Quantification of lung perfusion blood volume with dual-energy CT: assessment of the severity of acute pulmonary thromboembolism.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of quantification of lung perfused blood volume (PBV) with dual-energy CT (DECT) for assessment of the severity of acute pulmonary thromboembolism (PTE). MATERIALS AND METHODS: We retrospectively analyzed the records of 72 patients with PTE and 168 without PTE who underwent DECT. The PTE patients were divided into high-, intermediate-, and low-risk groups based on clinical symptoms and right ventricular dysfunction. Correlations between quantification of whole-lung PBV and clinical severity were evaluated. Also evaluated was the relation between quantification of whole-lung PBV and right-to-left ventricular diameter ratio on CT images, which was used as an indicator of right ventricular dysfunction. RESULTS: In the PTE and control groups, the whole-lung PBVs were 27.6 ± 7.9 and 29.9 ± 6.8 HU with a significant difference between them (p < 0.0281). In the high-, intermediate-, and low-risk PTE groups, the whole-lung PBVs were 16.0 ± 2.9, 21.0 ± 4.2, and 31.4 ± 5.8 HU with a significant difference between them (p < 0.05). There was no significant difference in whole-lung PBV between the control group and the low-risk PTE group, but there was a significant difference between the control group and the other two PTE groups. In PTE patients, whole-lung PBV had negative correlation with right-to-left ventricular diameter ratio (R = -0.567, p < 0.001). CONCLUSION: Quantification of lung PBV with DECT is useful for assessment of the clinical severity of PTE and can be used as an indicator of right ventricular dysfunction.

Comparison of outcome in aortic dissection with single false lumen versus multiple false lumens: CT assessment.

PURPOSE: To investigate the clinical features and outcomes of type B multibarreled (multiple false lumens) aortic dissection (AD) compared with those of double-barreled (single false lumen) AD by using computed tomography (CT). MATERIALS AND METHODS: The ethics committee approved this study. Informed consent was waived. A total of 221 consecutive patients (127 men; median age, 62 years) with acute type B AD were evaluated by using CT. The clinical outcome, including AD-related events, AD-related deaths, and long-term survival, was retrospectively reviewed and compared with that of patients with double-barreled AD during the follow-up period (median, 60 months). Survival analysis was performed by using Kaplan-Meier analysis with the log-rank test within 10 years after onset. The Cox proportional hazards model was used to estimate the risk for AD-related events and death. RESULTS: In 201 of 221 patients (91.0%), double-barreled AD was identified at initial CT. In 20 of 221 patients (9%), multibarreled AD was identified at initial CT (n = 16) and follow-up CT (n = 4). In 15 of 20 patients (75%) with multibarreled AD, AD-related events occurred, and nine patients (45%) died of AD-related complications. Patients with multibarreled AD showed significantly poorer survival rates than patients with double-barreled AD (P = .0002). The presence of a multibarreled false lumen was the most powerful risk factor for AD-related deaths according to multivariate analysis (hazard ratio, 5.61; 95% confidence interval: 2.44, 12.90; P < .0001). CONCLUSION: Multibarreled AD occurs in 9% of acute type B dissections. The presence of multibarreled AD is a powerful predictor of AD-related deaths.