RSNA 2007 

Abstract Archives of the RSNA, 2007


SSG20-05

Quantification of Late Enhancement: Intra- and Interobserver Variability

Scientific Papers

Presented on November 27, 2007
Presented as part of SSG20: Cardiac (MR)

Participants

Wolfram Machann MD, Presenter: Nothing to Disclose
Sabrina Koeppe, Abstract Co-Author: Nothing to Disclose
Frank Breunig, Abstract Co-Author: Nothing to Disclose
Christoph Wanner, Abstract Co-Author: Nothing to Disclose
Herbert Koestler PhD, Abstract Co-Author: Nothing to Disclose
Dietbert Hahn MD, Abstract Co-Author: Nothing to Disclose
Meinrad Johannes Beer MD, Abstract Co-Author: Nothing to Disclose
et al, Abstract Co-Author: Nothing to Disclose
et al, Abstract Co-Author: Nothing to Disclose

PURPOSE

Late enhancement (LE) is often used to detect myocardial fibrosis none invasively in MR-Imaging. However LE often has an irregular pattern, which makes quantification difficult. Until now the reproducibility of measuring LE was only determined for large myocardial infarctions. Purpose of this study was, to investigate intra- and interobsever variability of LE-measurements in patients with Fabry disease at baseline and after 12 months of enzyme replacement therapy.

METHOD AND MATERIALS

We examined 14 patients at baseline and 10 at follow up. We used an inversion revovery gradientecho sequence (TR 7.5 ms; TE 3.4 ms; flipangle 25°, TI determined individually) on a 1.5T MR-Scanner 10 to 15 minutes after injection of 0.2 mmol Gadolinium per kg bodyweight. The borders of the enhanced areas were traced manually using ARGUS. The mass of LE was computed by summing the amount of every shortaxis slice. Variabilities wer determined on the basis of the results by one (intra-) or two experienced and blinded radiologists using the bland altman analysis.

RESULTS

Volumes at baseline were 4.2±4.2ml or 2.1±1.7% of left ventricular mass (mean 207±70g, range 111-346g). At follow up LE volumes increased (p<0.05) to 6.4±6.0ml or 3.5±3.0% of left ventricular mass (mean 194±60g; range 140-308g). 95% confidence intervals for intraobserver variability were -0,6 to 1,4 at baseline and -0,6 to 2,0 at follow up. 95% confidence intervals for interobserver variability were -0,3 to 0,7 at baseline and -0,4 to 0,4 at follow up.

CONCLUSION

Manual planimetry of LE shows both a very low intra- and interobserver variability. LE can be used as a follow up parameter for the determination of the amount of myocardial fibrosis in patients with cardiomyopathies.

CLINICAL RELEVANCE/APPLICATION

Planimetry of LE in cardiomyopathies is an important parameter to determine the course of disease exactly and a tool to define a starting point of a specific therapy like an enzyme replacement.

Cite This Abstract

Machann, W, Koeppe, S, Breunig, F, Wanner, C, Koestler, H, Hahn, D, Beer, M, et al, , et al, , Quantification of Late Enhancement: Intra- and Interobserver Variability.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5010150.html Accessed December 29, 2024