Assessment of Haemodynamic Response to Nonselective Beta-Blockers in Portal Hypertension by Phase-Contrast Magnetic Resonance Angiography

A significant unmet need exists for accurate, reproducible, noninvasive diagnostic tools to assess and monitor portal hypertension (PHT). We report the first use of quantitative MRI markers for the haemodynamic assessment of nonselective beta-blockers (NSBB) in PHT. In a randomized parallel feasibility study in 22 adult patients with PHT and a clinical indication for NSBB, we acquired haemodynamic data at baseline and after 4 weeks of NSBB (propranolol or carvedilol) using phase-contrast MR angiography (PC-MRA) in selected intra-abdominal vessels. T1 mapping of liver and spleen was undertaken to assess changes in tissue composition. Target NSBB dose was achieved in 82%. There was a substantial reduction from baseline in mean average flow in the superior abdominal aorta after 4 weeks of NSBB therapy (4.49±0.98 versus 3.82±0.86 L/min, P=0.03) but there were no statistically significant differences in flow in any other vessels, even in patients with >25% decrease in heart rate (47% of patients). Mean percentage change in liver and spleen T1 following NSBB was small and highly variable. In conclusion, PC-MRA was able to detect reduction in cardiac output by NSBB but did not detect significant changes in visceral blood flow or T1. This trial was registered with the ISRCTN registry (ISRCTN98001632)

The risk of skin cancer in renal transplant recipients in Queensland, Australia: A follow-up study

A long-term retrospective follow-up study was performed to evaluate the risk of skin cancer in 1098 renal transplant recipients in Queensland, Australia. In a subgroup, we also assessed the influence of immunosuppressive therapy on the risk of developing skin cancer: cyclosporine alone or in combination with prednisolone; azathioprine alone or in combination with prednisolone; or the combination of cyclosporine and azathioprine with or without prednisolone. The cumulative incidence of developing skin cancer, calculated by life table analysis, increased progressively from 7% after 1 year of immunosuppression to 45% after 11 years and to 70% after 20 years of immunosuppression. Multivariate analysis in a subgroup comparing the risk of developing skin cancer in patients on either long-term cyclosporine or azathioprine (each with or without prednisolone) and in patients on the combination of cyclosporine and azathioprine (with or without prednisolone) showed no differences between the groups. We conclude that it is likely that the increased risk of skin cancer associated with immunosuppression is independent of the agent(s) used and is a result of the immunosuppression per se

Quantifying microcalcification activity in the thoracic aorta

Background: Standard methods for quantifying positron emission tomography (PET) uptake in the aorta are time consuming and may not reflect overall vessel activity. We describe aortic microcalcification activity (AMA), a novel method for quantifying 18F-sodium fluoride (18F-NaF) uptake in the thoracic aorta. Methods: Twenty patients underwent two hybrid 18F-NaF PET and computed tomography (CT) scans of the thoracic aorta less than three weeks apart. AMA, as well as maximum (TBRmax) and mean (TBRmean) tissue to background ratios, were calculated by two trained operators. Intra-observer repeatability, inter-observer repeatability and scan-rescan reproducibility were assessed. Each 18F-NaF quantification method was compared to validated cardiovascular risk scores. Results: Aortic microcalcification activity demonstrated excellent intra-observer (intraclass correlation coefficient 0.98) and inter-observer (intraclass correlation coefficient 0.97) repeatability with very good scan-rescan reproducibility (intraclass correlation coefficient 0.86) which were similar to previously described TBRmean and TBRmax methods. AMA analysis was much quicker to perform than standard TBR assessment (3.4min versus 15.1min, P<0.0001). AMA was correlated with Framingham stroke risk scores and Framingham risk score for hard cononary heart disease. Conclusions: AMA is a simple, rapid and reproducible method of quantifying global 18F-NaF uptake across the ascending aorta and aortic arch that correlates with cardiovascular risk scores