Marek Olszycki

Hand exercise test for the assessment of endothelium-dependent vasodilatation in subjects with type 1 diabetes.

BACKGROUND At present, endothelial dysfunction is best assessed in vivo with measurement of flow-mediated dilatation (FMD) with Doppler ultrasound scanning. This test, however, does not account for the subjects age and is uncomfortable for patients. The aim of the study was to compare a new test for endothelium function assessment using hand exercise load. METHODS The study group comprised 31 male patients with type 1 diabetes and 72 healthy men as controls. The subjects in both groups were subdivided into three age groups: 18-30 (subgroup A), 31-45 (subgroup B), and 46-60 (subgroup C) years. FMD of the brachial artery with induction of hand ischemia was conducted in all the subjects. Afterwards, an originally designed test using standardized hand exercise with the use of a training device was performed. RESULTS In the youngest group of type 1 diabetes patients the effect of hand ischemia on brachial artery diameter was greater than in the two older age subgroups: baseline artery diameter increased by 0.23 +/- 0.11 mm (5.7%), 0.19 +/- 0.09 mm (4.3%), and 0.13 +/- 0.02 mm (2.8%), respectively (P < 0.01). In the hand exercise test, artery diameter increased in the youngest subjects by 0.39 +/- 0.11 mm (9.5%) and in the two older groups by 0.26 +/- 0.07 mm (5.6%) and 0.18 +/- 0.09 mm (4.5%) (P < 0.05), respectively. In subgroups A, B and C, vasodilation after hand exercise test was greater by 67%, 30%, and 32% (P < 0.01), respectively, compared with the effect of the ischemic test. In the controls similar effects and relationship between ischemic and hand exercise tests were noted, however, with a smaller difference between the two tests. CONCLUSIONS The hand exercise test results in a greater difference in vessel diameter before and after the test stimulus, which might substantially improve its feasibility. The hand exercise test could be a useful alternative tool for endothelial function assessment, especially in type 1 diabetes subjects.

Age effect on vascular reactivity in Type 1 diabetes

Diabet. Med. 28, 833–837 (2011)

In vitro and in vivo imaging of ultra-high-molecular-weight polyethylene orbital implants.

The aim of this study is to compare magnetic resonance imaging (MRI) with computed tomography (CT) for visualization of an orbital alloplastic prosthesis made of ultra-high-molecular-weight polyethylene (UHMW-PE) both in vitro and in vivo. A study of 15 test implants from UHMW-PE visualized in vitro in CT and MRI and an in vivo visualization in a patient who suffered from orbital injury and underwent reconstructive surgery is presented. The postsurgery MRI showed the UHMW-PE material clearly, with no significant artifacts. The surrounding tissues could be satisfactorily evaluated. The CT scans did not present the graft material. Both techniques were sufficient tools for in vitro evaluation of the shape and measurement of the prosthesis.

Analysis of the Hand’s Small Vessels Based on MR Angiography and Level-Set Approach

The article describes a method for segmentation and analysis of small blood hand vessels in 3D magnetic resonance contrast angiography data obtained with collaboration of Department of Diagnostic Imaging, Medical University of Lodz. The main algorithm used for vasculature extraction implements a 3D version of level-set method based on Chan-Vese mathematical model. The image analysis was performed for two different contrast agents. Preliminary segmentation results were presented and discussed, along with further research plans.

Dynamic T1 functional MRI examinations with use of blood pool contrast agent--an approach to optimization of the technique.

The goal was to optimize dynamic T1 imaging for functional MRI (fMRI) examinations. For each of the 10 healthy subjects T1 3D gradient echo sequence (GRE) sequences were provided immediately after administration of blood pool contrast agent then every 2 h when subjects performed block finger tapings. Dynamic T1 fMRI is sensitive to detect cortical activations up to 6 h after BPCA administration. fMRI should be conducted within 2 h of CA administration, which is enough time for a typical fMRI experiment procedure.