Comparison between contrast-enhanced magnetic resonance imaging and technetium 99m glucohepatonic acid single photon emission computed tomography with histopathologic correlation in gliomas.
OBJECTIVE
: To determine and compare the accuracy of contrast-enhanced magnetic resonance imaging (MRI) and Technetium 99m glucohepatonic acid single photon emission computed tomography (Tc-GHA SPECT) in grading of gliomas, compared with neuropathologic findings.


METHODS
: The study included 20 adult patients (13 men and 7 women) with clinical/radiological suspicion of brain tumor (glial tumor) who were subjected to magnetic resonance examination and Tc-GHA brain SPECT.The lesions were evaluated by using MRI imaging score, based on 9 MRI criteria. Based on the discrimination threshold of 0.9 for mean MRI score, the gliomas were graded as low- or high-grade glioma. The Tc-GHA SPECT retention index was calculated as the ratio between delayed and early uptake ratios. Based on the discrimination threshold of 1 for Tc-GHA SPECT retention index, the gliomas were graded as low- or high-grade glioma.The diagnosis was verified by means of histopathologic examination in all patients (open surgery in 19 patients and stereotactic biopsy in 1 patient). Correlation between MRI findings/scores, SPECT scores, and histopathologic grades was done in all the patients, and comparison between MRI and Tc-GHA SPECT was made using paired Student t test and correlation coefficient.


RESULTS
: The study revealed significant difference between the mean MRI scores and early uptake ratio, delayed uptake ratio, and retention index of low-grade (grades I-II) and high-grade (grades III-IV) gliomas. No statistically significant difference could be demonstrated between the abilities of contrast-enhanced MRI and Tc-GHA SPECT to allow differentiation between high- and low-grade gliomas. The accuracy of MRI (78.4%), however, was slightly higher than that of Tc-GHA SPECT (73.68%). However, Tc-GHA SPECT allowed differentiation between high-grade gliomas (between grades III and IV gliomas).


CONCLUSIONS
: The accuracy of contrast-enhanced MRI in the distinction of high- and low-grade malignancy was higher than that of Tc-GHA SPECT. The performance of Tc-GHA SPECT adds little in determining tumor grade when MRI is performed. However, it may act as a useful adjunct to differentiate between grades III and IV gliomas.
Kumar
R Ashok
RA
Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Khandelwal
Niranjan
N
Sodhi
Kushaljit Singh
KS
Pathak
A
A
Mittal
B R
BR
Radotra
B D
BD
Suri
Sudha
S
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D019786:Gadolinium DTPA; D005910:Glioma / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D013667:Technetium; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D003287:Contrast Media; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C514391:technetium 99m glucohepatonic acid; D013667:Technetium; D019786:Gadolinium DTPA