Canine neonatal transcranial ultrasonography from birth until closure of bregmatic fontanelle.

Ultrasonography is a valuable diagnostic tool that has been used for diagnosis of neonatal brain diseases. The purpose of the present study was to describe the sequential ultrasonographic appearance of the normal canine neonatal brain from birth till closure of the bregmatic fontanelle. In total, 16 clinically normal neonates of mixed breed dogs were used. The bregmatic fontanelle was used as an acoustic window to record 5 transcranial scans (3 transverse, 1 sagittal, and 1 parasagittal scans) at 3, 10, 20, and 30 days of age. The appearance, echogenicity, and developmental differentiation of the structures within the cranium were described. Good images were obtained at 10 and 20 days of age. At 30 days of age, the obtained images presented poor details, as the fontanelle was small. Data obtained from this study represent the basis of brain ultrasound in neonates until 30 days of age, which could be beneficial in diagnosing congenital brain diseases.

Effects of medetomidine and medetomidine-butorphanol on transcranial color-coded duplex ultrasonography in healthy dogs.

The study was designed to determine the effects of two protocols of sedation, medetomidine and medetomidine-butorphanol, on cerebral blood flow (CBF) by transcranial color-coded Duplex ultrasonography in healthy dogs. Transcranial Doppler ultrasonographic examination was performed in 20 dogs before and 20 min after sedation with either medetomidine (group 1) or medetomidine-butorphanol (group 2). The left and right middle cerebral arteries (LMCA and RMCA) were evaluated using the temporal windows, and the basilar artery (BA) was studied through the suboccipital window. Peak systolic velocity (PSV), mean velocity (MV), end diastolic velocity (EDV), resistance index (RI), and pulsatility index (PI) were measured for each vessel. Blood pressure (BP) and heart rate (HR) were also recorded before and after sedation in both groups. Statistically significant differences were found for PSV, MV and EDV when RMCA and LMCA were interrogated before and after sedation. PSV, RI and PI were found to be statistically significantly different when the study was performed on the BA. These results should be taken in account when a transcranial Doppler is performed in dogs sedated with the mentioned protocols and it might suggest some degree of neuroprotection.

Vibrography: first experimental results in swine brains.

OBJECT: The aim of this study was to determine whether vibrography, an ultrasound-based real-time strain imaging method for registering the elastic properties of tissue, is superior to conventional ultrasound imaging techniques for detecting low-contrast space-occupying lesions in brain tissue and for delineating the boundaries between such lesions and the surrounding tissue. METHODS: As our experimental model we used swine brains taken from freshly slaughtered pigs. After injecting agarose into these brains at different depths, we compared both the conventional ultrasonographic images and the elastographic images of the region of interest with the corresponding anatomical brain sections. RESULTS: In 83.6 % of the experiments, it was possible to detect the polymerized agarose in the brain tissue with vibrographic techniques. In 17 experiments agarose lesions which were not detectable by ultrasound were visualized via vibrography. Furthermore, statistical analysis revealed that elastography is a more precise tool than conventional ultrasound for determining lesion size. CONCLUSION: These findings indicate that vibrography is a promising real-time imaging method with numerous potential applications in the field of neurosurgery. Visualization of the elastic properties provides the neurosurgeon with additional data on the lesion and the boundary between the lesion and the surrounding tissue.

Transorbital echoencephalography in cattle.

The purpose of this study was establishment of the criteria of transorbital echoencephalography in cattle and experimental applications to bovine practice. Quantitative investigations using magnetic resonance (MR) imaging revealed that this examination could be applied to cattle under 3 months of age. The method of transducer positioning was established in Japanese Black (J.B.) and filial (F1) cattle (turning caudally at an angle of about 16 degrees and dorsally at an angle of about 23 degrees) or in Holstein cattle (turning caudally at an angle of about 20 degrees and dorsally at an angle of about 21 degrees). Examinations in clinical calves revealed that the cerebral parenchyma and the lateral ventricle could be detected antemortem or postmortem. In this study, the diagnoses of hydrocephalus or hydranencephaly was possible using antemortem transorbital echoencephalography. Transorbital echoencephalography was especially useful as the imaging method for bovine hydranencephaly.

Neurosonography.

This article discusses the current state of neurosonography in veterinary medicine. After a brief introduction, indications, normal appearance, and appearance in pathology are discussed in separate sections for brain, spinal cord, and peripheral nerves. Each section is illustrated by selected images showing normal anatomy and pathology.

Brain imaging.

Advances in medical technology have revolutionized diagnostic brain imaging. Traditional radiography and invasive contrast studies for intracranial imaging have been superseded by several newer imaging modalities which provide high resolution, cross-sectional images. Ultrasonography, computed tomography, magnetic resonance, and nuclear scintigraphy are now used for anatomical and functional imaging of the brain. These noninvasive modalities are available at most veterinary teaching institutions and are offered through many larger referral practices. The diagnostic usefulness and clinical limitations for each of these modalities are described.

Surgical treatments for seizure. Adaptability for dogs.

Surgical treatments are often used for human epileptics who are refractory to more conventional anticonvulsant therapies. The goals of surgery are to decrease seizure morbidity or, ideally, bring about a cure to the seizure disorder. As a sizable subpopulation of dogs with seizures are also refractory to currently available anticonvulsant therapies, consideration has been given to evaluating alternative treatments for seizures in dogs. This article discusses the adaptability of surgical treatments used in humans for use in seizure control in affected dogs.

Hydrocephalus.

Hydrocephalus may be an acquired or congenital condition. Clinical signs often reflect the level of brain involvement. In young dogs, the presence of a dome-shaped head and/or persistent fontanel are suggestive of hydrocephalus. Ventriculoperitoneal shunting is often used for definitive treatment of hydrocephalus.

Cerebrovascular disease.

Cerebrovascular disease may be secondary to various disorders including hypothyroidism, sepsis, neoplasia, hypertension, vascular malformation, and coagulopathy. Brain infarction or hemorrhage should be suspected in an animal with a sudden onset of a focal brain lesion. The recent availability of CT and MRI has improved our ability to diagnose cerebrovascular disease in animals. Treatment is directed at maintaining adequate oxygenation of the brain, controlling elevations of ICP, treating seizures, and identifying and treating any underlying disease. With appropriate care, many animals can recover.

Ultrasound-guided brain biopsy in dogs.

Ultrasound-guided brain biopsy of the cingulate gyrus and the head of the caudate nucleus was performed in clinically normal dogs. Dogs survived the surgery, and neurologic deficits were not detected in the 14-day postoperative period. Magnetic resonance imaging detected changes in the brain associated with biopsy in 9 dogs (90%) immediately after surgery and in 6 dogs (60%) 14 days after surgery. Fourteen days after surgery, sonography of the brain, performed through the skin overlying the burr hole, detected changes associated with biopsy in 9 dogs (90%). Histopathologic changes evident in the brain 14 days after surgery consisted of focal malacia and hemorrhage with associated subacute encephalomeningitis. Postmortem examination indicated that the biopsy specimen was accurately obtained from the desired site in 9 dogs (90%). Tissue specimens suitable for histologic examination were obtained from 10 dogs (100%). Accuracy and low morbidity of ultrasound-guided biopsy indicate that this may be a useful technique for diagnosis of focal brain disease in dogs.