Toshihiko Sugiura, Abstract Co-Author: Nothing to Disclose

Nobusada Funabashi MD, PhD, Presenter: Nothing to Disclose

Nobuhiro Tanabe, Abstract Co-Author: Nothing to Disclose

Koichiro Tatsumi, Abstract Co-Author: Nothing to Disclose

Naoko Kawata MD, Abstract Co-Author: Nothing to Disclose

Masae Uehara MD, Abstract Co-Author: Nothing to Disclose

Issei Komuro MD, Abstract Co-Author: Nothing to Disclose

Noriyuki Yanagawa MD, Abstract Co-Author: Nothing to Disclose

Conventional scans with 320 slice CT do not need to overlap acquisition data like helical scans, and can evaluate morphology of the right ventricle (RV) as well as the pulmonary artery (PA) with reduced radiation dose. To estimate PA pressure in subjects with pulmonary hypertension (PH), we evaluated the configuration of the RV obtained by ECG gated conventional scan using 320 slice CT compared with PA systolic (PASP) and mean pressure (PAMP), and PA resistance (PAR) obtained by right heart catheterization (RHC).

18 subjects (4 men, average 57.8±12.5 yrs) with proven PH (10 chronic pulmonary thromboembolism [CPTE], 6 idiopathic PH) underwent enhanced CT (Aquilion one) and RHC 1 month apart with no cardiac accidents between examinations. CT images were reconstructed at end-systole (ES) and end-diastole (ED). We quantified wall thickness of the RV myocardium in ED and ratio of RV to left ventricle (LV) short axis diameter in ES and evaluated abnormal shifts of the interventricular septum (IVS) to LV in ES, and compared with RHC findings.

RV wall thickness was 3.5±1.0 (median 3.4) mm in ED and the ratio of RV/LV diameter in ES was 1.9±0.8 (median 1.8). Abnormal shift of IVS to LV in ES was detected in 9 subjects. PASP, PAMP, and PAR were 75.4±27.1 (median 53), 43.0±13.0 (median 43.5) mmHg, and 700.3±370.4 (median 678.7) dyne.sec.cm-5, respectively. The correlation coefficients of RV wall thickness in ED and ratio of RV/LV diameter in ES were 0.53 (P<0.05) and 0.17 (P=0.49) with PASP, 0.52 (P<0.05) and 0.39 (P=0.11) with PAMP, and 0.41 (P=0.09) and 0.36 (P=0.15) with PAR, respectively. PASP, PAMP, and PAR were numerically higher in subjects with abnormal shift of IVS to LV in ES but were not significant (78.9±22.2 vs 71.9±32.3mmHg, [PASP]; 45.3±12.1 vs 41.0±14.6mmHg, [PAMP] and 746±323.0 vs 654.6±427.2 dyne.sec.cm-5, [PAR]). As some subjects with CPTE required evaluation of coronary arteries before thrombectomy, we were able to evaluate coronary arteries with normal results in all subjects.

RV wall thickness in ED in ECG gated conventional scan using 320 slice CT significantly correlated with PASP and PAMP in subjects with PH, and may estimate PA pressure in these subjects.

Conventional ECG gated scans with 320 slice CT can evaluate morphology of the RV as well as the PA and coronary arteries and can estimate PA pressure in subjects with PH.

Sugiura, T, Funabashi, N, Tanabe, N, Tatsumi, K, Kawata, N, Uehara, M, Komuro, I, Yanagawa, N, Estimation of Pulmonary Arterial Pressure in Subjects with Pulmonary Hypertension by Configuration of Right Ventricle Obtained by Electrocardiogram Gated Conventional Scan in 320 Slice CT.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9014641.html