Learning objectives
● Show the usefulness of different MRI techniques and positron emission tomography for studying brain focal lesions.
● Illustrate the utility of positron emission tomography with radiotracer Choline for the study of brain tumors and its utility for differential diagnosis between radionecrosis and tumoral remnant / recurrence.
Background
Differential diagnosis of brain focal lesions is complex and requires the use of multiple imaging techniques.
Benign lesions,
malignant lesions,
demyelination,
radionecrosis and metastases can produce similar imaging findings,
both on CT and MRI.
Regarding the metabolic study of this lesions,
it is frequent to find an increased glucose uptake in all of them,
regardless of they are benign lesions,
inflammatory or malignant lesions.
Therefore,
the PET glucose (FDG-PET) may show unspecific results.
To improve diagnosis,
there are new MRI techniques that provide greater structural...
Findings and procedure details
CT allows initial diagnosis and assessment of the impact of the lesion on the other brain structures: displacement of the midline,
existence of herniations,
obstruction of the ventricular system and development of hydrocephalus ...
However,
MRI allows better characterization of the lesion.
Traditional sequences provide additional information about the nature of the tumor: exact information on the location of the tumor,
determining their origin on intra or extra axial space,
presence of solids or cystic components,
existence of intralesional hemorrhage,
homogeneous or heterogeneous nature of...
Conclusion
Differential diagnosis of brain tumors and other lesions that can simulate tumor (stroke,
demyelinating diseases...) is complex and requires a study involving in multiple techniques.
Besides MRI morphological sequences and FDG-PET,
new advanced MRI techniques (diffusion,
perfusion and spectroscopy) and new nuclear medicine radiotracers (Cho-PET) help grading brain tumors and detect early recurrences.
References
1.Bolcaen J,
Acou M,
Boterberg T,
Vanhove C,
De Vos F,
Van den Broecke C,
et al.
18F-PET and MRI FCho for the prediction of response in glioblastoma Patients ACCORDING TO the RANO criteria.
Nucl Med Commun.
2017 Mar; 38 (3): 242-9.
2.
Kwee SA,
Ko JP,
Jiang CS,
MR Watters,
MN Coel.
Solitary brain lesions at MR imaging Enhancing: evaluation With Fluorine 18 fluorocholine PET.
Radiology.
2007 Aug; 244 (2): 557-65.
3.
Mertens K,
J Bolcaen,
Ham H,
Deblaere K,
Van den Broecke C,...