Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association
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Vet Radiol Ultrasound · May 2011
Ultrasound-guided mesenteric lymph node iohexol injection for thoracic duct computed tomographic lymphography in cats.
Computed tomographic (CT) lymphography was performed in cats using percutaneous ultrasound-guided injection of contrast medium into a mesenteric lymph node. The thoracic duct and its branches were clearly delineated in CT images of seven cats studied. The thoracic duct was characterized by anatomic variation and appeared as single or multiple branches. ⋯ Small volumes of extranodal contrast medium leakage were identified in all cats. After injection, the mesenteric lymph nodes were cytologically normal. Ultrasound-guided CT lymphography via percutaneous mesenteric lymph node injection appears safe and effective in cats.
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Vet Radiol Ultrasound · Jan 2011
Does changing the orientation of a thoracic radiograph aid diagnosis of rib fractures?
To test the hypothesis that changing the orientation of a thoracic radiograph aids diagnosis of rib fractures, a case-control study was carried out using 120 radiographs of small animal patients with recent thoracic trauma. Six independent observers representing three levels of experience viewed the radiographs in randomized order in conventional and unconventional orientations at 15-s intervals in a PowerPoint presentation. Sensitivity for rib fractures was 53-69% and specificity was 74-97%, depending on the observer. ⋯ Rotating radiographs 90 degrees clockwise was associated with increased specificity of one intern (from 74 to 90%, P = 0.03), but had no effect on accuracy of diagnosis by other observers (P > 0.16). Turning DV/VD views upside down had no effect on accuracy of diagnosis of any observers (P > 0.40). Changing the orientation of a thoracic radiograph may make it easier for some novices to examine the ribs; hence it could be considered a training aid rather than a technique that will benefit an experienced radiologist.
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Vet Radiol Ultrasound · Sep 2010
An in-house phantom as an alternative to commercially available Doppler flow phantoms.
Learning the principles and application of Doppler ultrasound is difficult and requires repeated practice. Flow phantoms provide a method of teaching Doppler techniques before their application in clinical patients; however, commercially available flow phantoms are expensive. Herein we describe an easily constructed, economic Doppler flow phantom, utilizing readily available products, for use as a training aid.
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Vet Radiol Ultrasound · Sep 2010
Ultrasonographic percutaneous anatomy of the caudal lumbar region and ultrasound-guided lumbar puncture in the dog.
Subarachnoid lumbar puncture is used commonly in the dog for cerebrospinal fluid collection and/or myelography. Here in we describe the percutaneous ultrasound anatomy of the lumbar region in the dog and a technique for ultrasound-guided lumbar puncture. Ultrasound images obtained ex vivo and in vivo were compared with anatomic sections and used to identify the landmarks for ultrasound-guided lumbar puncture. ⋯ The anatomic landmarks for the ultrasound-guided puncture, which should be identified on the parasagittal oblique ultrasound image are the articular processes of the fifth and sixth lumbar vertebrae and the interarcuate space. The spinal needle is directed under ultrasound-guidance toward the triangular space located between the contiguous articular processes of the fifth and sixth lumbar vertebrae and then advanced to enter the vertebral canal. Using these precise ultrasound anatomic landmarks, an ultrasound-guided technique for lumbar puncture is applicable in the dog.
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Contrast-enhanced ultrasound offers a noninvasive means of subjectively and quantitatively evaluating renal perfusion in cats with renal disease, or in renal transplant patients. In this study, we characterized the pattern of ultrasonographic contrast enhancement in 16 normal feline kidneys in eight cats using contrast-enhanced power Doppler and contrast-enhanced harmonic ultrasound techniques. Mean time to peak contrast enhancement for the whole kidney was longer using contrast-enhanced harmonic ultrasound (16.8s, SD 4.7s) than contrast-enhanced power Doppler ultrasound (12.2s, SD 1.8s). ⋯ The half time for washout of contrast agent was 39s (SD 14.5s) for contrast-enhanced harmonic ultrasound. The pattern of contrast enhancement in these normal feline kidneys can be used as normal reference values for the evaluation of clinical patients. Contrast-enhanced harmonic ultrasound may allow the differentiation between cortical and medullary perfusion patterns.