Cardiothoracic Ratio (CTR) Calculator

Calculation Result

--%

--

Radiological Equation

$$\text{CTR (\%)} = \frac{\text{Transverse Heart Diameter (A + B)}}{\text{Internal Thoracic Diameter (C)}} \times 100$$

Clinical Indications & Diagnostic Methodology

Diagnostic laboratory tests and physiological calculators serve as foundational clinical reference tools. Automated web applications evaluate entered patient parameters against established demographic reference intervals derived from population health studies.

Understanding High and Low Value Deviations

Pre-Analytical Variables and Confounding Factors

Isolated lab values must always be contextualized alongside formal clinical examinations. Measurement values can be altered by temporary variables such as acute dehydration, recent physical exertion, or pharmacological interference.