Evaluation of semi-quantitative bone scintigraphy in canine elbows

Scintigraphy is an extremely sensitive tool for the detection of early changes in bone metabolism. Sixty-eight lame dogs underwent a scintigraphic examination. For each elbow lateromedial (LM), caudomedial (CdM) flexed and caudomedial (CdM) extended scintigraphic views were obtained. Semi-quantitative analysis was performed to determine radiopharmaceutical uptake at the medial coronoid process (MCP) and at the attachment of the flexor muscles at the medial humeral epicondyle, normalised to activity registered in either the total elbow joint or the radius/ulna. MCP pathology/flexor enthesopathies were divided into simple (containing one abnormality) or complex (containing more than one abnormality) lesions. The influence of different views or normalisation procedures on sensitivity and specificity was evaluated. MCP lesions were detected on radiography, ultrasound, computed tomography, magnetic resonance imaging and/or arthroscopy in 49 elbows, with 13 simple and 36 complex lesions. Flexor enthesopathy was diagnosed in 54 elbows, with 14 simple and 40 complex lesions. In seven elbows only degenerative changes were present, whereas in 50 elbows no abnormalities could be detected. MCP lesions were best detected with the CdM extended view, whereas for flexor enthesopathy the CdM flexed view offered the best result. To detect simple lesions, the normalisation procedure to the elbow gave the best result, whereas normalisation to the radius/ulna was the best choice for complex lesions. This study suggests that semi-quantification is a valuable method in case of simple pathology, especially when MCP lesions are considered. For elbows with complex lesions, the quantification procedure is less reliable.

The histological appearance of the proximal aspect of the dorsal condylar sagittal ridge of the third metacarpal and metatarsal bone in young warmblood horses: normal appearance and correlation with detected radiographic variations

The objective of this study is to describe the normal histological appearance of the dorsoproximal aspect of the sagittal ridge of the third metacarpal/metatarsal bone in young Warmblood horses, and to compare it to the different radiographic variations (irregular, indentation, lucency, notch) described at this level. A total of 25 metacarpo/metatarsophalangeal joints of 12 Warmblood horses were used. Five samples of each radiographically described group were selected for histological processing. Each category was compared with the normal control group. Each group showed a bone cortex, covered by hyaline cartilage and longitudinally aligned collagen fibres covered by loosely organized connective tissue proximally. The normal and irregular group showed a smooth bone cortex. In the indentation and lucency group, a depression in the cortex was detected. The notch group presented an expansion of the cortex. The collagen fibres and connective tissue were located in the depression in the indentation group whereas the location varied in the lucency and notch group. The radiologic detected differences are translated into detectable histological differences. Further research is warranted to determine whether these variations are developmental or congenital and to evaluate their potential influence on the joint function during hyperextension.

Cross-sectional anatomy and comparative ultrasonography of the equine medial femorotibial joint and its related structures

REASONS FOR PERFORMING STUDY

Injuries of the equine stifle are frequent causes of hindlimb lameness. Ultrasonography is useful for the diagnosis of many soft tissue lesions but, until recently, its application to the equine stifle has been limited to a description of normal and abnormal structures. A comparative study using gross anatomical sections to identify all structures visible on ultrasonographic images of the equine stifle has not previously been reported.

OBJECTIVES

To provide a comprehensive comparative cross-sectional atlas of the normal equine medial femorotibial (MFT) joint and its related structures using ultrasonography.

METHODS

The stifle joints of 15 cadaver limbs were examined ultrasonographically using a systematic approach. Ten different scanning planes were defined. The lateral and medial femorotibial and the femoropatellar joints were injected with pigments of different colours. Each leg was frozen (10 in extension and 5 in flexion) and cut into slices corresponding to the different scanning planes. According to the different ultrasonographic reference images, 10 representative anatomical images were selected and digitised.

RESULTS

All bony and soft tissue structures were identified on the anatomical sections and subsequently located on the corresponding ultrasonographic images, except the caudal meniscotibial ligaments. Visualisation of the cruciate ligaments was a challenge due to their position and oblique orientation.

CONCLUSIONS

Ultrasonography is a very useful technique for imaging both soft tissue and bony structures of the MFT joint and its related structures, although a protocol is required to perform a systematic and standardised ultrasonographic examination. Good anatomical knowledge is mandatory for identification of the different structures.

POTENTIAL RELEVANCE

This study should contribute to 1) knowledge of the ultrasonographic anatomy of the equine MFT joint and its related structures, 2) use of a protocol for a standardised ultrasonographic examination and 3) the ability to recognise abnormal structures.

Short- and long-term follow-up of glomerular and tubular renal markers of kidney function in hyperthyroid cats after treatment with radioiodine

Hyperthyroidism can mask co-existing chronic kidney disease (CKD). Previous studies showed that post-treatment renal azotemia can be predicted by pre-treatment assessment of glomerular filtration rate (GFR). We hypothesized that treatment of hyperthyroidism may have different effects on glomerular and tubular function and these changes might be predicted by additional pre-treatment variables than GFR. Serum total T4 (TT4), creatinine and blood urea nitrogen (BUN), blood pressure (BP), body weight (BW), GFR, urine specific gravity (USG), urinary protein/creatinine ratio (UPC) and retinol binding protein/creatinine ratio (uRBP/c) were evaluated before and 1, 4, 12 and 24 weeks post-treatment with radioiodine ((131)I) in 21 non-azotemic hyperthyroid cats. Cats were divided 24 weeks post-treatment into group A (normal kidney function, n=16) and group B (impaired kidney function, n=5). Serum TT4, GFR, UPC and uRBP/c decreased significantly after treatment for the complete group and group A (P<0.05), although GFR and uRBP/c did not change in group B. Serum creatinine and BW increased significantly from 1 week after treatment (P<0.05). There was no change in BUN, USG or BP. Pre-treatment serum TT4, GFR and USG differed significantly between group A and B (P<0.05). GFR at 4 weeks after treatment and maximum decrease in GFR could be partially predicted by a formula using pre-treatment GFR, serum TT4, serum creatinine, BUN and/or USG. Significant changes in kidney function occur within 4 weeks post-treatment and none thereafter. Pre-treatment measurement of GFR, USG and serum TT4 can have possible predictive value regarding the development of post-treatment renal azotemia.

Thyroid imaging in the dog: current status and future directions

This review describes the advantages and disadvantages of radiography, ultrasonography, and nuclear medicine in the 2 most frequent thyroid pathologies of the dog: acquired primary hypothyroidism and thyroid neoplasia. Ultrasonography and scintigraphy remain the 2 most indicated imaging modalities for these thyroid abnormalities. However, as in human medicine, computed tomography and magnetic resonance imaging also have potential indications. This is especially the case in the evaluation of the extent, local invasiveness, and local or distant metastases of thyroid neoplasia. Based on experience with different imaging modalities in people, we suggest future directions in the imaging of the canine thyroid gland.

Ultrasonographic assessment of fracture healing after plate osteosynthesis

The goals of this study were to assess the ability of ultrasonography (US) to assess uncomplicated fracture healing and to establish normal images. Twenty-two dogs, ranging in age from 6 to 180 months were studied. Body weight ranged from 2.2 to 60 kg. All fractures were treated by plate osteosynthesis. US (B-mode and power Doppler) and radiography were performed until both were consistent with complete healing. B-mode US was performed in all dogs, and power Doppler US in 14. Fracture healing was judged to be complete based on US earlier than when based on radiography. The tissue immediately adjacent to the plate appeared vascularized on power Doppler images at a time when the tissue at the fracture site had a negative power Doppler exam. US appears useful for assessment of primary fracture healing and power Doppler was useful for detecting vascularization at the fracture site in nonhealed fractures. Power Doppler interrogation should be performed away from any metal implant, as a result from an interrogation adjacent to an implant will not reflect actual vascularization at the fracture site.

Interobserver agreement in the diagnosis of canine hip dysplasia using the standard ventrodorsal hip-extended radiographic method

OBJECTIVES

To determine the agreement between observers and to investigate the effect of observer experience in diagnosing canine hip dysplasia and providing final scoring of hips using the standard ventrodorsal hip-extended radiographic method. The agreement of the final scoring, with a presumed correct assessment based on the Norberg angle, is also investigated.

METHODS

Thirty observers were requested to read 50 ventrodorsal hip-extended radiographs of 25 dogs according to Federation Cynologique International criteria. Groups of experienced (nine members) and inexperienced (21 members) observers were used.

RESULTS

For providing the distinction between dysplastic versus non-dysplastic dogs, the average interobserver agreement was 72 per cent and was significantly higher (P<0.0001) than the score that could be expected by chance without any agreement between observers. For providing the final score (A, B, C, D or E), an average interobserver agreement of 43.6 per cent was found. In the experienced group, an agreement score of 76 per cent was found for the distinction between AB versus non-AB and an agreement score of 81 per cent was found for the distinction between C versus non-C. The agreement score was significantly higher (P<0.0001) for the experienced group than for the inexperienced group in all cases. Agreement between the presumed correct assessment based on the Norberg angle and the observer's evaluation was low (P=0.35), irrespective of whether the observers were experienced (71.8 per cent correct assessments) or inexperienced (69 per cent correct assessments).

CLINICAL SIGNIFICANCE

Although interobserver agreement is low, observer experience increases agreement.

Idiopathic megaoesophagus and intermittent gastro-oesophageal intussusception in a cat

An eight-month-old domestic shorthair cat was presented with chronic vomiting for three months, with an acute increase in frequency during the past two days. A diagnosis of megaoesophagus was made by chest radiography. Diagnostic work-up for megaoesophagus was performed. A gastro-oesophageal intussusception was identified during endoscopy. Medical and nutritional therapy was instituted with a good response to the treatment.