Journal of Pharmacy and Pharmacology 2 (2014) 59-69 Quantitative T2*-Mapping of the Knee Using a Spoiled Gradient Echo Sequence at 3 Tesla: Preliminary Results Georg Riegler 1 , Xeni Deligianni 2 , Vladimir Juras 1, 3 , Štefan Zbýň 1 , Sebastian Apprich 1 , Pavol Szomolanyi 1 , Michael Weber 1 , Oliver Bieri 2 and Siegfried Trattnig 1 1. Department of Biomedical Imaging and Image-guided Therapy, MR Center of Excellence for High Field MR, Medical University of Vienna, Vienna 1090, Austria 2. Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel 4031, Switzerland 3. Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava 84104, Slovakia Received: November 28, 2013 / Accepted: January 08, 2014 / Published: February 28, 2014. Abstract: Purpose: To evaluate a me-vTE-SPGR (multi echo variable TE Spoiled Gradient Echo Sequence) approach for quantitative T2* mapping of the ME (menisci), the PT (patellar tendon), the ACL (anterior cruciate ligament), the PCL (posterior cruciate ligament) and to compare the results between normal and pathological tissue of the ME in the knee joint at 3T (3 Tesla). Methods: Eighteen consecutive knee patients (35.7 ± 11.6 years) were examined on 3T. In addition to standard morphological MRI, T2*-maps were derived from a 0.7 mm isotropic me-vTE-SPGR scan. T2*-values were assessed by two independent observers using an ROI analysis for the ME (4 different regions: posterior and anterior horn of the medial and lateral meniscus), PT, ACL and PCL. Intra-class correlation between readers was calculated. Results: On morphological MRI, the PT, ACL and PCL were diagnosed as normal in all cases. Degenerative meniscus and meniscal tears were diagnosed in 13 cases and 9 cases, respectively. T2*-values of the menisci on me-vTE-SPGR scans, in relation to morphological imaging, were normal (N = 50; 6.0 ± 0.9 ms); degenerative meniscus (N = 13; 8.0 ± 1.6 ms); meniscal tears (N = 9; 12.9 ± 3.9 ms), with significant differences between all groups (P < 0.05)/ significantly higher T2*-values in degenerative meniscus and meniscal tears. Mean T2* relaxation times for the PT, ACL and PCL were 2.9 ± 0.8 ms, 8.4 ± 1.6 ms and 8.9 ± 1.3 ms respectively. Intra-class correlation values between readers for the ME, PT, ACL and PCL were R² = 0.962, R² = 0.927, R² = 0.594 and R² = 0.648, respectively. Conclusion: Isotropic 3D (three-dimensional) me vTE-SPGR imaging is able to quantify T2* values of multiple tissues in the knee joint with short T2 relaxation times. Key words: Magnetic resonance imaging, quantitative imaging, T2* imaging, connective tissue, knee. 1. Introduction The human knee joint contains several different connective tissues, such as menisci, tendons, and ligaments, all of which are characterized by prominent short transverse relaxation times (T2) on MRI. Short T2 times are related to anatomical and biochemical properties that cannot be visualized with conventional MRI techniques [1, 2]. The structure and composition of these tissues is crucial for the integrity of the knee joint. The knee Corresponding author: Georg Riegler, M.D., research field: high field magnetic resonance imaging. E-mail: georg.riegler@meduniwien.ac.at. menisci consist of concentrically and radially arranged collagen fibers that play an important role in absorbing impact load [3]. Ligaments are short bands of fibrous connective tissue composed mainly of long, stringy collagen fibers, which connect with the osseous structures of a joint to afford stability [4, 5]. Tendons are tough bands of fibrous connective tissue that attach muscles to bone [6]. In the clinical routine, the most effective strategy for the diagnosis of knee diseases with MRI is the use of intermediate to long T2w (T2-weighted) imaging sequences to detect an increase in signal from abnormal tissue [7]. Standard MR sequences, however, DAVID PUBLISHING D