Self-Efficacy and Student Satisfaction in a Clinical-Year Diagnostic Imaging Course Using an Online Instruction Format.

Accurate interpretation of radiographic images is critical to diagnosing clinical patients. Remote instruction in radiology has become more common at veterinary colleges as academic institutions struggle to fill open veterinary radiologist positions and as a result of the COVID-19 pandemic. This study sought to gather the feedback of fourth-year veterinary students via pre- and post-study surveys (n = 45) and focus groups (n = 7) about a newly implemented 2-week long radiology rotation. Ninety-eight percent of students reported having taken an online course before, and on both pre- and post-study surveys, students commonly reported feeling interested, determined, and attentive. On average, students reported that they were neither more nor less engaged than they would have been in an in-person course and that they understood the material neither better nor worse than they would have in an in-person course. Students reported that the key to their success was primarily hard work; secondarily, instructor availability and student ability were important. Students did not rate luck as having much influence on their success. Although diagnostic imaging can be a challenging subject to master, students effectively learned this subject through online instruction. They provided feedback for the course's continued improvement; their comments centered around improved interactivity, including providing automated quiz questions' answers and increased instructor availability. Data collected in this study will help to guide further development of the radiology course.

Comparison of three imaging modalities used to evaluate bone healing after tibial tuberosity advancement in cranial cruciate ligament-deficient dogs and comparison of the effect of a gelatinous matrix and a demineralized bone matrix mix on bone healing - a pilot study.

BACKGROUND: Bone healing and assessment of the state of bone bridging is an important part of clinical orthopedics, whether for fracture healing or for follow up of osteotomy procedures. Tibial tuberosity advancement (TTA) is designed to restore stability in cruciate deficient stifle joints by advancing the tuberosity while creating an osteotomy gap. The current study aims to: 1) compare three different imaging modalities to assess bone healing: ultrasound, radiographs and computed tomography (CT) and, to 2) compare the effect of a gelatinous matrix (GM) versus a demineralized bone matrix mix (DBM mix) on bone healing and bridging of this osteotomy gap in 10 otherwise healthy client-owned dogs with cranial cruciate ligament insufficiency. Osseous union of the osteotomy gap was evaluated with ultrasound, radiographs and CT at one, two, and 3 months postoperatively. Dogs were randomly selected to receive GM or DBM mix to fill the osteotomy gap created during the TTA procedure. Bone healing was assessed subjectively on all modalities as well as scored on radiographs and measured using Hounsfield units (HUs) on CT. Time to heal based on ultrasound, radiographs and CT were statistically compared between groups with significance set at p < 0.05. RESULTS: All osteotomy gaps were bridged with bone within 3 months for all modalities. Bridging bone was diagnosed in 5.6 weeks, 10.4 weeks and 9.6 weeks based on ultrasound, radiographs, and CT, respectively, in dogs treated with DBM mix. In dogs treated with GM osseous union was diagnosed in a mean of 4.0 weeks, 9.6 weeks and 7.2 weeks based on ultrasound, radiographs and CT. Ultrasound diagnosed osseous union significantly faster than both CT and radiographs (p < 0.001). The dimensions of the newly formed bone differed between treatment groups with the central portion of the bone only providing a small bridge in GM cases. Although bridging of the osteotomy gap occurred earlier in the group that received GM, no significant statistical difference was found between the two groups. CONCLUSIONS: Radiographs overestimate the time needed for osseous union of the osteotomy gap. All osteotomy sites healed radiographically within 3 months.

Diagnostic usefulness of laparoscopy versus exploratory laparotomy for dogs with suspected gastrointestinal obstruction.

OBJECTIVE To evaluate the feasibility of laparoscopy versus exploratory laparotomy for the diagnosis of specific lesions in dogs with suspected gastrointestinal obstruction. DESIGN Controlled trial. ANIMALS 16 client-owned dogs with physical and radiographic findings consistent with gastrointestinal obstruction. PROCEDURES Single-incision laparoscopy with intracorporeal and extracorporeal examination of the gastrointestinal tract was performed by 1 surgeon. Immediately afterward, exploratory laparotomy was performed by a second surgeon. Accessibility and gross appearance of organs, surgical diagnoses, incision lengths, procedure duration, and complications were compared between diagnostic techniques. RESULTS Mean (95% confidence interval) incision length was 4.9 cm (3.9 to 5.9 cm) for laparoscopy and 16.4 cm (14.0 to 18.7 cm) for exploratory laparotomy. Mean (95% confidence interval) procedure duration was 36.8 minutes (31.6 to 41.2 minutes) and 12.8 minutes (11.4 to 14.3 minutes), respectively. Diagnoses of the cause of obstruction were the same with both methods. In 13 dogs, the laparoscopic examination was successfully completed, and in the other 3, it was incomplete. In 4 dogs in which laparoscopy was successful, conversion to exploratory laparotomy or considerable extension of the laparoscopic incision would have been required to allow subsequent surgical treatment of identified lesions. No dogs developed major complications, and minor complication rates were similar between procedures. CONCLUSIONS AND CLINICAL RELEVANCE Laparoscopy was feasible and clinically applicable in dogs with suspected gastrointestinal obstruction. Careful patient selection and liberal criteria for conversion to an open surgical approach are recommended when laparoscopy is considered for the diagnosis of gastrointestinal lesions in dogs.

Ultrasonographic and computed tomographic characterization and localization of suspected mechanical gastrointestinal obstruction in dogs.

OBJECTIVE To evaluate the usefulness of noncontrast abdominal CT and abdominal ultrasonography for the detection of mechanical gastrointestinal obstruction in dogs and compare intestinal diameter ratios between dogs with and without obstruction. DESIGN Controlled trial. ANIMALS 16 client-owned dogs with physical and radiographic findings consistent with mechanical gastrointestinal obstruction. PROCEDURES Abdominal ultrasonography and CT were performed for all dogs, followed by laparoscopy and exploratory laparotomy. Time required for image acquisition and presence and location of gastrointestinal obstruction were assessed with both imaging modalities. Findings were compared with those of exploratory surgery. Maximum and minimum intestinal diameters were recorded on CT scans; values were converted to a ratio and compared between dogs with and without obstruction. RESULTS Results of abdominal CT and exploratory surgery for the diagnosis of mechanical obstruction agreed for all 16 dogs; 10 dogs had complete obstruction, 3 had partial obstruction, and 3 had no obstruction. In 1 dog with functional ileus, abdominal ultrasonography resulted in an incorrect diagnosis of mechanical obstruction. Median (interquartile range) image acquisition time for abdominal CT (2.5 minutes [2.0 to 3.8 minutes]) was markedly and significantly shorter than that for ultrasonography (26.0 minutes [22.0 to 35.8 minutes]). In both dorsal and transverse CT planes, dogs with gastrointestinal obstruction (partial or complete) had significantly larger intestinal diameter ratios than dogs without obstruction. CONCLUSIONS AND CLINICAL RELEVANCE Abdominal CT was feasible, rapid, and accurate for the diagnosis of mechanical obstruction in dogs with clinical signs and physical examination findings consistent with partial or complete gastrointestinal obstruction.

CORRELATION OF ARTICULAR CARTILAGE THICKNESS MEASUREMENTS MADE WITH MAGNETIC RESONANCE IMAGING, MAGNETIC RESONANCE ARTHROGRAPHY, AND COMPUTED TOMOGRAPHIC ARTHROGRAPHY WITH GROSS ARTICULAR CARTILAGE THICKNESS IN THE EQUINE METACARPOPHALANGEAL JOINT.

Osteoarthritis of the metacarpophalangeal joint is common cause of lameness in equine athletes, and is hallmarked by articular cartilage damage. An accurate, noninvasive method for measuring cartilage thickness would be beneficial to screen for cartilage injury and allow for prompt initiation of interventional therapy. The objective of this methods comparison study was to compare computed tomographic arthrography (CTA), magnetic resonance imaging (MRI), and magnetic resonance arthrography (MRA) measurements of articular cartilage thickness with gross measurements in the metacarpophalangeal joint of Thoroughbred horses. Fourteen cadaveric, equine thoracic limbs were included. Limbs were excluded from the study if pathology of the metacarpophalangeal articular cartilage was observed with any imaging modality. Articular cartilage thickness was measured in nine regions of the third metacarpal bone and proximal phalanx on sagittal plane MRI sequences. After intra-articular contrast administration, the measurements were repeated on sagittal plane MRA and sagittal CTA reformations. In an effort to increase cartilage conspicuity, the volume of intra-articular contrast was increased from 14.5 ml, to maximal distention for the second set of seven limbs. Mean and standard deviation values were calculated, and linear regression analysis was used to determine correlations between gross and imaging measurements of cartilage thickness. This study failed to identify one imaging test that consistently yielded measurements correlating with gross cartilage thickness. Even with the use of intra-articular contrast, cartilage surfaces were difficult to differentiate in regions where the cartilage surfaces of the proximal phalanx and third metacarpal bone were in close contact with each other.

MAGNETIC RESONANCE IMAGING SCORING OF AN EXPERIMENTAL MODEL OF POST-TRAUMATIC OSTEOARTHRITIS IN THE EQUINE CARPUS.

Magnetic resonance imaging (MRI) is the most sensitive imaging modality to detect the early changes of osteoarthritis. Currently, there is no quantifiable method to tract these pathological changes over time in the horse. The objective of this experimental study was to characterize the progression of MRI changes in an equine model of post-traumatic osteoarthritis using a semiquantitative scoring system for whole-organ evaluation of the middle carpal joint. On day 0, an osteochondral fragment was created in one middle carpal joint (OCI) and the contralateral joint (CON) was sham-operated in 10 horses. On day 14, study horses resumed exercise on a high-speed treadmill until the completion of the study (day 98). High-field MRI examinations were performed on days 0 (preosteochondral fragmentation), 14, and 98 and scored by three blinded observers using consensus agreement. Images were scored based on 15 independent articular features, and scores were compared between and within-groups. On days 14 and 98, OCI joints had significantly (P ≤ 0.05) higher whole-organ median scores (29.0 and 31.5, respectively), compared to CON joints (21.5 and 20.0, respectively). On day 14, OCI joints showed significant increases in high-signal bone lesion scores, and osteochondral fragment number and size. On day 98, high-signal bone lesion, low-signal bone lesion, osteophyte formation, cartilage signal abnormality, subchondral bone irregularity, joint effusion, and synovial thickening scores were significantly increased in OCI joints. Study results suggest that the MRI whole-organ scoring system reported here may be used to identify onset and progression of pathological changes following osteochondral injury.

In vitro evaluation of bursting pressure and intestinal luminal area of three jejunostomy tube placement techniques in dogs.

OBJECTIVE: To compare pursestring, Witzel (seromuscular inversion), and seromuscular incision jejunostomy tube placement techniques in vitro. SAMPLE: Jejunal specimens from 10 dogs. PROCEDURES: Jejunal segments (50 cm) were harvested immediately prior to euthanasia from 10 mixed-breed dogs Specimens were harvested with the orad and aborad ends clamped and stored in saline (0.9% NaCl) solution-soaked towels during instrumentation. Three jejunostomy tubes were placed via 3 techniques (pursestring, Witzel, and seromuscular incision), and 2 double lumen central venous catheters were placed at each intestinal end for luminal filling and leak testing. Intestinal luminal area was measured ultrasonographically with specimens suspended in a warm undyed saline solution bath with the intestinal lumen filled with dyed saline solution (intraluminal pressure, 6 mm Hg). Leak testing was performed by means of infusion of dyed saline solution (4 mL/min) until each jejunostomy site failed. Intestinal luminal area and leakage pressure were compared between the 3 tube placement techniques. RESULTS: The Witzel and seromuscular incision techniques decreased the intestinal luminal area measured at the tube insertion site, albeit nonsignificantly. For the seromuscular incision technique, a significant decrease in intestinal luminal area at the intraluminal site of measurement was found. For 2/30 specimens (1/10 pursestring and 1/10 seromuscular incision), failure occurred at pressures within the range of previously reported peak peristaltic pressure for dogs. Failure occurred at supraphysiologic peristaltic pressures for the remaining 28 specimens, including all 10 specimens for the Witzel technique. CONCLUSIONS AND CLINICAL RELEVANCE: In this in vitro study, all specimens for the Witzel technique withstood physiologic peristaltic pressures during leak testing. Both tunneling techniques (Witzel and seromuscular incision) created a decrease in intestinal luminal area. Further investigation, including in vivo testing, is indicated to evaluate the clinical relevance of these findings.

Dynamic exophthalmos and lateral strabismus in a dog caused by masticatory muscle myositis.

CASE DESCRIPTION: A 5.5-year-old neutered male mixed-breed dog was presented for evaluation of a 5-month history of deviation of the right globe upon opening the mouth and a 1-month history of conjunctivitis in the same eye. Clinical findings, diagnostic imaging results, treatment and follow-up are described. CLINICAL FINDINGS: When the mouth was opened, the right globe deviated rostrally and laterally. There was no pain or resistance to opening the mouth, or resistance to retropulsion of the globe. No other abnormalities were observed. Computed tomography was performed, revealing a contrast-enhancing region associated with the right masseter muscle impinging into the right orbit; this was more pronounced with the mouth open. Cytology revealed a small number of mildly to moderately atypical mesenchymal cells. Histopathology was consistent with polyphasic myositis, with a predominance of lymphocytes and plasma cells. No infectious agents were identified. Serum antibody titers for Toxoplasma gondii and Neospora caninum were negative. Serum titers for 2 M antibody were positive at 1:500, consistent with a diagnosis of masticatory muscle myositis. TREATMENT AND OUTCOME: Therapy with prednisone was initiated. During a follow-up period of 5 months, there was no recurrence of clinical signs, and the dose of prednisone was reduced by 25%. CLINICAL SIGNIFICANCE: To the authors' knowledge, this is the first reported case of masticatory muscle myositis causing dynamic exophthalmos and strabismus in a dog.

Associations between 'valentine' heart shape, atrial enlargement and cardiomyopathy in cats.

'Valentine' heart shape is a common qualifier used in veterinary radiology to describe a cardiac silhouette with focal enlargement at the level of the base of the heart in feline patients. Anecdotally, this sign has been thought to be related to biatrial enlargement and also to hypertrophic cardiomyopathy (HCM). However, to our knowledge, there has been no study performed to assess the association between cardiac chamber enlargement and cardiac disease with the 'valentine'-shaped heart. The aim of this study was to verify the association between the 'valentine' heart shape observed in ventrodorsal thoracic radiographs and the presence of singular or combined cardiac chamber enlargement, and also the presence and type of cardiomyopathy (CM) in cats. A search of the database of the Small Animal Veterinary Hospital of the University of Florida for cats with a radiology report of thoracic radiographs that contained the words 'valentine' and 'biatrial', and echocardiography performed within 1 week, was undertaken; 41 cases met the inclusion criteria. Eighty-two percent of the cats of the study sample had some form of CM. The 'valentine' heart shape was associated with biatrial enlargement in 41% of the patients in our study sample that had some form of CM and just 8% of cases diagnosed with HCM, suggesting that the 'valentine' heart shape has a low association with HCM or biatrial enlargement; however, it should be considered a sign of feline CM.

Compartment syndrome associated with expansile antebrachial tumors in two dogs.

CASE DESCRIPTION: A 10-year-old spayed female Jack Russell Terrier and a 7-year-old neutered male mixed-breed dog were evaluated because of acute, progressive, unilateral forelimb lameness associated with signs of pain and turgid antebrachial swelling. CLINICAL FINDINGS: For either dog, there were no salient pathological or diagnostic imaging abnormalities. A diagnosis of compartment syndrome was confirmed on the basis of high caudal antebrachial compartmental pressure in the affected forelimb. TREATMENT AND OUTCOME: Both dogs underwent surgical exploration of the affected forelimb. In each case, an intramuscular tumor (mast cell tumor in the Jack Russell Terrier and suspected sarcoma in the mixed-breed dog) was detected and presumed to be the cause of the high compartmental pressure. At 6 months following tumor excision, the dog with the mast cell tumor did not have any clinical signs of disease. The dog with a suspected sarcoma underwent tumor excision and forelimb amputation at the proximal portion of the humerus followed by chemotherapy; the dog was euthanized approximately 1 year following treatment because of pulmonary metastasis. CLINICAL RELEVANCE: Compartment syndrome is a serious but rarely reported condition in dogs and is typically ascribed to intracompartmental hemorrhage. These 2 cases illustrate the potential for expansile intramuscular antebrachial tumors to cause compartment syndrome in dogs.

Validation of a novel technique for creating simulated radiographs using computed tomography datasets.

Understanding radiographic anatomy and the effects of varying patient and radiographic tube positioning on image quality can be a challenge for students. The purposes of this study were to develop and validate a novel technique for creating simulated radiographs using computed tomography (CT) datasets. A DICOM viewer (ORS Visual) plug-in was developed with the ability to move and deform cuboidal volumetric CT datasets, and to produce images simulating the effects of tube-patient-detector distance and angulation. Computed tomographic datasets were acquired from two dogs, one cat, and one horse. Simulated radiographs of different body parts (n = 9) were produced using different angles to mimic conventional projections, before actual digital radiographs were obtained using the same projections. These studies (n = 18) were then submitted to 10 board-certified radiologists who were asked to score visualization of anatomical landmarks, depiction of patient positioning, realism of distortion/magnification, and image quality. No significant differences between simulated and actual radiographs were found for anatomic structure visualization and patient positioning in the majority of body parts. For the assessment of radiographic realism, no significant differences were found between simulated and digital radiographs for canine pelvis, equine tarsus, and feline abdomen body parts. Overall, image quality and contrast resolution of simulated radiographs were considered satisfactory. Findings from the current study indicated that radiographs simulated using this new technique are comparable to actual digital radiographs. Further studies are needed to apply this technique in developing interactive tools for teaching radiographic anatomy and the effects of varying patient and tube positioning.

Ultrasonographic evaluation of relative gastrointestinal layer thickness in cats without clinical evidence of gastrointestinal tract disease.

The objectives of this study were (1) to measure normal thickness values of the muscularis, submucosal, mucosal and serosal layers in each gastrointestinal (GI) segment (gastric fundus, body and pyloric antrum; duodenum; jejunum; ileum; colon), and (2) to calculate a ratio of muscularis and mucosal layer thickness to aortic diameter measured at the level of the celiac artery (Musc:Ao and Muc:Ao) in each GI segment in a sample of healthy cats. Ultrasonographic examination of the GI tract was performed, and measurements of the individual layers in each GI segment were obtained in 38 healthy cats without clinical evidence of disease. The muscularis layer was significantly thickest in the ileum, compared with other segments, and it was thicker than the submucosa in all segments except the colon. The mucosa was the thickest layer in all segments, and was thickest in the duodenum and ileum. Measurements of the submucosal and serosal layers were not significantly different between all segments. Musc:Ao and Muc:Ao in each segment were 0.12 and 0.25 (gastric fundus), 0.12 and 0.18 (gastric body), 0.11 and 0.16 (pyloric antrum), 0.08 and 0.27 (duodenum), 0.08 and 0.22 (jejunum), 0.14 and 0.25 (ileum), and 0.05 and 0.08 (colon), respectively. Musc:Ao and Muc:Ao are clinically relevant values that can be used to objectively identify thickening of the muscularis and mucosal layers in response to GI diseases.

Validation of stress magnetic resonance imaging of the canine stifle joint with and without an intact cranial cruciate ligament.

OBJECTIVE: To validate use of stress MRI for evaluation of stifle joints of dogs with an intact or deficient cranial cruciate ligament (CrCL). SAMPLE: 10 cadaveric stifle joints from 10 dogs. PROCEDURES: A custom-made limb-holding device and a pulley system linked to a paw plate were used to apply axial compression across the stifle joint and induce cranial tibial translation with the joint in various degrees of flexion. By use of sagittal proton density-weighted MRI, CrCL-intact and deficient stifle joints were evaluated under conditions of loading stress simulating the tibial compression test or the cranial drawer test. Medial and lateral femorotibial subluxation following CrCL transection measured under a simulated tibial compression test and a cranial drawer test were compared. RESULTS: By use of tibial compression test MRI, the mean ± SD cranial tibial translations in the medial and lateral compartments were 9.6 ± 3.7 mm and 10 ± 4.1 mm, respectively. By use of cranial drawer test MRI, the mean ± SD cranial tibial translations in the medial and lateral compartments were 8.3 ± 3.3 mm and 9.5 ± 3.5 mm, respectively. No significant difference in femorotibial subluxation was found between stress MRI techniques. Femorotibial subluxation elicited by use of the cranial drawer test was greater in the lateral than in the medial compartment. CONCLUSIONS AND CLINICAL RELEVANCE: Both stress techniques induced stifle joint subluxation following CrCL transection that was measurable by use of MRI, suggesting that both methods may be further evaluated for clinical use.

Ultrasound appearance of the outer medulla in dogs without renal dysfunction.

Ultrasound findings of the canine kidney include a hyperechoic cortex and a hypo to anechoic medulla. In this study, the sonographic appearance of the outer renal medulla in dogs without evidence of renal disease is described. Dogs that underwent abdominal ultrasound over a 6-month period were subjected to review and then divided into six groups based on body weight (kg): < 4.9, 5.0-9.9, 10-19.9, 20-29.9, 30-39.9, and ≥ 40. Chi-square analysis was used to determine if the frequency of a hyperechoic outer medulla was significantly different between weight groups, sex, and age (P-value < 0.05). Of the 145 dogs that met the inclusion criteria, 45 had a hyperechoic outer medulla relative to the cortex and inner medulla. In the remaining dogs, the outer medulla was isoechoic to the cortex. Dogs less than 5 kg had the highest frequency of a hyperechoic outer medulla (P < 0.0001) and dogs greater than 40 kg did not have a hyperechoic outer medulla (P < 0.0001). Sex had no influence on the presence or absence of the hyperechoic outer medulla; however, younger dogs were overrepresented (6.4 ± 0.6 years compared with 7.8 ± 0.4 years; P = 0.04). Ultrasound descriptions of the canine kidney have not taken into account the contributions of the renal cortex and outer medulla. Based on this study of dogs with no clinically significant renal disease, the outer medulla can be isoechoic or hyperechoic to the cortex and a hyperechoic outer medulla is more commonly seen in small breed dogs.

Radiographic characterization of presumed plate-like atelectasis in 75 nonanesthetized dogs and 15 cats.

Discrete discoid or linear areas of increased soft opacity have been observed within the pulmonary parenchyma in thoracic radiographs of dogs and cats. Similar radiographic findings have been described in humans and termed plate-like atelectasis. The purpose of this retrospective study was to describe locations and characteristics of presumed plate-like atelectasis, presence of concurrent thoracic disease(s), and presence of persistent pulmonary changes on recheck thoracic radiographic studies in a cohort of dogs and cats. Hospital records between 2004 and 2011 were searched and a total of 90 cases were included (75 dogs and 15 cats, 2-17 years of age). Plate-like atelectasis was most commonly found in left lateral radiographs. Plate-like atelectasis was observed in the cranial thorax and was oriented in a dorsocranial to ventrocaudal direction in 68 (75%) patients. Plate-like atelectasis averaged 29.6 ± 14.4 mm in length and 2.6 ± 1.3 mm in width. In 57 of the 90 patients (63%), plate-like atelectasis was the only abnormality found. Plate-like atelectasis was present in 7 of 22 cases where follow-up radiographs were available. Findings from the current study indicated that, while the etiology of plate-like atelectasis remains unknown, anatomic variations in sublobar pulmonary anatomy might account for pleural areas of atelectasis. The authors propose that the presence of plate-like atelectasis may represent areas of atelectasis that track along sublobar lung lobe separations, an area of hypoventilation or decreased collateral ventilation, and/or area of decreased localized surfactant deficiency.

The basics of musculoskeletal magnetic resonance imaging: terminology, imaging sequences, image planes, and descriptions of basic pathologic change.

The usefulness of magnetic resonance (MR) imaging in the diagnosis of equine lameness is unquestionable. As with most imaging modalities, advances in technology happen quickly, and the information that can be obtained can seem limitless. An understanding of MR sequences, expected signal intensity of normal tissues, and the role of multiplanar imaging is the foundation for interpreting MR images. The rapid development of new techniques and sequences and the potential for biochemical changes to be indirectly assessed using MR spectroscopy offer possibilities for the continued development of this modality and ensure its continued application in the diagnosis of equine lameness.

Assessment of fracture healing after minimally invasive plate osteosynthesis or open reduction and internal fixation of coexisting radius and ulna fractures in dogs via ultrasonography and radiography.

OBJECTIVE: To evaluate fracture healing after minimally invasive plate osteosynthesis (MIPO) or open reduction and internal fixation (ORIF) of coexisting radius and ulna fractures in dogs via ultrasonography and radiography. DESIGN: Prospective cohort study. ANIMALS: 16 dogs with radius-ulna fractures that underwent MIPO (n = 9; 2 dogs were subsequently not included in the analyses because of incomplete follow-up information) or ORIF (7). PROCEDURES: Dogs in the 2 treatment groups were matched by age, body weight, and configuration of the fractures. Fracture healing was evaluated with ultrasonography, power Doppler ultrasonography, and radiography every 3 to 4 weeks until healing was complete; a semiquantitative score based on the number of Doppler signals was used to characterize neovascularization, and subjective B-mode ultrasonographic and radiographic scores were assigned to classify healing. RESULTS: Fractures in dogs that underwent MIPO healed in significantly less time than did fractures in dogs that underwent ORIF (mean ± SD; 30 ± 10.5 days and 64 ± 10.1 days, respectively). Radiography revealed that fractures in dogs that underwent MIPO healed with significantly more callus formation than did fractures in dogs that underwent ORIF. Although Doppler ultrasonography revealed abundant vascularization in fractures that were healing following MIPO, no significant difference in neovascularization scores was found between groups. CONCLUSIONS AND CLINICAL RELEVANCE: For dogs with radius-ulna fractures, data indicated that bridging osteosynthesis combined with a minimally invasive approach contributed to rapid healing after MIPO. The MIPO technique may offer some clinical advantage over ORIF, given that complete radius-ulna fracture healing was achieved in a shorter time with MIPO.

Surgical management of a subepiglottic thyroglossal duct cyst in a dog.

A 2 yr old dog presented for dysphagia and coughing secondary to a 4 cm × 4 cm turgid subepiglottic mass. Cervical radiographs, an esophagram, and computed tomography confirmed the presence of a cystic mass that was not intimately associated with any surrounding structures. An incisional biopsy confirmed the cystic nature of the mass and helped to rule out a malignancy. A marginal surgical excision was performed via a ventral approach. Histopathology of the mass was consistent with a thyroglossal duct cyst. This is the first report of a thyroglossal duct cyst in this location in a dog. There was no recurrence of clinical signs 14 mo after surgery.

Stabilization of juxta-physeal distal tibial and fibular fractures in a juvenile tiger using a hybrid circular-linear external fixator.

OBJECTIVE: To report stabilization of closed, comminuted distal metaphyseal transverse fractures of the left tibia and fibula in a tiger using a hybrid circular-linear external skeletal fixator. STUDY DESIGN: Clinical report. ANIMAL: Juvenile tiger (15 months, 90 kg). METHODS: From imaging studies, the tiger had comminuted distal metaphyseal transverse fractures of the left tibia and fibula, with mild caudolateral displacement and moderate compression. Multiple fissures extended from the fractures through the distal metaphyses, extending toward, but not involving the distal tibial and fibular physes. A hybrid circular-linear external skeletal fixator was applied by closed reduction, to stabilize the fractures. RESULTS: The fractures healed and the fixator was removed 5 weeks after stabilization. Limb length and alignment were similar to the normal contralateral limb at hospital discharge, 8 weeks after surgery. Two weeks later, the tiger had fractures of the right tibia and fibula and was euthanatized. Necropsy confirmed pathologic fractures ascribed to copper deficiency. CONCLUSION: Closed application of the hybrid construct provided sufficient stability to allow this 90 kg tiger's juxta-articular fractures to heal with minimal complications and without disrupting growth from the adjacent physes.

Effect of sedation protocol on glomerular filtration rate in cats as determined by use of quantitative renal scintigraphy.

OBJECTIVE: To evaluate the effect of several sedation protocols on glomerular filtration rate (GFR) in cats as measured by use of quantitative renal scintigraphy and to analyze interobserver differences in GFR calculation. ANIMALS: 5 cats (1 sexually intact male, 1 neutered male, and 3 sexually intact females). PROCEDURES: Effects on GFR of 3 sedation protocols commonly used at the Iowa State University College of Veterinary Medicine were evaluated. The protocols were medetomidine (11 µg/kg) and butorphanol tartrate (0.22 mg/kg) administered i.m.; ketamine hydrochloride (10 mg/kg) and midazolam (0.5 mg/kg) administered i.v.; and ketamine (10 mg/kg), midazolam (0.5 mg/kg), and acepromazine maleate (0.05 mg/kg) administered i.m.. Results for the 3 protocols were compared with results of GFR measurements obtained in these same cats without sedation (control protocol). RESULTS: No significant difference between GFR measurements was associated with the 3 sedation protocols, compared with GFR measurements for the control protocol. The greatest mean GFR values were for the medetomidine-butorphanol and ketamine-midazolam protocols. There were no significant differences between observers for calculation of GFR. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that none of the 3 sedation protocols had significant effects on GFR calculated by use of quantitative renal scintigraphy, compared with results for GFR evaluations performed in the cats when they were not sedated. No significant interobserver error was evident. However, the statistical power of this study was low, and the probability of a type II error was high.