10. In PMOD software for image analysis, there are many options
of image visualization scale, from grayscale to different colors
scales. In our analyses, we normally selected the “color scale,”
which goes from a dark blue color for the lowest attenuation to
an intense red color for the highest one, passing through
green, yellow, and orange colors for intermediate attenuation
in increasing order (see Figs. 3, 4, and 6).
11. An example of samples we have thoroughly analyzed is ovarian
tissue (bovine and human). We normally prepare ovarian tissue
samples in strips of about 5 Â 5 Â 1 mm
3 dimensions, which
are placed at the bottom of the cryovial where they are going to
be cryopreserved. To analyze the samples and quantify the
X-ray attenuation and therefore the Me 2 SO concentration
inside the samples, we created VOIs of dimensions slightly
shorter than the ovarian tissue samples, to make sure the
VOIs contain only tissue. For example, a typical VOI dimension we use for these samples is 3 Â 3 Â 1 mm
3 (see Fig. 4).
12. For our CT measurements at temperatures below À140
C, we
used an outlet nitrogen gas of about 0.4 bars. To optimize this
pressure, previous tests should be performed to fix this
parameter.
13. In the case of ovarian tissue samples, we use 1.8 mL cryovials
which need around 10 min to cool at that temperature and
with that nitrogen gas pressure. Previous tests are necessary for
different vials, depending on the volume. To monitor the time
needed to reach the required temperature, connect a thermocouple to the Picolog data logger and place the hot junction
inside the container, immersed in the solution.
Acknowledgments
This work has been supported by the Junta de Andalucı ´a, Proyectos
de Investigacio ´ n de Excelencia (P08-CTS-03965), and Siemens
Healthcare S.L.U. (2729/0708).
References
1. Corral A, Balcerzyk M, Parrado-Gallego A,
Fernandez-Gomez I, Lamprea DR, Olmo A,
Risco R (2015) Assessment of the cryoprotectant concentration inside a bulky organ for
cryopreservation using X-ray computed
tomography. Cryobiology 71:419–431
2. Knoll GF (2010) Radiation detection and measurement, 4th edn. John Wiley & Sons,
New York
3. Seibert JA, Boone JM (2005) X-ray imaging
physics for nuclear medicine technologists.
Part 2: X-ray interactions and image formation.
J Nucl Med Technol 33:3–18
4. Bischof JC, Mahr B, Choi JH, Behling M,
Mewes D (2007) Use of X-ray tomography to
map crystalline and amorphous phases in frozen biomaterials. Ann Biomed Eng
35:292–304
X-Ray Computed Tomography
329
of image visualization scale, from grayscale to different colors
scales. In our analyses, we normally selected the “color scale,”
which goes from a dark blue color for the lowest attenuation to
an intense red color for the highest one, passing through
green, yellow, and orange colors for intermediate attenuation
in increasing order (see Figs. 3, 4, and 6).
11. An example of samples we have thoroughly analyzed is ovarian
tissue (bovine and human). We normally prepare ovarian tissue
samples in strips of about 5 Â 5 Â 1 mm
3 dimensions, which
are placed at the bottom of the cryovial where they are going to
be cryopreserved. To analyze the samples and quantify the
X-ray attenuation and therefore the Me 2 SO concentration
inside the samples, we created VOIs of dimensions slightly
shorter than the ovarian tissue samples, to make sure the
VOIs contain only tissue. For example, a typical VOI dimension we use for these samples is 3 Â 3 Â 1 mm
3 (see Fig. 4).
12. For our CT measurements at temperatures below À140
C, we
used an outlet nitrogen gas of about 0.4 bars. To optimize this
pressure, previous tests should be performed to fix this
parameter.
13. In the case of ovarian tissue samples, we use 1.8 mL cryovials
which need around 10 min to cool at that temperature and
with that nitrogen gas pressure. Previous tests are necessary for
different vials, depending on the volume. To monitor the time
needed to reach the required temperature, connect a thermocouple to the Picolog data logger and place the hot junction
inside the container, immersed in the solution.
Acknowledgments
This work has been supported by the Junta de Andalucı ´a, Proyectos
de Investigacio ´ n de Excelencia (P08-CTS-03965), and Siemens
Healthcare S.L.U. (2729/0708).
References
1. Corral A, Balcerzyk M, Parrado-Gallego A,
Fernandez-Gomez I, Lamprea DR, Olmo A,
Risco R (2015) Assessment of the cryoprotectant concentration inside a bulky organ for
cryopreservation using X-ray computed
tomography. Cryobiology 71:419–431
2. Knoll GF (2010) Radiation detection and measurement, 4th edn. John Wiley & Sons,
New York
3. Seibert JA, Boone JM (2005) X-ray imaging
physics for nuclear medicine technologists.
Part 2: X-ray interactions and image formation.
J Nucl Med Technol 33:3–18
4. Bischof JC, Mahr B, Choi JH, Behling M,
Mewes D (2007) Use of X-ray tomography to
map crystalline and amorphous phases in frozen biomaterials. Ann Biomed Eng
35:292–304
X-Ray Computed Tomography
329