Pathological comparison of tumors from Th-<i>ALK^F1174L</i>/Th-<i>MYCN</i> and Th-<i>MYCN</i> mice with abdominal neuroblastoma.

<p><b>A</b>) Gross pathology, <b>B</b>) composite images, and <b>C</b>) high magnification (x200) images from hematoxylin and eosin stained sections. Note the presence of large hemorrhagic regions filled with aggregated erythrocytes (*, blood lakes) extravasated from blood vessels (arrowed) in the tumor from the Th-<i>MYCN</i> mouse. <b>D</b>) Composite fluorescence images of uptake of the perfusion marker Hoechst 33342 into tumors from Th-<i>ALK^F1174L</i>/Th-<i>MYCN</i> and Th-<i>MYCN</i> mice with abdominal neuroblastoma. <b>E</b>) Quantitation of Hoechst 33342 uptake revealed significantly lower functionally perfused vasculature in tumors of Th-<i>ALK^F1174L</i>/Th-<i>MYCN</i> mice (n = 5) compared with tumors in Th-<i>MYCN</i> mice (n = 5). Data are mean ±1 s.e.m, p, Student's 2-tailed unpaired t-test with a 5% level of significance.</p

Identification of tumors harboring the <i>ALK^F1174L</i> mutation in <i>MYCN</i>-driven transgenic mice with intrinsic susceptibility MRI.

<p><b>A</b>) Anatomical transverse T₂*-weighted MR images acquired at TE = 6.8 and 15.6 ms from representative Th-<i>ALK^F1174L</i>/Th-<i>MYCN</i> and Th-<i>MYCN</i> mice with abdominal neuroblastoma during initial air breathing, and at TE = 15.6 ms after 5 minutes of continuous inhalation of 100% oxygen. <b>B</b>) Corresponding parametric tumor transverse relaxation rate R₂* maps calculated during initial air breathing and after 3 minutes of continuous inhalation of 100% oxygen. <b>C</b>) Resulting parametric tumor ΔR₂*_oxygen-air (R₂*_oxygen−R₂*_air) maps. <b>D</b>) Tumor R₂* during initial air breathing, <b>E</b>) tumor R₂* after 5 minutes of breathing 100% oxygen, and <b>F</b>) tumor ΔR₂*_oxygen-air (R₂*_oxygen−R₂*_air) were determined from Th-<i>ALK^F1174L</i>/Th-<i>MYCN</i> and Th-<i>MYCN</i> mice with abdominal neuroblastoma. Individual data points represent the mean of the median values determined from all three imaging slices for each animal, as well as the mean ±1 s.e.m, p, Student's 2-tailed unpaired t-test with a 5% level of significance.</p

Radiological comparison of the Th-<i>ALK^F1174L</i>/Th-<i>MYCN</i> and Th-<i>MYCN</i> mice with abdominal neuroblastoma.

<p><b>A</b>) Anatomical transverse T₂-weighted MR images acquired with a rapid acquisition with refocused echoes (RARE) sequence and <b>B</b>) anatomical transverse T₂*-weighted MR images acquired at increasing gradient echo times as indicated, from representative presenting with abdominal neuroblastoma. <b>C</b>) Note the rapidly decaying tumor signal intensity in the Th-MYCN mouse, compared to the more sustained tumor signal observed in the Th-<i>ALK^F1174L</i>/Th-<i>MYCN</i> mouse.</p