Split-bolus contrast injection protocol enhances the visualization of the thoracic vasculature and reduced radiation dose during chest CT.

OBJECTIVE: To investigate the visualization of mediastinal lymph nodes during thoracic CT employing a multiphasic contrast media (CM) protocol. METHODS: Institutional review board approved retrospective study consisting of 300 patients with known chest malignancy. Patients were allocated to one of two CM protocols: Protocol A, consisted of dual bolus (Phase 1:100 ml CM followed by 100 ml saline chaser) i.v. injected at 2.5 ml s-1; Protocol B employed 100 ml of CM using a multiphasic injection protocol (Phase 1 and 2:60 ml contrast and saline, followed by Phase 3 and 4:40 ml contrast and saline injected at 2.5 ml s-1) with a fixed scan delay of 70 s for each acquisition. Attenuation profiles of the thoracic arteries and veins were calculated as well as the arterio-venous contrast ratios (AVCR). Receiver operating characteristic (ROC), visual grading characteristic (VGC), and Cohen's kappa analysis were assessed. RESULTS: Arterial opacification was up to 24% (p < 0.032) higher in protocol B than A, whereas, in the veins it was significantly lower in protocol B than A, with a maximum reduction of up to 84% (p < 0.0001). There was no statistical significance between the central and peripheral pulmonary arteries [>263 Hounsfield units (HU)] in each protocol. Protocol B, demonstrated significant improvement in AVCR at various anatomical sites (p < 0.002). Radiation dose was significantly reduced in protocol B compared to A (p < 0.004). Both ROC and VGC demonstrated significantly higher Az score for protocol B compared to A (p < 0.0001) with an increased inter reader agreement from poor to excellent. CONCLUSION: Employing a multiphasic CM protocol significantly improves opacification of the thoracic vasculature and visualization of mediastinal lymph nodes during thoracic CT. ADVANCES IN KNOWLEDGE: Uniform opacification between thoracic arteries and veins increases the delineation between vasculature and lymph nodes, reduces radiation dose when employing a multiphase contrast media injection protocol.

Effect of chest tube size on pleurodesis efficacy in malignant pleural effusion: a meta-analysis of randomized controlled trials.

BACKGROUND: Malignant pleural effusion (MPE) develops in approximately 50% of all patients with metastatic cancer. The efficacy of small- vs. large-bore chest tube for pleurodesis in patients with MPE is still not clear. METHODS: We performed a meta-analysis to evaluate the efficacy and safety of chest tube size in the management of MPE. A systematic search of Medline (Ovid) and Embase (from 1980 to March 2016) was performed. Randomized clinical trials (RCTs) evaluating the effect of small (≤14 French) vs. large (>14 French) chest tube size on successful pleurodesis for patients with MPE. Of 708 potentially relevant publications, four matched the selection criteria and were included in the meta-analysis. RESULTS: Overall relative risk (RR) with 95% confidence intervals (CI) was pooled using a random-effects model. Heterogeneity was assessed using Q statistic (significant at P<0.1). In the 231 patients, the success proportion of pleurodesis as well as complication proportion were comparable between large and small chest tube groups with a pooled RR of 0.90 (95% CI, 0.77-1.05; P=0.19; I2 =17.4%) and 0.95 (95% CI, 0.42-2.15; P=0.90; I2 =0.9%) respectively. Successful pleurodesis and complication proportion for small vs. large chest tubes were 73.8% vs. 82.0% and 13.0% vs. 10.5%, respectively. CONCLUSIONS: This meta-analysis suggests that small and large chest tubes are both effective treatment for MPE with similar successful pleurodesis and complication proportion. Further RCTs are needed to more clearly determine which size tube is superior.

Using Ultrasound-Guided Peripheral Catheterization of the Internal Jugular Vein in Patients With Difficult Peripheral Access.

Vascular access is necessary in patients admitted to the intensive care unit and the medical ward. Currently, there are multiple modalities to achieve adequate vascular access, each with their own difficulties and drawbacks. Often, in patients with certain comorbidities, it is difficult to obtain a peripheral intravenous (IV) line, which can lead to multiple failed attempts in achieving access. We describe the feasibility of inserting an ultrasound (US)-guided peripheral IV catheter into the internal jugular vein (IJ) in such populations. This was a prospective observational case series in patients with difficult or failed peripheral IV access. All patients underwent sterile insertion of a peripheral IV catheter (2.5″, 18 gauge) into the IJ under US guidance. Catheter placement was confirmed by ultrasonography. Nineteen consecutive patients were included in this series. A total of 20 US-guided peripheral IJ catheters were placed. The mean patient age was 57. Sixty percent of patients were male and the mean body mass index was 26 (14.1-51.5). The mean time taken to place the peripheral IJ catheter was 5.3 minutes. Eighty-five percent of catheters placed were mostly placed in the right IJ. There were no complications on follow-up. US-guided placement of peripheral IV catheters in the IJ is feasible to achieve short-term IV access in a select patient population who failed traditional peripheral IV placement. Furthermore, larger trials are needed to confirm safety and long-term complications of this method.

Synchronisation between contrast media administration and caudocranial scan direction increases visualisation of altered coronary artery blood flow in patients presenting with dual left anterior descending coronary artery.

Coronary CT angiography (CCTA) has the advantage over invasive coronary angiography in that its non-invasive nature and minimal risk on patients. CCTA enables accurate assessment of the entire heart, coronary artery system and thorax, displaying three-dimensional information about the spatial relations of the anomalous vessels and surrounding intraluminal and extraluminal anatomy, and thereby contributing clinically important prognostic information. Dual left anterior descending (LAD) coronary artery consists of of two LAD arteries within the anterior interventricular sulcus (AIVS). Type 4 is infrequently reported subtype and differs from the others, with a long LAD originating from the right coronary artery (Mercado, A., Johnson Jr, G., Calver, D., & Sokol, R. J. (1989). Cocaine, pregnancy, and postpartum intracerebral hemorrhage. Obstetrics & Gynecology, 73(3, Part 2), 467-468. and the short LAD originating from the left main coronary artery. However, the radiological features between the short LAD and septal coronary arteries remain a controversy, with the latter being determined by CCTA. We present a case report based on short LAD terminating proximally in the AIVS and the long LAD originating from the RCA and terminating into the distal AIVS with the later having a long septal travelling parallel to the long LAD.

Contrast medium administration and image acquisition parameters in renal CT angiography: what radiologists need to know.

Over the last decade, exponential advances in computed tomography (CT) technology have resulted in improved spatial and temporal resolution. Faster image acquisition enabled renal CT angiography to become a viable and effective noninvasive alternative in diagnosing renal vascular pathologies. However, with these advances, new challenges in contrast media administration have emerged. Poor synchronization between scanner and contrast media administration have reduced the consistency in image quality with poor spatial and contrast resolution. Comprehensive understanding of contrast media dynamics is essential in the design and implementation of contrast administration and image acquisition protocols. This review includes an overview of the parameters affecting renal artery opacification and current protocol strategies to achieve optimal image quality during renal CT angiography with iodinated contrast media, with current safety issues highlighted.