MEDICINE
CARDIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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(A) heart size is expressed as a ratio, the cardiothoracic ratio (CTR)
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b. Heart size is assessed by absolute measurement of the cardiac width.
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c. Must projection in Anterior-Posterior (AP) view.
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d. a normal CTR is always greater than 1:2 (50%)
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Detailed explanation-1: -The cardiothoracic ratio on CT can be easily obtained by measurement of the maximal cardiac width divided by the maximal thoracic width at the same scan level. When the cardiothoracic ratio on CT is over 0.5, the presence of cardiomegaly can be suggested.
Detailed explanation-2: -CTR is defined as the ratio between the maximal horizontal cardiac diameter and the maximal horizontal inner thoracic cage diameter [2]. A CTR > 0.5 (or > 50%) is considered abnormal. In radiology reports, terms like “cardiomegaly” or “increased heart size” are commonly used to describe an increased CTR.
Detailed explanation-3: -Transverse cardiac diameters of 15.5cm for males and 14.5cm for females are considered as the normal upper limits respectively; An increase in the transverse cardiac diameter by 1.5cm on two consecutive chest radiographs taken at short intervals is considered abnormal, and a sign of cardiomegaly.