Perbedaan Cardiothoracic Ratio (CTR) Normal antara Proyeksi Standar Foto Toraks dengan Proyeksi Anterio- Posterior (AP) Supine Ekspirasi Maksimal

Abstract

Cardiothoracic Ratio (CTR) is used to determine the widening of the heart in radiology measurement. CTR is measured by comparing the heart width to cavum thoracales in thorax PA projection. However, not all patients can be examined by chest X-ray examination with standard position (PA erect, maximal inspiration) because of the ambulatory defect that make the patient can not stand in erect position. Unfortunately, clinicians need the information about it. There is a different normal index between CTR in standard position of chest X-ray and AP projection, supine and maximal expiration. The aim after study is to determine the difference between CTR index in chest X-ray PA erect, maximal inspiration with AP projection supine, maximal expiration. This was a cross sectional study conducted in Radiology Installation Dr. Sardjito Hospital, Jogjakarta on August to October 2008. Subjects that recruited in this study have no radiologic abnormalities, the radiograph Thorax result were examined and recorded in PA erect and AP supine projection. Then measurement of the CTR done in those two projection . Data were analyzed by a comparative descriptive method that compared the mean value in PA erect and AP supine group using independent sample t-test. From 150 subjects, 74 were men (49.3 %) and 76 were women (50.7%). Mean age between these subject were 39.8 + 12.42 years old. The ratio of CTR in PA erect projection, maximal inspiration was 0.43 ± 0.03 and in AP supine projection 0.52 ± 0.03 (p<0.05; CI 95%). The differences of CTR index in standard position (PA erect, maximal inspiration) with AP supine, maximal expiration projection were 0,09. Result: found that CTR index of AP supine projection was< 0.59 similar with CTR index PA erect projection (<0.5). The study implies that CTR index AP supine projection may be used for patient who could not perform chest X-ray PA erect projection.