ObjectiveTo assess the sensitivity of detection and accuracy of volumetry by manual and semi-automated quantification of artificial pulmonary nodules in an anthropomorphic thoracic phantom on low-dose CT.MethodsFifteen artificial spherical nodules (diameter 3, 5, 8, 10 and 12 mm; CT densities -800, -630 and +100 HU) were randomly placed inside an anthropomorphic thoracic phantom. The phantom was examined on 16- and 64-row multidetector CT with a low-dose protocol. Two independent blinded observers screened for pulmonary nodules. Nodule diameter was measured manually, and volume calculated. For solid nodules (+100 HU), diameter and volume were also evaluated by semi-automated software. Differences in observed volumes between the manual and semi-automated method were evaluated by a t-test.ResultsSensitivity was 100 % for all nodules of >5 mm and larger, 60–80 % for solid and 0–20 % for non-solid 3-mm nodules. No false-positive nodules but high inter-observer reliability and inter-technique correlation were found. Volume was underestimated manually by 24.1 ± 14.0 % for nodules of any density, and 26.4 ± 15.5 % for solid nodules, compared with 7.6 ± 8.5 % (P < 0.01) semi-automatically.ConclusionIn an anthropomorphic phantom study, the sensitivity of detection is 100 % for nodules of >5 mm in diameter. Semi-automated volumetry yielded more accurate nodule volumes than manual measurements.Key Points• Computed tomography has become the definitive investigation of the chest.• Low-dose CT techniques have recently been introduced.• Low-dose CT is reliable for detecting spherical pulmonary nodules of >5 mm.• Semi-automated volumetry is more accurate than manual measurement for pulmonary nodules.• No difference in the accuracy of volumetry was found between 16- and 64- MDCT.

Infusion therapy is medically and technically challenging and frequently associated with medical errors. When administering pharmaceuticals by means of infusion, dosing errors can occur due to flow rate variability. These dosing errors may lead to adverse effects. We aimed to systematically review the available biomedical literature for in vitro measurement and modeling studies that investigated the physical causes of flow rate variability. Special focus was given to syringe pump setups, which are typically used if very accurate drug delivery is required. We aimed to extract from literature the component with the highest mechanical compliance in syringe pump setups. We included 53 studies, six of which were theoretical models, two articles were earlier reviews of infusion literature, and 45 were in vitro measurement studies. Mechanical compliance, flow resistance, and dead volume of infusion systems were stated as the most important and frequently identified physical causes of flow rate variability. The syringe was indicated as the most important source of mechanical compliance in syringe pump setups (9.0×10-9 to 2.1×10-8 l/Pa). Mechanical compliance caused longer flow rate start-up times (from several minutes up to approximately 70 min) and delayed occlusion alarm times (up to 117 min).

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For critical drug delivery, it is important to have a constant and well-known infusion rate delivered by the complete infusion set-up (pump, tubing, and accessories). Therefore, various drug delivery devices and accessories were tested in this article in terms of their infusion accuracy, start-up delay, response time, and dependency on the viscosity. These measurements were performed as part of the European funded research project MeDD. The obtained results show that the infusion accuracy of the devices is flow rate and accessory depended, especially for low flow rates. Viscosity does not have a significant impact on the flow rate accuracy.