PET FISH RADIOGRAPHY: TECHNIQUE AND CASE HISTORY REPORTS

Radiography can be used to aid in the diagnosis and treatment of pet fish diseases. Handling, restraint and radiographic technique for the radiographic examination of pet fish is described. Quality diagnostic images can be obtained with standard radiographic equipment and radiographic techniques. Fishes with undifferentiated sarcoma, swim bladder herniation and scoliosis are three clinical examples that are described where radiography was used in the management of the patient. Conventional radiography appears to be best for evaluating skeletal and swim bladder diseases. Alternate imaging techniques such as computed tomography and magnetic resonance imaging may enhance the evaluation of coelomic soft tissue structures.     

Assessment of the quality of radiographs in 44 veterinary clinics in Great Britain

The quality of radiographic images, radiographic equipment and radiation safety were assessed objectively in 44 veterinary clinics in Great Britain, and a questionnaire was used to survey opinion on the general standard of radiography and aspects of the radiographic techniques used. Good or tolerable films were produced by 56 per cent of the clinics but there was a tendency to produce films that were too dark. Poor exposure factors were chosen in 49 per cent of the films. A significant number of films (27 per cent) were underdeveloped whereas only 11 per cent were overdeveloped. Many of the errors were due to operator error or inadequate technique, whereas, in the questionnaire, many clinics suggested that their problems were due mainly to faulty or inadequate equipment.     

Diagnostic imaging of the canine and feline ear.

Radiographic evaluation of the tympanic bulla is limited. Improper obliquity or angulation of the skull for radiographs or malpositioning of the tongue can result in an inadequate study [4]. Additionally, because of the complex anatomy of the canine and feline skull, with superimposition of multiple osseous structures, radiography can result in false-negative examinations or understimation of the disease present [2]. When compared with surgical findings of 19 clinical cases of presumptive middle ear disease, false-negative radiographic findings were found in 25% of the surgically confirmed cases of otitis media [4]. Therefore, radiographs are not considered to be a highly sensitive mode of diagnosing otitis media. Radiographs may be helpful in determining lysis associated with neoplasia; however, the extent of involvement is still underestimated. In a study comparing CT and radiographic evaluation of otitis media, CT was determined to be more sensitive but less specific than radiography [11]. CT is the preferred modality for the evaluation of the tympanic bulla at our institution. This opinion may be biased by the fact that most cases are presented for recurrent or chronic otitis. Although radiography is more accessible, the availability of CT in local referral settings is increasing as opposed to being limited to university settings. After the cost (i.e., anesthesia, radiographs) and amount of time necessary to make optimum radiographic studies are taken into account, a CT study may actually be faster and more informative. Given our preference for the CT examination, the cost of the examination has been adjusted to make it more appealing to the owner and clinician. For example, a bulla CT study is only 1.3 times the cost of a radiographic bulla study. In conclusion, imaging of the ear canal can provide important information about ear disease, including unilateral or bilateral ear disease, the degree of middle or inner ear involvement, peripheral versus central vestibular disease, an infectious or inflammatory versus neoplastic process, the chronicity of the disease process, involvement of adjacent structures, and postsurgical complications.     

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.     

Osteopenia and other radiographic signs in canine hyperadrenocorticism

The specificity of conventional radiography in assessing canine hyperadrenocorticism was evaluated by comparing the Incidence of related radiographic findings in 24 hyperadrenocorticoid, 15 diabetic and 20 hypothyroid dogs. Hyperadrenocorticoid dogs showed significantly more perihilar bronchial mineralisation than other groups. There was no significant variation between the disease groups with respect to obesity, hepatomegaly, contour of the caudoventral hepatic margin, peripheral bronchial mineralisation or osteopenia. Adrenal mineralisation and calcinosis cutis were rare findings observed only in hyperadrenocorticoid dogs. The effect of obesity on the radiographic appearance of bone was studied using a dissected lumbar spine from a canine cadaver. An osteopenic effect could be demonstrated by superimposition of a 10 cm-thick fat block. The low specificity of almost all common signs in canine hyperadrenocorticism and the low incidence of characteristic findings demonstrate the limited potential of radiography in assessing this condition. Radiographic assessment of bone density is unreliable because of artefactual osteopenic effects of high kVp settings necessary in obese dogs.     

Evaluation of the radiographic liver length/11th thoracic vertebral length ratio as a method for quantifying liver size in cats

Abdominal radiography is a standard diagnostic test for cats with suspected liver disease, however, absolute measurements of radiographic liver size can be affected by other factors such as positioning, radiographic technique, and obesity. This prospective and retrospective, analytical, cross‐sectional study evaluated the liver length/11th thoracic vertebral length (LL/T11) ratio as a method for minimizing these outside effects. In a prospectively recruited sample of 25 clinically healthy cats, measurements of radiographic LL/T11 ratio were compared with CT measurements of liver volume. Effects of radiographic technical factors (body posture, recumbency state, and beam center to LL/T11 ratio) and observer were also tested. In a retrospectively recruited sample of 324 cats with no evidence of liver disease, radiographic measurements of the LL/T11 ratio were performed using right lateral radiographs and compared among signalment groups (age, sex, body weight, and body condition score). There was a strong significant correlation between the LL/T11 ratio and CT liver volume (P < .001), and this ratio was not affected by radiographic technical factors. The reference value of the LL/T11 ratio was 4.22 ± 0.54 and the LL/T11 ratio did not differ among signalment groups. Findings supported the use of the LL/T11 ratio as a novel quantitative index of radiographic liver size in cats. Future studies in clinically affected cats are needed to further validate this method.     

COMPARISON OF RADIOGRAPHY AND COMPUTED TOMOGRAPHY FOR THE DIAGNOSIS OF CANINE NASAL ASPERGILLOSIS

To compare the radiographic and computed tomographic (CT) findings and to evaluate the sensitivity of radiography and CT for diagnosis of nasal aspergillosis in dogs, the radiographic and CT studies of 48 dogs with chronic nasal disease were reviewed separately. The radiographic and CT findings were recorded, and a diagnosis was made. The results obtained in the dogs with nasal aspergillosis (n = 25) were used. Based on definite aspergillosis as diagnosis, CT had a sensitivity of 88% and radiography of 72%. Considering definite and probable aspergillosis as equivalent, CT had a sensitivity of 92% and radiography of 84%. The sensitivity was higher in dogs with lesions affecting the entire nasal cavity and frontal sinus on at least one side (n = 20) with a sensitivity of 100% for CT and 90-95% for radiography than in dogs with lesions restricted to the nasal cavities (n = 5) where CT had a sensitivity of 60-80% and radiography of 0-40%. CT was superior to radiography for evaluation of the nasal cavities (mucosal thickening along the nasal bones, surrounding bone hyperostosis/lysis), frontal sinuses (mucosal thickening along the frontal bone, fluid/soft tissue, frontal bone hyperostosis/lysis), and differentiation between a cavitated-like or a mass-like process. This study suggests that CT is more sensitive than radiography for diagnosis of nasal aspergillosis in the dog because of a better demonstration of some changes suggestive of nasal aspergillosis. A diagnosis of a nasal aspergillosis restricted to the nasal cavities or associated with an FB is challenging, even with the use of CT.     

The use of advanced vs. conventional imaging modalities for the diagnosis of subchondral bone injuries

Damage to the subchondral bone has been associated with a number of orthopaedic diseases. Diagnostic imaging is, therefore, critical in identifying disease and damage of the subchondral bone, not only for the diagnosis of joint and subchondral bone disease causing lameness, but also for identifying early/pre-symptomatic damage. The aims of this Critically Appraised Topic (CAT) were to assess the published evidence for the use of advanced imaging techniques (magnetic resonance imaging [MRI] and computed tomography [CT]) in the diagnosis of subchondral bone disease in the distal limb joints (metacarpo/metatarsophalangeal and interphalangeal joints) of the adult horse, and to compare the diagnostic value of these techniques with radiography. In the studies reviewed in this CAT, advanced imaging modalities (MRI and CT) were superior to routine radiography for the diagnosis of subchondral bone injury of the distal limb joints. In a small percentage of horses, post-MRI reevaluation of the initial radiographs or acquiring further lesion-orientated radiographs allowed the identification of the subchondral bone injury. Extended radiographic examinations, including non-standard views, might increase the sensitivity of radiography to detect subchondral bone injuries, however, currently CT and MRI may be considered the “gold standard” imaging modalities. More studies comparing the identification of subchondral bone lesions on imaging and by histopathological/gross examination would be useful to assess more precisely the sensitivity and specificity of the different modalities.     

LOSS OF UROCYSTOLITH ARCHITECTURAL CLARITY DURING IN VIVO RADIOGRAPHIC SIMULATION VERSUS IN VITRO VISUALIZATION

Urocystoliths of 9 mineral types from 434 canine patients submitted to the University of Minnesota Urolith Bank were imaged in a urinary bladder phantom. Imaging techniques simulated were survey radiography and double contrast cystography. Morphologic characteristics visually observed in vitro or by interpretation of high-resolution specimen radiographs were compared to those seen using the simulated in vivo imaging techniques. Shape characteristics that were accurately detected > or = 25% of the time on simulated survey or double contrast radiography were faceted, irregular, jackstone, ovoid, and round. Surface characteristics that were accurately detected > or = 25% of the time on simulated survey or double contrast radiography were rough, smooth, and smooth with blunt tips. Internal architecture characteristics that were accurately detected > or = 25% of the time on simulated survey or double contrast radiography were lucent center, random-nonuniform, and uniform. Shapes such as bosselated, faceted-ovoid, and rosette; surfaces such as botryoidal, and knife-edged; and internal architecture characteristics such as dense center, dense shell, laminated, and fissures were of almost no value either due to poor detectability or poor accuracy of recognition. Based on optimized simulated survey and double contrast radiographic procedures, it appears that a number of shape, surface, and internal architecture characteristics may be of limited or no value in discriminating among urocystolith mineral types under clinical circumstances. Shapes and surfaces were more accurately characterized by the simulated double contrast technique, but for internal architecture, the simulated survey radiographic technique seemed slightly superior overall.     

A bronchial foreign body in a chimpanzee

The paper reports a bronchial foreign body with unusual clinical signs in a chimpanzee. The illness lasted some months and was manifested by malaise, reduced appetite, loss in body weight and a spontaneous abortion. Routine auscultation and radiography could not be performed initially because of the size and disposition of the animal but chest radiography was later carried out under general anaesthesia and revealed a foreign body which was extracted through a bronchoscope from the right main bronchus. Methods of anaesthesia suitable for bronchoscopy are discussed but the Venturi technique using a jet air injector seems to be the method of choice.     

A follow-up study of neurologic and radiographic findings in working German Shepherd Dogs with and without degenerative lumbosacral stenosis

OBJECTIVE: To identify radiographic abnormalities associated with degenerative lumbosacral stenosis (DLSS) in German Shepherd Dogs (GSDs) and determine whether specific radiographic abnormalities could be used to identify dogs at risk of developing DLSS. DESIGN: Cohort study. ANIMALS: 33 GSDs working as police dogs. PROCEDURES: Results of physical, neurologic, and orthopedic examinations were used to identify dogs with DLSS. Survey radiography of the lumbosacral junction was performed, and radiographs were compared with radiographs obtained 3 years earlier. RESULTS: DLSS was diagnosed in 15 of the 33 (45%) dogs. Thirteen of the 15 dogs with DLSS and 14 of the 18 dogs without DLSS had radiographic abnormalities of the lumbosacral junction. Twenty-two (67%) dogs were able to perform unrestricted duties, including 3 dogs with suspected DLSS. Six (18%) dogs had been excluded from active duty during the period of surveillance because of DLSS. Significant progression in specific clinical and radiographic signs was detected, but multiple logistic regression analysis did not identify any radiographic signs that could be used to predict the development of DLSS. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that survey radiography cannot be used to predict development of DLSS in working GSDs.     

The Role of Bronchoscopy in Foreign Body Removal in Dogs and Cats: 37 Cases (2000–2008)

Background: Foreign body aspiration is a differential diagnosis for acute or chronic cough that requires medical or surgical management in animals. Hypothesis: Success of bronchoscopy in airway foreign body removal is dependent on the size of the animal, duration of clinical signs, and location of the foreign body. Animals: Thirty‐two dogs and 5 cats with airway foreign bodies identified at the UC Davis Veterinary Medical Teaching Hospital. Methods: Retrospective case study evaluating the role of duration of clinical signs and body size in successful bronchoscopic removal of foreign bodies. In addition, radiographic localization of disease was compared with bronchoscopic identification. Bronchoalveolar lavage (BAL) culture and cytologic findings are reported. Results: Bronchoscopy was successful for removal of airway foreign bodies in 76% of animals (24/28 dogs and 2/5 cats), and in dogs was independent of duration of clinical signs or body size. One‐third of thoracic radiographs lacked distinctive features of an airway foreign body, and therefore radiography was unable to predict the affected site. BAL fluid at the site of the foreign body contained more neutrophils and more often had intracellular bacteria than lavage fluid from a separate site. Conclusions and Clinical Importance: Bronchoscopy was successful in removing airway foreign bodies regardless of animal size or long duration of clinical signs. Results of this study confirm the utility of bronchoscopy with lavage in management of suspected foreign bodies, even in the absence of localizing radiographic findings.     

RADIOGRAPHY OF THE BOVINE CRANIOVENTRAL ABDOMEN

This study consists of a review of 115 consecutively accrued bovine cranial abdomial radiographs. The sensitivity and specificity of radiography in detecting traumatic reticuloperitonitis or pericarditis was 83% and 90%, respectively. Increased reticular size was associated with vagal indigestion. Increased reticulo-diaphragmatic separation did not correlate with a specific disease process, 25/35 (71%) cattle presented for radiographic examination with a 1 cm or longer metallic reticular foreign body unattached to a magnet had traumatic reticuloperitonitis. Standing lateral abdominal radiographs were determined to be a valuable tool in the diagnosis of cranial abdominal disorders in the bovine.     

Use of radiographs and computed tomography for measurement of kidney size in healthy chinchillas (Chinchilla lanigera)

BackgroundChinchillas, being small mammals, are subject to many of the urinary disorders that affect other companion animals. In cats and dogs, relationships between renal length and the presence of renal pathology have been well documented through the use of diagnostic imaging. Radiography and computed tomography (CT) are two commonly utilized diagnostic imaging modalities for assessing renal pathology. Presently, there are no published data on chinchilla kidney size and appearance using radiography or CT. This study aimed to determine healthy adult chinchilla renal size and correlate renal size to L2 body length and aortic diameter by use of radiography and CT.MethodsTwenty-eight healthy adult chinchillas with no clinical evidence of renal disease were placed under sedation for acquisition of radiographs and CT imaging. Both kidneys were measured on the radiographic views (right lateral, left lateral and ventrodorsal), when identifiable. Renal length, L2 body length and abdominal aortic diameter were measured on CT multiplanar reformatted images in specified planes and windows.ResultsIn 25% (7/28) of chinchillas, the renal length of either kidney could not be obtained on any of the three radiographic views due to superimposition of fluid and ingesta within the alimentary tract. Both the right and left kidney were identified on CT images in 100% of chinchillas (28/28). The left renal and right renal 95% confidence intervals from the dorsal plane CT images were 2.26 – 2.33 cm and 2.31 – 2.39 cm, respectively. No correlation was found between kidney length, L2 body length and diameter of the abdominal aorta on CT images.ConclusionsBased on dorsal plane CT imaging, normal chinchilla renal length is proposed to be between 2.25–2.4 cm.Clinical RelevanceRadiographic evaluation of chinchilla renal length is greatly limited due to their large fluid- and ingesta-filled colon and cecum, as is typical of animals that are hindgut fermenters. Through establishment of a normal CT reference interval for renal length and the ever-increasing clinical utility of CT, clinicians can better evaluate chinchilla renal length and identify alterations that may indicate pathologic processes.     

Correlation between radiographie and arthroscopic findings in the equine carpus

The radiographic and arthroscopic findings in 150 carpal joints in 114 lame horses were compared. Chip, slab, or sagittal fractures were identified in 130 (87%) joints. In 101 (78%) of these there was good agreement between radiographic and arthroscopic findings on the number and position of fractures. In 23 (18%) joints, chip fractures additional to those seen radiographically were found arthroscopically. In one joint a large chip fracture from the craniolateral aspect of the distal radius was identified only by arthroscopy, while in 6 joints fractures were identified only by radiography. Observed causes of lameness, other than intra-articular fractures, included degenerative joint disease, synovitis, ruptured intra-carpal ligaments, and haemarthrosis. Correlation between the radiographic and arthroscopic assessment of degenerative joint disease was poor. It was concluded that both radiography and arthroscopy should be used to obtain the most accurate assessment of the equine carpus.     

Comparison of radiography and ultrasonography for the diagnosis of osteochondritis dissecans in the equine femoropatellar joint

Reasons for performing study: Osteochondritis dissecans (OCD) lesions of the femoropatellar (FP) joint are diagnosed routinely by radiography, but lesions located in the trochlear groove or without accompanying subchondral bone changes can be difficult to visualise. Ultrasonography allows evaluation of articular cartilage and subchondral bone in the FP joint. Objectives: To document the radiographic and ultrasonographic appearance of OCD lesions in the equine FP joint, grade ultrasonographic lesions and compare their accuracy in the diagnosis of these lesions. Methods: The medical records of all horses diagnosed with FP OCD between 1995 and 2006 were assessed. Inclusion criteria included availability of both radiographic and ultrasonographic images. Lesion characteristics were evaluated in each trochlear ridge and trochlear groove. For assessment of the accuracy (sensitivity and specificity) of both imaging techniques in the diagnosis of OCD, only cases with an arthroscopic or necropsy examination were studied. Results: Twenty‐one horses were included. OCD lesions were diagnosed by radiography (30/32 joints) and ultrasound (32/32 joints). The lateral trochlear ridge (LTR, 91%) and the medial trochlear ridge (MTR, 17%) were involved on radiography. The localisation on ultrasound examination was similar (97% LTR, 25% MTR). All but one lesion seen on radiography were also detected with ultrasound; 2 LTR and 3 MTR lesions, not seen on radiography were diagnosed by ultrasound and confirmed at arthroscopy or necropsy. The specificity was 100% regardless of the site and imaging procedure except for the distal third of the MTR (94% for ultrasound). The sensitivity varied, depending on lesion site. Conclusion: Ultrasonography is a valuable diagnostic tool to diagnose OCD lesions in the FP joint and more sensitive than radiography for lesions affecting the MTR of the distal femur. Clinical relevance: Ultrasound should be considered as a useful adjunct to radiography for diagnosing equine FP OCD, especially in cases of high clinical suspicion but equivocal radiographic findings. Images can be generated immediately when digital radiography is not available, permitting an immediate on‐site diagnosis.     

Comparison between radiography and computed tomography for diagnosis of equine skull fractures

The equine head is a complex structure prone to traumatic injuries. To determine the value and limitations of radiography and (CT) for the diagnosis of skull fracture, the differences between the two modalities were described. Two observers retrospectively reviewed the radiographic and CT images of 18 horses with a skull fracture. To allow direct comparison between the two modalities, a simplified fracture classification system was used. In 3/18 cases the evaluation of the radiographic examination concluded no injuries visible. In 2/15 cases soft tissue involvement was not detected and in 7/15 cases the extension of the fracture was underestimated with radiography. Radiography classified 4/10 multiple fractures incorrectly as single fracture and 5/15 comminuted fractures on CT were diagnosed as simple fracture with radiography. The number of fragments was underestimated with radiography in 14/15 cases. In conclusion, radiography is able to diagnose a skull fracture in most cases. Skull fractures however are not similarly classified after radiographic and CT evaluation, which causes a difference in interpretation and perception of the fractures. Therefore, CT should be the modality of choice for surgical planning and prognosis.     

Assessment of the accuracy of thoracic radiography in the diagnosis of canine chronic bronchitis

Thoracic radiographs from 23 dogs with chronic bronchitis were mixed with those taken from 11 dogs (matched by age and bodyweight) without respiratory disease and interpreted twice by two blinded, independent examiners in an attempt to determine the accuracy of radiography for the diagnosis of chronic bronchitis. The only radiographic signs found more often in dogs with chronic bronchitis were thickening of the bronchial walls and increased numbers of visible bronchial walls (P<0·01). Other signs, including bronchial calcification and interstitial pattern, occurred with similar frequency in both groups of dogs. The examiners were consistent in their interpretations (kappa >0·64). The accuracy of radiographic diagnosis of chronic bronchitis is limited principally by insensitivity for bronchial lesions.     

Effect of expiratory phase for radiographic detection of left heart enlargement in dogs with mitral regurgitation

Radiography is a standard diagnostic test for characterizing left heart enlargement in dogs however limited information is available on the effects of respiratory phases. This prospective and retrospective method comparison study investigated the respiratory effect on the size and shape of the left heart in dogs to determine the usefulness of expiratory radiographs to detect enlargements in the left atrium (LA) and left ventricle (LV). Thoracic radiographs taken at full inspiration and expiration were evaluated in 20 normal beagles and 100 dogs diagnosed with mitral regurgitation (MR). Vertebral heart score (VHS), vertebral left atrial size, elevation of the carina, and dorsal bulging of LA on lateral view and lateral bulging of the left auricular appendage and LV on ventrodorsal view were assessed. In normal dogs, there were no significant differences in the evaluative factors between inspiration and expiration. In dogs with MR, VHS did not change according to respiration. However, bulging of the LA, left auricular appendage, and LV had sharp margin during expiration compared with inspiration. The expiratory radiographic finding of LA bulging had a higher correlation with the LA to aorta ratio compared with LA bulging in the inspiratory radiography. Using a LA to aorta echocardiographic ratio greater than 1.5 as the gold standard, the radiographic sensitivity for LA enlargement was higher during expiration than inspiration. These findings of our study indicated that expiratory radiography can be helpful to support the detection of left heart enlargement, although it can overestimate LA enlargement in dogs with MR.