![Page 1: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/1.jpg)
![Page 2: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/2.jpg)
Assistant Lecturer Of Neurosurgery, Alexandria, Egypt
MAGNETIC RESONANCE SPECTROSCOPY VERSUS STEREOTACTIC BIOPSY FOR INTRA-AXIAL BRAIN LESIONS
Ahmed Belal
Presented By
Alex Neuro2014
![Page 3: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/3.jpg)
Intra-axial brain lesions could be neoplastic or non-neoplastic. Some non-neoplastic brain lesions can mimic the neoplastic lesions clinically, radiologically and sometimes histopathologically.
And this may lead to misdiagnosis and hence mismanagement.
![Page 4: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/4.jpg)
MRS is usually used as a complement to conventional MRI to improve the diagnosis of intra-axial parenchymal brain lesions
![Page 5: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/5.jpg)
Magnetic Resonance Spectroscopy (MRS) is based on the chemical shift properties of the atom. When a tissue is exposed to an external magnetic field, its nuclei will resonate at a frequency (f).
The most common nuclei used for MRS are protons (H1) mainly because of its high sensitivity and abundance.
![Page 6: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/6.jpg)
The Spectrum
![Page 7: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/7.jpg)
The MR spectrum is represented by:(x) axis that corresponds to the metabolite frequency in ppm according to the chemical shift (y) axis that corresponds to the peak amplitude Each metabolite is identified by the position of its peak on a frequency scale (the chemical shift)
![Page 8: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/8.jpg)
The Brain Metabolites
![Page 9: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/9.jpg)
N-acetylaspartate (NAA) :
Peak of NAA is the highest peak assigned at 2.02 ppm.
It is a marker of neuronal and axonal viability and density .
Absence or decreased concentration of NAA is a sign of neuronal loss or degradation
![Page 10: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/10.jpg)
Choline (Cho) :
Its peak is assigned at 3.22 ppm
Cho is a marker of cellular membrane turnover (phospholipids synthesis and degradation) reflecting cellular proliferation
In tumors, Cho levels correlate with degree of malignancy
![Page 11: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/11.jpg)
Creatine (Cr) :
The peak of Cr spectrum is assigned at 3.02 ppm
Cr is a marker of intracellular metabolism.
Concentration of Cr is relatively constant. Therefore it is used as an internal reference for calculating metabolite ratios.
In brain tumors, there is a reduced Cr signal
![Page 12: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/12.jpg)
Lactate (Lac) :
The peak of Lac is a doublet
Lac is a product of anaerobic glycolysis so its concentration increases under anaerobic metabolism such as cerebral ischemia.
Lac also accumulates in tissues with poor washout such as cysts, normal pressure hydrocephalus, necrotic and cystic tumors.
![Page 13: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/13.jpg)
Lipids (Lip)
Lipid peaks can be seen when there is cellular membrane breakdown or necrosis such as in metastases or primary malignant tumors.
![Page 14: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/14.jpg)
Myoinositol (Myo) :
Myo is considered a glial marker because it is primarily synthesized in glial cells, almost only in astrocytes
Elevated Myo occurs with proliferation of glial as found in inflammation , gliosis and in Alzheimer’s disease
![Page 15: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/15.jpg)
![Page 16: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/16.jpg)
Clinical applications of MR spectroscopy
![Page 17: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/17.jpg)
Differentiation between neoplastic and non- neoplastic lesions
The typical MRS spectrum for a brain tumor is one of high level of Cho, low NAA and minor changes in Cr
Cho elevation is usually evidenced by increase in Cho/NAA or Cho/Cr ratios, rather than its absolute concentration
Absence of NAA in an intra-axial tumor generally implies an origin outside of the central nervous system (metastasis) or a highly malignant tumor that has destroyed all neurons in that location.
![Page 18: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/18.jpg)
Grading of cerebral gliomas
Distinguishing between primary brain tumors and metastases
Distinguishing radiation necrosis from tumor recurrence
![Page 19: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/19.jpg)
This study was conducted on 27 patients presented to the Neurosurgery
Department at Alexandria Main University Hospital.
![Page 20: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/20.jpg)
METHODS
![Page 21: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/21.jpg)
All patients were subjected to:
• Complete history taking.
• Full clinical examination.
• Pre-operative investigations:
Routine laboratory investigations.Contrast enhanced Computed Tomography (CT)
scan of the brainContrast enhanced Magnetic Resonance Imaging
(MRI) of the brain.Magnetic Resonance Spectroscopy (MRS) of the
lesionEither single or multivoxel MRS was used with short and long TE
![Page 22: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/22.jpg)
• Surgical techniques:
Stereotactic biopsy using Leksell Stereotactic System.
• Histopathological examination
using appropriate stains including immunostains
![Page 23: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/23.jpg)
![Page 24: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/24.jpg)
RESULTS
![Page 25: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/25.jpg)
The preoperative MRS suggested diagnosis was
Neoplastic brain lesions in 15 (56%) cases
Non-neoplastic brain lesions in 12 (44%) cases
Neo-plas-tic
cases56%
Non-Neo-plas-tic
cases44%
![Page 26: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/26.jpg)
0
2
4
6
8
The most common MRS diagnosis was High grade gliomas, 7 cases (26%)
![Page 27: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/27.jpg)
Neoplastic cases63%
Non-neoplas-tic cases
37%
The histopathological diagnosis was Neoplastic lesions in 17 cases (63%)
Non-neoplastic lesions in 10 cases (37%)
![Page 28: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/28.jpg)
The commonest diagnosis following stereotactic biopsy was
Glioblastoma multiforme (GBM) , (WHO grade IV), 10 cases (37%)
The commonest diagnosis of the non-neoplastic cases was Brain abscess, 3 cases (11%)
![Page 29: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/29.jpg)
Histopathological diagnosisNumber of
casesPercentage
GBM (WHO grade IV) 10 37%
Low grade astrocytoma
(WHO grade I-II)4 15%
Abscess 3 11%
Tumefactive MS 2 7%
Cerebritis 1 4%
Primary CNS Lymphoma (PCNSL)
1 4%
Local tumor recurrence (low grade glioma WHO grade I-II)
1 4%
Metastases (from colonic carcinoma)
1 4%
Infarction 1 4%
Vasculitis 1 4%
Viral encephalitis 1 4%
Total 27 100%
![Page 30: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/30.jpg)
Correlation between the preoperative diagnosis by MRS and Histopathoplogical diagnosis following Stereotactic Biopsy for
Differentiation between Neoplastic and Non-neoplastic brain lesions revealed
Matching In 25 Out Of 27 Cases Sensitivity 88% Specificity 100%
![Page 31: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/31.jpg)
One case was diagnosed by MRS as a Neuroglial cyst but the histopathological diagnosis of the stereotactic biopsy was Cystic astrocytoma.
Another case was diagnosed by MRS as an Abscess but the histopathological diagnosis of the stereotactic biopsy was Glioblastoma multiforme (WHO grade IV).
However, the convential MRI was lacking the DWI/ADC map, which is diagnostic for brain abscess
![Page 32: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/32.jpg)
Correlation between the preoperative diagnosis by MRS and Histopathoplogical diagnosis following Stereotactic Biopsy For Grading of Gliomas (12 cases ) revealed
Matching in 10 out of the 12 cases Sensitivity 89% Specificity 67%
![Page 33: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/33.jpg)
Illustrative Cases
![Page 34: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/34.jpg)
Case 1
Rt thalamic lesion
![Page 35: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/35.jpg)
The MRS shows : Increassed Cho/Cr Increased Cho/NAA Decreased NAA/Cho ratio
Features suggestive of high grade glioma
![Page 36: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/36.jpg)
Histopathological diagnosis was
GBM (WHO IV)
![Page 37: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/37.jpg)
Case 2:
Rt thalamic cystic lesion
![Page 38: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/38.jpg)
The MRS from within the center of the lesion revealed very prominent Lip peak (block arrow) very prominent peak of succinate (long arrow) Small amino acid peak (arrow head) Lac peak (right angle arrow)
Such findings were typical for an anaerobic abscess
A
B
C
E
D
F
![Page 39: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/39.jpg)
![Page 40: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/40.jpg)
Case 3:
Rt lenticular cystic lesion
![Page 41: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/41.jpg)
The initial MRS was in favor of a Neuroglial Cyst. However, after subsequent revision of the MRS findings it revealed
Increased Cho/Cr, Cho/NAA ratiosDecreased NAA/Cho ratio
Features are matching with a Neoplastic lesion
![Page 42: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/42.jpg)
Case 4:
Multiple enhancing brain lesions
![Page 43: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/43.jpg)
The MRS shows Increased Cho/Cr , Cho/NAA ratios Decreased NAA/Cho, NAA/Cr ratios,Lip and Lac peaks are seenDetectable Glx peakmulticentric neoplastic lesion; Primary CNS lymphoma was the prime diagnosis
![Page 44: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/44.jpg)
Case 5:
Bithalamic ill defined lesion
![Page 45: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/45.jpg)
The MRS shows
Preserved NAA and NAA/Cho ratioDecreased NAA/Cr ratioIncreased Cr peakDetectable Lac peak
MRS features of Encephalitis
![Page 46: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/46.jpg)
A
B
C
D
E
Lac
NAACr
Cho
A
B
C
D
E
Lac
NAACr
Cho
Case 6
Multiple lesions
![Page 47: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/47.jpg)
A
B
C
D
E
Lac
NAACr
ChoA
B
C
D
E
Lac
NAACr
Cho
The MRS shows
High Cho/Cr , High Cho/NAA Decreased NAA/ChoLactate Peak Is Prominent (White Arrow) Small Lip Peak was also detected (block Arrow). Normal Spectroscopic findings in the peritumoral region
Overall data were matching with Metastatic Lesions
![Page 48: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/48.jpg)
Case 7:
Lt deep parietal enhancing lesion
![Page 49: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/49.jpg)
The initial MRS was in favor of Brain Abscess. However, after subsequent revision of the MRS findings it revealed
Marked increase in Cho/Cr and Cho/NAA ratios Prominent lip peak
Which were in favor of High Grade Glioma
![Page 50: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/50.jpg)
CONCLUSION AND RECOMMENDATIONS
![Page 51: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/51.jpg)
Magnetic resonance spectroscopy (MRS) should be part of the routine MRI examination when studying focal lesions and hence should be included in the imaging request.
The interpretation of the Magnetic resonance spectroscopy (MRS) findings should be conducted by a specialized radiologist to minimize falacies.
Intra-operative MRS could be used routinely to maximizes tumor resection and to reduces the need for subsequent operations.
![Page 52: Assistant Lecturer Of Neurosurgery, Alexandria, Egypt Alex Neuro 2014](https://reader038.vdocuments.us/reader038/viewer/2022103022/56649d195503460f949ee9dc/html5/thumbnails/52.jpg)
THANK YOU