Premium
TH‐D‐201C‐05: Monitoring Response of Liver Cancer to Targeted Radiation Therapy with a Novel 31P/1H MRS Coil
Author(s) -
Panda A,
Jones S,
Sandrasegaran K,
Dydak U
Publication year - 2010
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3469553
Subject(s) - nuclear medicine , electromagnetic coil , radiofrequency coil , radiation therapy , torso , magnetic resonance imaging , voxel , scanner , free induction decay , in vivo , medicine , nuclear magnetic resonance , physics , radiology , optics , anatomy , spin echo , microbiology and biotechnology , quantum mechanics , biology
Purpose : To present a novel multi‐channel dual‐tuned 31 P/ 1 H MRS coil which allows for non‐invasive acquisition of in‐vivo phosphorus ( 31 P) spectroscopy data from the whole liver. We hypothesize MRS data collected with this coil can improve the assessment of early tumor response to targeted radiation therapy. Method and Materials : A novel dual‐tuned 8‐channel 31 P/ 1 H coil for a Siemens 3T Tim Trio whole Body MRI scanner was designed and validated. The coil consists of two plates placed anterior and posterior of the patient's torso with four 31 P receive elements (24×20 cm 2 ) each. Furthermore each plate has one 31 P transmit element and one 1 H transmit‐receive element. Thus the coil allows for 31 P MRS conventional MRI and 1 H MRS during the same scan session. For our clinical study the 31 P MRS data was acquired with a 2D slice selective free‐induction‐decay (FID) sequence using the following parameters: TE 2.3 ms TR 1 s field of view (FOV) 400×400×30 mm 3 nominal voxel size 25×25×30 mm 3 30 weighted averages. Each free‐induction‐decay (FID) was acquired with 2048 points over a bandwidth of 5000 Hz. The resulting scan time was about 25 min. Results : In vivo 31 P liver spectra and 1 H MRI images of the entire liver were successfully acquired in healthy volunteers and patients undergoing targeted radiation therapy. The optimized 31 P MRS sequence allowed for identification and quantification of ATP phosphomonoesters (PME) phosphodiesters (PDE) and inorganic phosphate (Pi) metabolites throughout the liver on an axial slice. Metabolic differences between healthy and malignant liver tissue were clearly identified. Conclusions : We have shown that our novel 31 P/ 1 H MRS coil allows for assessing 31 P metabolites in lesions located in deep tissue while being able to run conventional MRI imaging scans during the same scan session.