Untitled Quiz

Neuroradiology Study Notes

• Doctor's and patient notes from PowerPoint presentations were compiled and included in the slides.
• Additional notes and clarifications were added by [email protected].
• Original work by Professor Essam Abdulbary and Dr. Maram served as a baseline for the lecture.

Objectives

• Recognize various imaging modalities used in neuroimaging.
• Understand basic brain cross-sectional anatomy.
• Identify and describe common pathologies.
• Learn about red flag cases.

Imaging Modalities

• Computed Tomography (CT)
• Magnetic Resonance Imaging (MRI)
• Plain X-ray
• Ultrasound (transcranial)
• Cerebral angiography
• Myelography
• Isotope scanning
• Interventional procedures

Commonly Used Examinations

• Transcranial ultrasound (US) is primarily used for infants due to the open fontanel to avoid ionizing radiation.
• Cerebral angiography (conventional angio) has been superseded by CT angiography. It is invasive and requires sedation and is used before procedures like aneurysm repair.
• Myelography is invasive and is now replaced by MRI except for when MRI is contraindicated. A contrast agent is injected into the thecal sac followed by CT or X-rays.
• Isotope scanning assesses brain function and helps confirm brain death or degenerative diseases such as Alzheimer's.
• Interventional procedures (aneurysm repair, thrombolysis, thrombectomy) are discussed separately.

Plain X-ray Views

• Skull X-rays have been replaced by CT.
• Occipitofrontal views (X-ray from posterior to lower exposure to the eye) are used for skull examination.
• Standard views include PA (occipitofrontal), lateral (right & left), and sinus (occipitomental or water's view) for skull.
• Vertebral column views consist of AP, lateral, and oblique views.

Plain X-ray Findings and Significance

• Plain skull films may reveal lytic deposits (multiple myeloma), fractures, abnormal calcifications (meningioma, glioma, AVM, post-infective foci), and pituitary fossa enlargement. In X-rays, focus is not on detailed anatomy.
• Important anatomical features (suture lines, sinuses, bones) are shown in plain X-ray views.
• Lateral views detail the frontal bone, frontal sinus, orbital plates, cribiform plate, sphenoid sinus, and maxillary sinus.
• Important anatomical features (sutures, sinuses, bones) are shown.

Fracture and Vascular Markings

• Fractures are characterized by well-defined sharp edges that end at sutures and rarely branch, located at the site of trauma and with clinical history of trauma.
• Vascular markings are less defined, cross sutures, and appear tortuous and branching, located anatomically at sites where vessels can be found.
• Fracture lines are smoother lines than vascular markings.

Water's View

• Water's view is used to assess paranasal sinuses, and specifically the maxillary sinus, nasal septum, and odontoid process (C2), frontal sinus.
• Water's view has been replaced by CT for paranasal sinus examination.

Sinusitis (Air Fluid Level)

• Air fluid level in the maxillary sinus suggests acute sinusitis.

Sinusitis (Air Fluid Level) - CT

• Enlarged turbinates due to allergic rhinitis can block sinus drainage, leading to sinusitis.
• Osteomeatal complex blockage impacts sinus drainage and can trigger sinusitis.
• Septal deviation (deviated septum) and hypertrophied turbinates are causes of sinusitis.
• Complications such as orbital cellulitis, abscess, meningitis, brain abscess, and venous sinus thrombosis can occur.
• Air bubbles and opacification in the maxillary sinuses or an air-fluid level in one suggests sinusitis.

Spinal Radiographs (AP, Lateral, & Oblique Views)

• Alignment (lordosis, kyphosis, straightening)
• Bone texture (normal, osteoporosis)
• Disc spaces (maintained, narrowed)
• Fat outlining the psoas muscle
• Paravertebral shadows (dorsal spine)
• Sacroiliac joints (lumbar spine - psoriasis)
• Cone view
• Examination views consist of AP, Lateral oblique , and Cone views.

Spinal Radiographic Findings & Significance

• Cone view used, predominantly for assessment of the L5-S1 disc
• Spine alignment (lordosis, kyphosis, cervical lordosis) is important.
• Bone texture assesses osteoporosis.
• Paravertebral shadows can indicate tumors.

Spondylolysis and Spondylolisthesis

• Spondylolysis: a defect in the pars interarticularis (portion of the vertebral arch)
• Most cases of spondylolysis occur in the lower lumbar vertebrae (L5).
• Spondylolysis can lead to spondylolisthesis (forward slippage of one vertebra).
• Causes of spondylolysis include: repeated microtrauma (especially in adolescent athletes), congenital abnormalities, weak bones in postmenopausal women (due to osteoporosis), trauma, tumors, and infections.

Cervical Spine (AP, Lateral, & Oblique Views)

• Assessment of cervical spine concerns the vertebral bodies; anterior, posterior, and transverse processes; vertebral foramina; articular processes and facet joints; and disc spaces.

Cross-Sectional Imaging of the Spine

• Assessment includes fracture analysis, bone texture appraisal, facet joint analysis (OA), disc lesion identification, spinal cord and infection analysis, and spinal neoplasm identification.

CT Scan

• Fractures, bone texture, facet joints (OA), spinal cord, infections, and tumors are evaluated.

Cut Spine

• Patient lies supine during CT scan.
• Axial cuts are taken.
• 3D image reconstruction is possible.
• Facet joint, Spinal canal, OA presence or absence is evaluated.
• Space between disc & posterior process is measured for spinal canal stenosis.

Bone Window vs. Soft Tissue Windows

• Bone window is used to differentiate bone density.
• Soft tissue window is used to show soft tissues.
• Cortical bone is clear in CT.

MRI (T1 and T2 weighted images)

• MRI is a highly detailed imaging method showing higher soft tissue resolution, excellent for recognizing bone marrow lesions and spinal cord pathology.
• CT scans have higher bone density definition than MRI scans which are denser for bone showing.
• Disc features, bone marrow integrity, and presence of coda equina are evaluated in MRI.

Degenerative Disc Changes

• X-ray, CT, and MRI show different features of degenerative disc disease.
• Loss of disc height, disc herniation, nerve compression are indications on MRI.

Tuberculosis of Spine (Pott's Disease)

• Infection of the vertebrae (spondylitis) or disc (discitis) or both (spondylodiscitis)
• Symptoms typically include gradual onset of constitutional symptoms such as night sweats, fever, anorexia, weight loss, and other symptoms; however, the presentation may not always be so pronounced given possible atypical manifestations.
• Pathogenesis is bacterial, viral, fungal, or parasitic.
• Can be seen in the thoracis or first lumbar vertebra predominantly.
• Imaging and aspiration/culture confirm diagnosis.

How to Diagnose Spinal Canal Adequacy/Stenosis (in MRI)

• Adequacy/stenosis in the spinal canal is evaluated using T2 weighted imaging.
• The amount of CSF anterior and posterior to the spinal cord is assessed.
• One-sided loss of CSF indicates mild stenosis; bilateral loss, a severe stenosis.
• Causes of narrowing include disc lesions, tumors, and hypertrophy of the ligamentum flavum.

Additional Points

• Details on specific views, terminology, and relevant conditions are provided.