title: Myocardial Fibrosis in Hypertrophic Cardiomyopathy: Volumetric Assessment of Late Enhancement Provided by Cardiac Computed Tomography.
abstract: BACKGROUND
  With subgroups of patients with hypertrophic cardiomyopathy (HCM) confers a 4% to 5% risk for adverse prognosis. Besides left-ventricular muscle mass (LV-MM) myocardial fibrosis (MF) assessable by late gadolinium enhancement in cardiovascular magnetic resonance (LGE-CMR) has been related to that. Myocardial fibrosis can also be demonstrated by late enhancement (LE) in late-enhanced multislice computed tomography (leMDCT). This analysis investigates leMDCT whether to enable quantification of LE load in terms of LE mass by percent LV-MM in HCM.
  
  
  METHODS
  In a prospective validation study, we included 30 consecutive patients with HCM who underwent leMDCT (64 slice) and LGE-CMR (1.5 T). The leMDCT scan was performed 7 minutes after injection of iodine contrast (Iopromid). Endocardial and epicardial planimetry served for the assessment of LV-MM. Visually detectable LE was quantified using the manual quantification method resulting in LE by percent LV-MM (%LE). The LGE-CMR data served for validation.
  
  
  RESULTS
  Mean (SD) age was 64.1 (13.9) years. Myocardial fibrosis prevalence was 63.3% (19/30 patients indentified by both leMDCT and LGE-CMR). In leMDCT, tissue density in LE areas compared with normal myocardium was higher (138.2 [23.9] HU vs 98.4 [16.5] HU, P < 0.001) but lower than in the LV cavity (138.2 [23.9] HU vs 169.2 [35.9] HU, P < 0.001). Late enhancement mass in leMDCT seemed to be 7.9 (8.5) g LE versus 8.6 [11] g LGE in CMR (P = 0.497, r = 0.95) resulting in a leMDCT/LGE-CMR relation of 1.2. Referring LE mass to LV-MM gave an LE proportion measured by leMDCT of 4 (3.9) %LE versus 3.9 (4.1) %LGE in LGE-CMR (r = 0.88, P = 0.75). Intraobserver/interobserver reliability of LE mass assessment showed an intraclass correlation coefficient of 0.99 and 0.97.
  
  
  CONCLUSIONS
  In patients with HCM, leMDCT provides volumetric assessment of LE mass-absolutely and by percent LV-MM.
authors.affiliation: From the *Department of Cardiology, Angiology and Intensive Care Medicine, Universitätsklinikum Schleswig-Holstein, Christian-Albrechts University of Kiel; †DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck; ‡Department of Diagnostic Radiology, Universitätsklinikum Schleswig-Holstein, Christian-Albrechts University of Kiel, Kiel; and §Department of Cardiology, Heart and Diabetes Center North Rhine-Westphalia, University Clinic of the Ruhr-University Bochum, Bad Oeynhausen, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Langer
authors.forename: Philipp
authors.initials: P
authors.lastname: Schaefer
authors.forename: Matthias
authors.initials: M
authors.lastname: Lutz
authors.forename: Matthias
authors.initials: M
authors.lastname: Eden
authors.forename: Mirko
authors.initials: M
authors.lastname: Hohnhorst
authors.forename: Hauke
authors.initials: H
authors.lastname: Harders
authors.forename: Lothar
authors.initials: L
authors.lastname: Faber
authors.forename: Olav
authors.initials: O
authors.lastname: Jansen
authors.forename: Marcus
authors.initials: M
authors.lastname: Both
authors.forename: Norbert
authors.initials: N
authors.lastname: Frey
mesh_terms: D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging* / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D005355:Fibrosis / Q000000981:diagnostic imaging / Q000473:pathology; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D009206:Myocardium / Q000473:pathology*; D009929:Organ Size; D011446:Prospective Studies; D011856:Radiographic Image Enhancement; D015203:Reproducibility of Results
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide