ABSTRACT
Many women are pregnant during several percent of their lives. Occasionally, there is a need for neuroradiological examinations during pregnancy or lactation. In our clinical work, we regularly see that female patients are being withheld relevant diagnostic scans during pregnancy, due to insufficient knowledge or an unbalanced comparison between benefits and risks. This article describes the current knowledge regarding conditions for performing CT and MRI scans in pregnant and lactating patients, including the use of contrast media. PET scans and reactions to contrast media are briefly mentioned, but interventional radiology is not discussed.
Subject(s)
Contrast Media , Lactation , Pregnancy , Humans , Female , Magnetic Resonance Imaging , Breast Feeding , Tomography, X-Ray ComputedABSTRACT
Background Increased interest in radiation dose reduction in neurointerventional procedures has led to the development of a method called "spot fluoroscopy" (SF), which enables the operator to collimate a rectangular or square region of interest anywhere within the general field of view. This has potential advantages over conventional collimation, which is limited to symmetric collimation centered over the field of view. Purpose To evaluate the effect of SF on the radiation dose. Material and Methods Thirty-five patients with intracranial aneurysms were treated with endovascular coiling. SF was used in 16 patients and conventional fluoroscopy in 19. The following parameters were analyzed: the total fluoroscopic time, the total air kerma, the total fluoroscopic dose-area product, and the fluoroscopic dose-area product rate. Statistical differences were determined using the Welch's t-test. Results The use of SF led to a reduction of 50% of the total fluoroscopic dose-area product (CF = 106.21 Gycm2, SD = 99.06 Gycm2 versus SF = 51.80 Gycm2, SD = 21.03 Gycm2, p = 0.003884) and significant reduction of the total fluoroscopic dose-area product rate (CF = 1.42 Gycm2/min, SD = 0.57 Gycm2/s versus SF = 0.83 Gycm2/min, SD = 0.37 Gycm2/min, p = 0.00106). The use of SF did not lead to an increase in fluoroscopy time or an increase in total fluoroscopic cumulative air kerma, regardless of collimation. Conclusion The SF function is a new and promising tool for reduction of the radiation dose during neurointerventional procedures.
Subject(s)
Intracranial Aneurysm/diagnostic imaging , Radiation Dosage , Radiation Injuries/prevention & control , Radiography, Interventional/methods , Brain/diagnostic imaging , Female , Fluoroscopy , Humans , Male , Middle Aged , Prospective StudiesABSTRACT
PURPOSE: To establish the concentrations of iodine contrast media (I-CM) iso-attenuating with 0.5M gadolinium contrast media (Gd-CM), regarded diagnostic in catheter angiography and vascular interventions in azotemic patients, at various X-ray tube potentials with correlation to skin radiation dose. MATERIALS AND METHOD: 20-mL syringes filled with 30, 40, 50, 70 and 90 mgI/mL, 0.5M Gd-CM and air were placed in a water-equivalent phantom and exposed at about 50, 60, 70, 80 and 90 kV in an X-ray angiographic system. Relative contrast between the contrast materials and the background phantom material was measured on a PACS workstation. Radiation entrance dose, measured with a dose meter and estimated from the dose-area-product (DAP), was adjusted for radiation backscatter to simulate absorbed skin dose. RESULT: The iodine concentrations 30, 40, 50, 70 and 90 mg/mL resulted in the same relative contrast as 0.5M gadolinium at 53, 57, 62, 71 and 85 kVp, respectively. Air had lower relative contrast than all iodine concentrations at all kVp-settings except for 30 mgI/mL above 84 kVp. The measured skin radiation dose was less than 1 mGy per exposure at all kVp-settings, and around 25-30% lower than the dose estimations derived from the angiographic system's in-built DAP meter. CONCLUSION: Low-kilovoltage X-ray technique and ultra-low concentrations of I-CM iso-attenuating with 0.5M Gd-CM may be utilizable in peripheral arteriography and endovascular interventions, to minimize the total CM-dose to avoid CIN in azotemic patients.
