Measurements of the Pulmonary Vasculature on Thoracic Radiographs in Healthy Dogs Compared to Dogs With Mitral Regurgitation

Abstract

This study reassessed the previously reported radiographic method of comparing pulmonary vessels versus rib diameter for differentiating healthy dogs and dogs with mitral regurgitation. The width of the right cranial pulmonary artery and vein at the fourth rib level, right caudal pulmonary artery and vein at the ninth rib level, and the diameters of the fourth rib and ninth rib were measured in prospectively recruited healthy dogs (n = 40) and retrospectively recruited dogs with mitral regurgitation (n = 58). In healthy dogs, the pulmonary arteries and accompanying veins were similar in size. The cranial lobar vessels were smaller than the fourth rib. However, 67.5% of right caudal pulmonary artery diameters and 65% of vein diameters were larger than the ninth rib in healthy dogs. The right caudal pulmonary vein diameter in dogs with mitral regurgitation, particularly those within moderate and severe grades, was significantly larger than that in healthy dogs (P < 0.001). The comparative method used to detect enlargement of the right caudal pulmonary vein relative to the accompanying pulmonary artery had the highest sensitivity (80.2%) and specificity (82.5%) for predicting mitral regurgitation. A cut-off of 1.22 when applying the ninth rib criterion had better specificity (73%) than the most used value ≤ 1 (89.7% sensitivity and 63.8% specificity), although it has less sensitivity (73%). We recommend using the accompanying pulmonary artery and 1.22 × the diameter of the ninth rib as a radiographic criterion for assessing the size of the right caudal pulmonary vein and differentiating healthy dogs from those with mitral regurgitation.

CT and radiographic evaluation of bronchial collapsibility at forced expiration in asymptomatic brachycephalic dogs

“…This is the first study with brachycephalic dogs that used CT to measure bronchial collapsibility at forced expiration and compare the bronchial collapsibility quantitatively for each pulmonary lobe. The measurement of bronchial collapsibility at forced expiration is considered important in brachycephalic dogs as upper respiratory disorders are common in these animals and bronchial collapse can cause elevation of pulmonary pressure and contribute to pulmonary hypertension in these breeds …”

“…and conducted using commercially available statistics software (SPSS Statis- In comparisons between the collapsibility determined by cross sectional CT images versus CT MPR images and cross-sectional CT images versus radiographs, the collapsibility of the right caudal lobar bronchi determined by CT MPR images and radiographs was significantly greater than that in cross sectional CT images in all respiratory are common in these animals and bronchial collapse can cause elevation of pulmonary pressure and contribute to pulmonary hypertension in these breeds. 23 Various studies have focused on bronchial abnormalities in brachycephalic dogs. 4,17,24,25 However, none of these studies have evaluated the bronchial collapsibility of brachycephalic dogs at forced expiration using CT images.…”

Computed tomographic and radiographic bronchial collapse may be a normal characteristic of forced expiration in dogs

“…Only the diameters of bronchi for the right cranial lobe and right caudal lobe were visually inspected because the other bronchi were frequently superimposed on one another on the radiographs and could not be finely visualized. The following were measured on thoracic radiographs and dorsal and sagittal CT multiplanar reconstruction images: (1) The distance between the right cranial pulmonary artery and vein at the level of the fourth rib on the left lateral radiographic image and the sagittal CT multiplanar reconstruction images; (2) the distance between the right caudal pulmonary artery and vein at the level of the ninth rib on the dorsoventral radiographic image and dorsal CT multiplanar reconstruction images (Figure ) . It should be noted that the distance between the pulmonary artery and vein is an approximation of the diameter of the bronchus on radiographs .…”

A syndrome of severe idiopathic pulmonary parenchymal disease with pulmonary hypertension in Pekingese

“…A recent publication reported that the mean CrPV/CrPA and CdPV/CdPA in dogs without cardiac disease (controls) were 0.99±0.6 and 1.04±0.19, respectively, as the focus of the study was venous congestion. 28 Our study measured arterial-to-venous ratios as pulmonary artery dilation is the main vascular radiological pattern of PH. An additional discrepancy between this paper and ours was that our CdPA/CdPV measurements were made at the level of the ninth as opposed to the eleventh intercostal space.…”