Monday, 11 May 2015

MR Perfusion Imaging in Recurrence of Neoplasm with Subependymal spread : A Case Report

A fifty seven years old man, operated case of left parieto-temporal glioblastoma multiforme, post chemotherapy and post radiotherapy status.

Protocol:

Scan done on GE DISCOVERY 750 W 3 T scanner after injecting 10 ml of Dotarem.
Pre and post contrast MRI of the brain was performed using T1 and T2 weighted sequences in multiple planes, using a quadrature head coil. Perfusion studies of the brain were performed after intravenous injection of Dotarem using EPI sequences. Negative enhancement integral was evaluated. ROIs were placed within different parts of the lesion and normal appearing contralateral parenchyma and time intensity curves were plotted.
Single and multi voxel spectroscopy and chemical shift imaging were performed through the lesion using short TE (35 ms) PRESS sequences. Post processing was performed using FUNCTOOL on ADVANTAGE GE workstation.

Findings :

There is a large ill-defined, mixed signal intensity lesion in left parietotemproal region.  Multiple areas of blooming are seen within, suggestive of hemorrhagic changes.  Areas of restricted diffusion are also seen within the lesion which correspond to infarcts, likely treatment induced. Heterogeneous post-contrast enhancement is detected with non-enhancing areas representing necrosis.

These findings are suggestive of post-treatment changes admixed with residual neoplasm in left temporo-parietal region. Diffuse subependymal enhancement is detected along both lateral and third ventricles, suggestive of subependymal spread of neoplasm.

Single voxel spectroscopy from the enhancing component of the lesion showed . elevated choline and reduced NAA peak, along with elevated lactate levels. Cho / Cr ratio is 1.531 and Cho / NAA ratio is 4.529.

Multivoxel spectroscopy of necrotic areas reveal elevated lactate peak and diminished choline and NAA peaks suggestive of post radiation change.

The enhancing areas show increased perfusion with maximum rCBV ratio (calculated from signal intensity value) of 2.8.  The right subependymal areas of enhancement also demonstrate hyper perfusion with rCBV ratio calculated from signal intensity value) of 3 suggestive of high grade neoplastic infiltration.
The necrotic areas are hypoperfused.

Diagnosis:

Post treatment recurrence of neoplasm with sub ependymal spread.

CE - MRI, Dynamic susceptibility contrast MRI and MRS increase the diagnostic confidence of detecting tumor recurrence in a treated case of glioblastoma multiforme.

Contributors:

Dr. Deepak P. Patkar (HOD) Nanawati Superspeciality Hospital, Mumbai
Dr. Amit J. Choudhari Consultant Radiologist, Nanawati Superspeciality Hospital, Mumbai
Dr Balaji Anvekar

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