NORMAL XERORADIOGRAPHIC AND RADIOGRAPHIC ANATOMY OF THE RED-TAILED HAWK (BUTEO JAMAICENCIS), WITH REFERENCE TO OTHER DIURNAL RAPTORS

The purpose of this study was to provide a reference for xeroradiographic and conventional radio-graphic anatomy of the red-tailed hawk (Buteo jamaicencis) as a representative of the avian Order Falconiformes. The head, body, wing, and pelvic limb of three adult birds were radiographed using xeroradiographic and conventional radiographic techniques. Twelve xeroradiographs and their corresponding conventional radiographs were selected, and the xeroradiographs labeled to illustrate the normal anatomy of these regions.     

NORMAL XERORADIOGRAPHIC AND RADIOGRAPHIC ANATOMY OF THE BOBWHITE QUAIL (Colinus virginianus), WITH REFERENCE TO OTHER GALLIFORM SPECIES

The purpose of this study was to provide a reference for xeroradiographic and conventional radiographic anatomy of the bobwhite quail ( Colinus virginianus ) as a representative of the avian order Galliformes. The heads, bodies, wings, and pelvic limbs of four adult birds were radiographed using xeroradiographic and conventional radiographic techniques. Nine xeroradiographs and their corresponding conventional radiographs were selected, and the xeroradiographs labeled to illustrate the normal anatomy of these regions. A xeroradiograph of the transometatarsus of the domestic peacock ( Pavo cristatus ) was also included to demonstrate the metatarsal spur, which is not present in the quail.     

THE NORMAL XERORADIOGRAPHIC AND RADIOGRAPHIC ANATOMY OF THE COCKATIEL (NYMPHZCUS HOLLANDZS)

The purpose of the study was to provide a reference for the normal radiographic anatomy of the cockatiel ( Nymphicus hollundis ). The head, body, wing, and pelvic limb of mature males were radiographed using xeroradiographic and conventional radiographic techniques. Ten xeroradiographs and ten corresponding conventional radiographs were selected, and the xeroradiographs appropriately labeled to illustrate the normal radiographic anatomy of these regions.     

THE NORMAL XERORADIOGRAPHIC AND RADIOGRAPHIC ANATOMY OF THE ORANGE-WINGED AMAZON PARROT (AMAZONA AMAZONICA AMAZONICA)

The purpose of the study was to provide a reference for xeroradiographic and conventional radio-graphic anatomy of the orange-winged Amazon parrot ( Amazona amazonica amazonica ) as a representative of medium-sized psittacine birds that are commonly kept as pets. The head, body, wing, and pelvic limb of a mature bird were radiographed using xeroradiographic and conventional radiographic techniques. Ten xeroradiographs and ten corresponding radiographs were selected, and the xeroradiographs labeled to illustrate the normal radiographic anatomy of these regions. Also included is a short discussion of unique avian anatomic features which are important to clinical evaluation.     

XERORADIOGRAPHIC AND RADIOGRAPHIC ANATOMY OF THE CHANNEL CATFISH, ICTALURUS PUNCTATUS

The purpose of this study was to provide an anatomic reference for the channel catfish ( Ictalurus punctatus ) using xeroradiography * and conventional radiography. The entire body of three adult fish was radiographed using standard xeroradiographic and conventional radiographic techniques. Two xeroradiographs and their corresponding conventional radiographs were selected, and the xeroradiographs labeled to illustrate the normal skeletal and soft-tissue anatomy of the channel catfish.     

RADIOGRAPHIC ANATOMY OF THE CRIBRIFORM PLATE (LAMINA CRIBROSA)

The radiographic appearance of the cribriform plate was investigated in 16 canine cadaver heads. The cribriform plate appeared as a "V"-shaped multilinear bone-opaque stripe in the caudal nasal region in projections perpendicular to the hard palate in 6 dogs with a skull index between 50.00 and 54.00. In 9 dogs with a skull index between 55.40 and 74.40, the cribriform plate had a more "C"-shaped and sharp appearance. In vertically oblique projections with an obliquity greater than 20 degrees, the cribriform plate lost its sharp outline and finally (40 degrees) disappeared. In lateral projections the cribriform plate appeared as a "C"-shaped interrupted bone-opaque stripe in all 16 dogs. In more brachycephalic dogs frontal bone structures superimposed on the cribriform plate on ventrodorsal and dorsoventral views and accentuated the radiographic appearance of the plate. Vertically oblique views separated both structures to produce two lines.     

MAGNETIC RESONANCE IMAGING OF THE NORMAL EYE AND ORBIT OF A SCREECH OWL (OTUS ASIO)

Magnetic resonance images of a screech owl ( Otus asio ) were acquired to identify the normal anatomic components of the eye'and orbit. T1-weighted, proton-density, and T2-weighted images were obtained in the straight sagittal, oblique dorsal, and oblique sagittal planes. Signal intensity for the various orbital structures differed between the three resonance techniques. T1-weighted images provided the best anatomic detail of ocular and orbital structures. The oblique dorsal and oblique sagittal planes were superior for evaluating the optic nerve in its entirety.     

MAGNETIC RESONANCE IMAGING ANATOMY OF THE NORMAL EQUINE LARYNX AND PHARYNX

The purpose of the present study was to describe normal magnetic resonance (MR) imaging anatomy of the equine larynx and pharynx and to present the optimal protocol, sequences, and possible limitations of this examination technique. Using a 0.3 T unit, the laryngeal and pharyngeal regions was imaged in two horses. The protocol consisted of sagittal and transverse T2-weighted (T2w) fast spin echo, transverse T1-weighted (T1w) spin echo, and dorsal high-resolution T1w gradient echo (both pre- and postcontrast enhancement) sequences. Euthanasia was performed at the end of the imaging procedure. Macroscopic anatomy of the cadaver sections were compared with the MR images in transverse, midsagittal, and parasagittal planes. There was good differentiation of anatomic structures, including soft tissues. The laryngeal cartilages, hyoid apparatus, and upper airway muscle groups with their attachments could be clearly identified. However, it was not always possible to delineate individual muscles in each plane. Most useful were both T2w and T1w transverse sequences. Intravenous application of contrast medium was helpful to identify blood vessels. The MR images corresponded with the macroscopic anatomy of cadaver sections.     

A XERORADIOGRAPHIC STUDY OF THE DEVELOPING QUARTERHORSE FOREDIGIT AND METACARPOPHALANGEAL REGION FROM SIX TO TWELVE MONTHS OF AGE

The purpose of the project was to provide a reference for radiographic anatomy of the developing equine foredigit and metacarpophalangeal region. Using xeroradiographic techniques, both foredigits and metacarpophalangeal regions of six Quarter Horse foals were radiographed at 1 day of age and then at 2-week intervals until the foals were 6 weeks old. The foals were then radiographed at 4-week intervals until they were 12 months old. The period from birth to 6 months has been described in a previous report. This paper deals with the period from 6 to 12 months of age. Lateromedial and dorsopalmar xeroradiographs of each foredigit and metacarpophalangeal region and a dorsal 65° proximal-palmarodistal oblique view of the distal part of the digit were made at each examination. Foals were weighed and were measured at the withers immediately prior to each examination. Representative xeroradiographs were selected and appropriately labeled to demonstrate normal radiographic anatomy of these regions. Earliest radiographic visualization of distal epiphyseal ossification in metacarpal 2 and metacarpal 4 was extremely variable and ranged from 4 to 38 weeks. It was not possible to determine accurately the ages at which distal physes of the small metacarpal bones closed. In one foal, three of four of these physes were closed at 26 weeks, while in another foal, none had closed when last radiographed at 54 weeks. Radiographic closure of the proximal physis of the middle phalanx ranged from 18 to 30 weeks (mean = 26 weeks). Radiographic closure of the proximal physis of the proximal phalanx ranged from 22 to 38 weeks (mean = 30 weeks). Radiographic closure of the distal physis of metacarpal 3 ranged from 18 to 38 weeks (mean = 29 weeks).     

ULTRASONOGRAPHY OF THE CALIFORNIA DESERT TORTOISE (Xerobates agassizi): ANATOMY AND APPLICATION

Ultrasonographic examinations were performed on healthy California desert tortoises to evaluate the utility of the anatomic acoustic windows available and to gain information about the normal echoanatomy of the tortoise. A major objective was to evaluate the potential clinical value of this diagnostic tool in these species. The soft tissue areas of the integument were used as acoustic windows. Three imaging approaches were described as mediastinal, axillary, and inguinal openings. The mediastinal and axillary approaches offered good visualization of the heart, liver, and gallbladder. The inguinal window allowed imaging of the intestines, urinary/accessory bladders, kidneys, and gonads. The pancreas and spleen could not be visualized. A tortoise with pericardial effusion and a tortoise with hepatic lipidosis are presented to illustrate clinical applications of ultrasound in diagnosing diseases of the tortoise.     

ULTRASONOGRAPHIC ANATOMY OF THE NORMAL CANINE SPINAL CORD AND CORRELATION WITH HISTOPATHOLOGY AFTER INDUCED SPINAL CORD TRAUMA

Prior to trauma, intraoperative ultrasound of the spinal canal in 31 normal dogs was performed through a hemilaminectomy in the left pedicle of L2. A ventral compressive model of spinal cord injury was performed as part of a clinical drug trial. Maximum ultrasonographic spinal cord diameter ranged from 4.9–7.2 mm (5.7 × 0.6). Significant positive correlation (p = 0.023, r = 0.49) was found between age and spinal cord diameter. The dura mater was a separate, well-defined, echogenic horizontal line in 28 (90%) dogs, dorsally, and in 29 (94%) dogs, ventrally. Cerebrospinal fluid was anechoic. Eighteen (58%) dogs had a well-defined anechoic dorsal subarachnoid space, whereas 22 (71%) had a well-defined ventral space. Pia mater was thin but strongly echogenic and covered spinal cord. Central canal was a double hyperechoic line in 17 (55%) dogs and a single-line in 14 (45%) dogs. A difference in the ultrasonographic appearance between gray and white matter was not seen. Epidural fat and connective tissue was a lobular echogenic material in the ventral epidural space. The periosteal-vertebral body interface was seen as a bright curvilinear echo with distal acoustic shadowing. Spinal cord parenchyma could be classified subjectively into four groups based upon ultrasonographic appearance. Spinal cord parenchyma had a uniform hypoechogenicity in 8 (27%) dogs (Group 1), subtle low level echoes in 7 (23%) dogs (Group 2), multiple clusters of defined echogenic foci in 12 (37%) dogs (Group 3), and multiple sharply-defined linear echoes in 4 (13%) dogs (Group 4). There was a significant relationship between pre-trauma ultrasonographic appearance of the spinal cord and histopathology 21 days after trauma. One (13%) dog in Group 1, 4 (57%) dogs in Group 2,10 (91%) dogs in Group 3, and 3 (75%) dogs in Group 4 had malacia on histological evaluation. Therefore, dogs with echogenic spinal cords or linear echoes within cord parenchyma were significantly more likely to develop malacia rather than Wallerian degeneration after induced spinal cord trauma (p = 0.002). Spinal cord echogenicity may indicate vascularity in a segment of spinal cord and might be prognostic following spinal cord trauma. No complications were found related to intraoperative ultrasound. Hematoma or fibrous tissue formation appeared to impede percutaneous ultrasound of the spinal cord in dogs re-evaluated forty-eight hours and one week after surgery.     

COMPARISON OF RADIOGRAPHIC SUBCHONDRAL BONE CHANGES WITH ARTHROSCOPIC FINDINGS IN THE EQUINE FEMOROPATELLAR AND FEMOROTIBIAL JOINTS: A RETROSPECTIVE STUDY OF 72 JOINTS (50 HORSES)

Radiographs of 72 femoropatellar and femorotibial joints from 50 horses were evaluated. Ninety four arthroscopically evaluated areas were graded according to a predetermined system. The radiographic grade was then compared to arthroscopic findings in the same location. Statistical analysis was performed to determine the association between the radiographic subchondral bone changes and arthroscopic findings. Radiographically normal areas in the femoropatellar joint were arthroscopically positive for cartilaginous changes in 40% of the femoropatellar joints. Areas of mild subchondral bone flattening (grade I) in the lateral trochlear ridge were arthroscopically positive for cartilage changes 78% of the time. Ninety six percent of moderate to severe subchondral bone changes (grades II-V) were arthroscopically positive for cartilage damage. This research demonstrates that (1) a significant number of radiographically normal joints will have cartilage changes, (2) areas of mild subchondral bone flattening have cartilage changes present in the majority of cases and (3) areas of moderate to severe subchondral bone changes have arthroscopically detectable cartilage changes present.     

THORACIC AND ABDOMINAL ORGAN UPTAKE OF 2-DEOXY-2-[18F]FLUORO-d-GLUCOSE (18FDG) WITH POSITRON EMISSION TOMOGRAPHY IN THE NORMAL DOG

Positron emission tomography (PET) has found widespread application for staging and monitoring neoplastic diseases in humans. PET is becoming more available in veterinary medicine, therefore biodistribution of 2-deoxy-2-[¹⁸F]fluoro- d -glucose (¹⁸FDG) in normal dogs is needed for lesion interpretation in disease states. A large field-of-view (FOV) PET scanner with a 70 cm bore diameter and a 53-cm FOV was used in this study to acquire dynamic ¹⁸FDG uptake data from parenchymal organs in seven normal dogs. A 2-h, dynamic list-mode acquisition was initiated simultaneously with intravenous ¹⁸FDG injection. Regions of interest (ROIs) were manually drawn over liver, spleen, left and right renal cortices, left ventricular free wall, and thymus. Standardized uptake values (SUVs) of these organs were calculated for 24 5-min frames over the 2-h acquisition. This SUV data from parenchymal organs of normal dogs compares favorably with those of normal humans and will be used in ongoing canine studies using PET to evaluate various diseases.