Breed‐specific vertebral heart score, vertebral left atrial size, and radiographic left atrial dimension in Cavalier King Charles Spaniels: Reference interval study

Figures

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  FIGURE 1. Right lateral thoracic radiographic image of a CKCS demonstrating the radiographic measurements of vertebral heart size (VHS) performed in this study (kVp 75, mAs 2.5). A line was drawn from the central and ventral border of the carina to the most distant point of the cardiac apex (solid line). The short‐axis (dotted line) line was measured at the widest part of the cardiac silhouette within the central one‐third region, typically near the ventral border of the caudal vena cava (#), and perpendicular to the long‐axis. The measurements of the two axes were then indexed to the thoracic vertebral bodies starting at the cranial edge of T4 (*) and summed (9.6 vertebrae in this example)

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  FIGURE 2. Right lateral thoracic radiographic image of a CKCS demonstrating the radiographic measurements of vertebral left atrial size (VLAS) perfomed in this study (kVp 75, mAs 2.5). A line was drawn from the central and ventral border of the carina to the caudal most border of the left atrium, where it intersected with the dorsal border of the caudal vena cava (#). This line was indexed to the thoracic vertebral bodies starting at the cranial edge of T4 (*) and summed (1.7 vertebrae in this example)

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  FIGURE 3. Right lateral thoracic radiographic image of a CKCS demonstrating the radiographic measurements of modified version of vertebral left atrial size (M‐VLAS) performed in this study (kVp 75, mAs 2.5). An initial line (solid line) was drawn from the center of the most ventral aspect of the carina to the intersection between the most caudal aspect of the left atrium and the dorsal border of the caudal vena cava (#). A second additional line (dotted line) was then drawn from the most distal border of the left atrium towards the first line, intersecting it perpendicularly. Two separate straight lines corresponding to the lengths of the first 2 lines were then drawn from the cranial edge of the T4 (*) and summed (2 vertebrae in this example)

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  FIGURE 4. Right lateral thoracic radiographic image of a CKCS demonstrating the radiographic measurements of radiographic left atrial dimension (RLAD) performed in this study (kVp 75, mAs 2.5). The computer software was used to ensure a line (double line) bisecting the 90° angle formed by the intersection of the VHS long (solid line) and short (dotted line) axes connecting this point with the radiographic projection of the dorsal edge of the LA, both for RL and LL projection. These length was then drawn starting from the cranial edge of T4 (*), summed, and used as RLAD (1.4 vertebrae in this example)

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  FIGURE 5. Right lateral thoracic radiographic image of a CKCS demonstrating the radiographic measurements of thoracic depth (solid line) measured from xiphoid process to the perpendicular of vertebral column in right lateral recumbency (kVp 75, mAs 2.5)

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  FIGURE 6. Dorso‐ventral thoracic radiographic image of a CKCS demonstrating the radiographic measurements of thoracic width measured as the distance between medial borders of eighth rib at their most lateral curvatures in dorso‐ventral recumbency (kVp 75, mAs 2.5)