QModeling: a Multiplatform, Easy-to-Use and Open-Source Toolbox for PET Kinetic Analysis.

Kinetic modeling is at the basis of most quantification methods for dynamic PET data. Specific software is required for it, and a free and easy-to-use kinetic analysis toolbox can facilitate routine work for clinical research. The relevance of kinetic modeling for neuroimaging encourages its incorporation into image processing pipelines like those of SPM, also providing preprocessing flexibility to match the needs of users. The aim of this work was to develop such a toolbox: QModeling. It implements four widely-used reference-region models: Simplified Reference Tissue Model (SRTM), Simplified Reference Tissue Model 2 (SRTM2), Patlak Reference and Logan Reference. A preliminary validation was also performed: The obtained parameters were compared with the gold standard provided by PMOD, the most commonly-used software in this field. Execution speed was also compared, for time-activity curve (TAC) estimation, model fitting and image generation. QModeling has a simple interface, which guides the user through the analysis: Loading data, obtaining TACs, preprocessing the model for pre-evaluation, generating parametric images and visualizing them. Relative differences between QModeling and PMOD in the parameter values are almost always below 10-8. The SRTM2 algorithm yields relative differences from 10-3 to 10-5 when [Formula: see text] is not fixed, since different, validated methods are used to fit this parameter. The new toolbox works efficiently, with execution times of the same order as those of PMOD. Therefore, QModeling allows applying reference-region models with reliable results in efficient computation times. It is free, flexible, multiplatform, easy-to-use and open-source, and it can be easily expanded with new models.

Treatment of arterial pseudoaneurysms with percutaneous ultrasound-guided thrombin injection.

BACKGROUND: The pseudoaneurysms or false aneurysms are one of the most common complications after arterial invasive manipulation. Different methods of treatment have been described, such as surgical repair, ultrasound-guided compression and endovascular procedures. Ultrasound-guided thrombin injection has shown efficacy, safety and low cost, and, in some cases, the procedure is considered the treatment of choice. Preliminary results are presented. DESIGN: Case series. We studied adult patients with iatrogenic arterial pseudoaneurysms demonstrated clinically and corroborated with ultrasound. We describe the technique used for the management of the arterial pseudoaneurysms by ultrasound-guided thrombin application, as well as complications and follow-up. RESULTS: Twelve patients were included with a mean age of 63 years (SD 12.4), 33% were male and 67% female. Associated comorbid states were hypertension 83%, 50% diabetes, obesity 66%. All pseudoaneurysms were located in the femoral artery (2:1 right/left ratio). The mean size of the pseudoaneurysm was 48.2 mm SD 11.9, (range of 30 to 65 mm) by 44.3 mm SD 9.3, (range 20 to 53 mm). The average neck diameter was 2.2 mm SD 0.54 (range of 1.5 to 3 mm). Eleven cases were unilobulated (87.5%), and one bilobulated (12.5%). All reported arterial integrity with complete occlusion after one thrombin application without recurrence and morbidity after 90 days of follow up. CONCLUSIONS: In our study we obtained a 100% of thrombosis without pseudoaneurysm recurrence or complications. However a longer follow-up time and more number of cases are required to confirm these results.