小型犬隻右側躺胸腔放射線影像脊椎心臟比率之研究

Abstract

客觀的測量放射線影像之心臟大小，如脊椎心臟比率法（vertebral heart scale, VHS），因其使用簡便，且於觀察者之間的差異有限，已成為目前最常被使用於測量犬貓放射線影像之心臟大小的方法之一，並可克服早期其它方法所遺留的限制。有一百零二隻無心臟問題之小型犬隻參與第一項研究，以確定性別、年齡、體重及品種是否會影響脊椎心臟比率之數值。研究結果指出，小型犬隻之年齡及性別並不會影響放射線影像中之心臟大小，且其體重與脊椎心臟比率呈現正相關；博美犬與其它四種流行犬種的脊椎心臟比率之間於第一項研究中具有統計上顯著之差異。在第二項研究中，我們測量了二百七十五隻小型犬的右側躺之放射線影像脊椎心臟之比率，並統計其與紐約心臟協會分級系統修正版（modified New York heart association functional classification）之間的關聯性。研究結果顯示小型犬隻心衰竭之嚴重程度與其右側躺胸腔放射線學脊椎心臟比率呈現正相關，且心衰竭發生之代償性機制應與心衰竭的嚴重程度和放射線影像之心臟大小相連結，以增加犬隻心臟情況評估之準確性。

Objective measurement of radiographic cardiac size, such as the vertebral heart scale (VHS) method, has become one of the most common methods to evaluate the canine and feline cardiac size in radiographs due to its simplicity and limited inter-observer variation which can overcome the limitations of previous reported measuring methods. One hundred and two small breed dogs without cardiac diseases joined in the first study to determine the effects of sex, age, body weight and breed on the VHS in small breed dogs. The results presented that age and sex did not affect the radiographic cardiac size in small breed dogs free from cardiac diseases, and the body weight was positively correlated to the VHS value; the mean VHS value of Pomeranian was significantly different from other four popular breeds in the first study. In the second study, VHS was measured in right recumbent lateral thoracic radiographs of 275 small breed dogs to investigate the relationship between VHS and the modified New York heart association functional classification in small breed dogs. The results suggested that severity of heart failure was positively correlated with the VHS revealed by the lateral thoracic radiographs in small breed dogs, and the development of heart failure compensatory mechanisms should be linked together with the heart failure severity and the radiographic cardiac size to evaluate the cardiac condition of dogs more accurately.