Computed tomography and magnetic resonance imaging study of a normal tarsal joint in a Bengal tiger (Panthera tigris).

BACKGROUND: In this research, using computed tomography (CT) and magnetic resonance imaging (MRI), we provide a thorough description of the standard appearance of a right tarsal joint in a Bengal tiger (Panthera tigris). CT scans were performed using a bone and soft tissue window setting, and three-dimensional surface reconstructed CT images were obtained. The MRI protocol was based on the use of Spin-echo (SE) T1-weighted and Gradient-echo (GE) STIR T2-weighted pulse sequences. Magnetic resonance (MR) images were taken in the transverse, sagittal and dorsal planes. We also performed anatomical dissections to facilitate the interpretation of the different structures of the tarsus joint and allow comparisons with CT and MRI images. RESULTS: The CT images allowed us to observe differences between the bones and soft tissues of the tarsal joint. When applying the bone window setting, the obtained footage showed the anatomy between the medulla and cortex. Additionally, the trabecular bone was delineated. By contrast, the soft tissue window allowed the main soft tissue structures of the tarsal joint, including ligaments, muscles and tendons, to be differentiated. Footage of the main anatomical structures of the standard tiger tarsus was obtained through MRI. The SE T1-weighted images showed the best evaluation of the cortical, subchondral and trabecular bone of the tibia, fibula, tarsus and metatarsus bones. Nonetheless, the GE STIR T2-weighted images allowed us to better visualize the articular cartilage and synovial fluid. In both MRI pulse sequences, the ligaments and tendons appeared with low signal intensity compared with muscles that were visible with intermediate signal intensity. CONCLUSIONS: The results of this CT and MRI study of the Bengal tiger tarsal joint provide some valuable anatomical information and may be useful for diagnosing disorders in this large non-domestic cat.

Magnetic resonance imaging study in a normal Bengal tiger (Panthera tigris) stifle joint.

BACKGROUND: The purpose of this study was to describe the normal appearance of the bony and soft tissue structures of the stifle joint of a Bengal tiger (Panthera tigris) by low-field magnetic resonance imaging (MRI), and the use of gross anatomical dissections performed as anatomical reference. A cadaver of a mature female was imaged by MRI using specific sequences as the Spin-echo (SE) T1-weighting and Gradient-echo (GE) STIR T2-weighting sequences in sagittal, dorsal and transverse planes, with a magnet of 0.2 Tesla. The bony and articular structures were identified and labelled on anatomical dissections, as well as on the magnetic resonance (MR) images. RESULTS: MR images showed the bone, articular cartilage, menisci and ligaments of the normal tiger stifle. SE T1-weighted sequence provided excellent resolution of the subchondral bones of the femur, tibia and patella compared with the GE STIR T2-weighted MR images. Articular cartilage and synovial fluid were visualised with high signal intensity in GE STIR T2-weighted sequence, compared with SE T1-weighted sequence where they appeared with intermediate intensity signal. Menisci and ligaments of the stifle joint were visible with low signal intensity in both sequences. The infrapatellar fat pad was hyperintense on SE T1-weighted images and showed low signal intensity on GE STIR T2-weighted images. CONCLUSIONS: MRI provided adequate information of the bony and soft tissues structures of Bengal tiger stifle joints. This information can be used as initial anatomic reference for interpretation of MR stifle images and to assist in the diagnosis of diseases of this region.

Anatomic Study of the Elbow Joint in a Bengal Tiger (Panthera tigris tigris) Using Magnetic Resonance Imaging and Gross Dissections.

The objective of our research was to describe the normal appearance of the bony and soft tissue structures of the elbow joint in a cadaver of a male mature Bengal tiger (Panthera tigris tigris) scanned via MRI. Using a 0.2 Tesla magnet, Spin-echo (SE) T1-weighting, and Gradient-echo short tau inversion recovery (GE-STIR), T2-weighting pulse sequences were selected to generate sagittal, transverse, and dorsal planes. In addition, gross dissections of the forelimb and its elbow joint were made. On anatomic dissections, all bony, articular, and muscular structures could be identified. The MRI images allowed us to observe the bony and many soft tissues of the tiger elbow joint. The SE T1-weighted MR images provided good anatomic detail of this joint, whereas the GE-STIR T2-weighted MR pulse sequence was best for synovial cavities. Detailed information is provided that may be used as initial anatomic reference for interpretation of MR images of the Bengal tiger (Panthera tigris tigris) elbow joint and in the diagnosis of disorders of this region.

Role of Tibial Tuberosity Fracture/Fissure through the Maquet Hole in Stifle Osteoarthritis after Porous Tibial Tuberosity Advancement in Dogs at Mid-Term Follow-Up.

Tibial tuberosity advancement (TTA) is used to treat cranial cruciate ligament rupture of the stifle joint in dogs. Tibial tuberosity fracture/fissure is a complication of TTA that may have a favorable prognosis. The aim of this study was to detect how tibial tuberosity fracture/fissure through the Maquet hole worsens the progression of osteoarthritis (OA) in the stifle joint of dogs treated with porous TTA. Seventeen cases were included in the study, divided into two groups. The first group (n = 10) included subjects that had tibial tuberosity fracture/fissure through the Maquet, and the second group included subjects that had no complications (n = 7). Both groups showed significant progression compared to OA at 3 months after surgery. We observed that at T0, the control group showed a higher level of OA. For this reason, we normalized the OA scores, evaluating the percentage difference from T0 and T1. We verified that there were no statistically significant differences between the two groups. The results confirm that OA progression in subjects undergoing TTA was not significantly influenced by fracture/fissure of the tibial tuberosity through the Maquet hole. Therefore, fracture fissure through the Maquet hole should be considered as a common minor complication during TTA.

Anatomic study of the normal Bengal tiger (Panthera tigris tigris) brain and associated structures using low field magnetic resonance imaging

The aim of this paper was to study the brain and associated structures of the Bengal tiger’s (Panthera tigris tigris) head by low-field magnetic resonance imaging (MRI). A cadaver of a mature female was used to perform spin-echo T1 and T2-weighting pulse sequences in sagittal, transverse and dorsal planes, using a magnet of 0.2 Tesla. Relevant anatomic structures were identified and labelled on the MRI according to the location and the characteristic signal intensity of different organic tissues. Spin-echo T1 and T2-weighted MR images were useful to demonstrate the anatomy of the brain and associated structures of the Bengal tiger’s head. This study could enhance our understanding of normal brain anatomy in Bengal tiger

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