title: Assessment of acute myocarditis by cardiovascular MR: diagnostic performance of shortened protocols.
abstract: The recommended cardiovascular magnetic resonance (CMR) diagnostic criteria for active myocarditis ("Lake Louise Criteria") are based on edema-sensitive (T2-weighted) imaging and two different contrast-enhanced techniques, the early gadolinium enhancement ratio (EGEr) and late gadolinium enhancement (LGE). Because fast spin echo sequences used for determining the EGEr and edema-sensitive T2-weighted sequences have inconsistent image quality, these components are often skipped in institutional standard protocols. We aimed to compare the diagnostic performance of the Lake Louise Criteria with and without T2-weighted or early gadolinium-enhanced CMR imaging in a clinical setting. We investigated 35 patients with suspected acute myocarditis (27 males; Age 39.8 ± 16.6) and 10 healthy controls (5 males; age 33.8 ± 10.4). CMR sequences investigated included an edema-sensitive short-T1 triple inversion recovery, T1-weighted turbo spin echo imaging before and within 4 min after gadolinium injection (EGEr), and a phase sensitive inversion-recovery gradient echo sequence 5-10 min after gadolinium injection (LGE). Quantitative and qualitative image analyses, respectively, were performed for EGEr and areas with increased signal in LGE and edema-sensitive images. EGEr, T2, and LGE burden were significantly higher in patients than in controls (EGEr: 5.8 ± 3.0 vs. 2.5 ± 1.7; p = 0.002, T2: 24 vs. 0; p < 0.001, LGE: 27 vs. 4; p < 0.05). The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were as follows: EGEr: 66, 90, 96, 43, and 72%; T2: 69, 100, 100, 53, and 76%; LGE: 77, 60, 87, 43 and 73%; T2 and/or LGE: 91, 60, 89, 67, 84% Lake Louise Criteria, "two out of three": 80, 90, 96, 53, and 82%. The sensitivity of "T2 and/or LGE" was significantly higher than the Lake Louise Criteria (p < 0.05), while the overall diagnostic accuracy was not statistically different. The overall diagnostic accuracy "T2 and/or LGE" was significantly better than that of LGE alone. The positive likelihood ratio was higher for the Lake Louise Criteria (7.7) than for EGE alone (6.3), T2 and/or LGE (2.3) or LGE alone (1.9). In patients with clinical evidence for relevant active myocarditis, skipping T2-weighted imaging or early GD enhancement is associated with a significantly lower positive likelihood ratio, while the removal of Early Gd Enhancement imaging does not change diagnostic overall accuracy, while reducing sensitivity. Thus, in patients where a high positive likelihood ratio is needed, the full Lake Louise Criteria including Early Gd enhancement and edema-sensitive T2-weighted imaging should be used until alternative approaches are developed.
authors: Stephenson Cardiovascular MR Centre at the Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, Foothills Medical Centre, University of Calgary, Suite 0700 Special Services Building, 1403-29th St. NW, Calgary T2N 2T9, Canada.
authors: Gavin C W
authors: GC
authors: Chu
authors: Jacqueline A
authors: JA
authors: Flewitt
authors: Yoko
authors: Y
authors: Mikami
authors: Emmanuelle
authors: E
authors: Vermes
authors: Matthias G
authors: MG
authors: Friedrich
mesh_terms: D000208:Acute Disease; D000328:Adult; D016022:Case-Control Studies; D003287:Contrast Media; D004489:Edema, Cardiac / Q000473:pathology; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009205:Myocarditis / Q000473:pathology*; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
references: Int J Cardiovasc Imaging. 2002 Feb;18(1):539-42
references: 12135124
references: Herz. 2007 Mar;32(2):129-37
references: 17401755
references: Circulation. 1999 Nov 9;100(19):1992-2002
references: 10556226
references: N Engl J Med. 2000 Nov 16;343(20):1445-53
references: 11078769
references: Circulation. 2004 Mar 16;109(10):1250-8
references: 14993139
references: JACC Cardiovasc Imaging. 2012 May;5(5):513-24
references: 22595159
references: Circulation. 2002 Jan 15;105(2):224-9
references: 11790705
references: Heart. 2008 Nov;94(11):1456-63
references: 18230640
references: J Am Coll Cardiol. 2009 Oct 6;54(15):1457-66
references: 19682818
references: J Renin Angiotensin Aldosterone Syst. 2003 Dec;4(4):234-43
references: 14689371
references: Chest. 2002 Nov;122(5):1638-48
references: 12426265
references: Circulation. 2006 Oct 10;114(15):1581-90
references: 17015795
references: Radiology. 2008 Feb;246(2):401-9
references: 18180335
references: J Am Coll Cardiol. 2005 Jun 7;45(11):1815-22
references: 15936612
references: Circulation. 1998 May 12;97(18):1802-9
references: 9603535
references: Magn Reson Med. 1989 May;10(2):246-55
references: 2761383
references: Acta Radiol. 1987 Jan-Feb;28(1):79-83
references: 2952148
references: J Am Coll Cardiol. 2009 Apr 28;53(17):1475-87
references: 19389557