Here are some of the latest articles that have to do with veterinary diagnostic imaging. You can view the list at CiteULike, under group VetRadiology.
Britt T, Clifford C, Barger A, et al. Diagnosing appendicular osteosarcoma with ultrasound-guided fine-needle aspiration: 36 cases. Journal of Small Animal Practice 2007;48:145-150.
Objectives: To determine the ability to obtain diagnostic cytology samples from appendicular bone lesions using ultrasound-guided needle aspirations. Secondary objectives were to compare cytological evaluations with histopathological results and to determine the utility of staining malignant mesenchymal cells for the presence of alkaline phosphatase.
Methods: Aspirations from 36 aggressive appendicular bone lesions with histological diagnoses were included in the study. Ultrasound was used to guide the needle to the medullary cavity or the adjacent soft tissue mass. The smears stained with Wright-Giemsa and nitroblue tetrazolium chloride/5-bromo-4-chloro-3-indoyl phosphate toluidine salt (NBT/BCIP) were examined.
Results: A diagnostic sample was obtained in 32 of the 36 cases. Of the 32 diagnostic samples, cytology indicated sarcoma, with a sensitivity of 97 per cent (confidence interval: 83 to 100 per cent) and a specificity of 100 per cent (confidence interval: 16 to 100 per cent). When a diagnosis of sarcoma was made on cytology, alkaline phosphatase staining indicated osteosarcoma, with a sensitivity of 100 per cent (confidence interval: 87 to 100 per cent).
Clinical Significance: The results of this study indicate that ultrasound-guided needle aspiration of aggressive bone lesions is a viable technique for identifying malignant mesenchymal cells and for diagnosing sarcomas. It is cost-effective and minimally invasive. Furthermore, identifying alkaline-phosphatase-negative malignant mesenchymal cells from a bone aspiration may rule out osteosarcoma, whereas alkaline-phosphatase-positive malignant mesenchymal cells are suggestive of osteosarcoma.
AZ: I would interpret this article with caution. There were 32 osteosarcoma lesions, and 4 other lesions, which is nowhere near equal sample sizes for comparison. The authors note this will affect sensitivity and specificity. But the confidence interval for specificity is 9-99%, which is very wide.
There is also overlap in ALP staining between reactive bone and chondrosarcoma lesions; 2/4 non-osteosarcoma lesions in the study. Specificity remains to be determined.
The positive news is that there were 89% diagnostic samples.
Jones ID, Klein A. What is your diagnosis? Journal of Small Animal Practice 2007;48:177-179.
A seven year old, neutered female German shepherd dog cross was presented with a 10 day history of unproductive coughing, wheezing and a three day history of haemoptysis. Frequent coughing resulted in the animal voiding approximately 250 ml of fresh blood.
Physical examination revealed cyanotic mucous membranes, a respiratory rate of 25 breaths per minute, increased sounds in all fields bilaterally and increased effort during inspiration. A mild tachycardia (110 beats per minute), good pulse quality, and a capillary refill time of less than two seconds were recorded. Neurologically, the animal appeared alert and responsive. The remainder of the physical examination findings were unremarkable.
AZ: There is also a mediastinal shift to the left, and volume loss of the cranial subsegment of the left cranial lung lobe. Bronchial obstruction can result in atelectasis, though there was a component of hemorrhage in this case as well.
Jeffery ND, Smith PM, Talbot CE. Imaging findings and surgical treatment of hemivertebrae in three dogs. Journal of the American Veterinary Medical Association 2007;230:532-536.
Case Description—3 immature screw-tailed dogs were evaluated because of progressive pelvic limb paraparesis.
Clinical Findings—Each dog had marked ataxia and paresis of the pelvic limbs and a palpable deformity of the midthoracic portion of the vertebral column. Pain perception in the pelvic limbs was considered normal, and there was no evidence of fecal or urinary incontinence in any of the 3 dogs. Radiography and magnetic resonance imaging revealed hemivertebrae with severe dorsoventral stenosis of the vertebral canal resulting in spinal cord compression in 2 dogs and lateral compression in the other.
Treatment and Outcome—Each dog underwent decompressive surgery consisting of dorsal laminectomy or hemilaminectomy and vertebral stabilization by use of combinations of Kirschner wires or threaded external fixator pins plus polymethylmethacrylate bone cement. All dogs regained strong locomotor function with minimal residual pelvic limb ataxia.
Clinical Relevance—Little detailed information regarding surgical treatment of hemivertebrae in dogs is available; results of treatment in these 3 dogs suggest that spinal cord decompression and stabilization of the vertebral column can achieve a satisfactory, functional outcome.
Strom AM, Pacchiana P. What Is Your Diagnosis? Journal of the American Veterinary Medical Association 2007;230:505-506.
A 4-year-old sexually intact female Rottweiler was evaluated for emaciation and abdominal distension. On
physical examination, the dog was 7% to 8% dehydrated and had pink mucous membranes, a capillary refill time of
1.5 seconds, tachycardia (160 beats/min; reference range, 70 to 160 beats/min), and bounding femoral pulses. The
abdomen was tense and severely distended and abdominal palpation elicited signs of pain. The dog was ambulatory
on all 4 limbs and had a body condition score of 2/9 (1, severely emaciated; 5, ideal body condition; 9, severely
obese). Radiographs of the abdomen were obtained (Figure 1).
Thieman KM, Clark J, Johnson PJ, et al. What Is Your Diagnosis? Journal of the American Veterinary Medical Association 2007;230:509-510.
A 4-month-old female American Saddlebred was referred for increased respiratory effort, lethargy, inappetance,
weight loss, and insufficient growth of 4 weeks’ duration. Neither coughing nor nasal discharge had been observed.
Clinical signs had become worse despite treatment with ceftiofur sodium.
On admission, the foal was moderately thin, lethargic, 5% to 6% dehydrated, tachypneic (respiratory rate,
49 breaths/min; reference range, 10 to 30 breaths/min), tachycardic (156 beats/min; reference range, 30 to 45
beats/min), and febrile (40.2oC [104.3oF]; reference range, 37.5o to 39.0oC [99o to 102oF]) and had pale mucous
membranes, and its respiratory effort was increased. Normal breath sounds were detected during auscultation of
the lungs; however, adventitious breath sounds were not detected. Both eyes were affected with severe uveitis, and
the conjunctival mucosae were characterized by petechial hemorrhages. Moderate effusion was detected in both
tibiotarsal joints, but no signs of pain or lameness were evident.
Results of a CBC included anemia (PCV, 11%; reference range, 32% to 45%) and neutrophilia (17.7 X 103 cells/
μL; reference range, 5.4 to 14.3 X 103 cells/μL) with a degenerative left shift (band neutrophils, 0.35 X 103 cells/μL;
reference range, 0 to 0.1 X 103 cells/μL), and mild toxic changes were detected in the neutrophils. Abnormalities
detected on serum biochemical analysis included hypoglycemia (glucose, 66 mg/dL; reference range, 83 to 113
mg/dL); azotemia (urea nitrogen, 55 mg/dL; reference range, 8 to 23 mg/dL); hypoalbuminemia (1.4 g/dL; reference
range, 3.5 to 4.4 g/dL); high anion gap (22 mEq/L; reference range, 8 to 16 mEq/L); and low bicarbonate concentra-
tion (10 mEq/L; reference range, 26 to 35 mEq/L), compatible with metabolic acidosis. A blood sample obtained
aseptically was submitted for bacteriologic culture. No abnormalities were detected on radiography of the thorax.
Ultrasonography of the abdomen was performed (Figure 1).
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