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Journal of applied clinical medical physics [electronic resource] / American College of Medical Physics


PURPOSE: We explore the optimal cone-beam CT (CBCT) acquisition parameters to improve CBCT image quality to enhance intracranial stereotactic radiosurgery (SRS) localization and also assess the imaging dose levels associated with each imaging protocol.

METHODS: Twenty-six CBCT acquisition protocols were generated on an Edge

RESULTS: The Catphan data indicates that adjusting acquisition parameters had direct effects on the image noise level, low contrast detection, and CNR, but had minimal effects on uniformity, HU constancy, and spatial resolution. The noise level was reduced from 34.5 ± 0.3 to 18.5 ± 0.2 HU with a four-fold reduction in gantry speed, and to 18.7 ± 0.2 HU with a four-fold increase in tube current. Overall, the noise level was found to be proportional to inverse square root of imaging dose, and imaging dose was proportional to the product of total tube current-time product and the cube of the x-ray potential. Analysis of the anthropomorphic head phantom data and clinical SRS imaging data also indicates that noise is reduced with imaging dose increase.

CONCLUSIONS: Our results indicate that optimization of the imaging protocol, and thereby an increase in the imaging dose, is warranted for improved soft-tissue visualization for intracranial SRS.

Medical Subject Headings

Bone and Bones; Cone-Beam Computed Tomography; Head; Humans; Image Processing, Computer-Assisted; Organs at Risk; Phantoms, Imaging; Prognosis; Radiosurgery; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Intensity-Modulated; Soft Tissue Neoplasms

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