demonstrated the form and function of antroduodenal motility, including gastric and duodenal peristalsis, opening and closing of the pyloric canal, and duodenogastric reflux of fluid and gas.

Conclusions and Clinical Relevance

The use of a routine imaging protocol, accompanied by mensuration of the gastroduodenal junction, will permit an opinion to be given as to whether the structure and function of the region are normal or whether pathologic change exists. (Am J Vet Res 1996;57:1266-1273)

Free access
in American Journal of Veterinary Research

SUMMARY

Sonographic and anatomic observations were made of the kidneys of 23 Thoroughbreds or Standardbreds. In an in vitro study of 16 horses, precise correlations were established between the gross anatomic features of the kidneys and their sonographic appearance in images obtained in dorsal, sagittal, transverse, and transverse oblique anatomic planes. The renal cortex had a uniformly mottled echogenicity, and the renal medulla was relatively hypoechogenic, compared with the cortex. Acoustic anisotropy was observed in the cortex and medulla of the cranial and caudal extremities of each kidney. The distinctive renal pelvis was seen in the transverse plane as an echogenic pair of diverging lines that lead to the crescent shaped renal crest in the lateral half of the kidney. In images made in the sagittal plane, the renal pelvis was seen as a pair of parallel echogenic lines separated by the moderately echogenic line of the renal crest. The terminal recesses were best seen in the transverse oblique views of each extremity, where they appeared as moderately echogenic lines in the medulla of the cranial and caudal extremities. The interlobar vessels were represented as irregular echogenic lines in the medulla, and the arcuate vessels were seen as echogenic points at the corticomedullary junction. At the hilus, the renal artery or its branches was located cranial to the renal vein, which in turn was cranial to the position of the proximal portion of the ureter.

In an in vivo study of 7 horses, sonographic images of the right kidney were obtained in the sagittal, transverse, and transverse oblique anatomic planes in all horses, with the transducer positioned at the 15th, 16th, or 17th intercostal space; images in the dorsal plane were obtained, however, in only 3 of the horses. For the left kidney, sonographic images were obtained in each of the anatomic planes when the transducer was positioned at the 16th or 17th intercostal space or the paralumbar fossa; rectal location of the transducer gave images in the dorsal and sagittal planes.

In this study, a routine sonographic imaging protocol, using standard anatomic planes, enabled each kidney to be examined in its entirety. The protocol provided definition of normal renal sonographic anatomic features and may permit a more informed and accurate recognition of renal pathologic change.

Free access
in American Journal of Veterinary Research

SUMMARY

In a dorsal plane, an improved ultrasonographic off-set system was used to obtain serial ultrasonographic images with enhanced anatomic and pathologic detail of the tendons, ligaments, and associated structures of the limbs of 100 horses. The off-set provided good acoustic coupling between a linear array ultrasonographic transducer and the horse's skin. A water-soluble gel contained within the off-set had acoustic properties similar to those of mammalian soft tissues.

Free access
in American Journal of Veterinary Research

SUMMARY

Results of radiologic and anatomic studies of each cubital articulation (elbow) of a group of 50 adult cat cadavers indicated that a sesamoid bone may be located in a constantly present sesamoid cartilage associated with the tendon of origin of the supinator muscle. Radiography revealed a sesamoid bone in 40 of the 100 tendons of origin of the supinator muscles dissected from the elbows. The sesamoid bone articulated with the craniolateral aspect of the head of the radius, and the larger sesamoid cartilage, which contained the bone, articulated with the head of the radius and the capitulum of the humerus. Of several possible functions of the sesamoid cartilage (bone), it was considered that protection of the craniolateral part of the humeroradial articulation and maintenance of the complex anatomic system during joint movement were important. In radiographic views of the elbows of lame cats, the sesamoid bone should not be mistaken for a chip fracture or an osteocartilaginous loose body.

Free access
in American Journal of Veterinary Research

Summary

Observations were made in dorsal and sagittal planes of the ultrasonographic mean gray scale of the flexor tendons and ligaments of the metacarpal regions of 5 Thoroughbred geldings, during weight bearing and nonweight bearing. In images made when the horses were nonweight bearing, the mean gray scale of the superficial and deep digital flexor tendons and accessory ligament was significantly reduced, but that of the interosseous medius muscle (suspensory ligament) was not. When relaxed, collagen fiber bundles in the tendons and ligaments acted as diffuse, rather than specular, reflectors of ultrasonic waves leading to localized regions of hypoechogenicity and a consequent reduction in mean gray scale. The suspensory ligament, however, remained under tension during nonweight bearing and so mean gray scale was not reduced. Analyses of the ultrasonographic mean gray scale have the potential to provide quantitative data relating to the changes in echogenicity that develop in injured equine tendons and ligaments.

Free access
in American Journal of Veterinary Research

Summary

In a feasability study, a technique for constructing 3-dimensional sonographic images of the superficial digital flexor tendon (sdft) was established in 6 clinically normal horses and applied to 7 horses with injured sdft. Two-dimensional B-mode sonographic images were recorded on videotape as the sonographic transducer was manually moved along the palmar aspect of the metacarpal region. Selected videofields were digitized, and 3-dimensional images were constructed, using a computer work station and dedicated software program. The 3- dimensional images were of high quality and presented qualitative clinical information in unique fashion. Indication of the extent of sdft injuries was excellent. Such 3-dimensional images would be especially useful in explaining to owners and trainers the importance of the injury to their horse and would have a role in monitoring tendon healing and in the assessment of various treatments.

Free access
in American Journal of Veterinary Research

SUMMARY

Sonographic and/or anatomic observations were made of the spleen in 27 dogs. Anatomic studies were used to establish precise correlations between the gross anatomic features of the organ and its ultrasonographic image. In 8 anesthetized dogs, ultrasonographic images of the spleen were made in dorsal, transverse, and sagittal planes. When it was incident to the ultrasonic beam, the splenic capsule was represented by a fine echogenic line that defined the boundaries of the organ. The splenic substance had a uniformly mottled echogenicity apart from the anechoic lumen of the splenic venous rami, which were detected at and near the hilus of the spleen. Less regularly, splenic arterial rami were detected at the hilus, but not within the splenic substance. Dorsal and transverse images were made with the ultrasonic transducer perpendicular to the left thoracic and abdominal wall at the 11th intercostal space and caudoventrad to it. Sagittal images were produced with the transducer's face directed craniad, placed parallel to the left lateral abdominal wall, and pushed under the costal arch. The adoption of such an ultrasonographic imaging protocol ensures that all of the spleen is inspected. A definitive opinion can then be given as to whether the spleen is normal or abnormal. Pathologic changes in the spleen must also be differentiated from changes in adjacent organs or structures.

Free access
in American Journal of Veterinary Research