Use of an enhanced gradient system for diffusion MR imaging with motion-artifact reduction

Summary, in English

PURPOSE: A spin-echo diffusion-sensitized pulse sequence using high gradients (23 mT/m) is introduced. MATERIAL AND METHODS: In order to minimize motion artefacts, velocity-compensating gradients, ECG-triggering and post-processing with phase correction and raw data averaging using navigator echoes was performed. The in vitro ratio of diffusion coefficients for water and acetone was determined and the water self-diffusion coefficient at different temperatures was evaluated. The pulse sequence was tested in 7 healthy volunteers and in 2 tumour patients with astrocytomas of grades I-II and III-IV. Both single-slice and multi-slice techniques were used. RESULTS: The incorporation of phase correction clearly improved the quality of both diffusion-encoded images and the calculated diffusion maps. Mean values of the diffusion coefficients in vivo were for CSF 2.66 x 10(-9) m2/s and for white and grey matter 0.69 x 10(-9) m2/s and 0.87 x 10(-9) m2/s, respectively. CONCLUSION: Velocity-compensating gradients in combination with a high gradient strength were shown to be useful for in vivo diffusion MR imaging.

• Författare: Sara Brockstedt; C Thomsen; Ronnie Wirestam; J De Poorter; C De Wagter; Leif Salford; Stig Holtås; Freddy Ståhlberg
• Avdelning/ar: Medicinsk strålningsfysik, Lund; Neurokirurgi; Diagnostisk radiologi, Lund
• Publiceringsår: 1995
• Språk: Engelska
• Sidor: 662-670
• Publikation/Tidskrift/Serie: Acta Radiologica
• Volym: 36
• Issue: 6
• Dokumenttyp: Artikel i tidskrift
• Förlag: SAGE Publications
• Ämne: Radiology, Nuclear Medicine and Medical Imaging
• Aktiv: Published
• ISBN/ISSN/Övrigt: ISSN: 1600-0455