PMID- 22480269
OWN - NLM
STAT- MEDLINE
DCOM- 20120821
LR  - 20240417
IS  - 1532-429X (Electronic)
IS  - 1097-6647 (Print)
IS  - 1097-6647 (Linking)
VI  - 14
IP  - 1
DP  - 2012 Apr 6
TI  - Cardiovascular magnetic resonance evaluation of aortic stenosis severity using 
      single plane measurement of effective orifice area.
PG  - 23
LID - 10.1186/1532-429X-14-23 [doi]
AB  - BACKGROUND: Transthoracic echocardiography (TTE) is the standard method for the 
      evaluation of the severity of aortic stenosis (AS). Valve effective orifice area 
      (EOA) measured by the continuity equation is one of the most frequently used 
      stenotic indices. However, TTE measurement of aortic valve EOA is not feasible or 
      not reliable in a significant proportion of patients. Cardiovascular magnetic 
      resonance (CMR) has emerged as a non-invasive alternative to evaluate EOA using 
      velocity measurements. The objectives of this study were: 1) to validate a new 
      CMR method using jet shear layer detection (JSLD) based on acoustical source term 
      (AST) concept to estimate the valve EOA; 2) to introduce a simplified JSLD method 
      not requiring vorticity field derivation. METHODS AND RESULTS: We performed an in 
      vitro study where EOA was measured by CMR in 4 fixed stenoses (EOA = 0.48, 1.00, 
      1.38 and 2.11 cm(2)) under the same steady flow conditions (4-20 L/min). The in 
      vivo study included eight (8) healthy subjects and 37 patients with mild to 
      severe AS (0.72 cm(2) </= EOA </= 1.71 cm(2)). All subjects underwent TTE and CMR 
      examinations. EOA was determinated by TTE with the use of continuity equation 
      method (TTE(CONT)). For CMR estimation of EOA, we used 3 methods: 1) Continuity 
      equation (CMR(CONT)); 2) Shear layer detection (CMR(JSLD)), which was computed 
      from the velocity field of a single CMR velocity profile at the peak systolic 
      phase; 3) Single plane velocity truncation (CMR(SPVT)), which is a simplified 
      version of CMR(JSLD) method. There was a good agreement between the EOAs obtained 
      in vitro by the different CMR methods and the EOA predicted from the potential 
      flow theory. In the in vivo study, there was good correlation and concordance 
      between the EOA measured by the TTE(CONT) method versus those measured by each of 
      the CMR methods: CMR(CONT) (r = 0.88), CMR(JSLD) (r = 0.93) and CMR(SPVT) (r = 
      0.93). The intra- and inter- observer variability of EOA measurements was 5 +/- 5% 
      and 9 +/- 5% for TTE(CONT), 2 +/- 1% and 7 +/- 5% for CMR(CONT), 7 +/- 5% and 8 +/- 7% for 
      CMR(JSLD), 1 +/- 2% and 3 +/- 2% for CMR(SPVT). When repeating image acquisition, 
      reproducibility of measurements was 10 +/- 8% and 12 +/- 5% for TTE(CONT), 9 +/- 9% and 
      8 +/- 8% for CMR(CONT), 6 +/- 5% and 7 +/- 4% for CMR(JSLD) and 3 +/- 2% and 2 +/- 2% for 
      CMR(SPVT). CONCLUSION: There was an excellent agreement between the EOA estimated 
      by the CMR(JSLD) or CMR(SPVT) methods and: 1) the theoretical EOA in vitro, and 
      2) the TTE(CONT) EOA in vivo. The CMR(SPVT) method was superior to the TTE and 
      other CMR methods in terms of measurement variability. The novel CMR-based 
      methods proposed in this study may be helpful to corroborate stenosis severity in 
      patients for whom Doppler-echocardiography exam is inconclusive.
FAU - Garcia, Julio
AU  - Garcia J
AD  - Quebec Heart & Lung Institute, Laval University, Quebec, Canada.
FAU - Marrufo, Oscar R
AU  - Marrufo OR
FAU - Rodriguez, Alfredo O
AU  - Rodriguez AO
FAU - Larose, Eric
AU  - Larose E
FAU - Pibarot, Philippe
AU  - Pibarot P
FAU - Kadem, Lyes
AU  - Kadem L
LA  - eng
GR  - MOP 79342/Canadian Institutes of Health Research/Canada
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120406
PL  - England
TA  - J Cardiovasc Magn Reson
JT  - Journal of cardiovascular magnetic resonance : official journal of the Society 
      for Cardiovascular Magnetic Resonance
JID - 9815616
SB  - IM
MH  - Adult
MH  - Aortic Valve/*pathology
MH  - Aortic Valve Stenosis/*diagnosis
MH  - Diagnosis, Differential
MH  - Female
MH  - Humans
MH  - *Image Interpretation, Computer-Assisted
MH  - Magnetic Resonance Imaging, Cine/*methods
MH  - Male
MH  - Middle Aged
MH  - Observer Variation
MH  - Severity of Illness Index
PMC - PMC3366866
EDAT- 2012/04/07 06:00
MHDA- 2012/08/22 06:00
PMCR- 2012/04/06
CRDT- 2012/04/07 06:00
PHST- 2011/06/21 00:00 [received]
PHST- 2012/04/06 00:00 [accepted]
PHST- 2012/04/07 06:00 [entrez]
PHST- 2012/04/07 06:00 [pubmed]
PHST- 2012/08/22 06:00 [medline]
PHST- 2012/04/06 00:00 [pmc-release]
AID - S1097-6647(23)00650-6 [pii]
AID - 1532-429X-14-23 [pii]
AID - 10.1186/1532-429X-14-23 [doi]
PST - epublish
SO  - J Cardiovasc Magn Reson. 2012 Apr 6;14(1):23. doi: 10.1186/1532-429X-14-23.