Coronal Whole-Body Imaging For Bone Metastasis Staging At 3 Tesla – Initial Experiences With The Matrix Coil MR System

• Published in: RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren
• Main Authors: Lichy, MP, Boss, A, Horger, W, Rodegerdts, EA, Plathow, C, Schwenzer, N, Claussen, CD, Schick, F, Schlemmer, HP
• Format: Conference Proceeding
• Language: English
• Published: 20.03.2006
• ISSN: 1438-9029; 1438-9010
• DOI: 10.1055/s-2006-931860

Purpose: Establishment of clinical MR protocols for a fast assessment of bone metastasis by 3 Tesla MRI, equipped with a total imaging matrix (TIM) coil system. Methods: All MR examinations were performed using a 3 T MR scanner (Magnetom Tim Trio, Siemens Medical), equipped with 32 independent RF-channels. This MRI system allows the connection of up to 102 coil elements (Total Imaging Matrix (TIM) system). In all cases, a combination of body and spine matrix coils (for pelvis and abdomen imaging) was applied. For coronal whole-body MRI head and neck multi-channel volume coils were used additionally for signal reception. Volunteer examinations were also conducted on a 1.5 T MR scanner (Magnetom Avanto, Siemens Medical) with a comparable coil and gradient system equipment. MR protocols were optimized at 5 healthy volunteers. Data analysis included also signal- and contrast-to-nose (SNR, CNR) measurements. In 10 oncology patients, coronal whole-body 2D T2w fat-suppressed STIR-TSE (short tau inversion recovery turbo-spin-echo) was performed. Sequence parameters were: TR/TE=4280/72 ms, TI=180 ms, 31 slices, distance factor=20%, FoV=(450mm), base matrix=384, PAT factor=3 (Grappa, triple matrix coil mode,), bandwidth=260Hz/Px. As a function of body size, 3 to 4 stages covering the whole head, thorax and body trunk including the upper legs, were acquired and composed with the scanners integrated software. All patients were breathing freely and no dielectric pads were used. Results were compared with clinically indicated computed tomography whole-body examinations. Results: SNR and CNR for volunteer examinations were superior or comparable to examinations at 1.5 T. However, signal inhomogeneity (due to dielectric resonance effects) especially in the upper abdomen is pronounced at 3T but did not compromise the detection of bone metastasis. The use of dielectric pads can reduce these inhomogenities. Results of bone lesion detection were comparable to literature data. Patient comfort and coil handling is equal to the 1.5T TIM system. Conclusion: A fast assessment of bone metastasis is feasible at 3 Tesla at a high image quality.