title: The relative atrial volume ratio and late gadolinium enhancement provide additive information to differentiate constrictive pericarditis from restrictive cardiomyopathy.
abstract: BACKGROUND
  The differentiation of constrictive pericarditis (CP) from restrictive cardiomyopathy (RCM) is often difficult. This study sought to determine the clinical utility of cardiovascular magnetic resonance imaging (CMR) for differentiating both these disorders.
  
  
  METHODS
  Twenty-three patients with surgically documented CP, 22 patients with RCM and 25 normal subjects were included in the study. CMR yielded information about cardiac morphology, function and tissue characteristics. The left (LA) and right atrial (RA) volume was calculated using the area-length method. The relative atrial volume ratio (RAR) was defined as the LA volume divided by RA volume. Receiver operating characteristic curve analysis was used to test the ability of different variables in differentiating CP from RCM.
  
  
  RESULTS
  The maximal pericardial thickness in CP patients was significantly larger than in normal subjects and RCM patients. The RA volume index in RCM patients (90.5 ± 35.3 mL/m2) was significantly larger than in CP patients (71.4 ± 15.7 mL/m2, p = 0.006) and normal subjects (38.1 ± 9.0 mL/m2, p < 0.001). The LA volume index in RCM (96.0 ± 37.0 mL/m2) and CP patients (105.6 ± 25.1 mL/m2) was significantly larger than in normal subjects (39.5 ± 9.5 mL/m2, p < 0.001 for all). The RAR in CP patients (1.50 ± 0.29) was significantly larger than in RCM patients (1.12 ± 0.33, p < 0.001) and normal subjects (1.06 ± 0.20, p < 0.001). There were no differences between RCM patients and normal subjects in the RAR (p = 0.452). At a cut-off value of 1.32 for the RAR, the sensitivity was 82.6%, and the specificity was 86.4% in the detection of CP. Septal bounce was identified in 95.7% CP patients, in none of RCM patients and normal subjects. Late gadolinium enhancement (LGE) was present in 31.8% RCM patients and absence in all CP patients and normal subjects.
  
  
  CONCLUSIONS
  CMR with LGE and RAR can facilitate differentiation of CP from RCM.
authors.affiliation: Department of Radiology, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors.forename: Huaibing
authors.initials: H
authors.lastname: Cheng
authors.forename: Shihua
authors.initials: S
authors.lastname: Zhao
authors.forename: Shiliang
authors.initials: S
authors.lastname: Jiang
authors.forename: Minjie
authors.initials: M
authors.lastname: Lu
authors.forename: Chaowu
authors.initials: C
authors.lastname: Yan
authors.forename: Jian
authors.initials: J
authors.lastname: Ling
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Qiong
authors.initials: Q
authors.lastname: Liu
authors.forename: Ning
authors.initials: N
authors.lastname: Ma
authors.forename: Gang
authors.initials: G
authors.lastname: Yin
authors.forename: Renate
authors.initials: R
authors.lastname: Jerecic
authors.forename: Zuoxiang
authors.initials: Z
authors.lastname: He
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002313:Cardiomyopathy, Restrictive / Q000175:diagnosis* / Q000473:pathology; D002681:China; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D006325:Heart Atria / Q000473:pathology; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D010494:Pericarditis, Constrictive / Q000175:diagnosis* / Q000473:pathology; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA