Skin dose mapping for fluoroscopically guided interventions
Methodology for determining in-field skin locations: In Fig. 1(a), a unit vector from the source to each skin location is determined. In Fig. 1(b), these vectors are rotated such that they align with a known axis. In Fig 1(c), angles α and β are calculated from the FOV and source-to-detector distance and define a four-sided projection pyramid. In Fig 1(d), corresponding angles γ and θ are defined for each unit vector and compared to α and β within a conditional statement.
Six measurements used to create patient-sculpted contour phantoms.
For each patient-specific model, peak skin dose was also calculated for a reference stylized, reference hybrid, patient-dependent hybrid, and patient-sculpted contour phantom. Accuracy was quantified using the PSD calculated using the patient-specific model as the standard.
Relative skin dose maps as calculated for seven patient exams. Skin doses are relative to the PSD for each individual patient.
Skin dose comparison between a real patient and anthropometrically matched hybrid patient dependent phantom (view is posterior). [Reprinted with permission from the Radiological Society of North America (RSNA). Balter, Hopewell, Miller, Wagner, and Zelefsky, “Fluoroscopically guided interventional procedures: A review of radiation effects on patients’ skin and hair,” Radiology 254, 326-341 (2010)].
(a) Prototype display of clinical skin dose mapping system. (b) Prototype display of dose map on the Siemens Artis Zee console. Co-author Dr. Dan Siragusa is shown in the left.
Geometric and dose parameters extracted from the RDSR. These parameters are used by the skin dose mapping program to orient the tube with respect to the anthropomorphic model and to determine PSD.
The skin dose mapping program determines the amount of skin area receiving doses within the four ranges where effects can be expected.
Mean absolute percent difference in PSD between patient-specific models and four different phantom types. Results are grouped according to patient size, tube projection, and orientation.
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