American Journal of Roentgenology, Vol 155, 873-880, Copyright © 1990 by American Roentgen Ray Society
Benign lumbar arachnoiditis: MR imaging with gadopentetate dimeglumine
CE Johnson and G Sze
Sloan-Kettering Cancer Center, New York, NY.
MR imaging was performed in 13 patients with benign lumbar arachnoiditis
both before and after IV injection of gadopentetate dimeglumine. The
arachnoiditis was proved by previous myelography in 12 patients and by
noncontrast MR imaging in one patient. The disease was presumably the
result of previous myelography and/or surgery. It was characterized as mild
in two patients, moderate in two patients, and severe in nine patients.
Imaging was performed on a 1.5-T unit, and both short and long TR images
were obtained before and after contrast administration. Noncontrast MR
images demonstrated changes consistent with arachnoiditis in all patients.
After contrast, three patients had no enhancement, three patients had
minimal enhancement, three patients had mild enhancement, and four patients
had moderate enhancement. In no case did contrast enhancement alter the
diagnosis or reveal additional findings that could not be seen on the
noncontrast images. Gadopentetate dimeglumine enhancement plays little role
in the diagnosis of lumbar arachnoiditis. If used for another reason,
however, short TR scans may show enhancement of adherent roots in some
cases. In addition, administration of gadopentetate dimeglumine will not
cause sufficient enhancement to hinder the detection of arachnoiditis on
long TR images and may aid in recognition of adherent roots on short TR
images.