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Department of Radiology University of California San Diego. MR Imaging of the Brain. John R. Hesselink, M.D. MR System Components. Transmitter. Gradient Amplifier. RF Coil. Gradient. Computer. Gradient. RF Coil. Magnet. Receiver. Digitizer. Source of Signal and Contrast.
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Department of Radiology University of California San Diego MR Imaging of the Brain John R. Hesselink, M.D.
MR System Components Transmitter Gradient Amplifier RF Coil Gradient Computer Gradient RF Coil Magnet Receiver Digitizer
Source of Signal and Contrast Proton density T1 relaxation time T2 relaxation time Flow effects MR Imaging
RF TR TE Signal Spin-echo Pulse Sequence Single Echo T1-weighted 1st echo 2nd echo
RF TR TE TE Signal Spin-echo Pulse Sequence Dual Echo T2-weighted 1st echo 2nd echo
Normal FLAIR Images TR = 6000 msec, TI = 2000 msec, TE = 102 msec
T1-Weighted Images
T1W T2W Solid Brain Lesion PDW
T1W Cystic Lesion FLAIR T2W 236
Subacute Hemorrhage PDW T1W T2W
T2W FLAIR Acute Hemorrhage T1W GRE
Hemorrhage Sequence Gradient-echo
Fat or Lipoma T2W PDW T1W
MR Signal Intensities T2WI PD/FLAIR T1WI Solid mass Bright Bright Dark Cyst Bright Dark Dark Subacute blood Bright Bright Bright Acute & chronic blood Dark Dark Gray Fat Dark Bright Bright
Acute Stroke Sequence Diffusion Weighted Imaging
MR Spectroscopy Dx: Anaplastic astrocytoma > GBM
Sagittal T1-weighted images Axial T2-weighted images Axial FLAIR images Diffusion-weighted images Gradient-echo images Axial T1-weighted images Gadolinium: Axial & Coronal T1 Brain Screening Protocol
History: 46 y.o. man with headaches & increasing confusion 2 1 T2W PDW
4 3 T1W T1W 5 {Page 2} T1W / Gd
Increasing confusion {Page 3} 6 7 Dx: Meningioma & right MCA infarct
Student Cases "May the FORCE be with you!"
History: 69 y/o man with nausea & memory deficits for several weeks Case 1 413
{Page 2} Dx: Glioblastoma
Case 2 History: 5 y/o girl with seizures 361
{Page 3} Dx: Amoebic abscesses
Case 3 History: 62 y.o. man with mumbling speech 1 2 26
{Page 2} 3 4
{Page 4} 7 8 Dx: Enhancing subacute infarct
Case 4 History: 48 y.o. male with a sensorineural hearing loss 2 1
3 5 4 {Page 2} Dx: Acoustic neuroma
Case 5 History: 48 y.o. man with headaches & confusion 1 2 32
{Page 2} 3 4
5 {Page 3} 7 6
8 9 {Page 4} 10 Dx: Brain metastases - Lung carcinoma
Case 6 History: 36 y.o. man with seizures 2 1
5 3 4 History: Seizures {Page 2}
6 {Page 3} 7 8 Dx: AVM & basilar tip aneurysm
Case 7 History: 62 y/o woman with headaches
{Page 2} Dx: Arachnoid cyst
Case 8 History: 27 y.o. man with increasing confusion & lethargy 1 2 5
5 {Page 3} 6 Dx: Herpes simplex encephalitis
1 2 3 History: 72 y.o. woman with headaches Case 9 49