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MRD301 - MRI Capstone 1
Transcript of MRD301 - MRI Capstone 1
(with an Unusual Twist) December 17, 2012 a I i t s o i c A n R R T Il b S W w L C R D D S W S C T C M http://ckom.com/sites/default/files/news-image/Buildings-MA-Downtown%20Saskatoon%20City%20Hospital-April%2025%202011-1_1.JPG Senior tech from RUH End of evening shift at SCH Unknown radiologist, anesthetist and surgeon Unusual patient came in for scan of lumbar spine/iliopsoas region. Patient: 4 yr old male German Shepherd (Owner: K-9 unit police officer) Radiologist, anesthetist and surgeon from Western College of Veterinary Medecine at University of Saskatchewan http://news.usask.ca/archived_ocn/08-july-11/images/wcvm.jpg Requisition and Screening Verbal (prior to patient arrival) - situation is simpler than human MRI Fewer medico-legal concerns.
(Dog will probably not sue us.) Smaller chance of MRI contraindications 10- to 15-year lifespan: less-likely to have developed conditions requiring medical treatment.
(Probably doesn't have pacemaker, aneurysm clips, or dentures.) Narrow range of career possibilities.
(Unlikely to have done any grinding or welding.) Fewer lifestyle choices.
(Probably has no body piercings or nicotine patches.) Preparation Police officer and medical personnel removed all potentially projectile metallic objects.
(No guns allowed in scan room.) Patient brought into scan room and laid down on sheet on floor;
anesthetized with gas;
IV started in left front paw. After unconscious, lifted onto scanner table and intubated. No hearing protection. (GA required, as patient may not follow "exact" instructions to remain in position and motionless, especially considering loud noises.) Patient was agitated, barking. Positioning and Monitoring Patient was positioned feet-first supine on the scanner table. Straps and foam pads placed on either side of the patient to keep him immobile in a supine position. Normally, pads not required to maintain patient's supine position. However, in this case, patient's back musculature is curved anteriorly rather than flat, torso is wider dorso-ventrally than laterally, and limbs extend anteriorly, so difficult to balance patient on back without rolling onto side. Limited healthcare options. After exam, patient lifted onto floor and revived; seemed subdued. Scanner and Coils Siemens MAGNETOM Aera Photo credit: Susan Gregorash 70 cm wide, short bore 1.5 T static field http://healthcare.siemens.com/magnetic-resonance-imaging/0-35-to-1-5t-mri-scanner/magnetom-aera?stc=wwhim800001# Undocking table GA equipment set up in scan room. Photo credit: Susan Gregorash 32-channel spine array coil 8 individually-selectable elements activate/deactivate according to position and size of imaging volume - eliminates noise from unused elements. Easy to use - embedded in table, so patient simply lays on it. Surface coil is near anatomy - provides high SNR. Anesthetist stayed in scan room during exam to monitor patient visually. (She wore ear plugs.)
Otherwise, no physiological monitoring; no verbal monitoring.
(Unconscious; patient doesn't speak English anyway.) #1 - 3pl FLASH localizer #2 - 3pl FLASH localizer #3 - 3pl FLASH localizer - extension #4 - SAG T2 TSE - extension #5 - SAG T1 TSE - extension #6 - AX T2 TSE - extension #7 - SAG T2 HASTE #8 - COR T2 HASTE #9 - 3pl FLASH localizer - neutral #10 - SAG T2 TSE - neutral #11 - SAG T1 TSE - neutral #12, 14, 15 - COR T2 TSE #13 - AX T2 TSE - neutral Radiologist Report A 1 2 3 4 Treatment and Prognosis drugs: anti-inflammatories, muscle relaxers, pain relievers. surgery: laminectomy to relieve spinal cord pressure. http://www.mayoclinic.com/images/image_popup/mcdc7_lumbar_laminectomy.jpg Mild: Severe: Duration of recovery depends on severity, but prognosis is good. Diagnosis Myelogram (X-ray image with contrast media injected into spinal canal) http://cal.vet.upenn.edu/projects/saortho/chapter_62/62f19.jpg CT or MRI Etiology Epidemiology, Signs and Symptoms http://www.cavalierhealth.org/images/hansen_types.jpg Hansen Type I: calcified annulus fibrosus ruptures; extruding nucleus pulposus compresses nerves. More common in C-spine of smaller breeds. Hansen Type II: hypertrophied and thickened annulus fibrosus compresses nerves. More common in larger breeds. Not to be confused with this type of Hanson. Most common neurologic disorder in veterinary patients. back pain
ataxia in rear limbs
paralysis in rear limbs
loss of bladder/bowel control Questions? (Patient registered as head-first supine, but actually feet-first supine.) ("Coil-memory" was left on from previous patient. Spine array elements 1-3 active.) FLASH = fast low-angle shot (incoherent GRE) FA = 20° TA = 0:33 Slices = 8 mm, 50% gap FOV = 300 mm, 100% phase TR = 7 ms TE = 2.44 ms Resolution = 256, 70% phase NEX = 2 TSE = turbo spin echo TA = 2:30 Slices = 11 × 3 mm, 0% gap FOV = 330 mm, 100% phase TR = 4000 ms TE = 92 ms Resolution = 512, 65% phase ETL= 19 ("Auto-coil-select" enabled. Spine array elements 3-6 active.) 80 mm sat band NEX = 1 TA = 3:58 Slices = 13 × 3 mm, 0% gap FOV = 330 mm, 100% phase TR = 656 ms TE = 10 ms Resolution = 448, 60% phase ETL= 3 80 mm sat band NEX = 2 http://www.caninechiro.com/sitebuildercontent/sitebuilderpictures/canineanatomy.jpg L7-S1...wut? TA = 1:49 Slices = 23 × 4 mm, 20% gap FOV = 180 mm, 100% phase TR = 4300 ms TE = 98 ms Resolution = 320, 55% phase ETL= 15 80 mm sat band NEX = 1 Extra sequences: MR-Myelography - extension HASTE = half-fourier single-shot turbo spin echo TA = 0:18 Slices = 1 × 50 mm FOV = 280 mm, 100% phase TR = 8000 ms TE = 1200 ms Resolution = 512, 72% phase ETL= 369 NEX = 2 TA = 2:51 Slices = 19 × 4 mm, 20% gap FOV = 330 mm, 100% phase TR = 4580 ms TE = 92 ms Resolution = 512, 65% phase ETL= 19 80 mm sat band NEX = 1 Incidental finding:
benign prostatic hyperplasia L7 L6 L5 L4 L3 L2 S1 S2 S3 Cx1 Cx2 Cx3 spinal
equina L3 spinous
process L5 vertebral
body L7 vertebral
body L7 superior
process ilium sacroiliac
joint ala of
sacrum L7 inferior
disc L7 transverse
process L7 pedicle cauda
equina kidneys small
intestines bladder prostate acetabulum hip joint femoral
crest ilium sacroiliac
joints ala of
discs pedicles superior
articular processes facet
roots Intervertebral disc herniation (no prior images) Extra sequences: coronal (dorsal) plane - neutral (to evaluate cord compression) (to demonstrate nerve roots) T2 Sagittals - to demonstrate pathology compressing the cord T2 Axials - to evaluate pathologies in cross-section T1 Sagittals - to evaluate anatomy Protocol FLASH 3-plane localizers T2 TSE Sagittal T1 TSE Sagittal T2 TSE Axial HASTE Sagittal/Coronal T2 TSE Coronal MR Myelography Patient anesthetized, so no trouble holding still. Saturation bands placed over abdomen to reduce breathing motion/peristalsis. Sagittals and axials repeated with hips in extension and neutral position. Phase H-F Phase H-F Phase A-P Phase H-F Phase R-L Phase R-L annulus fibrosus nucleus