title: Combined transesophageal and surface MRI provides optimal imaging in aortic atherosclerosis.
abstract: OBJECTIVE
  Surface magnetic resonance imaging (MRI) for aortic plaque assessment is limited by the trade-off between penetration depth and signal-to-noise ratio (SNR). For imaging the deep seated aorta, a combined surface and transesophageal MRI (TEMRI) technique was developed 1) to determine the individual contribution of TEMRI and surface coils to the combined signal, 2) to measure the signal improvement of a combined surface and TEMRI over surface MRI, and 3) to assess for reproducibility of plaque dimension analysis.
  
  
  RESULTS
  In 24 patients six black blood proton-density/T2-weighted fast-spin echo images were obtained using three surface and one TEMRI coil for SNR measurements. Reproducibility of plaque dimensions (combined surface and TEMRI) was measured in 10 patients. TEMRI contributed 68% of the signal in the aortic arch and descending aorta, whereas the overall signal gain using the combined technique was up to 225%. Plaque volume measurements had an intraclass correlation coefficient of as high as 0.97.
  
  
  CONCLUSIONS
  Plaque volume measurements for the quantification of aortic plaque size are highly reproducible for combined surface and TEMRI. The TEMRI coil contributes considerably to the aortic MR signal. The combined surface and TEMRI approach improves aortic signal significantly as compared to surface coils alone.
  
  
  CONCLUSIONS
  Conventional MRI aortic plaque visualization is limited by the penetration depth of MRI surface coils and may lead to suboptimal image quality with insufficient reproducibility. By combining a transesophageal MRI (TEMRI) with surface MRI coils we enhanced local and overall image SNR for improved image quality and reproducibility.
authors.affiliation: Cardiology Division of the Department of Medicine, Johns Hopkins Hospital, Baltimore, Maryland 21287, USA.
authors.forename: Henning
authors.initials: H
authors.lastname: Steen
authors.forename: William P
authors.initials: WP
authors.lastname: Warren
authors.forename: Milind
authors.initials: M
authors.lastname: Desai
authors.forename: Sandeep
authors.initials: S
authors.lastname: Gautam
authors.forename: Shanghan
authors.initials: S
authors.lastname: Lai
authors.forename: Scott
authors.initials: S
authors.lastname: Heath
authors.forename: Matthias
authors.initials: M
authors.lastname: Stuber
authors.forename: João A C
authors.initials: JA
authors.lastname: Lima
mesh_terms: D000368:Aged; D001013:Aorta, Thoracic / Q000473:pathology*; D001018:Aortic Diseases / Q000175:diagnosis* / Q000473:pathology; D050197:Atherosclerosis / Q000175:diagnosis* / Q000473:pathology; D004947:Esophagus; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results