th  - 1987 - 51st ENC Conference

WF70
NATURAl, ABUNDANCE CARBON-13 NMR IMAGING
IN BIOLOCICAL SYSTEMS
Donald W. Kormos
Department of Radiology, University Hospitals,
C~RU, Cleveland, Ohio ~I06
and Hong N. Yeung
Technlcare Corporation, 29000 Aurora Road, Solon, Ohio 44139
The feasibility of natural abundance carbon-13 NMR imaging was
evaluated. Spin-echo, undecoupled images were obtained at 4.7 T (Oxford
Instruments, 33-cm bore magnet) using a broadbanded Technicare Teslacon
MR imaging system. A cylindrical volume coll (= 3,500 cm 3) and a single-
turn surface coll (3 cm diameter), tuned to 50.6 MHz, excited and
received the carbon signals. Polypropylene spheres containing isotop-
Ically enriched methanol (= 99%) and ethylene glycol with carbon-13 in
natural abundance (= 1.1%) were used as phantoms for setting the imaging
parameters. Natural abundance carbon-13 images were obtained from an
unfertilized chicken egg and a fresh oxtail (both obtained at a local
supermarket!).
Phantom images clearly showed =image multiplicity" due to carbon-
proton J-coupllngs. The chicken egg image depicted only the methylene
(-CH2-) carbons of the egg yolk. This finding was confirmed by high-
resolution carbon spectra of separated egg white and egg yolk.
Similarly, transverse and saglttal carbon-13 images obtained from the
oxtail phantom exclusively mapped lipid carbons. Separated fat and water
proton images of the oxtail using a modified Dixon method (with in situ
inhomogeneity correction) were also obtained. A very good correlation
between the carbon-13 image and the proton fat image was observed.
We conclude that natural abundance carbon-13 imaging is feasible at
high fields with reasonable (= i hour) imaging times. Hardware
improvements, proton decoupllng, and carbon-13 labeling will undoubtably
decrease the degree of difficulty.