The predictive value of low-field strength   magnetic resonance imaging for intraoperative   residual tumor detection.   Clinical article.
OBJECTIVE
Neurosurgeons have been utilizing intraoperative MR (iMR) imaging to evaluate the extent of tumor resection since the 1990s. A low-field strength (0.12 T) MR imaging unit (PoleStar N20, Medtronic) is a practical and relatively inexpensive iMR imaging system that has found increased use in neurosurgery. The gold standard for post operative detection of residual tumor has been high-strength MR imaging performed within 48 hours of resection.The object of this study was to determine the predictive concordance of low-strength iMR imaging with standard high-strength MR imaging for detection of residual tumor.


METHODS
The authors retrospectively evaluated the MR images from 74 intracranial tumor resections, comparing the intraoperative images obtained using a 0.12-T iMR imaging unit to the immediate postoperative images obtained using a standard 1.5-T MR imaging unit within 48 hours after surgery.


RESULTS
The sensitivity of low-field MR imaging for detection of residual tumor was 0.74 (95% CI 0.58-0.86),and its specificity was 0.97 (95% CI 0.83-1). When only glial tumors (42 of the 74 lesions) were analyzed, the sensitivity was 0.82 (95% CI 0.59-0.94) and the specificity was 0.95 (95% CI 0.73-1).


CONCLUSIONS
These data could assist the neurosurgeon who has to decide intraoperatively whether the observed iMR images show residual tumor or not.
Hirschl
Robert A
RA
Dardinger Neuro-oncology Center, Department of Neurological Surgery, The Ohio State University Medical Center, Columbus, Ohio 43210, USA.
Wilson
Jeff
J
Miller
Brandon
B
Bergese
Sergio
S
Chiocca
E  Antonio
E
D001932:Brain Neoplasms / Q000175:diagnosis* / Q000601:surgery; D006801:Humans; D007432:Intraoperative Period; D008279:Magnetic Resonance Imaging / Q000379:methods*; D018365:Neoplasm, Residual / Q000175:diagnosis*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity