Whole-body Radiography Research Articles

Comparisons of longitudinal radiographic measures of keel bones, tibiotarsal bones, and pelvic bones versus post-mortem measures of keel bone damage in Bovans Brown laying hens housed in an aviary system.

Keel bone damage, include deviations and fractures, is common in both white and brown laying hens, regardless of the housing system. Radiography for assessing birds' keel bones is was proposed by previous studies. However, radiographs show only 2 out of 3 dimensions of the dissected keel bones. The current study aimed to (1) investigate the association of radiographic optical density (keel and tibiotarsal) and geometry (keel) with dissected keel bone pathology. Previous studies suggested that keel bone fractures may result from internal pressure exerted by pelvic cavity contents. The current study also aimed to (2) investigate the potential associations between pelvic dimensions and measures of keel bone damage. A sample of 200 laying hens on a commercial farm were radiographed at 16, 29, 42, 55, and 68 weeks, and culled at the end of the laying period (week 74). The birds were examined post-mortem for pelvic dimensions and underwent whole-body radiography, followed by keel and tibiotarsal bone dissection and radiography, and keel bone scoring. The radiographs were used to estimate radiographic optical density (keel and tibiotarsal bone) and keel bone geometry (ratio of keel bone length to mid-depth). The method for on-farm radiography of laying hens, including live bird restraint, positioning for live keel imaging, and post-imaging measurements, was developed, tested, and found to be reproducible. The radiographs (1,116 images of 168 birds) and the respective measurements and post-mortem scores of keel bones are also provided for further development of radiographic metrics relevant to keel bone damage. Some longitudinal radiographic measurements of keel geometry (ratio of length to mid-depth) and optical density (keel and tibiotarsal) showed associations with the damage (deviations/fractures) observed on the dissected keel bones. The associations of keel damage were clearer with the radiographic keel geometry than with keel and tibiotarsal optical density, also clearer for the keel deviations than for keel fractures. The higher radiography ratio of keel length to mid-depth at weeks 42, 55 and 68 of age, the larger deviations size observed on the dissected keels at age of 74 weeks. The higher the tibiotarsal radiographic optical density at week 55 of age, the lower deviations size and fractures count observed on the dissected keels at age of 74 weeks. Pelvic dimensions showed a positive correlation with body weight, but a larger pelvic cavity was associated with increased keel bone damage. These findings lay the foundations for future use of on-farm radiography in identifying appropriate phenotypes for genetic selection for keel bone health.

Computed tomography with adjusted dose for body mass index may be superior to whole-body radiography especially in elderly patients with multiple myeloma.

Whole-body skeletal radiography has traditionally been used in the management of multiple myeloma for defining treatment strategies. For several reasons, radiography has been replaced by computed tomography (CT) covering the same regions. To evaluate the body mass index (BMI) adjusted effective radiation dose from two different methods of whole-body radiologic imaging for multiple myeloma assessment. The current investigation analyses the dose to patients resulting from the two methods, conventional radiography supplemented with tomosynthesis (203 examinations) and CT (264 examinations). All patients subject to myeloma staging for 4.5 years were included in the study. Exposure parameters were collected from the PACS and conversion factors were calculated using the software packages PCXMC and VirtualDose enabling the calculation of the effective dose to each patient based on BMI. The Mann-Whitney U test was used for comparisons between groups. Patients were subject to a median effective dose of 2.5 mSv for conventional radiography and 5.1 mSv for CT, a statistically significant difference. The effective dose for whole-body CT in assessing multiple myeloma is twice as high as for whole-body skeletal survey with modern digital radiography, but at a low level and considerably less than the levels quoted in the earlier studies of ∼30 mSv when the technique was first explored.

Magnetic resonance imaging measurements of organs within the coelomic cavity of red-eared sliders (Trachemys scripta elegans), yellow-bellied sliders (Trachemys scripta scripta), Coastal plain cooters (Pseudemys concinna floridana), and hieroglyphic river cooters (Pseudemys concinna hieroglyphica)

OBJECTIVE To determine anatomic reference points for 4 turtle species and to evaluate data on relative anatomic dimensions, signal intensities (SIs), and position of selected organs within the coelomic cavity by use of MRI. ANIMALS 3 turtle cadavers (1 red-eared slider [Trachemys scripta elegans], 1 yellow-bellied slider [Trachemys scripta scripta], and 1 Coastal plain cooter [Pseudemys concinna floridana]) and 63 live adult turtles (30 red-eared sliders, 20 yellow-bellied sliders, 5 Coastal plain cooters, and 8 hieroglyphic river cooters [Pseudemys concinna hieroglyphica]). PROCEDURES MRI and necropsy were performed on the 3 turtle cadavers. Physical examination, hematologic evaluation, and whole-body radiography were performed on the 63 live turtles. Turtles were sedated, and MRI in transverse, sagittal, and dorsal planes was used to measure organ dimensions, position within the coelomic cavity, and SIs. Body positioning after sedation was standardized with the head, neck, limbs, and tail positioned in maximum extension. RESULTS Measurements of the heart, liver, gallbladder, and kidneys in sagittal, transverse, and dorsal planes; relative position of those organs within the coelom; and SIs of the kidneys and liver were obtained with MRI and provided anatomic data for these 4 turtle species. CONCLUSIONS AND CLINICAL RELEVANCE MRI was a valuable tool for determining the position, dimensions, and SIs of selected organs. Measurement of organs in freshwater chelonians was achievable with MRI. Further studies are needed to establish reference values for anatomic structures in turtles. Results reported here may serve as guidelines and aid in clinical interpretation of MRI images for these 4 species.

Clinical management of an ectopic egg in a Timneh African grey parrot (Psittacus erithacus timneh)

A 13-year-old female Timneh African grey parrot (Psittacus erithacus timneh) was evaluated because of the presence of a bald patch of skin caudal to the sternum and increased territorial and nesting behavior of 2 weeks' duration. Whole-body radiography revealed a mineralized egg of normal size and shape. However, no oviposition occurred, and the bird had no signs consistent with dystocia. After 7 days, repeated radiography revealed that the egg had rotated by approximately 180° along its short axis, leading to a diagnosis of ectopic egg retention, which was supported by the results of ultrasonography. Surgical removal of the ectopic egg was performed by means of a ventral midline approach 14 days after administration of leuprolide acetate (800 μg/kg [364 μg/lb], IM). No intracoelomic abnormalities, such as coelomitis or oviductal disease, were diagnosed, and the bird recovered without complications. Physical examination and whole-body radiography at 8 months and a follow-up phone call with the owner at 16 months after surgical treatment revealed no evidence of ectopic egg recurrence or reproductive behavior. Clinical management of ectopic egg retention differs considerably from treatment of intraoviductal egg binding. Therefore, careful evaluation of avian patients with radiographic evidence of egg binding should be performed to avoid possible iatrogenic deterioration of the patient's condition, secondary to inappropriate treatment attempts such as hormonal induction of oviposition or attempts to remove the retained egg via the cloaca. Repeated radiography and ultrasonography and close monitoring of the patient's general condition as well as the lack of clinical signs consistent with dystocia will facilitate the diagnosis of ectopic egg retention.

Cystic endometrial hyperplasia and chronic endometritis in a chinchilla

A 4-year-old nulliparous sexually intact female chinchilla (Chinchilla lanigera) was evaluated because of a 2-month history of blood being sporadically observed in its cage. Results of physical examination of the chinchilla were unremarkable except for the presence of blood-stained fur around the perineum. There were no external lesions to account for the bleeding. Findings on urinalysis, bacteriologic culture of urine, and whole-body radiography were unremarkable. The chinchilla's littermate had been evaluated because of similar clinical signs 2 years earlier, and these signs resolved following ovariohysterectomy. Ovariohysterectomy was performed, and gross changes were not observed in the reproductive tract. However, microscopic examination revealed multifocal cystic dilation of the endometrial glands, foci of microhemorrhage, and chronic suppurative inflammation consistent with a final diagnosis of cystic endometrial hyperplasia and chronic endometritis. Clinical signs did not recur. Cystic endometrial hyperplasia has been documented in a variety of animals, but to the authors' knowledge, this was the first reported case in a chinchilla. Cystic endometrial hyperplasia and chronic endometritis should be considered as a differential diagnosis in an adult sexually intact female chinchilla with a history of suspected hemorrhagic vaginal discharge, suspected hematuria, or hemorrhage from an unknown source.

Diagnosis of presumed acute ischemic stroke and associated seizure management in a Congo African grey parrot

A 14-year-old Congo African grey parrot (Psittacus erithacus erithacus) was evaluated for an acute onset of falling off of its perch and tonic-clonic movements. Clinical signs were consistent with partial seizures. Findings on whole-body radiography, CBC, and plasma biochemical analysis were unremarkable. Plasma magnesium, ionized calcium, and bile acids concentrations were within reference limits. A magnetic resonance imaging (MRI) examination of the head revealed the presence of a focal hyperintensity at the central to left side of the optic chiasm and a hyperintense focus in the right side of the midbrain area in T2-weighted and FLAIR pulse sequence images. These findings were most consistent with an acute ischemic stroke with 2 brain infarcts. Seizures were initially managed with potassium bromide and phenobarbital administration. On the basis of poor results and difficulties to reach therapeutic blood concentrations, the treatment plan was changed to levetiracetam and zonisamide administration. Blood concentrations were monitored for both drugs, and the frequency of seizures substantially decreased thereafter. A follow-up MRI examination 2 months later revealed resolution of the hyperintense signals. During the 20-month follow-up period, subsequent clusters of seizures were managed by adjusting levetiracetam and zonisamide dosages and adding clonazepam and gabapentin administration to the treatment plan. Regression of intraparenchymal hyperintense lesions and improvement of clinical signs made a diagnosis of acute ischemic stroke most likely. Findings for this Congo African grey parrot indicated that an antemortem diagnosis of an acute ischemic stroke followed by long-term seizure management may be possible in affected psittacines.

Forelimb amputation for treatment of a peripheral nerve sheath tumor in an African pygmy hedgehog

A 6-year-old female African pygmy hedgehog was evaluated because of a mass of unknown duration on the lateral aspect of the right shoulder region. A fine-needle aspirate of the mass was collected for cytologic examination; findings were consistent with a spindle cell tumor. A CBC, plasma biochemical analyses, and whole-body radiography revealed no other abnormalities. An initial surgery performed in an attempt to remove the mass with preservation of the limb failed in that tumor-free surgical margins were not obtained. Histologically, the mass was identified as a peripheral nerve sheath tumor (neurofibrosarcoma). A second surgery to amputate the forelimb was successful. After 1 year, there had been no further development of peripheral nerve sheath tumor at this or other sites. In African pygmy hedgehogs, potential differential diagnoses for a subcutaneous mass should include peripheral nerve sheath tumor. If necessary, forelimb amputation can be performed successfully in this species with procedures modified from those used in dogs. Information gathered during the treatment and recovery of the hedgehog of this report may assist practicing veterinarians in counseling owners of hedgehogs that are undergoing forelimb amputation with regard to the course of recovery that may be expected following this procedure.

The G-Protein-Coupled Receptor GPR103 Regulates Bone Formation

GPR103 is a G-protein-coupled receptor with reported expression in brain, heart, kidney, adrenal gland, retina, and testis. It encodes a 455-amino-acid protein homologous to neuropeptide FF2, neuropeptide Y2, and galanin GalR1 receptors. Its natural ligand was recently identified as 26RFa, a novel human RF-amide-related peptide with orexigenic activity. To identify the function of GPR103, we generated GPR103-deficient mice. Homozygous mutant mice were viable and fertile. Their body weight was undistinguishable from that of their wild-type littermates. Histological analysis revealed that GPR103-/- mice exhibited a thinned osteochondral growth plate, a thickening of trabecular branches, and a reduction in osteoclast number, suggestive of an early arrest of osteochondral bone formation. Microcomputed tomography confirmed the reduction in trabecular bone and connective tissue densities in GPR103 knockout animals. Whole-body radiography followed by morphometric analysis revealed a kyphosis in mutant animals. Reverse transcription-PCR analysis showed that GPR103 was expressed in human skull, mouse spine, and several osteoblast cell lines. Dexamethasone, a known inhibitor of osteoblast growth and inducer of osteoblast differentiation, inhibited GPR103 expression in human osteoblast primary cultures. Altogether, these results suggest that osteopenia in GPR103-/- mice may be mediated directly by the loss of GPR103 expression in bone.

Hand development in trisomy 21

The purpose of the present study was to evaluate hand size and maturity in fetuses with trisomy 21 (Down syndrome). Twenty-five fetuses, crown-rump length (CRL) 55-222 mm, foot length (FL) 8-42 mm, were included in the study. After whole-body radiography (Hewlett Packard Faxitron), special radiographs of the hand and foot were taken. Hand length was measured as the length of the third finger from the distal tip of the distal phalanx to the proximal tip of the metacarpal bone, the digital-metacarpal length (DML). The lengths of the proximal phalangeal bone (PPL) and the metacarpal bone (MCL) of the third finger were also measured. The DML, PPL, and MCL values of each fetus were related to CRL and FL. The individual hand bones were evaluated with regard to time of appearance on radiographs, sequence in comparison with the normal sequence of appearance, and morphology. The hand length is normal during the first half of the fetal period, whereas the length of individual bones in the third finger is reduced. The normal sequence of ossification, with the middle phalanx of the fifth finger last to ossify, also occurred in Down syndrome; however, this bone appeared later in Down syndrome. In four of the fetuses it did not appear.

Hand development in trisomy 21

The purpose of the present study was to evaluate hand size and maturity in fetuses with trisomy 21 (Down syndrome). Twenty-five fetuses, crown-rump length (CRL) 55–222 mm, foot length (FL) 8–42 mm, were included in the study. After whole-body radiography (Hewlett Packard Faxitron), special radiographs of the hand and foot were taken. Hand length was measured as the length of the third finger from the distal tip of the distal phalanx to the proximal tip of the metacarpal bone, the digital-metacarpal length (DML). The lengths of the proximal phalangeal bone (PPL) and the metacarpal bone (MCL) of the third finger were also measured. The DML, PPL, and MCL values of each fetus were related to CRL and FL. The individual hand bones were evaluated with regard to time of appearance on radiographs, sequence in comparison with the normal sequence of appearance, and morphology. The hand length is normal during the first half of the fetal period, whereas the length of individual bones in the third finger is reduced. The normal sequence of ossification, with the middle phalanx of the fifth finger last to ossify, also occurred in Down syndrome; however, this bone appeared later in Down syndrome. In four of the fetuses it did not appear (CRLs: 125, 158, 172, and 174 mm). Am. J. Med. Genet. 79:337–342, 1998. © 1998 Wiley-Liss, Inc.