Areas of sensitization and stimulation on the right lateral volar forearm.

<p>For orientation, the schematic drawing on the left shows a dermatome map of the right upper extremity (redrawn and modified from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0112325#pone.0112325-Trepel1" target="_blank">[20]</a>). The area of testing (marked by the circle) is situated on the right lateral volar forearm in the C6 dermatome. <i>Area A:</i> Site of sensitization with the heat/capsaicin model (3×3 cm square area 3 cm distal to the elbow in the C6 dermatome). <i>Area B:</i> Site of mechanical stimulation corresponding to the area of secondary mechanical hyperalgesia (2×5 cm area distal to area A).</p

Spinal group activation patterns before (left column) and after (middle column) sensitization and contrast maps (right column).

<p>The transverse slices are in radiological orientation with the left side corresponding to the right body side and approximate the corresponding spinal cord segment for a rostral-caudal span from C4 to T1. They show spinal regions of signal intensity change before (left column) and after (middle column) sensitization with the heat/capsaicin model representing the significance (T-value) of each active voxel across the 16 subjects. The right column shows partial-least squares (PLS) results of contrast calculations on a voxel-by-voxel basis. The color bar in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0112325#pone-0112325-g003" target="_blank">figure 3</a> indicates the corresponding significance, i.e. T-value (left and middle column) or bootstrap-ratio (right column) for each color. <i>Left Column:</i> Activations in ipsilateral vGM of C4. Deactivations in bilateral deep dGM of C6 and C8 and contralateral deep dGM of C7. <i>Middle column:</i> Ipsilateral activations in superficial dGM of T1 and vGM of C4. Deactivations in ipsilateral superficial dGM of C7. <i>Right column:</i> Activations in ipsilateral superficial dGM (C7, C8) and in contralateral vGM (C7) and deep dGM (C8). Deactivations in ipsilateral vGM and contralateral dGM of C4.</p

Psychophysical data.

<p>(A) Mean ratings of pain intensity (dashed line) and temperature perception (solid line) during capsaicin application. Capsaicin was applied at time 0. Mean ± standard error of the mean (SEM). (B) Mean pain ratings for the mechanical stimulus before and after application of capsaicin. Capsaicin induced secondary mechanical hyperalgesia. Mean ± SEM. *: p<0.05.</p

Sagittal slices of group activation patterns and contrast maps.

<p>Columns 1 to 4 show areas of activity across brain stem and cervical spinal cord before (1^st and 2^nd column) and after (3^rd and 4^th column) sensitization with the heat capsaicin model representing the significance (T-value) of each active voxel across the 16 subjects. Columns 5 and 6 show partial-least squares (PLS) results of contrast calculations on a voxel-by-voxel basis. The left column of each 2 columns (e.g. 1^st, 3^rd and 5^th) corresponds to the ipsilateral side of the stimulus, the right column to the contralateral side. The color bar on the right indicates the corresponding significance, i.e. T-value (columns 1–4) or bootstrap-ratio (columns 5–6) for each color.</p

Time course of tumor development after intracerebral injection of 10,000 C6-glioma cells.

<p>T2-weighted images (T2w) revealed an increase in tumor mass over time which was accompanied by an increasing area of contrast enhancement (G1-T1w). At day 9 maps of percentage of signal recovery (PSR) and signal recovery (SR) indicated a higher capillary permeability in the tumor center (white ring) extending over time. Higher PSR and SR values were also seen in the region of the choroid plexus (open arrow). Higher cerebral blood volume (CBV) was mainly found at the tumor rim (white arrow and ring).</p

Quantitative Evaluation of Performance in Interventional Neuroradiology: An Integrated Curriculum Featuring Theoretical and Practical Challenges

<div><p>Purpose</p><p>We sought to develop a standardized curriculum capable of assessing key competencies in Interventional Neuroradiology by the use of models and simulators in an objective, quantitative, and efficient way. In this evaluation we analyzed the associations between the practical experience, theoretical knowledge, and the skills lab performance of interventionalists.</p><p>Materials and Methods</p><p>We evaluated the endovascular skills of 26 participants of the Advanced Course in Endovascular Interventional Neuroradiology of the European Society of Neuroradiology with a set of three tasks (aneurysm coiling and thrombectomy in a virtual simulator and placement of an intra-aneurysmal flow disruptor in a flow model). Practical experience was assessed by a survey. Participants completed a written and oral examination to evaluate theoretical knowledge. Bivariate and multivariate analyses were performed.</p><p>Results</p><p>In multivariate analysis knowledge of materials and techniques in Interventional Neuroradiology was moderately associated with skills in aneurysm coiling and thrombectomy. Experience in mechanical thrombectomy was moderately associated with thrombectomy skills, while age was negatively associated with thrombectomy skills. We found no significant association between age, sex, or work experience and skills in aneurysm coiling.</p><p>Conclusion</p><p>Our study gives an example of how an integrated curriculum for reasonable and cost-effective assessment of key competences of an interventional neuroradiologist could look. In addition to traditional assessment of theoretical knowledge practical skills are measured by the use of endovascular simulators yielding objective, quantitative, and constructive data for the evaluation of the current performance status of participants as well as the evolution of their technical competency over time.</p></div

Cerebral blood volume (CBV) and vessel density.

<p>The highest CBV was found at the rim of the tumor which also showed the highest vessel density (bar graph) as revealed by immunohistochemistry for von Willebrand factor (vWF, lower row): (left) overview showing the position of the magnified view of the tumor rim (orange box) and tumor center (green box), upper row, left: the corresponding axially oriented T2-weighted image.</p

Spatial heterogeneity of cerebral blood volume (CBV) and signal recovery (SR).

<p>Maps of SR (purple) were overlaid on maps of CBV (green) obtained on day 21 after injection of 100,000 C6 cells. Areas of increased CBV were mostly found at the tumor rim whereas signal recovery exceeding the baseline was mainly seen in the tumor center excluding regions which were most likely necrotic (dark on T2 weighted images). Coronally and axially oriented T2-weighted images (T2w) are shown as reference.</p

Participants’ endovascular performance on a Virtual Reality Simulator.

<p>Participants’ endovascular performance on a Virtual Reality Simulator.</p

Robustness of signal recovery (SR) and percentage of signal recovery (PSR) maps.

<p>In case of alteration of the bolus peak PSR maps became unusable, while SR still provided exploitable results. On the right the corresponding axially oriented T2-weighted image.</p