66-dr ahmed esawy imaging oral board of function mri mrs dwi mri perfusion
TRANSCRIPT
The Art of Radiology
Clinical Applications of Magnectic Resonance
Spectroscopy
NAA ( N-acetyl aspartate ) 2.02 ppm in neuron & axon
Creatine 3.02ppm, 3.94ppm
Myo-inositol ( ml ) 3.56-4.06 ppm
Proton MR spectroscopy (1H MRS)
Commonly detectable Brain Metabolites at low field strength ( 1.5T)
1H MRS has the following steps:
Parameters characterizing the metabolite resonance peak
Approaches for interpretation of 1H MR spectra
Typical 1H MR Spectroscopic neoplastic profile demonstrates:
The most often used pulse sequences are:
Spectroscopic localization methods
Single-Voxel MRS Studies of Alzheimer’s Disease(Neurology 2001; 57: 626-632)
Single-Voxel MRS Studies of Alzheimer’s Disease
Single-Voxel MRS Studies of Alzheimer’s Disease
Single-Voxel MRS Studies of Down Syndrome ( Am J Psychiatry 1999; 156: 1879-1886)
Single-Voxel MRS Studies of Ts65Dn Mouse---Down Syndrome Model (NeuroReport 2000; 11: 445-448)
Single-Voxel MRS Studies of Ts65Dn Mouse---Down Syndrome Model
3D H MRSI is utilized for:
MRS of Brain Abscess
Abscess
Abscess in vitro 1 H MRS
Lipid 0.9 – 1.3 ppm
MRS vs. DWI & ADC map
MRS vs. DWI & ADC map
MRS vs. DWI & ADC map
Anaerobic vs. Aerobicin vivo 1H MRS
MRS vs. DWI & ADC map
Brain abscess
1H MRS Study of Breast Cancer
1H MRS Study of Breast Cancer
1H MRS Study of Breast Cancer
1H MRS Study of Breast Cancer
1H MRS Study of Breast Cancer
1H MRS Study of Brain Cancer
Localization of Spectroscopic Voxel for a Patient with Metastatic Squamous Cell Carcinoma
Proton Spectra of a Patient with Metastatic Squamous Cell Carcinoma
Localization of Spectroscopic Voxel for a Patient with Squamous Cell Carcinoma
Proton Spectra of a Patient with Squamous Cell Carcinoma
Changes of Cho/Water Ratio for Head and Neck Tumor Patients
Discriminating Neoplastic and Non-neoplastic Thyroid Lesions Using 1H MRS
Proton spectra from neoplastic thyroid lesion and normal-appearing contralateral region
Significant difference in Cho/Water ratio between neoplastic (3.36 2.55, n=22) and non-neoplastic (0.16 0.11,
n=7) thyroid lesions
Results
1H MRS Study of a child with NKH(Non Ketotic Hyperglycinemia)
(J Neuroimaging 2001; 11: 209-212)
WM proton spectra at 10 and 13 months(TE/TR 270/2000)
Correlation of plasma and brain glycine levels
1H MRS Study of a child with ADEM(Acute Disseminated Encephalomyelitis)
In vivo 1H MRS study of a rat model of autism(Physiol Behav 2002; 75: 403-410)
PRESS (TE/TR 40/2000), 0.2 cc voxel size
Significant decrease of NAA/Cr in autistic rats
Significant increase of Cho/Cr in autistic rats
Significant increase of mI/Cr in autistic rats
1H MRS study of autistic human subjects(PRESS, TE/TR 40/2000)
1H MRS study of autistic human subjects(PRESS, TE/TR 40/2000)
1H MRS study of autistic human subjects(PRESS, TE/TR 40/2000)
1H Spectra from Healthy Controls
DIFFUSION MRI IMAGING
-History-
Diffusion Weighted Image
-Diffusion contrast-
-Principles -Velocities and methods of measurement
-Principles -About the b factor
-Principles -About ADC
-Principles -Isotropic and Anisotropic diffusion
Diffusion weighted image
APPLICATIONS
ROLE OF DIFFUSION IN DIFFERENTIATING BENIGN VERSUS
MALIGNANT FRACTURE
ADC and rCBV Maps of a Patient with CNS Lymphoma
Perfusion imaging
Definitions
Principles
Some more Definitions
Principles
Cerebral blood perfusion by bolus tracking
Applications of Perfusion MRI
Perfusion Imaging: Findings in Infarction
Findings with Perfusion Imaging for Infarction
Alzheimer’s disease
Findings with Perfusion imaging for Neurophysiology and pharmacology
Findings with Perfusion imaging for Neuro-oncology
Neuro-oncology
Eg2 Diffused tumor:Abnormal capillary density
Diffusion-Tensor Imaging: Executive Function in
Subcortical Ischemic Vascular Disease and Mild Cognitive
Impairment
Diffusion-Tensor Imaging
DTI Basics – Water Diffusion
DTI Scalar Parameters
DTI Scalar Maps
DTI Basics – White Matter Integrity
Why study frontal systems in SIVD & MCI?
DTI TRACTOGRAPHYVisualization of Fibers at Risk for Neuronal Tract
Injury in Early MS by Streamtube Diffusion Tractography at 3 Tesla
at three patient
Background – Neuronal Tract Degeneration in Early MS
Goals/Question
Strategy
3T Pulse Parameters
T2-weighted magnetic resonance (MR)
Dynamic Contrast-enhanced MR Imaging
Diffusion-weighted Imaging
Diffusion-weighted Imaging
MR Spectroscopy
MR Spectroscopy
MR SPECTROSCOPY
IMAGING OF LYMPH NODE AND BONE METASTASIS
