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C. Blazek and V. Blazek
perfusion map (Fig. 12.5), we found highly spatial distributed increases in the tumor
perfusion, concentrated in some hot spots. Jünger et al. also reported in [17] on the
increased perfusion in the tumor area, but his group makes its investigations only in
the geometric center of the tumor. Our preliminary results indicate, however, that a
spatially resolved PPGI quantification of tumor perfusions should be performed in
the future and could provide a diagnostically relevant information gain.
12.4.2 Further Selected Results: Assessment of Allergic Skin
Reactions and Their Hemodynamical Quantification
Using PPGI
Skin tests, introduced by Blackley in 1856 [18], are today in several variations beside
the allergological anamnesis, which is the basic tool for the allergy diagnostics in
clinical dermatology [12, 19–21]. Prick/puncture tests are widely used for confirmation of clinical immediate hyper-sensitivity induced by a wide variety of naturally
occurring inhalant and food allergens. On a per-test basis, they are generally considered to be the most convenient, least expensive, and most specific screening method
for detecting the presence of immunoglobulin E antibodies in patients with appropriate exposure histories. Under carefully defined circumstances, these tests are also
useful in the diagnosis of drug and chemical hypersensitivity reactions. To properly interpret allergy skin tests that detect immediate hyper-sensitivity, standardized
testing procedures need to be performed. However, analysis of the extent of local
skin reaction is limited by the qualitative registration (erythema and wheal diameters) and interpretation of the test could vary between patients and testers. The
aim of the following pilot study is to quantify and qualitatively evaluate the skin
reaction (observing of the expansion and intensity of allergic skin reaction by clinical inspection and assessment of local reaction) with the help of the PPGI method.
The size of the observed skin region and the spatial resolution can be arbitrarily
chosen. Figure 12.6 shows the selected measuring geometry for this study. Both
positive (histamine) and negative (diluent) control solutions are applied to the skin
in standardized manner (prick and intracutaneous tests).
For each experiment, four PPGI sequences of two minutes duration were taken:
• shortly before application,
• 4 min after application,
• 10 min after application and,
• 16 min after application.
Typical results from the PPGI examination for allergy diagnostic testing of one
healthy control subject are shown in Fig. 12.7. A digital photography of the examined
skin area (volar surface of the forearm) with the applied substances in the three fields is
shown in this figure together with one b/w PPG image snapshot. In both pictures, both
erythema and wheal response can be observed. In addition to this photogrammetric
C. Blazek and V. Blazek
perfusion map (Fig. 12.5), we found highly spatial distributed increases in the tumor
perfusion, concentrated in some hot spots. Jünger et al. also reported in [17] on the
increased perfusion in the tumor area, but his group makes its investigations only in
the geometric center of the tumor. Our preliminary results indicate, however, that a
spatially resolved PPGI quantification of tumor perfusions should be performed in
the future and could provide a diagnostically relevant information gain.
12.4.2 Further Selected Results: Assessment of Allergic Skin
Reactions and Their Hemodynamical Quantification
Using PPGI
Skin tests, introduced by Blackley in 1856 [18], are today in several variations beside
the allergological anamnesis, which is the basic tool for the allergy diagnostics in
clinical dermatology [12, 19–21]. Prick/puncture tests are widely used for confirmation of clinical immediate hyper-sensitivity induced by a wide variety of naturally
occurring inhalant and food allergens. On a per-test basis, they are generally considered to be the most convenient, least expensive, and most specific screening method
for detecting the presence of immunoglobulin E antibodies in patients with appropriate exposure histories. Under carefully defined circumstances, these tests are also
useful in the diagnosis of drug and chemical hypersensitivity reactions. To properly interpret allergy skin tests that detect immediate hyper-sensitivity, standardized
testing procedures need to be performed. However, analysis of the extent of local
skin reaction is limited by the qualitative registration (erythema and wheal diameters) and interpretation of the test could vary between patients and testers. The
aim of the following pilot study is to quantify and qualitatively evaluate the skin
reaction (observing of the expansion and intensity of allergic skin reaction by clinical inspection and assessment of local reaction) with the help of the PPGI method.
The size of the observed skin region and the spatial resolution can be arbitrarily
chosen. Figure 12.6 shows the selected measuring geometry for this study. Both
positive (histamine) and negative (diluent) control solutions are applied to the skin
in standardized manner (prick and intracutaneous tests).
For each experiment, four PPGI sequences of two minutes duration were taken:
• shortly before application,
• 4 min after application,
• 10 min after application and,
• 16 min after application.
Typical results from the PPGI examination for allergy diagnostic testing of one
healthy control subject are shown in Fig. 12.7. A digital photography of the examined
skin area (volar surface of the forearm) with the applied substances in the three fields is
shown in this figure together with one b/w PPG image snapshot. In both pictures, both
erythema and wheal response can be observed. In addition to this photogrammetric