Effect of phase cycling and averaging on ex vivo prostate image quality.

<p>Cropped and enlarged sections of axial scans: A: 2 PC, 4 NEX, B: 4 PC, 2 NEX, C: 8 PC, 1 NEX. Black arrowheads indicate prostate, white arrowheads urethra, FP is the fat pad used for CNR measurements and LN are the inguinal lymph nodes. Scale bar is 1 cm. Axial scan, FOV 4×4 cm, 200 µm isotropic resolution, TR/TE = 3.9/2.0 ms, FA 30°, BW ±62.5 kHz, 20 minutes.</p

Sections of coronal view of mouse with prostate and lymph nodes identified.

<p>Tail is at left, head at right. White arrows indicate organs of interest as follows. A: popliteal lymph nodes; B: prostate; C: iliac lymph nodes; D: inguinal lymph nodes with lymph vessels visible; E: Renal lymph nodes. Scale bar is 0.5 cm. Coronal scan, FOV 6×3.3 cm, 200 µm isotropic resolution, TR/TE = 4.6/2.3 ms, BW ±62.5 kHz, FA 40°, 8 PC, 2 NEX, 26 minutes.</p

3 views of prostate from one in-vivo scan.

<p>A: axial, B: coronal, C: sagittal. White arrows indicate prostate. Scale bar is 0.5 cm. Axial scan, FOV 3×3 cm, 200 µm isotropic resolution, TR/TE = 4.6 ms/2.3 ms, 4 PC, 2 NEX, FA 50°, BW ±62.5 kHz, 14 minutes.</p

Comparison of in vivo axial views acquired with A: bSSFP, B: T1wSE and C: T2wSW.

<p>Black arrows indicate prostate, white arrows indicate urethra. Scale bar is 1 cm. bSSFP images acquired using optimized sequence with 3×3 cm FOV. Spin echo sequences acquired with axial orientation, FOV 3×3 cm, TR/TE = 600/25 ms (T1w), 2000/70 ms (T2w), 1 mm slice thickness, 128×128 matrix, 234 mm in-plane resolution, and 20 (T1w) and 17 (T2w) minutes acquisition time.</p

<i>In vitro</i> validation of ¹⁹F-MRI quantification accuracy.

<p>Quantification was validated in a phantom study using cell pellets ranging from 2x10⁵ to 2x10⁶ MSC. Pellets were imaged three times, with the error bars representing the standard deviation between scans. The ¹⁹F-MRI quantification is in very strong agreement with the true number of cells, and has a Pearson correlation coefficient of 0.99. The red line represents the ideal result of a 1:1 correlation.</p

Representative Day 0 MRI, fluorescence microscopy, and histology acquired as 10x magnification from both implant models.

<p>(A, E) Representative MRI from mice receiving either 2x10⁶ mMSC or 1.5x10⁶ hMSC respectively. The day 0 <i>in vivo</i>¹⁹F-MRI quantification correlates very well with the number of implanted cells. The reference tube is marked by “R”. (B) The red fluorescent fluorine agent is clearly visible in the tissue of the immune competent model, (F) as well as in the immune-compromised model. (C) Furthermore, the GFP+ mMSC are observable within the tissue section. (D) Overlaying the two fluorescent images, reveals the ¹⁹F agent colocalized with the GFP+ mMSC, as expected. (G, H) H&E stained tissue sections corresponding to the fluorescence microscopy clearly show the implant site of the mMSC and hMSC respectively. Scale bars in all images represent 250μm.</p

H&E sections of brachial lymph nodes from C57B/l6, Nude and C.B.-17 SCID mice.

<p>Whole nodes are shown at 5x magnification. The T cell rich paracortex (arrowsheads) and B cell rich follicles (arrows) can be easily seen in the nodes of C57B/l6 mice, where as in Nude mouse lymph nodes, only the B cell rich follicles can be seen (arrows). In the areas of the paracortex where T cells should be found, vacant areas are detected (arrowheads), helping to explain the hyperintense appearance of many of these nodes in MR images. Nodes in SCID mice lack both the paracortex and follicles, leaving these nodes underdeveloped and significantly smaller in size.</p

Lymph node volumes of C57Bl/6, Nude and CB-17 SCID mice. All volumes listed as mean ± standard deviation.

<p>Lymph node volumes of C57Bl/6, Nude and CB-17 SCID mice. All volumes listed as mean ± standard deviation.</p

Location of lymph nodes within the mouse body.

<p>(A) Whole mouse body bSSFP image of a C57Bl/6 mouse showing both the brachial and inguinal lymph nodes (arrows) and (B) 3D reconstruction showing the location of various lymph nodes within the mouse; 1 – axillary node, 2 – brachial node, 3 – inguinal node, 4 – popliteal node.</p

Cellular viability and loading with the ¹⁹F-agent.

<p>(A) Cellular viability was investigated before and after labeling with the ¹⁹F-agent, Cell Sense. Although a statistically significant difference was observed in hMSC after labeling, the viability remained high (>80%) in all experiments. There was no significant difference in mMSC viability. (B) Cellular loading was determined by performing NMR on a known number of cells alongside a reference peak with a known number of ¹⁹F atoms. We observed variation in cellular loading of both hMSC and mMSC between experiments. However, this variation does not affect in vivo ¹⁹F quantification since each transplant was only compared to its specific cellular loading.</p