The potential of iodinated contrast reduction in dual-energy CT thoracic angiography; an evaluation of image quality.

INTRODUCTION: The purpose of this study was to compare a dual energy CT (DECT) protocol with 50% reduction of iodinated contrast to a single energy CT (SECT) protocol using standard contrast dose in imaging of the thoracic aorta. METHODS: DECT with a 50% reduction in iodinated contrast was compared with SECT. For DECT, monoenergetic images at 50, 55, 60, 65, 68, 70, and 74 keV were reconstructed with adaptive statistical iterative reconstruction (ASiR-V) of 50% and 80%. Objective image quality parameters included intravascular attenuation (HU), image noise (SD), contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR). Two independent radiologists subjectively assessed the image quality for the 55 and 68 keV DECT reconstructions and SECT on a five-point Likert scale. RESULTS: Across 14 patients, the intravascular attenuation at 50-55 keV was comparable to SECT (p > 0.05). The CNRs were significantly lower for DECT with ASIR-V 50% compared to SECT for all keV-values (p < 0.05 for all). For ASIR-V 80%, CNR was comparable to SECT at energies below 60 keV (p > 0.05). The subjective image quality was comparable between DECT and SECT independent of keV level. CONCLUSION: This study indicates that a 50% reduction in iodinated contrast may result in adequate image quality using DECT with monoenergetic reconstructions at lower energy levels for the imaging of the thoracic aorta. The best image quality was obtained for ASiR-V 80% image reconstructions at 55 keV. IMPLICATIONS OF PRACTICE: Dual energy CT with a reduction in iodinated contrast may result in adequate image quality in imaging of the thoracic aorta. However, increased radiation dose may limit the use to patients in which a reduction in fluid and iodinated contrast volume may outweigh this risk.

Long-term quality of life after pregnancy-related deep vein thrombosis and the influence of socioeconomic factors and comorbidity.

BACKGROUND: Little is known about the long-term impact of pregnancy-related deep vein thrombosis (DVT) of the lower limbs. OBJECTIVES: To evaluate the long-term consequences of pregnancy-related DVT by assessment of self-reported, disease-specific quality of life (QOL) and symptom severity using the Venous Insufficiency Epidemiological and Economic Study (VEINES)-QOL/Sym questionnaire, and to investigate the influence of socioeconomic factors and comorbidity. PATIENTS/METHODS: In this cross-sectional case-control study, 313 women with validated pregnancy-related DVT and 353 controls completed a comprehensive questionnaire, including the disease-specific VEINES-QOL/Sym questionnaire. After exclusion of DVT outside the lower limbs and missing scores, the study population comprised 208 patients and 347 controls. A VEINES-QOL/Sym score < the 25th percentile was defined as a clinically relevant reduced outcome compared with scores ≥ the 50th percentile. Predictors for low scores were identified in multivariate logistic regression models. RESULTS: Cases reported lower mean VEINES-QOL/Sym scores than controls, 45.6/45.4 vs. 52.8/52.7, respectively (P < 0.001), and QOL among cases was still reduced compared with controls when adjusted for possible confounders. Low education was an independent predictor for both low VEINES-QOL and VEINES-Sym scores, and in addition being married/cohabitating predicted low VEINES-Sym scores. CONCLUSIONS: Long-term QOL and symptom scores as assessed with the VEINES-QOL/Sym questionnaire were lower in women with previous pregnancy-related DVT than in controls, and also when adjusted for possible confounders. By logistic regression, low education was an independent predictor for low scores. This supports the use of the VEINES-QOL/Sym questionnaire in studies on pregnancy-related DVT.