Four-and-one-half years' experience in monitoring of reproducibility of an MR spectroscopy system--application of in vitro results to interpretation of in vivo data.

Abstract

The primary purpose of this work was to assess long-term in vitro reproducibility of metabolite levels measured using 1H MRS (proton magnetic resonance spectroscopy). The secondary purpose was to use the in vitro results for interpretation of 1H MRS in vivo spectra acquired from patients diagnosed with Canavan disease. 1H MRS measurements were performed in the period from April 2006 to September 2010. 118 short and 116 long echo spectra were acquired from a stable phantom during this period. Change-point analysis of the in vitro N-acetylaspartate levels was exploited in the computation of fT factor (ratio of the actual to the reference N-acetylaspartate level normalized by the reciprocity principle). This coefficient was utilized in the interpretation of in vivo spectra analyzed using absolute reference technique. The monitored time period was divided into six time intervals based on short echo in vitro data (seven time intervals based on long echo in vitro data) characterized by fT coefficient ranging from 0.97 to 1.09 (based on short echo data) and from 1.0 to 1.11 (based on long echo data). Application of this coefficient to interpretation of in vivo spectra confirmed increased N-acetylaspartate level in Canavan disease. Long-term monitoring of an MRS system reproducibility, allowing for absolute referencing of metabolite levels, facilitates interpretation of metabolic changes in white matter disorders.

• Authors: Agnieszka Skorupa, Magdalena Wicher, Tomasz Banasik, Ewa Jamroz, Justyna Paprocka, Aleksandra Kiełtyka, Maria Sokół, Marek Konopka
• Journal: Journal of applied clinical medical physics (J Appl Clin Med Phys) Vol. 15 Issue 3 Pg. 323–334 (05 08 2014) ISSN: 1526-9914 [Electronic] United States
• PMID: 24892353 (Publication Type: Evaluation Study, Journal Article)

Chemical References

• Biomarkers
• Aspartic Acid
• N-acetylaspartate

Topics

• Adolescent
• Adult
• Algorithms
• Aspartic Acid (analogs & derivatives, metabolism)
• Biomarkers (metabolism)
• Brain (metabolism)
• Canavan Disease (diagnosis, metabolism)
• Child
• Child, Preschool
• Diagnosis, Computer-Assisted (methods)
• Female
• Humans
• In Vitro Techniques
• Longitudinal Studies
• Male
• Middle Aged
• Proton Magnetic Resonance Spectroscopy (instrumentation, methods)
• Reproducibility of Results
• Sensitivity and Specificity
• Translational Research, Biomedical
• Young Adult