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Solitary pulmonary nodules (SPNs) measuring 8 to 30 mm in diameter require further workup to determine the likelihood of malignancy.

IntroductionDynamic contrast-enhanced CT (DCE-CT) and positron emission tomography/CT (PET/CT) have a high reported accuracy for the diagnosis of malignancy in solitary pulmonary nodules (SPNs). The aim of this study was to compare the accuracy and cost-effectiveness of these.MethodsIn this prospective multicentre trial, 380 participants with an SPN (8–30 mm) and no recent history of malignancy underwent DCE-CT and PET/CT. All patients underwent either biopsy with histological diagnosis or completed CT follow-up. Primary outcome measures were sensitivity, specificity and overall diagnostic accuracy for PET/CT and DCE-CT. Costs and cost-effectiveness were estimated from a healthcare provider perspective using a decision-model.Results312 participants (47% female, 68.1±9.0 years) completed the study, with 61% rate of malignancy at 2 years. The sensitivity, specificity, positive predictive value and negative predictive values for DCE-CT were 95.3% (95% CI 91.3 to 97.5), 29.8% (95% CI 22.3 to 38.4), 68.2% (95% CI 62.4% to 73.5%) and 80.0% (95% CI 66.2 to 89.1), respectively, and for PET/CT were 79.1% (95% CI 72.7 to 84.2), 81.8% (95% CI 74.0 to 87.7), 87.3% (95% CI 81.5 to 91.5) and 71.2% (95% CI 63.2 to 78.1). The area under the receiver operator characteristic curve (AUROC) for DCE-CT and PET/CT was 0.62 (95% CI 0.58 to 0.67) and 0.80 (95% CI 0.76 to 0.85), respectively (p<0.001). Combined results significantly increased diagnostic accuracy over PET/CT alone (AUROC=0.90 (95% CI 0.86 to 0.93), p<0.001). DCE-CT was preferred when the willingness to pay per incremental cost per correctly treated malignancy was below £9000. Above £15 500 a combined approach was preferred.ConclusionsPET/CT has a superior diagnostic accuracy to DCE-CT for the diagnosis of SPNs. Combining both techniques improves the diagnostic accuracy over either test alone and could be cost-effective.Trial registration numberNCT02013063

The aim of the study was to investigate whether myocardial perfusion imaging at 15 min after injection (T15) is more accurate in detecting coronary artery disease than that at 45 min (T45).

Calcineurin inhibitors are substrates for P-glycoprotein (P-gp), the expression of which is associated with ABCB1C3435T polymorphism. Individual P-gp response to calcineurin inhibitor may be linked to nephrotoxicity or rejection. 99mTc-2-Methoxyisobutylisonitrile (99mTc-MIBI) is also a P-gp substrate. The aim of this study, therefore, was to determine 99mTc-MIBI organ kinetics and compare them with ABCB1genotype with a view to replacing 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) with 99mTc-MIBI in renal transplant care.

The intestinal absorption of vitamin D is linked to bile acid absorption. This link may be abnormal in patients with osteoporosis. The aim of this study was to investigate a possible relation between osteoporosis and bile acid turnover, measured as whole-body Se-75-HCAT retention (WBR), in postmenopausal women.

Objective: Technetium-99m-labelled hexakis-methoxy-isobutyl isonitrile (Tc-99m-MIBI) is a substrate for P-glycoprotein (P-gp), an ATP-binding cassette (ABC) transporter protein, and can be used to image P-gp expression. The aim was to study normal kinetics of Tc-99m-MIBI in the kidney and liver to help understand physiological studies of P-gp expression in these organs. Methods: Thirty healthy kidney transplant donors received intravenous Tc-99m-MIBI followed by dynamic scintigraphy for 20 min and static imaging at 30 and 120 min. Time-activity curves were generated from parenchymal ROI. An assumed mono-exponential Tc-99m-MIBI blood clearance with rate constant of 0.3 min-1 was used to predict the Tc-99m- MIBI that would have accumulated in the organs had none left. The activities leaving were then calculated by subtraction and expressed as percentages of the predicted total accumulated activities. Results: Kidney time-activity curves peaked at 2-4 min then declined to a plateau from ∼15-16 min equal to 31 [SD 5] of the total activity accumulated (corresponding to 69 [5] rapidly eliminated) (phase 1). Bladder activity followed a similar but opposite time course. Between 30 and 120 min (phase 2), activity left at 0.36 (0.13) .min-1. Liver curves peaked at 8-10 min. Differentiation of the elimination curve revealed that a variable proportion of tracer (5-56; mean 30 [14]) was rapidly excreted over ∼11 min. From 30 min, activity left at 1.02 (0.23) .min-1. There was no correlation between renal and hepatic elimination rates in either phase or between early and late phase elimination rates in either organ. Conclusions: Early renal elimination is predominantly via glomerular filtration and urinary excretion. The liver rapidly excretes a more variable and lower proportion of Tc-99m-MIBI than the kidney. P-gp located at the urine/tubule and bile/hepatocyte boundaries prevents Tc-99m-MIBI re-entering cells and thereby influences elimination and retention in both phases, although other ABC transporters are probably also involved.

51Cr-Ethylenediaminetetraacetic acid (51Cr-EDTA) is widely used to measure the glomerular filtration rate (GFR) in children and adults.