Sunday, 1 September 2019

Tumor Mimics MRI

FLAIR
T2W
DWI
T2*GRE
T1


MR SPECTROSCOPY
PERFUSION IMAGING

This MRI study of brain shows an intra axial space-occupying lesion measuring approximately 53x55mm involving left opercular parietal and adjacent insular cortex with marked focal parenchymal swelling, lesion non-enhancing on post contrast. No mid line shift or mid brain compression. No obvious cystic or necrotic component. No diffusion restriction or haemosiderin staining on GRE.

ASL 
3D arterial spin labelling (non-contrast perfusion) was performed. Cerebral blood flow (CBF) assessed in ml /100 gm / min

Findings: 
The lesion predominantly shows mixed perfusion, major portion show hypo perfusion with patchy areas of relative hyper perfusion with CBF in range of 11 ml / 100 gm / min , 160% of reference in its cranial aspect. 

PERFUSION IMAGING
Perfusion maps demonstrated with color scale used are as follows. 
CBF: cerebral blood flow; higher scale (red) means faster flow and lower scale (blue) mean less flow.
CBV: cerebral blood volume ; higher scale (red) means more volume and lower scale less volume.
MTT: mean transit time; higher scale (red) means longer time required to washout contrast and lower scale (blue) means short time early washout.
TTP: time to peak; higher scale (red) means longer TTP and lower scale (blue) means shorter TTP.

Findings:
Lesion is relatively hyper perfused. 
rCBF:          11  ml/100gm/ min   160% of reference
rCBV:        3.2   ml / 100gm tissue 482% of reference
MTT:        17; 296% of reference   

Interpretation:

Lesion show mixed perfusion, areas of hypo - iso perfusion, a focal hyper perfusion particularly left parietal sub cortical portion of lesion. 

MR SPECTROSCOPY 

Axial T2w localizer taken and multi voxel MR Spectroscopy performed. The voxel of size 2x2cm placed over the lesion. Water suppression obtained was 99% with optimum spectral waveform obtained at short as well as long TE.

Metabolites evaluated on short TE of  35ms and TR of 1500ms from right to left as follow. 
At 2.01ppm – short and wide peak of NAA. NAA is reduced.
At 3.03ppm – sharp and long peak of Creatinine. Creatinine is reduced.
At 3.2ppm – sharp and long peak of Choline. High choline.
No lipid lactate.

NAA/ Creatinine ratio is 2
Choline/ Creatinine ratio is 1.5

Interpretation: 

Lesion show high choline, reduced Creatinine. 

Summary: 

This MRI study of brain shows an intra axial lesion involving left opercular parietal and adjacent insular cortex with marked focal parenchymal swelling, sub cortical white matter oedema, non-enhancing on post contrast. No obvious cystic or necrotic component. 
No diffusion restriction or haemosiderin staining on GRE.
Lesion show high choline, reduced Creatinine on MR spectroscopy. 
Left parietal sub cortical portion of lesion is hyper perfused on ASL as well as perfusion imaging.

Imagingwise diagnosis: Glioma like Astrocytoma_ Low to Intermediate grade tumour.
But Histopathology report surprise to me.

HISTOPATHOLOGY REPORT : FOCAL CORTICAL DYSPLASIA TYPE III

Microscopic Description : 

The entirely submitted material shows surrounding odematous glial tissue. Punctate haemorrhages, fine micro cystic change, neuronal crowding, Cytomegaly neurons, Peri vascular cuffing and haemorrhages, Occasional Balloon cells. There is no granuloma. 
IHC : Ki 67 index less than 1 %

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