Effective Radiation Dose, Time, and Contrast Medium to Measure Fractional Flow Reserve

OBJECTIVES: This study sought to define the additional effective radiation dose, procedural time, and contrast medium needed to obtain fractional flow reserve (FFR) measurements after a diagnostic coronary angiogram. The FFR measurements performed at the end of a diagnostic angiogram allow the obtaining of functional information that complements the anatomic findings.

METHODS: In 200 patients (mean age 66 +/- 10 years) undergoing diagnostic coronary angiography, FFR was measured in at least 1 intermediate coronary artery stenosis. Hyperemia was achieved by intracoronary (n = 180) or intravenous (n = 20) adenosine. The radiation dose (mSv), procedural time (min), and contrast medium (ml) needed for diagnostic angiography and FFR were recorded.

RESULTS: A total of 296 stenoses (1.5 +/- 0.7 stenoses per patient) were assessed. The additional mean radiation dose, procedural time, and contrast medium needed to obtain FFR expressed as a percentage of the entire procedure were 30 +/- 16% (median 4 mSv, range 2.4 to 6.7 mSv), 26 +/- 13% (median 9 min, range 7 to 13 min), and 31 +/- 16% (median 50 ml, range 30 to 90 ml), respectively. The radiation dose and contrast medium during FFR were similar after intravenous and intracoronary adenosine, though the procedural time was slightly longer with intravenous adenosine (median 11 min, range 10 to 17 min, p = 0.04) than with intracoronary adenosine (median 9 min, range 7 to 13 min). When FFR was measured in 3 or more lesions, radiation dose, procedural time, and contrast medium increased.

CONCLUSIONS: The additional radiation dose, procedural time, and contrast medium to obtain FFR measurement are low as compared to other cardiovascular imaging modalities. Therefore, the combination of diagnostic angiography and FFR measurements is warranted to provide simultaneously anatomic and functional information in patients with coronary artery disease. 

PMID: 20723854

Posted in Invasive Imaging and tagged , , , , .


  1. Interesting article in the context of recent discussions about radiation dose of cardiovascular imaging.

    Also see:

    Ionizing Radiation Exposure to Patients Admitted With Acute Myocardial Infarction in the United States
    Prashant Kaul, Sofia Medvedev, Samuel F. Hohmann, Pamela S. Douglas, Eric D. Peterson, and Manesh R. Patel
    Circulation published 8 November 2010, 10.1161/CIRCULATIONAHA.110.973339


    Radiation dose and cancer risk in retrospectively and prospectively ECG-gated coronary angiography using 64-slice multidetector CT.
    Huang B, Li J, Law MW, Zhang J, Shen Y, Khong PL.
    Br J Radiol. 2010;83(986):152-8.

  2. Well designed study! The conclusion here is that the additional functional information provided by FFR on a single coronary can be obtained at the cost of an extra 2.8 mSv of effective radiation dose (plus contrast material).
    I guess the greater question here is which patients should go to the cath lab without a prior non-invasive test that requires the use of FFR? Or maybe more importantly is which patients with a prior non-invasive test require the added benefit of FFR at angiography?

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