Dynamic and simultaneous MR measurement of R1 and R2* changes during respiratory challenges for the assessment of blood and tissue oxygenation. Issue 1 (24th August 2012)

• Record Type: Journal Article
• Authors: Remmele, Stefanie; Sprinkart, Alois M.; Müller, Andreas; Träber, Frank; von Lehe, Marec; Gieseke, Jürgen; Flacke, Sebastian; Willinek, Winfried A.; Schild, Hans H.; Sénégas, Julien; Keupp, Jochen; Mürtz, Petra
• Is Part Of: Magnetic resonance in medicine. Volume 70:Issue 1(2013:Jul.)
• Page Start: 136
• Page End: 146
• Publication Date: 2012-08-24
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.24458
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>This work presents a novel method for the rapid and simultaneous measurement of <italic>R</italic><sub>1</sub> and <italic>R</italic><sub>2</sub>* relaxation rates. It is based on a dynamic short repetition time steady‐state spoiled multigradient‐echo sequence and baseline <italic>R</italic><sub>1</sub> and <italic>B</italic><sub>1</sub> measurements. The accuracy of the approach was evaluated in simulations and a phantom experiment. The sensitivity and specificity of the method were demonstrated in one volunteer and in four patients with intracranial tumors during carbogen inhalation. We utilized (Δ<italic>R</italic><sub>2</sub>*, Δ<italic>R</italic><sub>1</sub>) scatter plots to analyze the multiparametric response amplitude of each voxel within an area of interest. In normal tissue <italic>R</italic><sub>2</sub>* decreased and <italic>R</italic><sub>1</sub> increased moderately in response to the elevated blood and tissue oxygenation. A strong negative Δ<italic>R</italic><sub>2</sub>* and Δ<italic>R</italic><sub>1</sub> response was observed in veins and some tumor areas. Moderate positive Δ<italic>R</italic><sub>2</sub>* and Δ<italic>R</italic><sub>1</sub> response amplitudes were found in fluid‐rich tissue as in cerebrospinal fluid, peritumoral edema, and necrotic areas. The multiparametric approach was shown to increase the specificity and sensitivity of oxygen‐enhanced MRI compared to measuring Δ<italic>R</italic><sub>2</sub>* or Δ<italic>R</italic><sub>1</sub> alone. It is thus expected to provide an optimal tool for the identification of tissue areas with low oxygenation, e.g., in tumors with compromised oxygen supply. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.</p> </abstract>