<i>T</i>₁-weighted MR images of the torso of a mouse where enlargements of the indicated tumor site are shown in Panel A before administration of Spago Pix and at five time points thereafter.

<p>Panels B and C show enlargements of ten tumor sites (labeled 1–10) in different animals before administration of Spago Pix and 30 min (B) and 2–4 h (C) thereafter.</p

PEG surface area in tumor and muscle at 30 minutes and 2–4 hours post-injection of Spago Pix. p<0.01 for tumor at 2–4 h compared to muscle at 30 min and 2–4 h and compared to tumor at 30 min.

<p>The difference between tumor at 30 min and the muscle groups was not statistically significant.</p

Immunohistochemistry images of anti-PEG (brown) and hematoxylin counterstaining (blue) of tumor (A1–A3 and B1–B3) and muscle tissue (A4 and B4) 30 minutes (A) and 2 h (B) post injection of Spago Pix.

<p>Tumor tissue at both time points is shown at three different enlargements where the enlarged areas are indicated by the square boxes. Vessels (V), fibroblasts (Fb) and fat cells (Fc) are indicated with rounded lines. Note that the tumor tissue in panel B1–B3 originates from a mouse injected with a dose of 10 µmol Mn/kg, whereas the other tissues originate from animals administered 20 µmol Mn/kg.</p

Illustration of mammary gland localization in the mouse and <i>T</i>₁-weighted MR images of pre-injection and 1 h and 4.5 h post injection, respectively, of Spago Pix.

<p>The 1 h image has tumors (T), liver (L) and gall bladder (G) indicated with white arrows. Note that the pre-injection image is without applied fat saturation.</p

Boxplot of CNR values for pooled tumors at T = 0 min (24 tumors in 7 animals), 30 min (29 tumors in 7 animals) and >2 h (31 tumors in 6 animals).

<p>P_{0–30 min} <0.0001, P_{0 min–2 h} <0.0001, P_{30 min–2 h}  = 0.0074.</p

Immunohistochemistry image of anti-PEG (brown) and hematoxylin counterstaining (blue) of tumor tissue 30 min post injection of Spago Pix.

<p>The dense PEG-staining corresponds to vessels. Note the staining pattern radiating from the vessel to the right in the figure (see text for details).</p

Boxplots of manganese and silicon content in muscle and tumor tissue ∼40 min to 4.5 h post injection of Spago Pix in MRI study 1 (n = 3 for ∼40 min, n = 1 for 4 h). p<0.001 for manganese and p>0.05 for silicon.

<p>Background concentrations (n = 1) are indicated by stars (tumor) and circles (muscle). Note the interrupted y-axis in the boxplot for silicon content.</p