Spine Imaging & MYLEOGRAPHY RT 255 – SPRING(2010 rev) RADIOGRAPHIC EXAM OF THE CNS STRUCTURES WITHIN THE VERTERBRAL CANAL Pt info:
Myelography • Requires contrast introduction into the subarachnoid space by spinal puncture = • INTRATHECAL INJECTION • Puncture made at L2-L3 or L3-L4 space • May also be introduced into cisterna magna at C1 and occipital bone New Notes- • These pathologies are demonstrated radiographically as a deformity in the subarachnoid space or an obstruction of the passage of the contrast within the subarachnoid space. • It is also useful in identifying a stenosis or narrowing of the subarachnoid space by watching the dynamic flow patterns of the CSF.
Dx = HNP ? Herniated Nuculeus Pulposa
Meninges • Membranes that enclose the brain and spinal cord • Dura Mater- outer layer • Arachnoid = middle layer • Pia mater = innermost layer • Subarachnoid space = • wide space between • arachnoid and pia mater
Subarachnoid space • Wide space between arachnoid and pia mater • Filled with CSF • Bathes brain & spinal cord with nutrients • Cushions against shocks and blows • Where contrast is injected for myelograms
CSF & Spinal Canal • Circulates in the subarachnoid space • Betweeen the pia mater and spinal cord. • Space ends at 2nd sacral level • Cord ends at l1 or l2 • Lower portion of lumbar canal • encases the CAUDA EQUINA – • a collection of nerve roots
CONTAST MEDIA OMNIPAQUE Myelography • OLD – OIL BASED (Panopaque) • then – Metrizimide (water sol) • NOW • NON-IONIC water based • ISOVUE “M” 200 OR 300 M • INTRATHECAL INJECTION !! • FOLLOW UP WITH • CT SCAN W/IN 1 HR • Contrast is generally water-soluble, nonionic, iodinated medium ISOVUE
SPECIAL PROCEDURESCONTRAST MEDIA MYELOGRAMS • Injected INTRATHECALLY (into the subarachnoid space) • Nonionicwater-soluble contrast • (NO IONIC CONTRAST)
CONTAST MEDIA • INTRATHECAL INJECTION • L2-L3 OR L3-L4 • FOR LUMBAR AND CERVICAL INJECTION • CISTERNA CEREBELLOMEDULLARIS • C.SP
31 y/o male DIESafter Myelogram Procedure • Myelography is safely performed using • nonionic water-soluble radiographic contrast media intended for this route of administration • Misadministration of ionic contrast media intrathecally can result in a syndrome of spasms and convulsions, often leading to death • ISOVUE –M ( 20 or 30 cc)
PROCEDURE • CONSENT SIGNED !!! • Procedure Risks, Complications explained • Consent Witnessed - WHO? • HISTORY TAKEN • PATIENT PREP • PATIENT COMFORT* • MYELOGRAM TRAY READY • SCOUT FILMS TAKEN
Room should be prepared by RT before patient arrival FOOT BOARD • Table and equipment cleaned • Footboard and shoulder supports attached • Radiographic equipment checked • Image intensifier locked to prevent accidental contact with sterile field or spinal needle • Tray setup Provide for Patient Comfort When PA place sponge under Ankles….. SHOULDER PADS Hand grips
Additional Supplies • Blankets • Sterile towels • Non-ionic iodinated contrast media • Sterile gloves for DR • Shields for PT, DR, anyone else in room, and yourself • Varying sizes of spinal needles and needles • Extra syringes and tubing • Cleaning liquid – skin prep (Betadine*)
Syringes and Spinal Needles Syringes Spinal Needles (covered) More Spinal Needles (uncovered)
PRE- Procedure :Myelography • Premedication rarely needed • Patient should be well hydrated • Check orders, obtain history, labs results (if necessary), and previous exams • Informed consent: • Risks, benefits alternatives • Procedural details, including table movement and sensations should be explained, and get pt into a gown
Cross table lateral • With grid • Closely collimated SCOUT IMAGES • PA • CROSS TABLE LATERAL • CHECKS FOR • POSITIONING • TECHNIQUE • PATHOLOGY
Critique? What are the projections for the scout?
Dura mater Subarachnoid space Pt is placed in the ______ position Needle is inserted at the level of _______
Room must be R & F with Table movement capabilities
Radiation Safety • Have shields for PT’s, DR and yourself • Question LMP and the possibility of being pregnant • Use cardinal rules • Time • Distance • Shielding • ALARA • Use pulse if possible • Save the last image on screen when possible
Myelography • Local anesthesia given at puncture site • Lidocaine and sodium bicarbonate • Spinal needle inserted (pressure obtained) • CSF usually withdrawn and sent to laboratory • Contrast injected and needle removed • 9-12 ml • Table angle and gravity used to move contrast under fluoroscopy • Spot images taken as needed
Prone & Lateral Flexion • Prone • Sponge under abdomen for flexion of spine • Lateral flexion is not commonly used • Widens interspace for easier introduction of needle • CSP injection only used when pathology present in LSP
Spot Films • Central ray vertical or horizontal using CR or film screen cassettes • Images are taken at • Site of blockage • Level of distortion • If conus medullaris is area of concern: • Lay pt supine • Central ray at T12- L1 • Use 10x12 cassette and collimate tightly
For L.SP or C.SP – Contrast usually injected in Lumbar Table placed TRENDELBURG To move contrast To Cervical Area Myelogram
Myelography • If contrast is moved into cervical area, head is positioned in acute extension to prevent contrast from entering ventricular system • Acute extension compresses cisterna magna and is the only position that will prevent contrast from entering ventricles • Keep pt at 30 degrees post contrast injection – • Or may get a MIGRANE
Myelography • Usually performed as outpatient basis • Common for CT myelography (CTM) to be used with conventional Myelogram • MRI often used instead • Myelography and CTM still used for patients with contraindications for MRI • Pacemakers and metal fusion rods
Post procedure: Myelography • Monitoring required • Head and shoulders elevated 30 to 45 degrees • Bed rest for several hours • Fluid encouraged • Puncture site checked before release
Vomiting Vertigo Neck Pain MIGRANES Spinal Headache Due to loss of CSF during puncture Increased severity upright Decreased pain when recumbent. Possible Complications from Myelography
RISK • The main risk with a myelogram is the potential for a spinal headache. • The spinal headache usually resolves in one to two days with rest and fluids, and seems to be more common for patients with a history of migraine headaches.
CONTRAINDICATIONS • ?? CONTRAST ALLERGY/reaction • CEREBRAL ANERUYSMS, • AV MALFORMATIONS • MYELOGRAM CAN INCREASE INTRACRANAIL PRESSURE • RECENT LUMBAR PUNCTURE 1 week
Contraindications & Considerations • Heparin stopped 4 hours before • Can be restarted 2 hrs after procedure • Usually given as IP • Coumadin stopped 3-4 days before • Usually OP • Labs usually indicated • PT < 15.0 seconds (clotting time) • Preferable to reschedule exam if below 15 • Platelets >100,000 • If below 50,000 a platelet transfusion may be indicated before procedure
More Severe Complications • Nerve root damage • Meningitis • Epidural abscess • Contrast reaction (anaphylactic shock) • CSF leak • Hemorrhage
Initial treatment Tylenol Horizontal position Forced fluids Caffeine Persistent headache If a fever occurs, contact MD May be indicative of meningitis Beyond 48 hrs w/o fever (24 hrs if severe) Blood patch Treatment for Spinal Headache
Pt information: the patient Contrast www.nlm.nih.gov/medlineplus/tutorials/ myelogram
Explain Procedure to the Patient • “During the examination, you will lie on your side, or on your stomach, on an x-ray table. • After numbing medicine is injected, a needle is inserted into the spinal canal (in the low back or neck), and a small amount of spinal fluid is removed for testing. • The contrast material is then injected into the spinal canal. • The table is tilted to varying degrees to help move the contrast material through the spinal canal to the desired area. X-rays are taken to visualize the outlined canal.”
Explain Procedure to the Patient • If you received an oil-based contrast material, you will be able to turn on your back, stomach, or sides, but must remain flat in bed for 24 hours. • If you received a water-based contrast material, you must remain in bed for 24 hours, but the head of the bed may be up 15 to 30 degrees. • You will be routinely checked for blood pressure, temperature, pulse, and respirations. • Medication is available for headache, nausea, or vomiting -- if they should develop after the myelogram. • You will be encouraged to drink lots of fluids.
Explain Procedure to the Patient • “If you experience continuous mild to severe headaches, there may be a small leak of spinal fluid. This generally is not dangerous. • If symptoms do not resolve the leak can be sealed over with a blood patch. This is done by the anesthesiologist. • If you are on any antidepressant medication, please check with your doctor.”
After the Myelogram • Light activity for 24 hours after discharge • Drink plenty of fluids • No Heavy Lifting for 3 – 4 days • Aching in the area where the myelogram was done or muscle spasms in your back. • Various aches and discomfort in your arms/legs should not last longer than 1-2 days.
Blood Patch for Clot • Sterily injecting a small amount of patient’s blood into the epidural space • Clot will occur over puncture site • Usually will stop headache immediately • 1st patch is 70% effective • 2nd patch is 95% effective
PATHOLOGYMYELOGRAPHY DEMONSTRATE • EXTRENSIC SPINAL CORD COMPRESSION (HERNIATED DISK) HNP • BONE FRAGMENTS • TUMORS • SPINAL CORD SWELLING
ENCROACHMENTS ON SPINAL CANAL • Radiographically as a deformity of the Subarachnoid Space or • Obstruction of passage of column of contrast within space • Narrowing Identified