Comparison between infarcted and mirrored normoxic areas in patients.

<p>Histogram and scatter-plot of pooled 9 infarcted areas (‘stroke’) versus unaffected mirror areas (‘control’). <b>3.a</b>: Histograms demonstrated that the shift to lower values of lipids R₁ in stroke areas (0.408 s^-1; p<0.0001) is more pronounced than the corresponding shift observed with global R₁ values (0.154 s^-1; p<0.027). <b>3.b</b>: Scatter plots demonstrated a greater difference between medians for lipids R₁ at 0.409 s^-1 with p <0.0001 (in orange) than for global R₁ at 0.151 s^-1 with p<0.027 (in blue).</p

Full display of morphological/quantitative data sets obtained in a patient.

<p>Axial transverse FLAIR image (<b>1.a</b>) through centrum semiovale showing hyperintensity within acutely infarcted whole territory of the right middle cerebral artery (MCA), and corresponding global R₁-mapped image (<b>1.b</b>), lipids R₁-mapped image (MOBILE) (<b>1.c</b>) and R₂*-mapped image (<b>1.d</b>) in a similar slice location. Image 1.e: overlay of the two ROIs (right-sided contour of infarction and left-sided mirrored one) from the MOBILE map (<b>1.b</b>) on the FLAIR image (<b>1.a</b>). Images 1b-1e have been smoothed using the ‘Gaussian Blur’ function (radius of 2 pixels) of the GIMP software (GIMP 2, GNU Image Manipulation Program, GPLv3). Histograms of global R₁ (<b>1.f</b>), lipids R₁ (<b>1.g</b>) and R₂* (<b>1.h</b>) of the same patient demonstrating significant shift of the medians to lower values for the stroke area. Differences of 0.111 s^-1, 0.536 s^-1 and 6.09 s^-1 are observed for global R₁, lipids R₁ and R₂*, respectively.</p

Statistical details: statistical tests were performed depending on results of the D’Agostino & Pearson test for the normality of the data distribution with a parametric test (classic) used in cases of normal distribution, and non-parametric tests (bold and italic) used in cases of non-normal distribution.

<p>Calculations were performed using paired tests when both datasets were obtained from the same patient. The p values are given for each patient (P#X).</p

Healthy volunteers’ brain tissue (‘Volunteers’) versus unaffected mirror-areas in stroke patients (‘Control’) versus infarcts (‘Stroke’).

<p>Global R₁ plots (3.a), Lipids R₁ plots (3.b) and R₂* plots (3.c) demonstrated a statistically significant difference between infarcts and unaffected mirror-ROIs in patients. In turn, no difference was observed for all modalities between the values obtained in patient mirror-ROIs and healthy brain tissue in volunteers.</p

'Oxygen Level in a Tissue' - What Do Available Measurements Really Report?

The aim of the paper is to discuss what currently is feasible clinically to measure the level of oxygen and how that measurement can be clinically useful. Because oxygen in tissues is quite heterogeneous and all methods of measurement can only provide an average across heterogeneities at some spatial and temporal resolution, the values that are obtained may have limitations on their clinical utility. However, even if such limitations are significant, if one utilizes repeated measurements and focuses on changes in the measured levels, rather than 'absolute levels', it may be possible to obtain very useful clinical information. While these considerations are especially pertinent in cancer, they also pertain to most other types of pathology