RAD223 POSITIONING FINAL
For the CR to pass through & "open" the intervertebral spaced on a 45-degree posterior oblique projection of the cervical vertebrae, what CR angle (if any) is required?
15 degrees cephalad
What CR angulation (amount & direction) must be used with a posterior oblique projection of the cervical spine?
15 degrees cephalad
Where is the CR centered for a lateral L5-S1 projection of the lumbar spine?
1 1/2 inches (4 cm) inferior to iliac crest & 2 inches (5 cm) posterior to ASIS
How much rotation of the body is required for an oblique position of the thoracic spine from a true lateral position?
20 degrees from lateral position (70 degrees from plane of table or wall bucky)
For the Ferguson method, the elevated foot must be raised a minimum of _________ (inches/cm)
3 to 4 inches (8 to 10 cm)
How much rotation is required to visualize the zygapophyseal joints properly at the L5-S1 level?
30 degrees
What amount & direction of CR angulation is required for AP axial L5-S1 projection on a male patient?
30 degrees cephalad
A patient with a wide pelvis & narrow thorax may require a CR angle of __________ degrees ___________ (caudad or cephalad) for a lateral position of the lumbar spine.
5 to 8 degrees caudad
The degree of obliquity required for an oblique projection at the T12-L1 level is approximately _________, whereas the L5-S1 spine level requires a(n) __________ oblique. Therefore, a(n) _________ oblique is performed for the general lumbar spine.
50 degrees, 30 degrees, 45 degrees
What is the recommended SID for the cervicothoracic position of the cervical spine?
60 to 72 inches (152 to 183 cm)
The zygapophyseal joints for the second through seventh cervical vertebrae are at a ___________-degree angle to the midsagittal plane; the thoracic Zygapophyseal vertebrae are at a ______________-degree angle to the midsagittal plane.
90; 70 to 75
Situation: A patient with a clinical history of spondylolisthesis at the L5-S1 level comes to the radiology department. Which specific lumbar spine position is most diagnostic in demonstrating the extent of this condition?
A lateral L5-S1 position would demonstrate the degree of forward displacement of L5 onto S1
What are the 2 important benefits of using an SID 60 to 72 inches (152 to 183 cm) for the lateral cervical spine projection?
A. Compensates for increased OID; reduces magnification B. Less divergence of x-ray beam to reduce shoulder superimposition of C7
To ensure that the intervertebral joint spaces are open for lateral thoracic spine projections, it is important to: A. Keep the vertebral column parallel to the IR B. Use a small focal spot C. Use a breathing technique D. Angle the CR caudad
A. Keep the vertebral column parallel to the IR
List the specific joints or foramina that are demonstrated with the following lumbar spine positions: A. LPO B. RAO C. Lateral D. RPO E. LAO
A. Left zygapophyseal joints (downside) B. Left zygapophyseal joints (upside) C. Intervertebral foramina D. Right zygapophyseal joints (downside) E. Right zygapophyseal joints (upside)
Which 2 structures can be evaluated to determine whether rotation is present on a radiograph of an AP projection of the lumbar spine?
A. Sacroiliac (SI) joints are equidistant from the spine B. Spinous process should be midline to the vertebral column (transverse processes are equal length)
Situation: A young female patient comes to the radiology department for a scoliosis series. She has had repeated radiation exposure throughout a period of time & is understandably concerned about the radiation. What 3 things can the technologist do to minimize the dose delivered to the patient's breasts?
A. Use high kV technique B. Perform a PA rather than an AP projection C. Use breast shields
Which AP projection of the cervical spine demonstrates the entire upper cervical spine with one single projection?
AP "wagging jaw" projection (Ottonello method)
Conventional projections for clinical indication: Herniated nucleus pulposus (HNP)
AP & Lateral of affected spine
Situation: A patient enters the ER with a possible cervical spine fracture, but the initial projections do not demonstrate any gross fracture or subluxation. After reviewing the initial radiographs, the ER physician suspects either a congenital defect or a fracture of the articular pillars of C4. He wants an additional projection taken to see better this aspect of the vertebrae. What additional projection can be taken to demonstrate the articular pillars of C4?
AP axial - vertebral arch (pillar) projection
Conventional projections for clinical indication: Jefferson fracture
AP open mouth C1-C2
Situation: A patient comes to the ER with a possible Jefferson fracture. Other than a lateral projection or a CT scan, what specific radiographic projection will best demonstrate this type of fracture?
AP open mouth projection. The patient's mouth must be carefully opened without any movement of the cervical spine
Situation: A patient comes to the radiology department for a follow-up study for a compression fracture of L3. The radiologist requests that collimated projections be taken of L3. Which specific projections & centering would provide a quality study of L3 & the intervertebral joint spaces?
AP or PA & collimated lateral projections would provide the best view of the L3 region. The CR should be about 2 inches (5 cm) above the iliac crest.
Situation: A patient comes to the radiology department for a lumbar spine series. He has a clinical history of advanced spondylolysis. Which specific projection(s) of the lumbar spine series will best demonstrate this condition?
Although AP & lateral projections of the lumbar spine are helpful, posterior or anterior oblique positions best demonstrate advanced signs of spondylolysis
A radiograph of a cervicothoracic lateral position demonstrates superimposition of the humeral heads over the upper thoracic spine. Because of an arthritic condition, the patient is unable to rotate the shoulders any farther apart. What can the technologist do to separate the shoulders further during the repeat exposure?
Angle CR 3 to 5 degrees caudad
Clinical indication: A form of rheumatoid arthritis
Ankylosing spondylitis
Clinical indication: Inflammatory condition that is most common in males in their 30s
Ankylosing spondylitis
Which of the following structures is best demonstrated with an AP axial vertebral arch projection? A. Spinous processes of the lumber spine B. Articular pillars (lateral masses of the cervical spine) C. Zygapophyseal joints of the thoracic spine D. Cervicothoracic spine region
B. Articular pillars (lateral masses of the cervical spine)
Situation: A patient comes to the radiology department with a clinical history of HNP. Which of the following imaging modalities provide the most diagnostic study for this condition? A. Sonography B. MRI C. Nuclear Medicine D. Radiography
B. MRI
For lateral & oblique projections of the cervical spine, it is important to minimize magnification & maximize detail. This can be done by: A. Keeping the vertebral column parallel to the IR B. Using a small focal spot C. Increasing the SID D. Using a breathing technique
B. Using a small focal spot C. Increasing the SID
Name part of sternum or topographic landmark: Center portion of sternum
Body
Imaging modality that best demonstrates: Osteoporosis
Bone densitometry
What CR angle must be used with the AP axial-vertebral arch (Pillars) projection? A. 15- to 20-degree cephalad B. 5- to 10-degree cephalad C. 20- to 30-degree cuadad D. None (CR is perpendicular to IR)
C. 20 to 30 degrees caudad
For an AP axial of the cervical spine, a plane through the tip of the mandible & the ___________ should be parallel to the angled CR. A. Mastoid process B. Gonion C. Base of skull D. External auditory meatus (EAM)
C. Base of skull
Which of the following projections delivers the greatest skin dose to the patient? A. AP thoracic spine projection B. Lateral cervical spine projection C. Cervicothoracic lateral position D. Fuchs or Judd method
C. Cervicothoracic lateral position
Vertebral level for: Mastoid tip
C1
Vertebral level for: Gonion
C3
Vertebral level for: Thyroid cartilage
C4-C6 (Larangeal prominance or adams apple is at C5)
Which region of the spine must be demonstrated with a cervicothoracic lateral position?
C5 to T3
Vertebral level for: Vertebra prominens
C7-T1
Imaging modality that best demonstrates: Compression fractures of the lumbar spine
CT
Situation: A broad shouldered patient comes to the radiology department for a routine cervical spine series. The lateral projection demonstrates only the C1 to C5 region. The radiologist wants to see C6-T1. What additional projection can be taken to demonstrate this region of the spine?
Cervicothoracic (swimmer's) lateral position
Clinical indication: Fracture of the vertebral body caused by hyperflexion force
Chance fracture
Clinical indication: Avulsion fracture of the spinous process of C7
Clay Shoveler's fracture
Clinical indication: A type of fracture that rarely causes neurologic deficits
Compression fracture
What is the recommended kV range for lateral-hyperflexion & hyperextension positions of the spine for a digital imaging system? A. 70 to 75 B. 80 to 85 C. 85 to 95 D. 95 to 100
D. 95 to 100
Which of the following techniques or devices produces a more uniform density along the vertebral column for an AP/PA scoliosis projection? A. Use of a 14- x 36-inch IR B. Lower kV C. Higher mAs D. Compensating filter
D. Compensating filter
Which of the following projections is considered a "functional study" (to demonstrate anterior to posterior mobility) of the cervical spine? A. AP "wagging jaw" projection B. AP "open mouth" position C. Fuchs or Judd method D. Hyperextension & hyperflexion lateral positions
D. Hyperextension & hyperflexion lateral positions
A radiograph of an oblique position of the lumbar spine shows that the downside pedicle & zygapophyseal joint are posterior in relation to the vertebral body. What modification of the position must be made during the repeat exposure to produce a more diagnostic image?
Decrease rotation of the body of the spine
Conventional projections for clinical indication: Scoliosis
Erect (AP/PA) & lateral spine including bending laterals
A radiograph of an AP "open mouth" projection of the cervical spine shows that the base of the skull is superimposed over the upper odontoid process. Which specific positioning error is present on this radiograph?
Excessive extension of the skull
Which positioning error is present if the pedicles are projected too far posterior (CLOSER to midline) with a 45-degree oblique position of the lumbar spine?
Excessive rotation
The lateral projection of the cervical spine should be taken during _________ (inspiration, expiration, or suspended respiration). Why?
Expiration; for maximum shoulder depression
True/False: The lead blocker mat & close collimation must not be used when performing digital imaging of the lumbar spine
False
True/False: The use of higher kV & lower mAs for lumbar spine radiography improves radiographic contrast but increases patient dose.
False
True/False: The AP projection of the lumbar spine opens the intervertebral joint spaces better than the PA projection
False (PA would open intervertebral joint spaces better)
True/False: The lower margin of the cassette must include the symphysis pubis for a scoliosis series
False (lower margin 1 to 2 inches [3 to 5 cm] below iliac crest)
True/False: Gonadal shielding should always be used for male & female patients for studies of the lumbar spine, sacrum, & coccyx
False (not used for females if the shield would obscure essential anatomy)
True/False: The knees & hips should be extended for an AP projection of the lumbar spine
False (should be flexed)
True/False: The tip of the odontoid process does not have to be demonstrated on the AP "open mouth" projection, because it is best seen on the lateral projection.
False. The entire dens or odontoid process must be demonstrated. If trauma or injury is ruled out, the technologist could perform the AP or PA projection for the odontoid process to demonstrate the tip.
Clinical indication: Fracture through the pedicles & anterior arch of C2 with forward displacement of C3
Hangman's fracture
Clinical indication: Most common at the L4-L5 level & may result in sciatica
Herniated nucleus pulposus (HNP)
Situation: A patient with a possible cervical spine injury enters the emergency room. The patient is on a backboard. Which projection of the cervical spine should be taken first?
Horizontal beam lateral projection
Situation: A patient who has been in a motor vehicle accident (MVA) enters the emergency room. The basic projections of the cervical spine show no subluxation (partial dislocation) or fracture. The physician wants the spine evaluated for whiplash injury. Which additional projections would best demonstrate this type of injury?
Hyperextension & hyperflexion lateral positions
Situation: A patient comes to the radiology department for a lumbar spine study following spinal fusion surgery. Her surgeon wants a study to assess mobility of the spine at the fusion site. Which radiographic positions provide this information?
Hyperflexion & hyperextension lateral positions
A radiograph of a lateral projection of a female lumbar spine shows that the mid- to lower intervertebral joint spaces are not open. The technologist supported the midsection of the spine with sponges to straighten the spine. What else can be done to open the joint spaces during the repeat exposure?
If the patient has a wide pelvis, the CR can be angled 5 to 8 degrees caudad
When should the Judd or Fuchs method be performed?
If unable to demonstrate the upper portion of the odontoid process (dens) with the AP "open mouth" projection Judd is PA to see c1-c2 (less thyroid dose) Fuchs is AP to see c1-c2 (compared to judd dosage your thyroid is fuchsd)
With a 14- x 17-inch (35- x 43-cm) IR, the CR is centered at the level of the ___________ for AP & lateral lumbar spine projections
Iliac crest : L4 to L5
A radiograph of an AP axial projection of the cervical spine shows that the intervertebral disk spaces are not open. The following positioning factors were used: extension of the skull, CR angled 10-degrees cephalad, CR centered to the thyroid cartilage, & no rotation or tilt of the spine. Which of these factors must be modified to produce a more diagnostic image?
Increase CR angulation to 15 degrees cephalad
A radiograph on a lateral projection of the cervical spine shows that C7 is not clearly demonstrated. The following factors were used: erect position, 44-inch (112-cm) SID, arms down by the patient's side, & exposure made during inspiration. Which 2 of these factors should be changed to produce a more diagnostic image during the repeat exposure?
Initiate exposure during suspended expiration & increase SID to 72 inches (183 cm)
A radiograph of an LPO projection of the lumbar spine shows that the downside pedicles & zygapophyseal joints are projected over the anterior portion of the vertebral bodies. Which specific positioning error is present on this radiograph?
Insufficient rotation of the spine (pedicle "eye" should be to midvertebral bodies)
Clinical indication: Impact fracture from axial loading of the anterior & posterior arch of C1
Jefferson fracture
Name part of sternum or topographic landmark: Superior margin of the upper section of the manubrium (landmark)
Jugular (suprasternal) notch (T2 - T3)
Clinical indication: Abnormal or exaggerated convex curvature of the thoracic spine
Kyphosis
Vertebral level for: Lower costal margin
L2-L3
Vertebral level for: Iliac crest
L4-L5
Which position or projection of the lumbar spine series best demonstrates a possible compression fracture?
Lateral
Conventional projections for clinical indication: Teardrop burst fracture
Lateral cervical
Conventional projections for clinical indication: Unilateral subluxation of cervical spine
Lateral cervical spine
Which specific projection must be taken first if trauma to the cervical spine is suspected & the patient is in a supine position on a backboard?
Lateral, horizontal beam projection
What ancillary device should be placed behind the patient on the tabletop for a recumbent lateral projection of the thoracic spine?
Lead mat or masking
Which foramina are demonstrated with a LAO position of the cervical spine?
Left intervertebral foramina (downside)
Which 2 landmarks must be aligned for an AP "open mouth" projection?
Lower margin of upper incisors & base of skull
Imaging modality that best demonstrates: Soft tissues of lumbar spine
MRI
Imaging modality that best demonstrates: Structures within subarachnoid space
MRI (and Myelography)
Name part of sternum or topographic landmark: Upper portion of sternum
Manubrium
Which skull positioning line is aligned perpendicular to the IR for a PA (Judd) projection for the odontoid process?
Mentomeatal line (MML)
What is the name of the radiographic procedure that requires the injection of contrast media into the subarachnoid space?
Myelography
Imaging modality that best demonstrates: Inflammatory conditions such as Paget's disease
Nuclear medicine
Which imaging modality is ideal for detecting early signs of osteomyelitis?
Nuclear medicine
Situation: A patient comes to the radiology department for a cervical spine series. An AP "open mouth" radiograph indicates that the base of the skull & the lower edge of the front incisors are superimposed, but the top of the dens is not clearly demonstrated. What should the technologist do to demonstrate the upper portion of the dens? (A horizontal beam lateral projection has ruled out a C-spine fracture or subluxation.)
Perform either the (AP) Fuchs or (PA) Judd method
A radiograph of a lateral L5-S1 projection shows that the joint space is not open. The technologist did support the middle aspect of the spine with a sponge. What else can the technologist do to open up the joint space during the repeat exposure?
Place additional support beneath the spine, or use a 5- to 8-degree caudad angle
In addition to good collimation, what should be done to minimize overall "fogging" on a lateral lumbar spine or lateral sacrum & coccyx radiograph?
Place lead blocker on tabletop behind patient
Vertebral level for: Symphysis pubis
Prominence of greater trochanter
Why should the knees & hips be flexed for an AP lumbar spine projection?
Reduces lumbar curvature, which opens the intervertebral disk space
Which zygapophyseal joints are best demonstrated with an LPO position of the thoracic spine?
Right
Which zygapophyseal joints are demonstrated in a RAO projection of the thoracic spine?
Right (downside)
Which specific set of zygapophyseal joints is demonstrated with a Lumbar LAO position?
Right (upside)
Which foramina are demonstrated with a LPO position of the cervical spine?
Right intervertebral foramina (upside)
In addition to extending the chin, which additional positioning technique can be performed to ensure that the mandible is not superimposed over the upper cervical vertebrae for oblique projections?
Rotate the skull into a near lateral position
A radiograph of an AP projection of the lumbar spine shows that the spinous processes are not midline to the vertebral column & distortion of the vertebral bodies is present. Which specific positioning error is present on this radiograph?
Rotation of the spine
A patient comes to the radiology department for a lumbar spine series. She has a clinical history of severe kyphosis. How should the lumbar spine series be modified for this patient?
Routine lumbar spine projections should be performed erect
Vertebral level for: ASIS
S1-S2
Clinical indication: Mild form of scoliosis & kyphosis developing during adolescence
Scheuermann disease
Clinical indication: Abnormal lateral curvature of the spine
Scoliosis
Clinical indication: Lateral curvature of the vertebral column
Scoliosis
Conventional projections for clinical indication: Scheuermann disease
Scoliosis series
Situation: A patient comes to the radiology department with a clinical history of Scheuermann disease. Which radiographic procedure is often performed for this condition?
Scoliosis series
Clinical indication: Congenital defect in which the posterior elements of the vertebrae fail to unite
Spina bifida
Clinical indication: Inflammation of the vertebrae
Spondylitis
Clinical indication: Forward displacement of one vertebra onto another vertebra
Spondylolisthesis
Clinical indication: Dissolution & separation of the pars interarticularis
Spondylolysis
What are the major differences between spondylosis & spondylitis?
Spondylosis - a condition of the spine characterized by decreased vertebral joint space & arthritic changes of the zygapophyseal joints Spondylitis - inflammatory process of the vertebrae characterized by bony bridges between vertebrae (advanced stages)
Name part of sternum or topographic landmark: Joint between top (manubrium) & center portions (body) of sternum(landmark)
Sternal angle (T4 - T5)
The common name of the method for the cervicothoracic lateral position is the
Swimmer's method
Vertebral level for: Jugular notch
T2-T3
Vertebral level for: Sternal angle
T4-T5
Which specific thoracic vertebrae are classified as typical thoracic vertebrae (i.e., they least resemble cervical or lumbar vertebrae)?
T5 to T8
Vertebral level for: 3 to 4 inches (8 to 10 cm) below jugular notch
T7 (mid thorax)
Vertebral level for: Xiphoid process
T9-T10
Vertebral level for: Xiphoid process (tip)
T9-T10
Clinical indication: Comminuted fracture of the vertebral body with posterior fragments displaced into the spinal canal
Teardrop burst fracture
True/False: Nuclear medicine is often performed to diagnose bone tumors of the spine.
True
True/False: Placing a lead blocker mat behind the patient for lateral lumbar spine positions improves image quality
True
True/False: The female ovarian dose used for a PA lumbar spine projection is approximately 25-30% less than the dose for an AP projection
True
True/False: To a certain degree, MRI & CT are replacing myelography as the imaging modalities of choice for the diagnosis of a ruptured intervertebral disk.
True
True/False: When positioning the obese patient, the iliac crest is typically at the level the inferior margin of the flexed elbow
True
True/False: When using digital imaging for spine radiography, it is important to use close collimation, grids, & lead masking.
True
True/False: The thyroid dose delivered during a LPO or RPO cervical spine projection is greater than the thyroid dose for an RAO or LAO projection of the cervical spine.
True (anterior oblique (approx.) <5 mrad; posterior oblique <69 mrad)
True/False: Performing the cervicothoracic projection is often required to demonstrate the C7/T1 region for the obese patient
True - Cerivothoracic aka swimmers shows the C5-T3 region
Which side of the spine should be elevated for the second exposure for the AP/PA projection (Ferguson method) scoliosis series (by having the patient stand on a block with one foot)?
The convex side of the spine
In addition to the gonads, which other radiosensitive organs are of greatest concern during cervical & thoracic spine radiography?
Thyroid, parathyroid glands, & breasts
Where should the CR be placed for a cervicothoracic lateral position?
To T1; 1 inch (2.5 cm) above the jugular notch anteriorly & level of vertebra prominens posteriorly
What is the purpose of using an orthostatic (breathing) technique for a lateral projection of the thoracic spine?
To blur out rib & lung markings that obscure detail of thoracic vertebrae
What is the purpose of the 15- to 20-degree cephalad angle for the AP axial projection of the cervical spine?
To open up the intervertebral disk spaces
True/False: A PA or an AP projection for a scoliosis series frequently includes one erect & one recumbent position for comparison
True
True/False: A PA projection for a scoliosis series produces only about 1/10 the dose to the breasts as compared with the AP projection, even if proper collimation is used
True
True/False: An increased SID of 44 to 46 inches (112 to 117 cm) reduces magnification of the spine anatomy
True
True/False: Less CR angle is required for the AP axial projection of the cervical spine if the examination is performed supine rather than erect.
True
True/False: Many geriatric patient have a fear of falling off the radiographic table.
True
Clinical indication: Produces the "bow tie" sign
Unilateral subluxation
A radiograph of a lateral thoracic spine shows that lung markings & ribs make it difficult to visualize the vertebral bodies. The following factors were used: recumbent position, 40-inch (102-cm) SID, short exposure time, & exposure made during full expiration. Which of these factors must be modified to produce a more diagnostic image during the repeat exposure?
Use of an orthostatic (breathing) technique to blur lung markings & ribs more effectively
A radiograph of a RPO cervical spine projection shows that the lower intervertebral foramina are not open. The upper intervertebral foramina are well visualized. What positioning error most likely led to this radiographic outcome?
When the lower intervertebral foramina are narrowed while the upper foramina are well demonstrated, the positioning error most often is under-rotation of the upper body (shoulders). The upper body must be rotated 45 degrees.
How should the spine of a patient with scoliosis be positioned for a lateral position of the lumbar spine?
With the sag or convexity of the spine closest to the IR
Name part of sternum or topographic landmark: Most inferior aspect of sternum (landmark)
Xiphoid process (t9 - t10)
Which projections should be taken to evaluate flexibility following spinal fusion surgery?
hyperextension & hyperflexion lateral projections
The _______, which is the eye of the "Scottie dog," should be near the center of the vertebral body on a correctly oblique lumbar spine position
pedicle
During the AP (PA) right & left bending projections of the lumbar spine, the __________ serves as a fulcrum during positioning
pelvis
What is the unique feature of all thoracic vertebrae that distinguishes them from other vertebrae?
presence of facets for articulation with ribs
The lack of symmetry of the zygapophyseal joints between C1 and C2 may be caused by injury or may be associated with __________ (hint: positioning error).
rotation of the skull