Verification of brain ring enhancing lesions by advanced MR techniques

Peer review under responsibility of Alexandria University Faculty of Medicine.

Available online 25 May 2017

Figures & data

Table 1 The clinical presentation and final diagnosis of the examined population. MRS: MR spectroscopy. DTI: Diffusion Tensor Imaging.

Age	Complaint	Imaging	Added tests	Final diagnosis
35, 60 &70	Rt. UL heaviness	MRI with contrast, Perfusion	Improved with anti TB medications	Tuberculoma
33, 40 & 44	Bilateral UL numbness	MRI with contrast, MRS DTI	+ve oligoclonal bands	Multiple sclerosis
45&55	Known GBM	MRI with contrast, MRS MR perfusion	Histopathologically proven recurrent GBM	Recurrent GBM
50–62	Headache	MRI with contrast, MRS DTI	Histopathologically proven brain stem glioma	Brain stem glioma
57	Headache	MRI with contrast MRS	Histopathologically proven	Anaplastic meningioma
57,67 &69	Disturbed level of consciousness	MRI with contrast MRA	Follow up shows resolution	Subacute hematoma
54&63	Disturbed level of consciousness	MRI with contrast, MRS MR perfusion, DTI	Histopathologically proven fungal abscess	Fungal abscess
46&64	Imbalance, headache	MRI with contrast, MRS MR perfusion	Histopathologically proven tuberculosis	Tuberculosis
22&47	Headache	MRI with contrast, MRS	+ve anti cysticercosis antibodies	Cysticercosis
39–65 & 66	Right eye dropped vision	MRI with contrast MRS DTI	Histopathologically proven adenocarcinoma metastasis from the lung	Metastases from bronchogenic carcinoma
43 & 52	Known glioma Gr III resected	MRI + C, MRS, DTI	Histopathologiclly proven	Recurrent glioma

Fig. 1 45 year old male patient with history of left parietal GBM submitted to surgical excision followed by radiotherapy, he presented with this enhancing parenchymal nodule in post contrast axial T1WI (A) that could be recurrence or radiation necrosis. MRS (B) revealed increase in Choline/NAA ratio and Choline/Cr ratio with mild reduced NAA/Cr ratio. (C) DTI revealed decreased FA value with increased ADC value within the enhancing nodule (arrow) denoting high cellularity of the lesion. (D) Is follow up post contrast T1 after 5 months showing progression in size of the lesion which proved to be recurrent Glioblastoma multiform (GBM).

Table 2 Characteristics of MRS in different ring enhancing brain lesions: NAA: N-acetyl aspartate. Cho: Choline. Cr: Creatinine.

Lesion	MRS findings
Glioma	High choline/NAA ratio
	High choline in the surrounding oedema
Metastases	Mild elevation choline/NAA ratio and increased lipids and lactate.
	Choline is not elevated in the surrounding edema
Tuberculosis	Prominent decrease NAA/Cr and slight decrease Cho/NAA
	Lipid/lactate peaks are usually elevated
Fungal abscess	Absence of Cho, Cr, and NAA and also the increased concentrations of various aminoacids (acetate, alanine, lactate)
Cysticercosis	Elevated Choline, lactate and succinate
	Reduced NAA
Multiple sclerosis	Slightly increased Cho, decreased concentration of NAA, Glutamate peak and presence of lipid-lactate peaks
Meningioma	Prominent Choline and alanine.
	Absent or low NAA and Cr

Fig. 2 35 year old female patient with multiple patches of deep white matter hyperintensity on axial FLAIR (A), in post contrast axial T1WI (B) these lesions show irregular ring like marginal enhancement, no perifocal edema or mass effect, MR spectroscopy TE 30 from the lesion (C) shows mild elevation of choline/NAA ratio, marked elevation of glutamine peak at 2.1–2.5 ppm (arrow), large lactate peak at 1.3 ppm, and lipid peak at 0.9 ppm, suggesting tumefactive demyelination process. (D) 2 year follow up post contrast axial T1WI after medical treatment of MS shows remarkable regression.