Low-dose techniques in CT-guided interventions.

Computed tomography (CT)-guided interventions such as biopsy, drainage, and ablation may be significant sources of radiation exposure in both patients and radiologists. Simple CT techniques to reduce radiation dose may be employed without increasing the procedure time or significantly degrading image quality. To develop low-dose protocols, it is important to understand the key concepts of delivered radiation dose to patients and physicians during CT-guided interventions. Patient dose estimates are easily followed and are provided at CT workstations. Familiarity with dose estimates, which are expressed as CT dose index and dose-length product, is also important. Methods to reduce radiation exposure in patients and physicians include performing proper preprocedure planning and paying careful attention to technique during the planning stage, making use of personal protective equipment, performing CT fluoroscopy intermittently instead of in real time, and optimizing needle visualization. Representative examples of these techniques have resulted in dose reductions of as much as 89%. Alternative imaging technologies that do not use ionizing radiation, such as virtual and ultrasonographic guidance, may also be used to reduce radiation dose. Understanding dose contribution strategies to reduce radiation dose provides a safer, more efficient environment for patients and the radiology team.