CONTRAST ENHANCEMENT IN MAGNETIC RESONANCE IMAGING USING INTRAVENOUS PARAMAGNETIC CONTRAST MEDIA: A REVIEW

Interest in magnetic resonance (MR) imaging as a major diagnostic tool in veterinary clinical medicine is increasing. Most MR studies are performed with the use of contrast enhancement via intravenous injection of paramagnetic gadolinium-containing contrast media. A vast number of publications are available regarding the use of contrast media in humans. The purpose of this paper is to assist practicing veterinary radiologists in understanding mechanisms of MR contrast enhancement. This paper reviews certain aspects of MR contrast enhancement, including physical, chemical and biologic characteristics of most common MR contrast media targeted primarily at the central nervous system (CNS). Authors also describe processes that explain changes in signal intensity on the MR images.     

MAGNETIC RESONANCE ARTHROGRAPHY OF THE CANINE STIFLE JOINT TECHNIQUE AND APPLICATIONS IN ELEVEN MILITARY DOGS

The stifle joints of eleven military working dogs were evaluated using conventional magnetic resonance (MR) imaging and MR arthrography. A protocol optimizing MR imaging of the canine stifle joint is discussed, as well as potential uses for administration of intra-articular gadolinium. The technique for performing MR arthrography is described, and post-contrast image findings are reviewed. MR arthrography was performed by using an intra-articular injection of diluted gadolinium. Consistently good quality images were obtained, and no complications were clinically detected following MR arthrography. Cranial cruciate ligament abnormalities were seen in six dogs, meniscal abnormalities were visualized in nine menisci, and synovitis and medial ligament strain were seen in eight dogs. Surgical and post-mortem confirmation of these findings is discussed in seven dogs. Although MR arthrography adds an invasive procedure to conventional MR imaging, it can provide useful information on pathologic changes in the canine stifle joint.     

MAGNETIC RESONANCE IMAGING OF THE NORMAL AND DISEASED FELINE MIDDLE EAR

The magnetic resonance imaging appearance of the feline middle ear is described in three healthy cats and in five cats with middle ear disease. Owing to the good spatial resolution, multiplanar slice orientation as well as display high contrast resolution of soft tissue, in particular fluids, MR imaging was helpful prior to surgery. It is superior to radiography which failed to allow identification of the abnormality in two of our five cats. MR imaging for middle ear disease should include dorsal and transverse plane images using T1- and T2-weighted sequences. In the presence of a mass within the bulla or the external ear canal application of contrast medium is helpful.     

Versatile physiological functions of the Nudix hydrolase family in berry development and stress response in grapevine

Nudix hydrolases are widely distributed across all classes of organisms and provide the potential capacity to hydrolyze a wide range of organic pyrophosphates. Although Nudix hydrolases are involved in plant detoxification processes in response to abiotic and biotic stresses, the biological functions of Nudix hydrolases remain largely unclear in grapevine.In the present study, a total of 25 putative grapevine Nudix hydrolases(VvNUDXs) were identified by bioinformatics analysis and classified int...     

Eperythrozoon wenyonii infection in dairy cattle

Approximately 10 of 100 young heifers that had recently delivered their first calf--members of a large Colorado dairy herd--had a syndrome of swollen teats and distal portions of the hind limbs, prefemoral lymphadenopathy, transient fever, rough coat, decreased milk production, and subsequent weight loss and reproductive inefficiency. Acute clinical signs of disease were associated with large numbers of Eperythrozoon wenyonii seen on blood smears, and resolution of signs correlated with reduction or disappearance of the parasite. Other known causes of peripheral edema could not be documented. The parasite was transmitted to 4 of 7 nonlactating dairy cows destined to be culled and a splenectomized calf via IV inoculation of blood from parasitemic heifers, but clinical signs of infection were not induced.     

Therapeutic Potential of Marine Peptides in Prostate Cancer: Mechanistic Insights

Prostate cancer (PCa) is the leading cause of cancer death in men, and its treatment is commonly associated with severe adverse effects. Thus, new treatment modalities are required. In this context, natural compounds have been widely explored for their anti-PCa properties. Aquatic organisms contain numerous potential medications. Anticancer peptides are less toxic to normal cells and provide an efficacious treatment approach via multiple mechanisms, including altered cell viability, apoptosis, cell migration/invasion, suppression of angiogenesis and microtubule balance disturbances. This review sheds light on marine peptides as efficacious and safe therapeutic agents for PCa.     

Implantation of an Uncemented Total Hip Prosthesis Technique and Initial Results of 100 Arthroplasties

A porous-coated modular total hip system was developed for uncemented implantation in dogs. The operative technique was developed in cadaver bones and live animals. One hundred uncemented total hip arthroplasties were performed in 92 dogs. Results were successful in 98% of the joints during follow-ups of 3 months or more. Complications included three luxations of the prosthetic joint, two fissure fractures of the femoral cortex, and one complete displacement of the acetabular component from its bony bed. Four complications were resolved successfully.     

VOLUMETRIC IMAGE PROCESSING FOR THREE-DIMENSIONAL DISPLAY OF THE SKELETAL ANATOMY OF THE SEA OTTER

Volumetrically correct, three-dimensional color images of the sea otter, ( Enhydra lutris ), were generated from computed tomographic (CT) data using a Sun 3/160 workstation and a Pixar Imaging Computer. These images could be displayed as static images (1024×768) or rotated about any axis in real-time by displaying sequential rotation sequences generated by the Pixar Imaging Computer. The images provided realistic depth of field through overshadowing and differential opacification. This was obtained through an opacification algorithm which traced rays from a selected viewing plane through colored gel volumes, and calculated absorbance percentages as a function of the transparency of the gels penetrated. Reconstructions of this type serve as alternative anatomy tutorials for species otherwise unavailable for routine dissection. They also permit topographical studies without interfering with populations of endangered animals.