What risk does a low eGFR pose in CT imaging with contrast?

What risk does a low eGFR pose in CT imaging with contrast?

• A. Increased risk of allergic reactions
• B. Increased risk of radiation-induced tissue damage
• C. Decreased image quality
• D. Increased risk of contrast-induced nephropathy

Answer: (D)

Low eGFR means the kidneys have reduced filtering capacity, so they’re less able to clear iodinated contrast from the bloodstream. When iodinated contrast is used in CT, it can cause temporary kidney injury through both vasoconstriction of renal vessels and direct tubular toxicity. The weaker the kidneys are at baseline, the greater the risk of this contrast-induced nephropathy, which is why a patient with a low eGFR is at higher risk after contrast exposure. Clinically, this leads to careful assessment of renal function before imaging, using the lowest effective contrast dose, opting for iso-osmolar or low-osmolar agents when needed, ensuring adequate hydration, and considering alternatives if the risk is too high. CIN typically shows up as a rise in creatinine within 24 to 72 hours after contrast administration. Allergic reactions, radiation damage, and image quality are not directly determined by eGFR, so they’re not the primary concern tied to a low eGFR.

Low eGFR means the kidneys have reduced filtering capacity, so they’re less able to clear iodinated contrast from the bloodstream. When iodinated contrast is used in CT, it can cause temporary kidney injury through both vasoconstriction of renal vessels and direct tubular toxicity. The weaker the kidneys are at baseline, the greater the risk of this contrast-induced nephropathy, which is why a patient with a low eGFR is at higher risk after contrast exposure. Clinically, this leads to careful assessment of renal function before imaging, using the lowest effective contrast dose, opting for iso-osmolar or low-osmolar agents when needed, ensuring adequate hydration, and considering alternatives if the risk is too high. CIN typically shows up as a rise in creatinine within 24 to 72 hours after contrast administration. Allergic reactions, radiation damage, and image quality are not directly determined by eGFR, so they’re not the primary concern tied to a low eGFR.