Technical Note: Confirming the prescribed angle of CT localizer radiographs and c-arm projection acquisitions
| Autor: | Zacariah E. Labby, Charles R. Wallace, Timothy P. Szczykutowicz, Nicholas Rubert |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Cone beam computed tomography
Scanner business.industry Orientation (computer vision) medicine.medical_treatment Radiography Brachytherapy Detector General Medicine 01 natural sciences 030218 nuclear medicine & medical imaging 010309 optics 03 medical and health sciences 0302 clinical medicine 0103 physical sciences medicine Computed radiography Nuclear medicine business Projection (set theory) |
| Zdroj: | Medical Physics. 43:865-869 |
| ISSN: | 0094-2405 |
| DOI: | 10.1118/1.4940124 |
| Popis: | Purpose: Accurate CTradiograph angle is not usually important in diagnostic CT. However, there are applications in radiation oncology and interventional radiology in which the orientation of the x-ray source and detector with respect to the patient is clinically important. The authors present a method for measuring the accuracy of the tube/detector assembly with respect to the prescribed tube/detector position for CT localizer, fluoroscopic, and general radiographimaging using diagnostic, mobile, and c-arm based CTsystems. Methods: A mathematical expression relating the x-ray projection of two metal BBs is related to gantry angle. Measurement of the BBs at a prescribed gantry (i.e., c-arm) angle can be obtained and using this relation the prescribed versus actual gantry angle compared. No special service mode or proprietary information is required, only access to projection images is required. Projection images are available in CT via CT localizer radiographs and in the interventional setting via fluorography. Results: The technique was demonstrated on two systems, a mobile CTscanner and a diagnostic CTscanner. The results confirmed a known issue with the mobile scanner and accurately described the CT localizer angle of the diagnostic system tested. Conclusions: This method can be used to quantify gantry angle, which is important when projection images are used for procedure guidance, such as in brachytherapy and interventional radiology applications. |
| Databáze: | OpenAIRE |
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