The Mri Exam & Anatomy Part One

Front 1

What is the centering for the brain?

Back 1

At the glabella with the interpupillary line horizontal and perpendicular to the long axis of the body.

Front 2

How can you minimize flow artifact in brain imaging sequences?

Back 2

By using gradient nulling and application of an INFERIOR sat region. Or you can use PULSE TRIGGERING. Although it is NOT necessary.

Front 3

What are basic brain localizers?

Back 3

T one Sagittal to show skull base and cranio-vertebral junction.

*From the sag localizer T two weighted transverse images from base of skull to the top of head can be acquired.

Coronal images may be substitutted when looking for SEIZURE DISORDER.

Front 4

What is a typical head trauma protocol for MR?

Back 4

T one and T two weighted fast spin echo sequence

T two gradient echo sequences *this sequence is important due to its sensitivity to susceptibility changes from blood products identified in the brain tissue. Creates a DARK region in this sequence.

FLAIR sequence

Front 5

When performing a stroke protocol what is an important sequence that will aid in the detection of hyper-acute cerebral infarctions?

Back 5

Diffusion (DWI)

*It will demontrate ischemia within MINUTES of a vascular occlusion while other conventional MR imaging methods may take several hours for the ischemia to appear.

Front 6

What is a downfall of DWI sequences?

Back 6

It is more susecptable to artifacts.

ie. Evident at air/soft tissue interfaces (sinuses, mastoid cells) or near metal.

Front 7

Why are ACD maps used for diagnosises post processed?

Back 7

To determine if the abnormality is a true bleed rather than a case of "T two shine through".

Front 8

An acute infarct appears ____________ on a diffusion weighted image and it appears _________ on an ADC image.

Back 8

Hyperdense

Hypodense

Front 9

Disease related changes are detected by MRI in more than ____ percent of people suspected of having MS.

Back 9

90 percent

Front 10

White matter lesions associated with multiple sclerosis are often found in the _______ and ________ involving the __________.

Back 10

temporal lobes

periventricular lobes

corpus callosum

*(Lesions are also subcortical as well)

Front 11

Which area of the brain may show lesions that indicate MS?

Back 11

Pons

Cerebellum

Brachium pontis

Front 12

Since early demyelination can often be seen in the corpus callosum, what should be obtained in order to detect pathology?

Back 12

Thin sagittal FLAIR images should be obtained through the midline of the brain at a slice thickness of no more than THREE mm.

Front 13

_________ imaging is very sensitive to early MS pathology and it is a T two weighted pulse sequence with the ability to suppress the CSF signal within the ventricles. (ventricles appear dark)

Back 13

FLAIR

Front 14

MRI can be used to identify both TYPE and SYNDROME of seizure. T/F?

Back 14

True

Front 15

What is a traditional protocol for MRI of the brain for seizures?

Back 15

An isotropic Three D T One weighted sequence may be run to evaluate cortical thickness and the interface between gray and white matter in aberrant locations.

Coronal FLAIR or T two weighted images perpendicular to the temporal lobe are acquired to evaluate the hipppcampus and asymmetry in the temporal horns and cortical and subcortical hyperintensities.

Front 16

What is a standard protocol for brain imaging for CSF flow?

Back 16

A standard brain screening protcol is run and then thin sagittal and transverse slices through the AQUEDUCT are collected.

Front 17

CSF flow sequence may be acquired in both the _______ and _______ orientations.

Back 17

Sagittal

Transverse

Front 18

What does the intensity of the signal indiacte in CSF imaging?

Back 18

Indicates both the direction of the CSF motion as well as its velocity.

*A velocity encoding value must be selected to make the sequence sensitive to motion in the appropriate range of velocities.

Front 19

On contrast magnitude image the flow appears _______ and the background is _______.

Back 19

Bright

Suppressed

Front 20

On phase image: Forawd flow is __________ and reverse flow is _______ and background is ________.

Back 20

Bright

Dark

Medium

Front 21

What has become a key component of evaluating children with delayed development?

Back 21

Assessing myelination

*It allows an assessment of the state of maturation of the child's brain.

Front 22

What sequences can be run to assess whether brain maturation is progressing normally?

Back 22

T one and T two relaxation times reduced water diffusion, increased diffusion anisotrpy, and increased magneitzation transfer.

Front 23

As the white matter myelinates in children it changes from __________ to __________ relative to gray matter on T one weighted images. And from ______ to ______relative to gray matter on T two weighted images.

Back 23

Hypointense > Hyperintense

Hyperintense > Hypointense

Front 24

T one weighted images are most sensitive in children of what age?

Back 24

Less than one year of age

Front 25

Forty to fifty percent of primary brain tumors are: _________

And fifty percent of those tumors are: __________

Back 25

Gliomas

Glioblastomas

Front 26

Glioblastomas usually develop in the: ____________ __________ most often in the _______ lobe.

Back 26

Cerebral hemisphere

Frontal

Front 27

________________ grow as an irregular mass is the white matter and are frequently seen to cross the corpus callosum to the opposite side yeilding a "butterfly" appearance.

Back 27

Glioblastomas

Front 28

What does gadolinium do to the appearance of tumors in the brain>

Back 28

Defines as a ring like appearance around the tumor with thick irregular walls.

*It also helps distinguish tumor from the surrounding edema.

Front 29

What is a typical protocol for imaging the Pituitary?

Back 29

Gradient moment nulling and inferior saturation pulse (helps reduce artifacts caused by CSF.)

T one Sagittal brain (defines anatomy and also is used as localizers)

T two transverse images for signal abnormalities

T one thin slices through the pituitary (coronally and sagittally). Axials may also be used.

Post contrast thin slices T one coronal and sagittal

*Post contrast should enhance the pituitary gland and lesions will have a lower signal intensity.

Front 30

When imaging the orbits what type coils can be used in conjunction with one another only if the manufacturer allows them to?

Back 30

Head coil along with small round coil that is centered directly on the orbit.

Front 31

To best visualize the optic nerve you can see lesions that show bright on T two sequences and on what type of images?

Back 31

Contrast enhanced T one images.

*Without Fat/Sat images most lesions will be missed.

Front 32

Where should you center for a MRI soft tissue neck?

Back 32

Midsagittal on the manubrium

Front 33

What is a typical protocol for a soft tissue neck?

Back 33

T one coronal (demonstrates anatomy and serves as a localizer for T one sagittal)

T two axials

T one sagittal and axials

Front 34

Is physiological triggering or gating needed for imaging of the spine?

Back 34

No, although some facilities use this to minimize flow artfacts, called peripheral pulse triggering.

*This may also be accomphished with gradient moment nulling and an INFERIOR sat region.

*An additional sat region may be placed anterior to the spine to reduce swallowing artifacts when acquiring sagittal or transverse images.

Front 35

What is a typical Cervical spine protocol?

Back 35

T one sagittal (for imaging vertebral bodies, disc spaces and spinal cord)

T two or T two* sagittal

Front 36

For spinal cord abnormalities or suspected lesions what sequences should be run?

Back 36

T two imaging

Transverse images clearly demonstrate if any cord impingement exists

Front 37

What sequence yield T two* weighting images that are excellent for viewing degenerated disks but are poor at delineating tumors?

Back 37

Gradient echo pulse sequences.

Front 38

If you are looking for cord abnormalities which sequence should be run?

Back 38

True T two sequence

Front 39

What are two reasons for using contrast for spine imaging?

Back 39

*To differentiate recurrent disk disease from post surgical scarring (Scar tissue will enhance while the disk will not)

*To look for metatstatic lesions, multiple sclerosis, or cord tumors. (Contrast will perfuse these abnormal tissues and cause them to enhance on T one weighted images. Normally viewed in sagittal and transverse planes.

Front 40

Where should you center for a T spine MRI?

Back 40

Half way between the manubrium and the xiphoid process.

Front 41

What issues or artifacts is T spine imaging susceptable to?

Back 41

Repiration motion and cardiac motion

*The latter may be alleviated by careful placement of saturation pulses.

Front 42

What is sometimes used in T spine imaging to indicate a reference location of a marked disk?

Back 42

A vitamin E tablet

Front 43

A large FOV ________ localizer is obtained in order to establish the appropriate levels of the intervertebral disks of the T spine.

Back 43

Sagittal

Front 44

A smaller FOV quick T one _______ scan is acquired to ensure that the patient spine is straight, to serve as a localizer to set up sagittal images and guarantee that all twelve levels of T spine can be seen in the chosen FOV.

Back 44

coronal

Front 45

What is a typical T spine protocol?

Back 45

T one coronal (localizer to set up sag)

T one sagittal (to check for structural abnormalities)

T two or T two* (depending on indication) Sagittal

T one tranverse through all spine or area of interest

Front 46

____________ is a fluid filled cavity in the spinal cord. Is associated with Arnold Chiari I malformations, tumor, trauma, ischemia, and infection.

Back 46

Syrinx or syringohydromyelia

Front 47

___________ is given when the when the cavity is from dialation of the central canal.

Back 47

Hydromyelia

Front 48

___________ is when the cavity is outside the central canal.

Back 48

Spinal bifida

Front 49

What may occasionally imitate a syrinx?

Back 49

Truncation or ringing artifact

Front 50

Where should you center for imaging of the L spine?

Back 50

One and a half inches above the iliac crest

Front 51

What is a typical protocol for imaging the L spine?

Back 51

A quick T one coronal

T one sagittal images to visualize vertebral bodies and intervertebral disks and to determine structural abnormalities.

T two or T two* (depending on clinical indication)

Transverse images angled through the disk spaces of the area of abnormality

Front 52

Disk extrusions are characterized by:

Back 52

A relatively narrow base

Ruptured nucleus through annulus

Front 53

Disk protrousions are characterized by:

Back 53

Broad base

Annulus fibers remain

*Asymptomatic disk protrusions are not infrequent

Front 54

What is a typical protcol for MRi of sacrum/coccyx?

Back 54

Localizer mid pelvis with sagittal slices through the sacrum and coccyx parallel to the long axis.

Four mm slices with a minimual interspacing should provide good coverage for the sacrum. Use three mm slices if focused on the coccyx.

Coronal images will be angled so that they run parallel to the long axis while oblique transverse images are oriented perpendicular to it.

Routine protocol will usually include T one and T two fat sat or STIR weighted images.

Front 55

What should be covered in imaging the brachial plexus?

Back 55

Coverage should extend from the third cervical vertebra down to the fourth thoracic vertebra and out to the gleno-humeral joint space of the affected side.

Front 56

Which coil is used in conjunction with imaging the brachial plexus?

Back 56

A neurovascular array coil is ideal. Another coil that can be used is the thoracic or torso array.

Front 57

Where do you center for the brachial plexus?

Back 57

On the upper sternum (patient is head first)

Front 58

What is a typical protocol for the brachial plexus?

Back 58

Coronal images best demonstrate structures of brachial plexus. Coronal T one (shows structures and symmetry)Coronal T two (shows pathology and abnormal signal intensities)Sagittals give cross cut representation of the nerves and blood vessels.

Front 59

What are some ways to reduce motion artifacts for brachial plexus imaging?

Back 59

Respiratory compensation and triggering will limit artifacts from the patient's breathing.

Properly placed saturation region over the heart and gradient moment nulling will help minimize cardiac and blood flow related motion.

Front 60

What is the centering for imaging the liver, spleen, and pancreas?

Back 60

Xiphoid process

Front 61

What is a typical protocol for imaging the spleen, liver, and pancreas?

Back 61

A weighted T one coronal localizer is often followed by T one weighted and T two weighted transverse images.

Fat suppression helps us visualize abnormal signal intensities.

Tranverse images are always acquired

Sagittal and coronal t one and t two sequences are left up to the radiologist. Sometimes dynamic contrast studies is performed. ie. liver protocol (rescan at different times)

Front 62

What is the centering for a MRCP?

Back 62

At the gallbladder

Front 63

What is a typical protocol for a MRCP?

Back 63

T one localizer

T two with a long TE to increase T two weighting *makes the fluid in the bilary tree bright

Some palces do radial slices through the gallbladder

T two THREE D to obtain manu slices through the ROI alternatively

Front 64

What is the centering point for Kidneys and Adrenals?

Back 64

Head first, centered halfway between the iliac crest and xiphoid process

Front 65

What is a typical protocol for imaging the kidneys?

Back 65

Coronal localizer

Transverse T one and T two images

Coronal T one (illustrates the relative position of the adrenals compared to the kidneys)

*Dynamic contrast imaging may also be used.

For imaging the adrenal glands a gradient echo in and out of phase is often performed to differentiate metastases from adenomas.

Front 66

What is Enterography useful for?

Back 66

Imaging the small bowel

Crohn's disease

Ulcerative colitis

Diverticulitis

Colon cancer

Bowel masses

Abscesses

High and Low grade small bowel obstruction

Infection and Inflammation

Front 67

What is the centering for Enterography?

Back 67

Two inches below the xyphoid process

Front 68

What is a typical protocol for Enterography?

Back 68

Patient should fast and take laxitives or enemas.

Pre exam, patient will drink one to one and a half liters of oral contrast (VoLumen) in three to four batches with FIFTEEN to TWENTY minutes in between.

*Many feel that the PRONE position provides better imaging since the position causes the bowel loops to spread allowing for better visualization.

*Sometimes a spasmolytic such as glucagon is administered to slow the bowel motion.

Front 69

What is a typical Protocol for Enterography?

Back 69

Reduction of peristalisis and the use of fast imaging techniques such as SINGLE SHOT FAST SPIN ECHO sequences.

Coronal and transverse images are acquired using rapid breath hold pulse sequences such as SINGLE SHOT FAST SPIN ECHO.Balanced gradient echo and volume interpolated gradient echo sequences Gadolinium based contrast is adminisered to enhance images and delineate active disease proceses normally dynamic. MR enterography is PREFERRED over CT for small bowel detail, especially in the TERMINAL ILIUM. NO GAD on pregrant patients

Front 70

What areas are focused on for imaging of the soft tissue pelvis?

Back 70

Bladder

Rectum

Anus

Front 71

What is a typical protocol for imaging the soft tissue pelvis?

Back 71

Three plane localizer

Soft tissue of the pelvis typically includes T one images for anatomy and T two images for pathology.

*For male images depending on the indication (straight axial, coronal and sagittal images are common.)*For imaging the female pelvis depending on the indication (oblique cuts parallel and perpendicular to the uterus.)Some facilities will administer glucagon to minimize motion artifacts.Use of contrast is very common.

Front 72

What pathology can be seen in imaging the female pelvis?

Back 72

Uterine fibroids

Extent of pelvic endometriosis

Ovarian neoplasms

Front 73

What is a typicacl protocol for imaging the female pelvis?

Back 73

Center half way between the pubis and the iliac crest

T one coronal localizer

T one and T two transverse (shows cervical uterus and vagina)

T one sagittal (shows entire length of the uterus)

T one coronal (provides additional information about pelvic sidewall invasion in cases of uterine or cervical carcinoma)

Front 74

What is typical protocol for imaging the male pelvis?

Back 74

*For prostate imaging a dedicated pelvis coil or an endorectal coil may be used for better detail. (some manufactures may allow you to use a combination of the two coils)

*There are small circular surface coils that is usually used when imaging the testes.

T one sagittal localizer allows us to set up transverse slices.

Seminal vesicles and invasive cancers from the prostate can be seen on transverse images.

T two coronal and sagittal planes in which the bladder base and its relationship to the prostate can be seen.