Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
64 Cards in this Set
- Front
- Back
How should the knees be positioned for all projections of the lumbar spine?
|
Flexed
Greater patient comfort Less forward flexion of the pelvis |
|
What are the advantages of the PA projection of the lumbar spine over the AP projection?
|
Better visualization of disc spaces
Lower ovarian dose in females (15-30% less) |
|
What are the disadvantages of the PA projection of the lumbar spine over the AP projection?
|
Magnification
Loss of detail |
|
Why is close collimation vital when using high-kV technique of the spine?
|
Reduce scatter and fogging
|
|
Which requires greater kV, AP or lateral projections of the spine?
|
Lateral
Greater part thickness |
|
How is the lead mat on the table-top helpful when doing images of the lumbar spine?
|
Increases collimation to reduce scatter
|
|
What is the minimum SID for lumbar spine projections?
|
40"
|
|
How is the imaging technique altered in patients with osteoporosis?
|
Decreased kV of mAs
|
|
When is CT evaluation of the spine indicated?
|
Fractures, disc disease, neoplastic disease
Evaluation of vertebral canal |
|
When is MRI evaluation of the spine indicated?
|
Evaluation of soft-tissue structures, such as the cord and intervertebral discs and disc-spaces
|
|
When is NM evaluation of the spine indicated?
|
Metastasis, inflammatory conditions, Paget's disease, osteomyelitis, primary bone malignancies
|
|
When is bone densitometry indicated?
|
Osteoporosis
Can detect bone loss as little as 1% Conventional radiography needs a minimum of 30% bone loss to be detected |
|
What are the causes of loss of bone mass?
|
Osteoporosis
Hyperparathyroidism Estrogen deficiency Steroid use Advanced age & lifestyle factors |
|
When is myelography indicated?
|
Lesions of the spinal canal, nerve roots and discs
Much less commonly used because of CT & MRI |
|
What is ankylosing spondylitis?
|
Inflammatory autoimmune disease
Starts at sacroiliac joints and progresses cephalad Causes fusion of intervertebral and costovertebral joints More common in men |
|
What are the common causes of vertebral body compression fractures?
|
Osteoporosis
Trauma Metastatic disease |
|
What are 'chance' fractures?
|
Hyperflexion forces fracturing the vertebral body
Posterior vertebral elements may be fractured too Common lap-type seat belt injury |
|
What is HNP
|
Herniated nucleus pulposus
Nucleus pulposus protrudes through the annulus Occurs most commonly at the lower lumbar levels causing 'sciatica' Not seen on plain radiographs - use MRI or CT |
|
What is lordosis?
|
Abnormal concave curvature of the spine
Seen on lateral images May occur in pregnancy, obesity or tuberculosis |
|
What is metastatic disease of the spine?
|
Cancers that spread to the spine
|
|
What are osteolytic lesions?
|
Metastatic lesions that destroy bone
Have irregular margins |
|
What are osteoblastic lesions?
|
Proliferative bony lesions
|
|
What are combined lesions (osteolytic & osteoblastic)?
|
Moth-eaten appearance as bone is destroyed and replaced
|
|
What is scoliosis?
|
Lateral curvature of the vertebral column
|
|
What is spina bifida?
|
Congenital lesion where posterior parts of the vertebrae fail to develop
Most often at L5 |
|
What is osteogenesis imperfecta?
|
Hereditary disorder
Bones abnormally soft and fragile Patients often very short Wide cranial sutures |
|
What is spondylolisthesis?
|
Forward movement of one vertebra
Usually results from developmental defect in pars interarticularis Can result in severe osteoarthritis Most common at L5-S1 May require spinal fusion |
|
What is spondylolysis?
|
Dissolution of the vertebra with separation of the pars interarticularis
Scottie Dog appears to have a broken neck |
|
Where is the CR positioned for AP projection of the lumbar spine?
|
L4-5
Suspend breathing IR 35 x 43 |
|
What is visualized with the AP projection of the lumbar spine?
|
Lumbar vertebral bodies, joints, processes
SI joint and sacrum Grid |
|
What is the body position for AP or PA obliques of the lumbar spine?
|
45 degree rotation
(50 degrees for facets of L1-2) (30 degrees for facets of L5-S1) |
|
Where is the CR for AP or PA obliques of the lumbar spine?
|
L3 (2" above iliac crests)
Perpendicular and centered to IR Suspend breathing |
|
What is best visualized with the oblique views of the lumbar spine?
|
Facet joints
Pars interarticularis |
|
How is the patient with scoliosis positioned for lateral view of the spine?
|
With convexity down
|
|
Where is the CR positioned for a lateral lumbar spine?
|
L4-5
|
|
What is best visualized with a lateral projection of the lumbar spine?
|
Intervertebral foramina
Intervertebral joints Spinous processes L5-S1 junction |
|
What is the IR size for a lateral L5-S1 image?
|
8x10"
|
|
Where is the CR placed for an L5-S1 lateral image?
|
1.5" inferior to iliac crest
2" posterior to ASISO May angle 5-8 degrees caudat is less support used |
|
What is the indication of the L5-S1 lateral image?
|
Spondylolisthesis of L4-5 or L5-S1
Other L5-S1 pathologies |
|
What is the patient position for the AP axial L5-S1 projection?
|
Supine with head pillow and support under knees
|
|
How is the CR angled for the AP axial L5-S1 projection?
|
30 degrees cephalad in males
35 degrees cephalad in females |
|
What are the indications AP axial L5-S1 projection?
|
L5-S1 pathology
Sacroiliac joint pathology |
|
What is the patient position for the AP (PA) scoliosis series?
|
Erect or supine
Often both done for evaluation |
|
What is the IR position for a AP (PA) scoliosis series?
|
Lower margin 1-2" below iliac crests
|
|
What is the CR position for AP (PA) scoliosis series?
|
Perpendicular, centered to IR
|
|
What are the indications for the erect lateral position?
|
Spondylolisthesis
Evaluation of lordosis or kyphosis |
|
Where is the IR positioned for the erect lateral image?
|
1-2" below iliac crests
|
|
Where is the CR positioned for the erect lateral image?
|
Perpendicular and centered to IR
|
|
What is the Ferguson method?
|
PA spine images erect and then with one knee flexed
|
|
Why is the Ferguson method used?
|
Differentiates primary curve deformities from compensatory deformities.
Technique otherwise same as AP spine |
|
Why is the right and left bending AP (PA) projections used?
|
Assess range of motion of vertebral column
Patient asked to bend as far as possible Technique same as supine AP spine |
|
Why are the lateral hyperextension/hyperflexion projections used?
|
Assess mobility of spinal fusion sites
Patient flexes and extends as far as possible Technique otherwise same as lateral spine |
|
What is the patient position for the AP axial sacrum position?
|
Supine with knees supported and flexed
Arms at side |
|
What special instructions are give to patients prior to AP axial sacral imaging?
|
Empty bladder
Possible enema |
|
What is the CR position for AP axial sacral imaging?
|
15 degrees cephalad (caudad for PA images)
2" above symphysis pubis |
|
What is best visualized by AP axial sacral imaging?
|
SI joint
L5-S1 anatomy |
|
How is the patient positioned for AP axial coccyx images?
|
Supine, knees supported and flexed, pillow
Arms at side |
|
How is the CR positioned for AP axial coccyx images?
|
10 degrees caudad
Centered 2" above symphysis pubis |
|
What is the patient position for lateral sacrum and coccyx images?
|
Full lateral
Pillow and knees flexed with padding between knees |
|
What is the CR position for lateral sacrum and coccyx images?
|
Perpendicular to IR
3-4" posterior to ASIS |
|
What is the CR position for lateral coccyx images?
|
3-4" posterior to ASIS
2" distal to ASIS |
|
What is the CR position for AP axial projections of the sacroiliac joints?
|
30-35 degrees cephalad (males - 30, females - 35)
Midline 2" below ASIS Can be done as PA with caudad angulation at L4 |
|
What is the patient position for LPO or RPO of the SI joints?
|
25 - 30 degrees of rotation (side of interest elevated)
Support elevated hip and flex knee |
|
What is the CR position for LPO or RPO of the SI joints?
|
1" medial to upside ASIS
|