Low-dose whole-spine imaging using slot-scan digital radiography: a phantom study

• Published in: BMC medical imaging Vol. 23; no. 1; p. 17
• Main Authors: Ichikawa, Shigeji, Muto, Hiroe, Imao, Masashi, Nonaka, Takashi, Sakekawa, Kouji, Sato, Yasutaka
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 30.01.2023; BioMed Central; BMC
• Subjects: Aluminum; Beam-hardening filter; Digital imaging; Figure of merit; Humans; Image acquisition; Image quality; Medical imaging equipment; Parameters; Phantoms, Imaging; Radiation; Radiation Dosage; Radiation dose; Radiographic Image Enhancement - methods; Radiography; Radiography, Medical; Radionuclide Imaging; Scattering; Slot-scan technology; Spine; Thickness; Whole spine; Whole spine radiography; X-rays; Maryland; Whole spine; Radiation dose; Whole spine radiography; Beam-hardening filter; Slot-scan technology
• ISSN: 1471-2342; 1471-2342
• DOI: 10.1186/s12880-023-00971-1

Slot-scan digital radiography (SSDR) is equipped with detachable scatter grids and a variable copper filter. In this study, this function was used to obtain parameters for low-dose imaging for whole-spine imaging. With the scatter grid removed and the beam-hardening (BH) filters (0.0, 0.1, 0.2, or 0.3 mm) inserted, the tube voltage (80, 90, 100, 110, or 120 kV) and the exposure time were adjusted to 20 different parameters that produce equivalent image quality. Slot-scan radiographs of an acrylic phantom were acquired with the set parameters, and the optimal parameters (four types) for each filter were determined using the figure of merit. For the four types of parameters obtained in the previous section, SSDR was performed on whole-spine phantoms by varying the tube current, and the parameter with the lowest radiation dose was determined by visual evaluation. The parameters for each filter according to the FOM results were 90 kV, 400 mA, and 2.8 ms for 0.0 mm thickness; 100 kV, 400 mA, and 2.0 ms for 0.1 mm thickness; 100 kV, 400 mA, and 2.8 ms for 0.2 mm thickness; and 110 kV, 400 mA, and 2.2 ms for 0.3 mm thickness. Visual evaluation of the varying tube currents was performed using these four parameters when the BH filter thicknesses were 0.0, 0.1, 0.2, and 0.3 mm. The entrance surface dose was 59.44 µGy at 90 kV, 125 mA, and 2.8 ms; 57.39 µGy at 100 kV, 250 mA, and 2.0 ms; 46.89 µGy at 100 kV, 250 mA, and 2.8 ms; and 39.48 µGy at 110 kV, 250 mA, and 2.2 ms, indicating that the 0.3-mm BH filter was associated with the minimum dose. Whole-spine SSDR could reduce the dose by 79% while maintaining the image quality.