Cryptococcomas distinguished from gliomas with MR spectroscopy: an experimental rat and cell culture study.
OBJECTIVE
To use magnetic resonance (MR) spectroscopy to characterize clinical isolates of Cryptococcus neoformans and a glioma cell line in culture and in experimental rats.


METHODS
One- and two-dimensional hydrogen 1 MR spectra were acquired from fungi cultured in vitro (16 isolates of C neoformans, three of Candida albicans, three of Aspergillus fumigatus, three of Saccharomyces cerevisiae) and a C6 glioma cell line. Cerebral biopsy specimens were obtained from healthy rats and animals with experimental infections or gliomas (19 healthy brains, 20 cryptococcomas, and 19 gliomas). Unequivocal signal assignment was performed for cell suspensions and tissue samples by using homo- and heteronuclear two-dimensional correlation spectra.


RESULTS
MR spectra of C neoformans and cerebral cryptococcomas--but not of other fungi, healthy brains, or gliomas--were dominated by resonances from the cytosolic disaccharide alpha,alpha-trehalose. This spectral pattern was different from that of gliomas, which was dominated by lipids and an increased choline-creatine ratio, and that of healthy brain.


CONCLUSIONS
A remarkably high concentration of alpha,alpha-trehalose in relation to other metabolites that are visible with MR spectroscopy is diagnostic of C neoformans. Cerebral cryptococcomas are an uncommon but serious manifestation of cryptococcosis in humans. Application of these results to the noninvasive diagnosis of cerebral cryptococcomas would help reduce the risk and expense of unnecessary surgery or biopsy and expedite patient treatment.
Himmelreich
U
U
Institute for Magnetic Resonance Research, Department of Magnetic Resonance in Medicine, University of Sydney at Westmead Hospital, Rm 3114, Level 3, ICPMR, Darcy Rd, Westmead, New South Wales 2145, Australia.
Dzendrowskyj
T E
TE
Allen
C
C
Dowd
S
S
Malik
R
R
Shehan
B P
BP
Russell
P
P
Mountford
C E
CE
Sorrell
T C
TC
D000818:Animals; D001707:Biopsy, Needle; D001932:Brain Neoplasms / Q000175:diagnosis*; D020314:Central Nervous System Fungal Infections / Q000175:diagnosis*; D003453:Cryptococcosis / Q000175:diagnosis*; D003455:Cryptococcus neoformans / Q000302:isolation & purification*; D003937:Diagnosis, Differential; D004195:Disease Models, Animal; D005260:Female; D005910:Glioma / Q000175:diagnosis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D017208:Rats, Wistar; D012016:Reference Values; D012680:Sensitivity and Specificity; D014407:Tumor Cells, Cultured