Abstracts 0 L. A. MINKOFF, EDITOR 153

echo technique, with three pulse sequence variations, seems very promising. A short echo time (TE) pro- duces the best signal-to-noise ratio and spatial resolu- tion. Lengthening the TE enhances differentiation of various tissues by their signal intensity, while the combined increase of TE and recovery time (TR) produces selective enhancement of the cerebrospinal fluid signal intensity. Am. J. Roentg. 141:1129; 1983

NMR Imaging of the Spine

Jong S. Han,’ Benjamin Kaufman,’ Saba J. El You- sef,’ Jane E. Benson,’ Charles T. Bonstelle,’ Ralph J. Alfidi,’ John R. Haaga,’ Hong Yeung,* Richard G. Huss’

‘Department of Radiology, Case Western Reserve University School of Medicine, University Hospitals of Cleveland, 2074 Abington Rd., Cleveland, OH 44106. Address reprint requests to J. S. Han; ‘Techni- care Corporation, Solon, OH 44139

The usefulness of nuclear magnetic resonance (NMR) images in the evaluation of spinal disorders below the craniocervical junction was studied. Six normal sub- jects and 41 patients with various spinal abnormalities were examined. NMR proved capable of demonstrat- ing important normal and pathologic anatomic struc- tures; it was useful in the evaluation of syringohydro- myelia and cystic spinal cord tumors, and the bright signal intensity of lipoma was quite impressive. In the evaluation of herniated disk, NMR images offered a new perspective by visualizing abnormal degradation of the signal intensity of the nucleus pulposus itself. NMR images were least valuable in the evaluation of spondylosis and spinal stenosis. Although NMR imag- ing of the spine is still in a very early developmental stage, the absence of both ionizing radiation and risks associated with contrast material makes it especially attractive as a new diagnostic method. This limited experience with currently available equipment sug- gests that, with technical refinement, the efficacy of NMR of the spine will increase. Am. J. Roentg. 141:1137; 1983

Magnetic Resonance Imaging of the Spinal Cord and Canal: Potentials and Limitations

David Norman, Catherine M. Mills, Michael Brant- Zawadzki, Andrew Yeates, Lawrence E. Crooks, Leon Kaufman

Department of Radiology, University of California School of Medicine, San Francisco, CA 94143

Preliminary experience with magnetic resonance imaging (MRI) of the spinal cord and canal in 17 patients indicates considerable promise in the diag- nosis of neoplastic, degenerative, and congenital

lesions. The ability to image the cord directly rather than indirectly as in myelography, the absence of bone artifact as in computed tomography, and the multipla- nar capabilities indicate that MRI will be the proce- dure of choice in the examination of the spinal cord. Current limitations include partial-volume effects due to slice thickness and the inability to perform contigu- ous sections when using multiplanar techniques. The relative increase in signal from cerebrospinal fluid with long TR and TE sequences in spin-echo imaging may result in less sensitivity than in the brain for detection of cord edema and/or infarction. Am. J. Roentg. 141:1147; 1983

Recognition of Lumbar Disk Herniation with NMR

N. I. Chafetz,’ H. K. Genant,‘.2 K. L. Moon,’ C. A. Helms,’ J. M. Morris*

1 Department of Radiology, University of California School of Medicine, San Francisco, CA 94143; ‘De- partment of Orthopaedic Surgery, University of Cali- fornia School of Medicine, San Francisco, CA 94143

Fifteen nuclear magnetic resonance (NMR) studies of 14 patients with herniated lumbar intervertebral disks were performed on the UCSF NMR imager. Com- puted tomographic (CT) scans done on a GE CT/T 8800 or comparable scanner were available at the time of NMR scan interpretation. Of the 16 posterior disk ruptures seen at CT, 12 were recognized on NMR. Diminished nucleus pulposus signal intensity was pres- ent in all ruptured disks. In one patient, NMR scans before and after chymopapain injection showed retrac- tion of the protruding part of the disk and loss of signal intensity after chemonucleolysis. Postoperative fibrosis demonstrated by CT in one patient and at surgery in another showed intermediate to high signal intensity on NMR, easily distinguishing it from nearby thecal sac and disk. While CT remains the method of choice for evaluation of the patient with suspected lumbar disk rupture, the results of this study suggest that NMR may play a role in evaluating this common clinical problem. Am. J. Roentg. 141:1153; 1983

NMR Imaging of the Chest at 0.12 T: Initial Clinical Experience with a Resistive Magnet

Leon Axe],’ Herbert Y. Kressel,’ David Thickman,’ David M. Epstein,’ William Edelstein,* Paul Bottom- ley,= Rowland Redington,’ Stanley Baum’

‘Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce St., Philadelphia, PA 19104; ‘General Electric Research and Development Center, Schenectady, NY 12301

The chests of 40 subjects were imaged with an experi- mental nuclear magnetic resonance (NMR) imager