Hypertrophic Cardiomyopathy: Quantification of Late Gadolinium Enhancement with Contrast-enhanced Cardiovascular MR Imaging

Published Online:https://doi.org/10.1148/radiol.10090526

We found that semiautomated late gadolinium enhancement (LGE) cardiovascular MR gray-scale thresholding with 6 or more standard deviations above the mean signal intensity for the visually normal remote myocardium yields the closest approximation of the extent of LGE identified with visual assessment and is highly reproducible for LGE quantification in patients with hypertrophic cardiomyopathy.

Purpose

To determine the most reproducible semiautomated gray-scale thresholding technique for quantifying late gadolinium enhancement (LGE) in a large cohort of patients with hypertrophic cardiomyopathy (HCM).

Materials and Methods

All study patients signed a statement approved by the internal review boards of the participating institutions, agreeing to the use of their medical information for research purposes. LGE cardiovascular magnetic resonance (MR) imaging was performed in 201 patients (71% male) with a mean age of 41.5 years ± 17.6 (standard deviation [SD]) by using standard techniques with administration of 0.2 mmol of gadopentetate dimeglumine per kilogram of body weight. The presence and quantity of LGE were determined first with visual assessment; then with gray-scale thresholds of 2 SDs, 4 SDs, and 6 SDs above the mean signal intensity for the normal remote myocardium; and then with 2 SDs above noise. The LGE quantifications were repeated 4 or more weeks apart to assess reproducibility. Bland-Altman analysis and correlation coefficients were used to compare the visual and various thresholding methods, with normally distributed variables expressed as means ± SDs.

Results

LGE was identified in 103 (51%) subjects. The mean quantity of LGE at visual analysis was 13 g ± 20 compared with 12 g ± 17 at 6 SDs, 25 g ± 23 at 4 SDs, 55 g ± 31 at 2 SDs, and 64 g ± 69 at 2 SDs above noise. All gray-scale thresholds were significantly correlated with visual assessment. The 6-SD threshold had the strongest correlation (r = 0.913, P < .0001) compared with thresholds of 2 SDs (r = 0.81) and 4 SDs (r = 0.91) above the mean and 2 SDs above noise (r = 0.53) (P < .001 for all comparisons). In addition, compared with visual assessment, the 6-SD threshold yielded less intraobserver variability (difference, 0.6 g ± 8, κ = 0.66 [P < .0001] vs 1.4 g ± 9, κ = 0.49 [P < .0001]) and less interobserver variability (difference, 5.4 g ± 18, κ = 0.20 [P < .0001] vs −18.4 g ± 18, κ = 0.08 [P < .0001]).

Conclusion

Semiautomated LGE cardiovascular MR gray-scale thresholding with 6 or more SDs above the mean signal intensity for the visually normal remote myocardium yields the closest approximation of the extent of LGE identified with visual assessment and is highly reproducible. This objective method should be considered for quantifying LGE in patients with HCM.

© RSNA, 2010

References

  • 1 Bondarenko O, Beek AM, Hofman MB, et al.. Standardizing the definition of hyperenhancement in the quantitative assessment of infarct size and myocardial viability using delayed contrast-enhanced CMR. J Cardiovasc Magn Reson 2005;7(2):481–485.
  • 2 Kim RJ, Fieno DS, Parrish TB, et al.. Relationship of MRI delayed contrast enhancement to irreversible injury, infarct age, and contractile function. Circulation 1999;100(19):1992–2002.
  • 3 Choudhury L, Mahrholdt H, Wagner A, et al.. Myocardial scarring in asymptomatic or mildly symptomatic patients with hypertrophic cardiomyopathy. J Am Coll Cardiol 2002;40(12):2156–2164.
  • 4 Moon JC, Mogensen J, Elliott PM, et al.. Myocardial late gadolinium enhancement cardiovascular magnetic resonance in hypertrophic cardiomyopathy caused by mutations in troponin I. Heart 2005;91(8):1036–1040.
  • 5 Moon JC, McKenna WJ, McCrohon JA, Elliott PM, Smith GC, Pennell DJ. Toward clinical risk assessment in hypertrophic cardiomyopathy with gadolinium cardiovascular magnetic resonance. J Am Coll Cardiol 2003;41(9):1561–1567.
  • 6 Schmidt A, Azevedo CF, Cheng A, et al.. Infarct tissue heterogeneity by magnetic resonance imaging identifies enhanced cardiac arrhythmia susceptibility in patients with left ventricular dysfunction. Circulation 2007;115(15):2006–2014.
  • 7 Yan AT, Shayne AJ, Brown KA, et al.. Characterization of the peri-infarct zone by contrast-enhanced cardiac magnetic resonance imaging is a powerful predictor of post-myocardial infarction mortality. Circulation 2006;114(1):32–39.
  • 8 Fieno DS, Kim RJ, Chen EL, Lomasney JW, Klocke FJ, Judd RM. Contrast-enhanced magnetic resonance imaging of myocardium at risk: distinction between reversible and irreversible injury throughout infarct healing. J Am Coll Cardiol 2000;36(6):1985–1991.
  • 9 Mahrholdt H, Wagner A, Holly TA, et al.. Reproducibility of chronic infarct size measurement by contrast-enhanced magnetic resonance imaging. Circulation 2002;106(18):2322–2327.
  • 10 Amado LC, Gerber BL, Gupta SN, et al.. Accurate and objective infarct sizing by contrast-enhanced magnetic resonance imaging in a canine myocardial infarction model. J Am Coll Cardiol 2004;44(12):2383–2389.
  • 11 Assomull RG, Prasad SK, Lyne J, et al.. Cardiovascular magnetic resonance, fibrosis, and prognosis in dilated cardiomyopathy. J Am Coll Cardiol 2006;48(10):1977–1985.
  • 12 Maron MS, Appelbaum E, Harrigan CJ, et al.. Clinical profile and significance of delayed enhancement in hypertrophic cardiomyopathy. Circ Heart Fail 2008;1(3):184–191.
  • 13 van der Geest RJ, Buller VG, Jansen E, et al.. Comparison between manual and semiautomated analysis of left ventricular volume parameters from short-axis MR images. J Comput Assist Tomogr 1997;21(5):756–765.
  • 14 Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986;1(8476):307–310.
  • 15 Varnava AM, Elliott PM, Mahon N, Davies MJ, McKenna WJ. Relation between myocyte disarray and outcome in hypertrophic cardiomyopathy. Am J Cardiol 2001;88(3):275–279.
  • 16 Babu-Narayan SV, Kilner PJ, Li W, et al.. Ventricular fibrosis suggested by cardiovascular magnetic resonance in adults with repaired tetralogy of fallot and its relationship to adverse markers of clinical outcome. Circulation 2006;113(3):405–413.
  • 17 Wu KC, Weiss RG, Thiemann DR, et al.. Late gadolinium enhancement by cardiovascular magnetic resonance heralds an adverse prognosis in nonischemic cardiomyopathy. J Am Coll Cardiol 2008;51(25):2414–2421.
  • 18 Wu E, Ortiz JT, Tejedor P, et al.. Infarct size by contrast enhanced cardiac magnetic resonance is a stronger predictor of outcomes than left ventricular ejection fraction or end-systolic volume index: prospective cohort study. Heart 2008;94(6):730–736.
  • 19 Adabag AS, Maron BJ, Appelbaum E, et al.. Occurrence and frequency of arrhythmias in hypertrophic cardiomyopathy in relation to delayed enhancement on cardiovascular magnetic resonance. J Am Coll Cardiol 2008;51(14):1369–1374.
  • 20 Kim RJ, Wu E, Rafael A, et al.. The use of contrast-enhanced magnetic resonance imaging to identify reversible myocardial dysfunction. N Engl J Med 2000;343(20):1445–1453.
  • 21 Mahrholdt H, Wagner A, Judd RM, Sechtem U, Kim RJ. Delayed enhancement cardiovascular magnetic resonance assessment of non-ischaemic cardiomyopathies. Eur Heart J 2005;26(15):1461–1474.
  • 22 Jackson E, Bellenger N, Seddon M, Harden S, Peebles C. Ischaemic and non-ischaemic cardiomyopathies: cardiac MRI appearances with delayed enhancement. Clin Radiol 2007;62(5):395–403.
  • 23 Moon JC, Reed E, Sheppard MN, et al.. The histologic basis of late gadolinium enhancement cardiovascular magnetic resonance in hypertrophic cardiomyopathy. J Am Coll Cardiol 2004;43(12):2260–2264.

Article History

Received April 1, 2009; revision requested April 28; revision received July 14, 2010; accepted July 26; final version accepted August 5.
Published online: Jan 2011
Published in print: Jan 2011