Aims and objectives
Conventional techniques have low specificity and are not able to differentiate between low and high-grade CNS tumors.Spectroscopic,
diffusion and perfusion techniques can increase the diagnostic specificity, allowing for up to 90% of precision in the classification of central nervous system tumors.
The quantitative measurement such as relative cerebral blood flow (rCBF),
ADC and Col/NAA ratio decrease the interobserver variability.
Those,
the primary objectives of the study are:
To apply multimodal MRI with a 3-Tesla scanner in the diagnosis of the intraaxial tumors.
To increase the...
Methods and materials
Between 2008 and 2011,
134 patients in total (54 women and 80 men) were enrolled in a descriptive cross-sectional study.
Histologiccriteria were used for diagnostic confirmation.
The overall diagnostic strategy was based on the flowchart provided byRiyadh N.
Al-Okaili et all inIntraaxial Brain Masses: MR Imaging–based Diagnostic Strategy—Initial Experience published in Radiology in 2007.
As a working hypothesis,
the following parameters were considered to be predictive:
Col/NAA ratio and infiltration.
ADC.
rCBF.
Presence of blood products or necrosis.
The variableswere detected through CHAID analysis and...
Results
From the 134 patients with tumoral lesions in MRI,
123 were confirmed by the histologic examination as represented in Figure 1.
The use ofBiomarkers
The biomarker of tumor infiltrationwas found to be statistically relevant allowing for the differentiation between high and low-grade tumors:
Low-grade tumors: PPV 70%,
NPV 99%,
Sn 93% and Sp 94.4%
High-grade tumors: PPV 94.2%,
NPV 86.1%,
Sn 94.3% and Sp 86.1%
Metastasis: PPV 95%,
NPV 98.1%,
Sn 90% and Sp 99%
An example of a low-grade glial tumor can be found...
Conclusion
The MRI techniques increasethe diagnostic accuracy in the classification of intraaxial cerebral tumors,
establishing thevariable of tumoral infiltration as the most important metabolic biomarker in distinguishing between high-grade,
low-grade and metastatic tumors.
In conclusion,
multimodal MRI is a necessarytool in the management of patients with CNS intraaxial tumors.
References
Al-Okaili RN,
Krejza J,
Woo JH,
Wolf RL,
O'Rourke DM,
Judy KD,
Poptani H,
Melhem ER.
Intraaxial brain masses: MR imaging-based diagnostic strategy,
initial experience.
Radiology.
2007 May;243(2):539-50.
Law M,
Yang S,
Wang H,
et al.
Glioma grading: sensitivity,
specificity,
and predictive values of perfusion MR imaging and proton MR spectroscopic imaging compared with conventional MR imaging.
AJNR Am J Neuroradiol 2003;24:1989–1998
Majós Torró C.
Espectroscopia por Resonancia Magnética de Protón en el diagnóstico de tumores cerebrales.
Tesis doctoral.
Universidad de Barcelona.
Facultad de medicina.Programa...
