Study Guide RADIOLOGY - UMF
Study Guide RADIOLOGY - UMF
Study Guide RADIOLOGY - UMF
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<strong>Study</strong> <strong>Guide</strong> – Radiology – Faculty of Medicine - IV th Year 20• Long TE: 120 ms• Fluids = hypersignal• Fat = less intense signal compared to T1• Mucin = hyposignal• PD (proton density) weighting• Conditioned by the proton density• Characterized by long TR and short TEo MR Artifacts• Metallic - lack of signal (signal void) of large size, with peripheralenhancement• truncation = false bands or hyper - or hyposignal occurring where there is asharp transition in the signal - eg CSF-spinal cord (false appearance ofsyringomyelia)• Aliasing: object larger than FOV (field of view)• Chemical shift artifacts = band of hyposignal at the water-fat interface• Magnetic susceptibility: broad areas of hyposignal generated by theappearance of a magnetic field gradient at the interface of two structures withvery different magnetic susceptibility: ex air-watero Contraindications:• Absolute:• Cardiac pace-maker• Ferro-magnetic foreign body• Relative:• Pregnant women in the I trimester• Claustrophobia• Patients who are intubated, ventilatedSample Questions for the written exam of Radiology1. On standard sequences a subcutaneous lypoma appears:a. hypersignal T1b. black on T2c. hyposignal T1 and T2d. black on T1 and white on T2 weighted sequencese. It has an aspect of signal voidAnswer: a2. T1 weighting is:a. Conditioned by TRb. Conditioned by TEc. Proton density conditioned on the examined regiond. Characterized by long TR and TEe. Characterized by short TR and long TEAnswer: a3. The following statements are true, except one:a. Transverse magnetization can be measuredb. Longitudinal magnetization increases when a radio-frequency pulse isappliedc. Relaxation times are long for fluids compared to solid state.d. Adipose tissue has short relaxation timesAnswer: b