Correlation between Automated Quantification of Lung Perfusion Blood Volume (PBV) and Pulmonary Artery Pressure

Purpose: Dual-energy CT (DECT) can be used for quantification of lung perfusion blood volume (PBV), allowing objective evaluation. However, no reports have investigated pulmonary perfusion correlating with pulmonary artery pressure (PAP) in patients with chronic pulmonary diseases. The purpose was to evaluate automated quantification of the lung PBV using dual-energy CT, and its correlation with PAP. Methods: 274 patients who underwent echocardiography within two weeks also underwent CT. The population was divided into high (&ge;40 mmHg) and low (<40 mmHg) estimated systolic PAP (sPAP) groups (n = 63 and n = 211, respectively). We retrospectively eva-luated the lung PBV using Syngo software, and correlations between the lung PBV and estimated sPAP. Results: Lung PBV values were 25.0 ± 9.6 and 29.0 ± 9.3 Hounsfield units (HU) in high and low sPAP groups, respectively, with a significant difference between them (p = 0.003). In the high sPAP group with underlying lung diseases (n = 15), chronic thromboembolism (n = 25), pulmonary artery stenosis (n = 12), and left heart failure (n = 11), using the Dana Point classification system, lung PBV values were 18.6 ± 1.6, 25.1 ± 4.5, 25.8 ± 4.5, and 32.7 ± 9.4 HU, respectively. There were significant differences in quantification of the lung PBV among them. The mean sPAP of subjects with left heart failure was significantly higher than in the others. In subjects with left heart failure, a positive correlation between the lung PBV value and sPAP was noted (R = 0.721, p < 0.0001). Conclusions: Automated quantification of the lung PBV may estimate the high sPAP. The lung PBV may contribute to clarifying the etiology of a high PAP due to left heart failure.

Comparison Study on Different Quantification Methods of Diffuse Myocardial Fibrosis of Dilated Cardiomyopathy Using Myocardial T1 Value

Purpose: The purpose is to compare several quantification methods and clarify which quantification method is reliable to estimate diffuse myocardial fibrosis with cardiac MRI in patients with dilated cardiomyopathy (DCM) using myocardial T1 value. Methods and Results: Delayed enhancement imaging was performed in 52 patients with DCM and 10 control subjects to identify fibrosis using an inversion time scout sequence. The mean contrast-enhanced myocardial (M) T1 values of the pre and post contrast-enhanced myocardial and left ventricular lumen (L) of control and dilated cardiomyopathy cases were compared. The calculated post M T1 value, pre M T1 value-post M T1 value, and (pre M TI value-post M T1 value)/(pre L T1 value-post L T1 value) were significantly different between the patient group and the control group (344.5 ± 31.6 vs. 390.4 ± 19.3 msec, 239.9 ± 64.2 msec vs. 134.0 ± 28.9 msec, and 0.50 ± 0.11 vs. 0.30 ± 0.60, respectively). (Pre M T1 value-post M T1 value)/(pre L T1 value-post L T1 value) was significantly the most related to the left ventricular ejection fraction (r = 0.66, p Conclusion: (Pre M T1 value-post M T1 value)/(pre L T1 value-post L T1 value) was the most reliable quantification method to estimate the severity of DCM.