Magnetic Resonance Imaging and Pathologic Findings of 26 Cases With Uterine Adenomatoid Tumors.

OBJECTIVE: To analyze the magnetic resonance imaging (MRI) features and pathologic findings of uterine adenomatoid tumors (ATs) for improved diagnostic accuracy and facilitating differential diagnosis of the tumors. METHODS: We investigated retrospectively 26 patients with uterine ATs confirmed by pathology. Before operation, all patients accepted multiple MRI scans, including T1-weighted image (T1WI), T2-weighted image (T2WI), T2WI/spectrally adiabatic inversion recovery, and T1-weighted enhanced imaging. Two radiologists reviewed all the MRI sequences on PACS workstations for all patients to evaluate the location, shape, size, margin, intensity, and enhancement of ATs. RESULTS: All uterine ATs exhibited either single round solid (n = 24) or predominantly cystic (n = 2) masses with either well-defined (n = 23) or ill-defined margin (n = 3). The diameter range of the tumors was 1.0 to 7.0 cm (mean, 3.8 cm). Solid masses were isointensive on T1WI and hypointensive on T2WI with moderate enhancement. The degree of enhancement in solid tumors was either lower than (18/24 [75%]) or equal to (6/24 [25%]) that of the myometrium. Predominantly cystic masses presented as cystic lesions with a little irregular solid nodule inside. The cystic parts were hypointensive on T1WI and hyperintensive on T2WI without enhancement, whereas the solid nodules were isointensive on both T1WI and T2WI with moderate enhancement. A large part of the uterine ATs (69.2% [18/26]) coexisted with other uterine diseases. On pathology, uterine ATs were characterized as gland-like structures with irregular expansion of tubular cavities, which might be correlated with low enhancement of tumors. The tumors were lined with flat or cuboidal mesothelial cells and residue of smooth muscle component, which might contribute to their hypointensive appearance on T2WI. CONCLUSIONS: Small solid uterine masses with homogeneous hypointensity on T2WI and lower enhancement or cystic lesions with inner irregular solid nodule may indicate the diagnosis of uterine ATs, and final diagnosis can be determined with pathology.

Efficient in vitro labeling rabbit neural stem cell with paramagnetic Gd-DTPA and fluorescent substance.

OBJECTIVES: The aim of this study is to label rabbit neural stem cells (NSCs) by using standard contrast agents (Gd-DTPA) in combination with PKH26 and in vitro track them with MR imaging. MATERIALS AND METHODS: NSCs from prenatal brains of rabbits were cultured and propagated. Intracellular uptake of Gd-DTPA was achieved by using a non-liposomal lipid transfection reagent (Effectene) as the transfection agent. After labeling with Gd-DTPA, cells were incubated with cellular membrane fluorescent dye PKH26. The labeling effectiveness and the longevity of Gd-DTPA maintenance were measured on a 1.5T MR scanner. The influence of labeling on the cellular biological behaviors was assessed by cellular viability, proliferation and differentiation assessment. RESULTS: The labeling efficiency of Gd-DTPA was up to 90%. The signal intensity on T1-weighted imaging and T1 values of labeled cells were significantly higher than those of unlabeled cells (P<0.05). The minimal number of detectable cells for T1-weighted imaging was 5×10(3). Cellular uptake of Gd-DTPA was maintained until 15 days after initially labeling. There was no significant difference in the cellular viability and proliferation between the labeled and unlabeled NSCs (P>0.05). Normal glial and neuronal differentiation remained in labeled NSCs like unlabeled NSCs. CONCLUSION: Highly efficient labeling NSCs with Gd-DTPA could be achieved by using Effectene. This method of labeling NSCs allows for tracking cells with MR imaging, and without alterations of cellular biological behaviors.

Magnetic resonance imaging of mesenchymal stem cells labeled with dual (MR and fluorescence) agents in rat spinal cord injury.

RATIONALE AND OBJECTIVES: In vivo tracking cells using gadolinium-based contrast agents have the important advantage of providing a positive contrast on T1-weighted images, which is less likely to be confused with artifacts because of postoperative local signal voids such as metal, hemorrhage, or air. The aim of this study is to paramagnetically and fluorescently label marrow with dual agents (gadolinium-diethylene triamine penta-acetic acid [Gd-DTPA] and PEI-FluoR) and track them after transplantation into spinal cord injury (SCI) with magnetic resonance imaging (MRI). MATERIALS AND METHODS: Marrow mesenchymal stem cells (MSCs) from Sprague-Dawley rats were incubated with PEI-FluoR (rhodamine-conjugated PEI-FluoR) and Gd-DTPA complex for labeling. After labeling, cellular viability, proliferation, and apoptosis were evaluated. T1 value and longevity of intracellular Gd-DTPA retention were measured on a 1.5 T MRI scanner. Thirty-six SCI rats were implanted with labeled and unlabeled MSCs and phosphate-buffered saline. Then, serial MRI and Basso-Beattie-Bresnehan (BBB) locomotor tests were performed and correlated with fluorescent microscopy. The relative signal intensity (RSL) of the engraftment in relation to normal cord was measured and the linear mixed model followed by post-hoc Bonferroni test was used to identify significant differences in RSL as well as BBB score. RESULTS: MSCs could be paramagnetically and fluorescently labeled by the dual agents. The labeling did not influence the cellular viability, proliferation, and apoptosis. The longevity of Gd-DTPA retention in labeled MSCs was up to 21 days. The distribution and migration of labeled MSCs in SCI lesions could be tracked until 7 days after implantation on MRI. The relative signal intensities of SCI rats treated with labeled cells at 1 day and 3 days (1.34 +/- 0.02, 1.27 +/- 0.03) were significantly higher than rats treated with unlabeled cells (0.94 +/- 0.01, 0.99 +/- 0.02) and phosphate-buffered saline (0.91 +/- 0.01, 0.95 +/- 0.01) (P < .05). Rats treated with labeled MSCs or unlabeled MSCs achieved significantly higher BBB scores than controls at 14, 21, 28, and 35 days after injury (P < .05). CONCLUSIONS: Labeling MSCs with the dual agents may enable cellular MRI and tracking in experimental spinal cord injury.