p.6
CT vs. X-ray Comparison
What type of radiation do both X-ray and CT scanning use?
Ionizing radiation from a source.
p.8
CT Scanning Process and Advantages
How does CT imaging work?
CT imaging works by using ionizing radiation to create image slices of the body, which are then used to produce cross-sectional images.
p.2
X-ray Limitations and Capabilities
Why can't plain X-rays evaluate deeper soft structures effectively?
Because of superimposition, which leads to poor resolution.
p.6
CT Scanning Process and Advantages
What device absorbs penetrated X-rays in CT scanning?
An electronic device called a 'detector array'.
p.14
CT vs. X-ray Comparison
What capability do CT scans have that allows them to measure subtle differences in tissue density?
CT scans can measure subtle density differences.
p.15
CT vs. X-ray Comparison
How does the cost of CT scanning compare to MRI?
CT scanning is less expensive than MRI.
p.16
MRI Fundamentals and Signal Differences
What is the primary use of MRI?
To create detailed images of the organs and tissues in the body.
p.16
Advantages and Limitations of MRI
What are the advantages of MRI over X-ray?
MRI provides more detailed images of soft tissues and does not use ionizing radiation.
p.16
Advantages and Limitations of MRI
What is one limitation of MRI?
It can be expensive and time-consuming compared to other imaging techniques.
p.23
MRI Fundamentals and Signal Differences
What determines the different signals sent out by protons in MRI?
The type of tissue the proton is found in.
p.23
MRI Fundamentals and Signal Differences
How do signal differences in MRI help in imaging?
They allow a picture to be created and enable different tissues or structures to be distinguished from one another.
p.24
Interpreting MRI Images
What does a low signal lesion indicate in MRI?
A low signal lesion is hypointense and appears dark.
p.2
X-ray Limitations and Capabilities
What are the limitations of plain X-ray imaging?
Plain X-ray has limited detection ability with poor resolution and can't evaluate deeper soft structures very well due to superimposition.
p.10
CT Scanning Process and Advantages
What are the three terms used to describe abnormalities on a CT scan based on their density?
Hyperdense, hypodense, and isodense.
p.11
MRI Pulse Sequences and Imaging Techniques
What is the axial (transverse) plane?
A horizontal plane that passes through the body, dividing it into superior and inferior portions.
p.12
CT Scanning Process and Advantages
What does MPR stand for in medical imaging?
Multiplanar Reconstructions.
p.12
CT Scanning Process and Advantages
What anatomical structures can be visualized using 3D Volume Rendering?
Structures such as the skull and spine.
p.14
CT vs. X-ray Comparison
What is a key advantage of CT scans in terms of contrast resolution?
CT scans have better contrast resolution.
p.19
MRI Fundamentals and Signal Differences
What do protons emit as they return to their original positions after the magnetic field is switched off?
They send out radio waves of their own as a signal.
p.16
MRI Fundamentals and Signal Differences
What type of imaging technique is MRI?
A non-invasive imaging technique.
p.16
Safety Considerations in MRI Procedures
What safety consideration is important for MRI procedures?
Patients with metal implants or devices may not be able to undergo MRI due to the strong magnetic fields.
p.24
Interpreting MRI Images
How does a high signal lesion appear in MRI?
A high signal lesion is hyperintense and appears bright.
p.3
Skull and Spine X-ray Applications
What are the primary uses of skull X-rays?
Detection of foreign bodies, fractures for medico-legal purposes, and sinusitis.
p.8
CT Scanning Process and Advantages
What is Computed Tomography (CT)?
CT is a modality that uses ionizing radiation to cut the body into image slices, producing cross-sectional images to better view internal organs.
p.8
CT Scanning Process and Advantages
What is the main advantage of CT imaging?
The main advantage of CT imaging is its ability to produce cross-sectional images that provide a better view of the internal organs.
p.10
CT Scanning Process and Advantages
What does 'isodense' mean in the context of a CT scan?
An abnormality that is the same density as the reference structure.
p.11
MRI Pulse Sequences and Imaging Techniques
What is the coronal plane?
A vertical plane that passes through the body, dividing it into anterior (ventral) and posterior (dorsal) portions.
p.15
Cerebral Angiography Techniques
What is a notable application of CT scanning involving blood vessels?
CT angiography (use of contrast in blood vessels).
p.26
Interpreting MRI Images
What should be assessed to interpret MR images?
The signal intensity of the structure or lesion in both T1WI and T2WI.
p.31
Cerebral Angiography Techniques
What is a common clinical application of Cerebral MR Venography?
Diagnosing venous sinus thrombosis.
p.34
Advantages and Limitations of MRI
Why might sedation be required for children undergoing an MRI?
To help them remain still and calm during the procedure.
p.38
Safety Considerations in MRI Procedures
Are digital watches usually okay to wear?
Yes, digital watches are usually okay.
p.1
X-ray Limitations and Capabilities
What is the primary principle behind how X-rays work?
X-rays work by passing through the body and being absorbed at different rates by different tissues, creating an image based on the varying absorption levels.
p.1
X-ray Limitations and Capabilities
Why do bones appear white on an X-ray image?
Bones appear white on an X-ray image because they are denser and absorb more X-rays compared to other tissues.
p.4
Skull and Spine X-ray Applications
What are the primary uses of spine X-rays?
Trauma, Neoplasm, Infection, Degenerative disease.
p.12
CT Scanning Process and Advantages
What is 3D Volume Rendering used for in medical imaging?
To create three-dimensional images from CT scans.
p.15
CT Scanning Process and Advantages
What are potential complications associated with the use of contrast in CT scans?
Contrast complications, which can be substituted by MRI.
p.16
MRI Fundamentals and Signal Differences
What does MRI use to generate images?
Magnetic fields and radio waves.
p.23
MRI Fundamentals and Signal Differences
What is an example of how different tissues emit different MRI signals?
A proton found in bone will emit a very different radio wave signal compared to a proton found in blood.
p.25
MRI Pulse Sequences and Imaging Techniques
How are MRI pulse sequences chosen?
They are chosen to best suit the particular clinical application.
p.26
MRI Pulse Sequences and Imaging Techniques
How does cerebrospinal fluid (CSF) appear in T2-weighted imaging (T2WI)?
CSF appears as a high signal, or 'bright' (white).
p.6
X-ray Limitations and Capabilities
How does plain X-ray imaging absorb penetrated X-rays?
The film directly absorbs penetrated X-rays.
p.9
CT Scanning Process and Advantages
What are the two types of windows shown in the CT images?
Soft Tissue Window and Bone Window.
p.13
Cerebral Angiography Techniques
What are the key arteries visualized in cerebral CT angiography?
Anterior cerebral arteries, anterior communicating artery, middle cerebral arteries, and posterior cerebral arteries.
p.19
MRI Fundamentals and Signal Differences
What happens to protons once the magnetic field is switched off in MRI?
The protons begin to lose their alignment and go back to the position they were in before the magnetic field was applied.
p.16
Interpreting MRI Images
What is a common application of MRI in medicine?
Diagnosing brain and spinal cord abnormalities.
p.27
MRI Fundamentals and Signal Differences
What signal intensity does subacute blood (met Hb) show in T1 and T2 weighted MRI?
High signal in both T1 and T2 weighted MRI.
p.27
MRI Fundamentals and Signal Differences
How does normal flowing blood appear in T1 and T2 weighted MRI?
Black in both T1 and T2 weighted MRI.
p.31
Cerebral Angiography Techniques
What does MRA stand for?
Magnetic Resonance Angiography
p.33
Advantages and Limitations of MRI
What is one advantage of MRI in terms of tissue contrast?
Superior soft tissue contrast resolution, allowing excellent pathological discrimination.
p.34
Advantages and Limitations of MRI
Why can't MRI be performed on people with certain implanted metal objects?
Because the strong magnetic field can interfere with or be affected by metal objects like pacemakers and certain implants.
p.36
Safety Considerations in MRI Procedures
How can changing magnetic fields affect cellular telephones?
They can disrupt the electronic components and data stored in cellular telephones.
p.1
X-ray Limitations and Capabilities
What types of tissues appear in shades of gray on an X-ray image?
Muscles, organs, and other soft tissues appear in shades of gray on an X-ray image because they are less dense and absorb fewer X-rays.
p.6
CT Scanning Process and Advantages
What does the detector array do with the absorbed X-rays in CT scanning?
It measures the X-ray amount and transmits the data to a computer system.
p.6
CT vs. X-ray Comparison
What is the main similarity between X-ray and CT scanning?
Both use ionizing radiation from a source to produce an image.
p.11
MRI Pulse Sequences and Imaging Techniques
What is the sagittal plane?
A vertical plane that passes through the body, dividing it into right and left portions.
p.13
CT Scanning Process and Advantages
What are the common applications of virtual endoscopy?
Bronchoscopy and arteriography.
p.14
CT vs. X-ray Comparison
What is one advantage of CT scans over traditional X-rays regarding structure visualization?
CT scans have no superimposition of structures.
p.14
CT vs. X-ray Comparison
What advanced imaging technique is possible with CT scans but not with traditional X-rays?
Multiplanar reformations.
p.16
MRI Fundamentals and Signal Differences
What does MRI stand for?
Magnetic Resonance Imaging
p.24
Interpreting MRI Images
What is the appearance of an intermediate signal lesion in MRI?
An intermediate signal lesion is isointense and appears gray.
p.26
Interpreting MRI Images
What common practice should be followed when interpreting MR images?
Follow the well-known common signal behavior.
p.27
MRI Fundamentals and Signal Differences
What signal intensity does contrast injection (Gd-DTPA) show in T1 and T2 weighted MRI?
Low signal in T1 weighted MRI and high signal in T2 weighted MRI.
p.31
Advantages and Limitations of MRI
What advantage does MRA have over traditional angiography?
It is non-invasive and does not require the use of ionizing radiation.
p.35
Safety Considerations in MRI Procedures
Why are metal implants such as cochlear implants contraindicated for MRI?
Because the magnetic field can cause movement or malfunction of the implants.
p.1
X-ray Limitations and Capabilities
How do X-rays create images of the body's internal structures?
X-rays create images by passing through the body and being absorbed by denser materials like bones, which appear white on the X-ray film, while less dense materials like muscles and organs appear in shades of gray.
p.1
X-ray Limitations and Capabilities
What is the role of the X-ray film or detector in the imaging process?
The X-ray film or detector captures the varying levels of X-ray absorption by different tissues, creating a visual representation of the internal structures.
p.6
CT Scanning Process and Advantages
How does a computer system contribute to CT scanning?
It calculates and analyzes data from each detector in each level and reconstructs multiple, two-dimensional, cross-sectional images.
p.11
MRI Pulse Sequences and Imaging Techniques
What is the oblique plane?
A plane that passes diagonally between the axes of two other planes.
p.15
CT Scanning Process and Advantages
How does CT scanning perform in terms of soft tissue contrast?
Good soft tissue contrast.
p.16
MRI Fundamentals and Signal Differences
What kind of tissues can MRI best visualize?
Soft tissues, such as the brain, muscles, and connective tissues.
p.25
MRI Pulse Sequences and Imaging Techniques
What should be followed to differentiate diagnoses of lesions?
The behavior of the lesions in different pulse sequences.
p.26
MRI Pulse Sequences and Imaging Techniques
What is the primary use of T2-weighted imaging (T2WI) in MRI?
To detect a pathologic process such as edema or swelling.
p.27
MRI Fundamentals and Signal Differences
What signal intensity does fat (subcutaneous fat, dermoid cyst) show in T1 and T2 weighted MRI?
High signal in T1 weighted MRI and low signal in T2 weighted MRI.
p.31
Cerebral Angiography Techniques
What is the main difference between MRA and Cerebral MR Venography?
MRA focuses on arteries, while Cerebral MR Venography focuses on veins.
p.31
MRI Pulse Sequences and Imaging Techniques
What imaging planes are commonly used in Cerebral MR Venography?
Sagittal, coronal, and axial planes.
p.35
Safety Considerations in MRI Procedures
Why must individuals with pacemakers avoid MRI magnets?
Because the magnetic field can interfere with the pacemaker's function.
p.35
Safety Considerations in MRI Procedures
Why must individuals with electronic or magnetized foreign bodies avoid MRI?
Because the magnetic field can interfere with or move these foreign bodies.
p.38
Safety Considerations in MRI Procedures
Are snaps and zippers fastened to clothing usually okay?
Yes, snaps and zippers fastened to clothing are usually okay.
p.15
CT Scanning Process and Advantages
What is a major limitation of CT scanning related to patient weight?
Weight limitation of 160 kg.
p.21
MRI Fundamentals and Signal Differences
What are MRI images based on?
The location and strength of the incoming signals.
p.12
CT Scanning Process and Advantages
What types of images can be created using Multiplanar Reconstructions (MPR)?
Coronal, Sagittal, Para-axial, Oblique, and Curved images.
p.13
Cerebral Angiography Techniques
What is cerebral CT angiography?
A medical imaging technique that visualizes the blood vessels in the brain using CT scans and contrast material.
p.14
CT vs. X-ray Comparison
How do CT scans compare to traditional X-rays in terms of image detail?
CT scans produce more detailed images of internal organs than traditional X-rays.
p.19
MRI Fundamentals and Signal Differences
What role do RF coils play in MRI?
RF coils are used to detect the radio waves emitted by protons as they return to their original positions.
p.26
MRI Pulse Sequences and Imaging Techniques
How does cerebrospinal fluid (CSF) appear in T1-weighted imaging (T1WI)?
CSF appears as a low signal, or 'dark'.
p.27
MRI Fundamentals and Signal Differences
What signal intensity do fluids (CSF, urine, pleural effusion, ascites), edema, infarctions, and most tumors show in T2 weighted MRI?
High signal in T2 weighted MRI.
p.31
Cerebral Angiography Techniques
What is the purpose of Cerebral MR Venography?
To visualize the veins in the brain.
p.34
Advantages and Limitations of MRI
Why is MRI considered expensive?
Due to the high cost of the equipment and the procedure.
p.33
Advantages and Limitations of MRI
What is one advantage of MRI regarding bone artifacts?
MRI does not produce bone artifacts.
p.36
Safety Considerations in MRI Procedures
What is a potential risk to monitoring equipment in the presence of changing magnetic fields?
The magnetic fields can interfere with the operation and accuracy of monitoring equipment.
p.35
Safety Considerations in MRI Procedures
What types of stimulators are contraindicated for MRI?
Vagus nerve stimulators, implantable defibrillators, insulin pumps, and deep brain stimulators.
p.13
CT Scanning Process and Advantages
What is virtual endoscopy?
A non-invasive medical imaging technique that uses CT or MRI data to create a 3D visualization of the interior of a bodily organ.
p.13
CT Scanning Process and Advantages
What is virtual colonoscopy?
A non-invasive imaging procedure that uses CT scans to produce a detailed view of the colon.
p.17
MRI Fundamentals and Signal Differences
What elements make up 99% of the average human body?
Hydrogen (H), Oxygen (O2), and Carbon (C)
p.21
MRI Fundamentals and Signal Differences
What allows detailed MRI images to be created?
The location and strength of the incoming signals.
p.23
MRI Fundamentals and Signal Differences
What is the relationship between different protons and MRI signals?
Different protons emit different MRI signals.
p.25
MRI Pulse Sequences and Imaging Techniques
What is an MRI pulse sequence?
A programmed set of changing magnetic gradients.
p.25
MRI Pulse Sequences and Imaging Techniques
Why are different MRI pulse sequences used?
To image the same tissue in various ways and provide important diagnostic information about the tissue.
p.27
MRI Fundamentals and Signal Differences
What signal intensity do cortical bone, cartilage, mature fibrous tissue, and calcifications show in T1 and T2 weighted MRI?
Low signal in both T1 and T2 weighted MRI.
p.31
Cerebral Angiography Techniques
What anatomical structures are primarily visualized in MRA?
Blood vessels, particularly arteries.
p.33
Advantages and Limitations of MRI
How can MRI be used in vascular studies?
MRI can perform vascular studies non-invasively without the need for contrast.
p.35
Safety Considerations in MRI Procedures
Who must avoid going near the magnet in an MRI setting?
Subjects, staff, and visitors.
p.34
Advantages and Limitations of MRI
Why might MRI not be suitable for very large individuals?
Because the MRI machine may not accommodate their size.
p.37
Safety Considerations in MRI Procedures
Why is it important to keep metallic objects away from an MRI machine?
Because the strong magnetic field can turn them into dangerous projectiles.
p.38
Safety Considerations in MRI Procedures
Can you wear eyeglass frames?
Yes, eyeglass frames are usually okay.
p.28
Interpreting MRI Images
What is the MRI appearance of a chronic hematoma (>14 days) on T1-weighted imaging (T1WI)?
Isointense or Hypointense
p.31
MRI Fundamentals and Signal Differences
What type of imaging technique is used in MRA?
Magnetic Resonance Imaging (MRI)
p.33
MRI Pulse Sequences and Imaging Techniques
What planes can MRI directly image?
Transverse, coronal, sagittal, and any oblique plane.
p.36
Safety Considerations in MRI Procedures
Why are credit cards susceptible to damage from changing magnetic fields?
Because the magnetic strip on credit cards can be erased or corrupted by strong magnetic fields.
p.33
Safety Considerations in MRI Procedures
What are the safety benefits of MRI?
MRI involves no radiation or harmful side effects.
p.34
Advantages and Limitations of MRI
What is the noise level range of an MRI machine, and what is it equivalent to?
65-115 dB, equivalent to a jet engine at takeoff.
p.36
Safety Considerations in MRI Procedures
What types of equipment can be damaged by changing magnetic fields?
Monitoring equipment, credit cards, and cellular telephones.
p.37
Safety Considerations in MRI Procedures
Is the MRI magnet ever turned off?
No, the MRI magnet is never off.
p.34
Advantages and Limitations of MRI
What makes MRI a difficult exam for immobile, elderly, or sick patients?
The need to remain still for extended periods during the scan.
p.34
Advantages and Limitations of MRI
What precaution must be taken due to the noise produced by an MRI machine?
Subjects must be given ear plugs.
p.34
Advantages and Limitations of MRI
How can body movement affect an MRI test?
It can cause artifacts and reduce the quality of the images.
p.37
Safety Considerations in MRI Procedures
What can the strong magnetic field of an MRI magnet turn into dangerous projectiles?
Coins, scissors, safety pins, wheelchairs, oxygen tanks, I.V. poles, and keys.
p.38
Safety Considerations in MRI Procedures
Is dental work usually okay?
Yes, dental work is usually okay.
p.37
Safety Considerations in MRI Procedures
List some common items that should be kept away from an MRI machine due to the magnetic field.
Coins, scissors, safety pins, wheelchairs, oxygen tanks, I.V. poles, and keys.
