THE EFFECT OF A TECHNICAL QUALITY ASSESSMENT OF HIP‐EXTENDED RADIOGRAPHS ON INTEROBSERVER AGREEMENT IN THE DIAGNOSIS OF CANINE HIP DYSPLASIA

Experienced and inexperienced observers evaluated the assessability of 50 radiographs (25 dogs) and determined the hip status (dysplasia/nondysplasia and final scoring according Fédération Cynologique Internationale [FCI]‐criteria) individually. A radiographic technical quality assessment was performed in a separate reading session. Interobserver agreement in determining dysplasia/nondysplasia and FCI‐scoring did not significantly increase with the increasing quality of a radiograph, irrespective whether these observers are experienced or not. There was a significant agreement between the technical quality assessment and assessability (P<0.0005). Despite the effort to objectify radiographic quality and to present high‐quality radiographs to observers, interobserver agreement on dysplasia/nondysplasia and final scoring, remains low, even in the experienced group. Although increased radiographic quality narrows the range of scoring, the range remains unacceptably high.     

Physiological basis of differential phytotoxic activity between fenoxaprop-P-ethyl and cyhalofop-butyl-treated barnyardgrass

This study investigated the physiological causes of differences in phytotoxic symptoms shown in barnyardgrass from foliar applications of the herbicides fenoxaprop-P-ethyl and cyhalofop-butyl. When these were applied to the third leaves of the whole plant, the chlorosis and desiccation in the third leaf was greater in fenoxaprop-P-ethyl than cyhalofop-butyl. However, initial growth inhibition of the fourth leaf was greater when using cyhalofop-butyl than when using fenoxaprop-P-ethyl. In the shoot regrowth test, regrowth at five days after treatment (DAT) was smaller in cyhalofop-butyl than in fenoxaprop-P-ethyl; the regrowth at 10 DAT exhibited the reverse trend. The chlorosis (decrease of chlorophylls: carotenoids ratio) in barnyardgrass leaf segments that were floated on herbicide solution was greater in the fenoxaprop-P-ethyl treatment. These results indicate that different herbicidal responses induced by the two herbicides are likely to be related to differential translocation and metabolism. The relatively light chlorosis and desiccation in treated leaves, severe cessation of initial growth (but a lower final herbicidal efficacy in the cyhalofop-butyl treatment) are probably related to its rapid translocation to the meristem region from the treated leaf, followed by faster metabolism. In contrast, the relatively greater chlorosis and desiccation compared to inhibition of initial growth in the fenoxaprop-P-ethyl treatment is likely to be related to its relatively slower translocation and metabolism in the treated leaf.     

COMPARISON OF THE ULTRASONOGRAPHIC APPEARANCE OF OSTEOCHONDROSIS LESIONS IN THE CANINE SHOULDER WITH RADIOGRAPHY, ARTHROGRAPHY, AND ARTHROSCOPY

Osteochondrosis lesions in 29 shoulder joints (from 20 dogs) were evaluated with ultrasound (US) and the results were compared with survey radiography, arthrography, and arthroscopy. US was performed with a 7-12 MHz linear matrix transducer which was placed in cranio-caudal direction just distally to the acromion while the joint was adducted and maximally endorotated to visualize the caudal aspect of the humeral head. With US, the subchondral defect was completely visible in 21 joints and partially visible in 8 joints. The length of the subchondral defect measured on US was comparable with the length measured on survey radiographs. In two joints, the cartilage flap was mineralized and thus already visible on survey radiographs. The mineralized flap was visible on US as a straight hyperechoic line above the subchondral defect. In the other joints, survey radiographs could not assess the status of the articular cartilage. In 17 joints, the presence of a cartilage flap or cartilage fissuring was suspected based on the presence of a second hyperechoic line at the base of the subchondral defect, and this suspicion was confirmed by arthroscopic examination in 16 joints and also by arthrographic examination in 15 joints. One joint that was suspected of having a cartilage flap on US was normal on arthroscopy and arthrography. When US revealed only focal thickening of the anechoic cartilage layer (5 joints), the joints appeared normal on arthroscopic and arthrographic examination. Of the four joints where the subchondral defect was irregular and covered by heteroechogeneous material on US, arthroseopy revealed the presence of a lesion resembling chondromalacia in two joints, the presence of a small cartilage flap in one joint and the presence of scar tissue underneath the flap at the level of the subchondral defect in one joint. In conclusion, US is a helpful imaging modality in the identification of osteochondritic lesions in the canine shoulder joint. US also appears to be a satisfactory imaging tool for identifying lesions such as joint mice, joint effusion, and distinct new bone formation.     

PRE- AND POST-TREATMENT ULTRASONOGRAPHY IN HYPOTHYROID DOGS

Primary hypothyroidism is a frequent endocrine disorder in the adult dog. However, false-positive diagnoses are common because of the relatively low accuracy of most commonly used biochemical tests. The purpose of this study was to describe the ultrasonographic features of the thyroid gland in hypothyroid dogs, to calculate the diagnostic sensitivity of gray-scale ultrasound using a combination of clinical symptoms and biochemical thyroid tests as gold standard, and to investigate the evolution of the ultrasonographic features after treatment of hypothyroidism. Eighteen dogs were studied prospectively. All dogs underwent an ultrasound examination at first presentation and 13 underwent one or two additional ultrasound examinations over time. At first presentation, a sensitivity of 76.5% (95% CI [50.0-93.0% 1) for decreased echogenicity, 64.7% (95% CI [38.385.8% 1) for inhomogeneity, 70.6% (95% CI 144.0-89.7%]) for irregular capsule delineation, 64.7% (95% CI [38.3-85.8%]) for abnormal lobe shape and 47.1% (95% CI 123.0-72.2%]) for decreased relative thyroid volume was obtained. Combining these five parameters together resulted in an overall sensitivity of 94.1% (95% CI [71.3-99.9%]) for gray-scale ultrasound in the detection of acquired hypothyroidism at first presentation. A continuous decrease of thyroid volume was seen over time after treatment, while the other investigated parameters did not change significantly during the follow-up period. None of the thyroid glands were considered normal at the last presentation. Grayscale ultrasound is a sensitive and quick test for the diagnosis of primary hypothyroidism in dogs.     

ULTRASOUND APPROACH TO THE CANINE DISTAL TIBIA AND TROCHLEAR RIDGES OF THE TALUS

The aim of the present study was to evaluate to what extent the distal tibia and the trochlear ridges of the talus can be examined with ultrasound (US) in the dog and to establish a protocol for an optimal US examination of these ridges. Six hind limbs of deceased adult mixed-breed dogs were used. In two limbs, needles were placed using US guidance on the trochlea of the talus, just dorsal to and plantar to the distal tibia: one with the tarsal joint in extension and one with the joint in flexion. Then mediolateral (ML) radiographs of both joints were made with the needle in place to determine the percentage of the trochlear ridge of the talus that can be seen using US imaging. An US examination of the tarsal joint was performed on the four other limbs using microconvex (8 MHz) and linear (12 MHz) transducers (Logiq 7) and compound imaging. A three-step protocol was performed including a dorsal approach with the limb extended and the linear transducer (step I), a plantar approach with the limb flexed and the linear transducer (step II), and a plantar approach with the limb flexed and the microconvex transducer (step III). After the US examination, the four limbs were frozen and sectioned, two in a transverse and two in a sagittal plane. Bony structures on the US images were matched with the corresponding anatomic sections. The distal tibia and both trochlear ridges of the talus were easily recognized on the US images using the proposed protocol. When combining the dorsal and plantar approaches, it was possible to visualize up to 75% of the trochlear ridges of the talus in the dog.     

CONTRAST‐ENHANCED ULTRASONOGRAPHY OF THE NORMAL CANINE ADRENAL GLAND

Contrast‐enhanced ultrasonography is useful in differentiating adrenal gland adenomas from nonadenomatous lesions in human patients. The purposes of this study were to evaluate the feasibility and to describe contrast‐enhanced ultrasonography of the normal canine adrenal gland. Six healthy female Beagles were injected with an intravenous bolus of a lipid‐shelled contrast agent (SonoVue^®). The aorta enhanced immediately followed by the renal artery and then the adrenal gland. Adrenal gland enhancement was uniform, centrifugal, and rapid from the medulla to the cortex. When maximum enhancement was reached, a gradual homogeneous decrease in echogenicity of the adrenal gland began and simultaneously enhancement of the phrenicoabdominal vessels was observed. While enhancement kept decreasing in the adrenal parenchyma, the renal vein, caudal vena cava, and phrenicoabdominal vein were characterized by persistent enhancement until the end of the study. A second contrast enhancement was observed, corresponding to the refilling time. Objective measurements were performed storing the images for off‐line image analysis using Image J (ImageJ^©). The shape of the time–intensity curve reflecting adrenal perfusion was similar in all dogs. Ratios of the values of the cortex and the medulla to the values of the renal artery were characterized by significant differences from initial upslope to the peak allowing differentiation between the cortex and the medulla for both adrenal glands only in this time period. Contrast‐enhanced ultrasonography of the adrenal glands is feasible in dogs and the optimal time for adrenal imaging is between 5 and 90 s after injection.     

CONTRAST HARMONIC ULTRASOUND APPEARANCE OF CONSECUTIVE PERCUTANEOUS RENAL BIOPSIES IN DOGS

Ultrasound‐guided percutaneous renal biopsy may be associated with complications, especially when using larger needles. Contrast harmonic ultrasound increases blood pool echo intensity, enhancing parenchymal lesions. Therefore, contrast harmonic ultrasound is a potential alternative screening method for postbiopsy renal lesions. Renal biopsies were performed using 14 G needles in 11 healthy Beagles, at three occasions: 0 (“Baseline Biopsy”; BB), 4 (“Biopsy 2”; B2), and 6 months (“Biopsy 3”; B3). Ultrasound and contrast harmonic ultrasound of biopsied kidneys were performed approximately 30 min after biopsy (week 0) at BB and B2, and repeated once every week (weeks 1–3) until normal appearance. At B3, only contrast harmonic ultrasound was performed, both immediately and 30‐min postbiopsy. Contrast harmonic ultrasound images were reviewed using subjective and semiquantitative methods to describe lesions including number, shape, size, sharpness, echogenicity, and evolution. More renal lesions were detected with contrast harmonic ultrasound (22/22) compared with conventional ultrasound (14/22). The majority appeared at week 0 as hypoechoic tract(s) (27/33), the other (6/33) as ill‐defined areas or area/tract combination, all having variable size, shape, and echogenicity. Seven tracts had a small subcapsular hematoma. In most kidneys, similar or gradual decrease of size and sharpness, and increased echogenicity was observed until normal appearance occurred at week 1 (1/22), week 2 (18/22), or week 3 (22/22). Two Beagles developed complications. At B3, immediately postbiopsy, tracts were hyperechoic in 9/11 kidneys, becoming hypoechoic again 30 min later. Contrast harmonic ultrasound is a valuable method to evaluate postbiopsy renal lesions in dogs.     

90Sr THERAPY FOR ORAL SQUAMOUS CELL CARCINOMA IN TWO CATS

Two cats with a superficial oral squamous cell carcinoma responded favorably to treatment using a ⁹⁰Sr probe. From one to six fields were applied per tumor, depending on tumor size. The surface dose per treatment ranged from 75 to 150 Gy and the total surface dose ranged from 200 to 500 Gy. Adverse effects were minimal. The cats survived 7 months and 5 years 9 months from the time of diagnosis. These data indicate that with careful patient selection ⁹⁰Sr may be useful for the treatment of feline oral squamous cell carcinoma in some patients.     

SHORT‐TERM EFFECT OF RECOMBINANT HUMAN THYROID‐STIMULATING HORMONE ON THYROID VOLUME AND ECHOGENICITY IN HEALTHY BEAGLES

In humans, administration of recombinant human thyroid stimulating hormone (rhTSH) allows radioactive iodine dose reduction and higher efficacy in the treatment of multinodular goiter and thyroid cancer. A similar effect might be expected in dogs with thyroid carcinoma. However, if rhTSH leads to an increase in thyroid volume, it must be used carefully in dogs with large thyroid tumors to avoid compression of key anatomical structures. The aim of this study was to determine the short‐term effect of rhTSH on thyroid volume and echogenicity, measured by ultrasonography, in healthy Beagles. Seven beagles were divided randomly in two groups in a prospective placebo‐controlled blinded cross‐over study. On day 1, one group received 100 μg of rhTSH intravenously and the other group received placebo. After a wash‐out period of 3 weeks, the groups were crossed over. Evaluation of thyroid echogenicity, homogeneity, shape, capsule delineation, and measurement of thyroid length, width, and height were performed by the same observer at baseline, and at 6, 24, and 48 h after injection of rhTSH and placebo. There was no significant difference between the effect of rhTSH and placebo on thyroid volume (P=0.397), echogenicity, homogeneity, or capsule delineation. Time had a significant effect on thyroid volume (P=0.027). No adverse effects after rhTSH administration were noticed. The effect of rhTSH on thyroid volume in dogs with thyroid carcinoma needs to be assessed.