Common use of MAS Clause in Contracts

MAS. All images assessed were reconstructed on a sharp (B60) algorithm (Siemens). All dogs had been positioned in sternal recumbency, with the limb of interest extended, ensuring there was no supination or pronation of the elbow. For each elbow three dimensional multiplanar reconstruction (MPR) views were created using OsiriX (version 5.6 32-bit, Pixmeo, Geneva) open source DICOM viewer, permitting transverse, dorsal and sagittal images to be viewed concurrently. Repeatable slice alignment was achieved by aligning slices with the caudal cortex of the ulna in the sagittal view and lateral aspect of the ulna in the dorsal view (Fig 1). Once the alignment was complete, the sagittal view was used to center the image on the most cranial part of the proximal ulna, immediately distal to the humeral condyle resulting in a repeatable standardised transverse image through the apex of the MCP. The transverse plane was chosen as the medial coronoid process is best defined in this plane (▇▇▇▇▇▇▇ 1999). A window width of 3500 HU as previously recommended (▇▇▇▇▇▇▇▇ et al. 2007) and window level of 700 HU were used. A single transverse image for each elbow was archived as a JPEG file. Four board certified orthopaedic surgeons, two board certified radiologists, one diagnostic imaging resident and one surgical resident reviewed individually a single transverse CT image of the ulna at the level of the medial coronoid process from each elbow included in the study. All except one of the observers had been working together in the same institution for at least six months prior to the study. Each observer was asked to draw a line on the transverse CT image representing where, if present, they considered the junction between the normal and the sclerotic trabecular bone pattern to be delineated. This measurement was made on each transverse CT image by the eight observers twice (separated by 4 weeks). A single observer (XX) then used a sclerometer to quantify, as a percentage, the position of the observer’s line demarcating the transition between normal and sclerotic trabecular bone. The use of a sclerometer was firstly reported by ▇▇▇▇▇ et al. (2009) who applied the technique to quantify ulna sclerosis on lateral radiographs of the elbow from dogs with MCPD. Here, we applied the instrument to transverse CT images of the ulna at the level of the MCP. The sclerometer (Fig 2A) was superimposed on the image with the cranial line of the sliding scale being aligned with the most cranial cortex of the medial coronoid process of the ulna and the caudal line intersecting the most caudal cortex of the ulna. The hinged sclerometer line was then aligned with the line drawn by the observers (Fig 2B). If sclerosis was not deemed present the score was recorded to be 0%. (Fig 3) Each observers recorded whether they considered the ulna and medial coronoid process to be normal or abnormal, and they assessed images for the presence or absence of pre- determined variables (Table 1). Images were presented in a random sequence and observers did not communicate with each other. In addition to these binary variables, observers were requested to grade images using a four point ordinal grading scheme, with grade 0 representing a normal MCP and grade IV representing the MCP entirely sclerotic (Table 2). To assess intraobserver variability, each observer reviewed all CT images twice, with the same assessment criteria as in experiment 2, on occasions separated by at least four weeks. The order of the images presented to the observers was randomly assigned for the purpose of blinded image reading. ▇▇▇▇▇’▇ kappa (ƙ) for nominal data (experiment 2 and 3) and intraclass correlation coefficient (ICC(2,1)) for numeral values (experiment 1) were calculated to evaluate inter- and intraobserver agreement between the eight observers, and for each category of observers: surgeons (including board certified and resident), diagnostic imagers (including board certified and resident), board certified orthopaedic surgeons, board certified diagnostic imagers, board certified (including diagnostic imagers and surgeons). Interpretation of the ƙ and the ICC value were based on ▇▇▇▇▇▇ and ▇▇▇▇ (1977) as shown in Table 3. 84 transverse CT images were retrieved and included in the study. Mean age was 33 months (+/- 22 months) for the clinically unaffected dogs and 44 months (+/- 38 months) for the MCPD-affected dogs. Both normal and abnormal elbows (as confirmed by history, clinical examination, CT and arthroscopy findings) were included in the study. Breed and disease status represented included Greyhound clinically unaffected, Labrador Retriever clinically unaffected and MCPD-affected Labrador Retriever. When assessing the sclerosis percentage, the interobserver agreement varied between moderate to almost perfect between groups. The intraobserver agreement was moderate to almost perfect (Table 4).