approach to radiology of spinal cord.pptx

normal radilogy of spinal cord

1. Radiology of normal spinal cord and clinical syndromes Presentator - Dr. Shaitan Singh Senior Resident

2. Introduction: Imaging of the spinal cord plays a pivotal role in modern medicine, offering clinicians invaluable insights into the structure, function, and pathology of this vital neurological structure. Through advancements in imaging technology, healthcare professionals can now visualize the spinal cord with clarity, early detection, accurate diagnosis, and targeted treatment of various spinal cord disorders. In this section, we will discuss the significance of spinal cord imaging, providing an overview of the techniques utilized and the objectives of our exploration.

3. Overview of Spinal Cord Anatomy: it is essential to understand the anatomical structure of the spinal cord. The spinal cord extends from the base of the brain, known as the brainstem, to the level of the lumbar vertebrae. The spinal cord is further enveloped by layers of meninges, including the dura mater, arachnoid mater, and pia mater, which provide additional protection and support. Functionally, the spinal cord can be divided into different segments, each corresponding to specific regions of the body.

4. Objectives of the Presentation: The primary objective of this presentation is to provide a comprehensive overview of spinal cord imaging, encompassing the various modalities and techniques employed in clinical practice. By elucidating the principles underlying each imaging modality, we aim to equip healthcare professionals with the knowledge necessary to interpret spinal cord imaging studies accurately and effectively.

5. Imaging Modalities for Spinal Cord Evaluation: Introduction to Different Imaging Techniques: X-rays (Radiography) Computed Tomography (CT) Magnetic Resonance Imaging (MRI) Myelography Functional MRI (fMRI) and Diffusion Tensor Imaging (DTI)

6. (1) X- RAYS Principles of X-ray Imaging Applications in Spinal Cord Assessment

7. Principles of X-ray Imaging: X-ray imaging begins with the generation of X-ray photons by an X-ray tube, which emits a focused beam of radiation directed towards the patient's body. As the X-ray photons pass through the body, they are attenuated to different degrees by the various tissues encountered. Dense structures, such as bone, absorb more X-ray photons and appear white (radiopaque) on the resulting image, while less dense tissues, such as muscle and fat, allow more X-ray photons to pass through and appear darker (radiolucent). This differential attenuation forms the basis of contrast on X-ray images, enabling the visualization of anatomical structures and abnormalities.

8. Cervical spine radiograph standard view: anteroposterior view lateral view odontoid view (open mouth view ) extend view swimmers view : When lateral radiograph fail to show vertebrae down to T1

9. Cervical spine normal anatomy- open mouth view This view is considered adequate if it shows the alignment of lateral process of C1 to C2 The distance between the peg and the lateral masses of C1 should be equal on each side

10. Thoracic spine – Standard view AP & Lateral – Access both view systemically Images of the thoracic and lumbar spine are often large and bone should be scrutinized in detail

11. Lumber Spine- systemic view Coverage- the whole spine lumber spine should be visible on both view Alignment- follow the corner of vertebral body from one level to next level( dotted line) Bone: follow the cortical outline of each bone Spacing: Disc spaces gradually increase in height from superior to inferior

12. Indications: Screening for fractures and dislocations Evaluation of spinal alignment (e.g., scoliosis) Assessment of bone density (e.g., osteoporosis) Technique: Anteroposterior (AP) and lateral views are commonly obtained. Oblique views may be used to visualize specific spinal segments. Specialized techniques such as flexion-extension views can assess spinal stability. Limitations: Limited visualization of soft tissues, including the spinal cord and intervertebral discs. Lower sensitivity for detecting subtle abnormalities compared to advanced imaging modalities . Clinical Applications of X-ray Imaging in Spinal Cord Evaluation

13. Computed Tomography : Principles of CT Imaging Advantages and Limitations Clinical Applications:

14. Principles of CT Imaging : CT imaging utilizes X-ray technology and advanced computer algorithms to generate cross-sectional images of the body. Unlike conventional X-rays, which produce two-dimensional images, CT scans acquire multiple X-ray projections from different angles around the patient, which are then reconstructed into detailed cross-sectional images using computer processing. This ability to visualize the body in three dimensions allows for superior spatial resolution and contrast, enabling the detection of subtle anatomical abnormalities and pathological changes.

15. 6 5 4 3 2 1 1- Vertebral body 2- Intervertebral disc 3- Spinous process 4- sacrum 5- Pedicle 6- Neural foramen/canal

16. Clinical Applications of CT Imaging in Spinal Cord Evaluation: Indications: Assessment of traumatic injuries (e.g., fractures, dislocations) Evaluation of spinal canal dimensions and bony anatomy Detection of spinal tumors or infections Technique: High-resolution axial images are acquired during a single scan. Multiplanar reconstructions (MPR) and three-dimensional (3D) reconstructions provide additional anatomical detail. Limitations: Exposure to ionizing radiation, which may limit use in certain patient populations. Limited soft tissue contrast compared to MRI, making it less suitable for evaluating non-bony structures.

17. Magnetic Resonance Imaging (MRI) Principles of MRI Imaging Different MRI Sequences and Their Applications: Advantages over X-rays and CT

18. Principles of MRI Spine Imaging MRI utilizes a powerful magnetic field and radiofrequency pulses to generate detailed images of the body's internal structures. Unlike other imaging modalities, such as X-ray and CT, which use ionizing radiation, MRI relies on the interaction of hydrogen atoms in the body's tissues with magnetic fields and radio waves. By manipulating these magnetic properties, MRI produces high-resolution images that differentiate between different types of tissues based on their inherent properties, such as water content, fat composition, and protein content .

19. MRI sequences : T1 T2 IR( inversion recovery) T1 Contrast STIR DWI SWI Functional MRI (fMRI) and Diffusion Tensor Imaging (DTI)

20. T1W

21. T2W

22. Functional MRI (fMRI) Principles : fMRI detects changes in blood oxygenation levels associated with neural activity, allowing for the mapping of functional areas within the spinal cord . Clinical Applications : Pain Processing : fMRI can identify regions of the spinal cord involved in pain processing, aiding in the assessment and management of chronic pain conditions. Motor Function : By mapping motor pathways, fMRI helps localize motor function within the spinal cord and assess integrity following injury or disease. Neuroplasticity : fMRI facilitates the study of neuroplastic changes in response to injury or rehabilitation, guiding treatment strategies and assessing functional recovery.

23. Areas of activity are displayed in axial slices from spatially normalized functional MRI data, with colors corresponding to the T-value The results are shown separately for analyses with paradigms corresponding to right-hand stimulation and left-hand stimulation, and demonstrate spatial specificity.

24. Diffusion Tensor Imaging (DTI) Principles : DTI measures the diffusion of water molecules within neural tissue, providing information about the microstructural organization and integrity of white matter tracts. Clinical Applications : Tractography : DTI enables visualization and mapping of white matter tracts within the spinal cord, facilitating the assessment of connectivity and integrity. Spinal Cord Injury : DTI can detect and quantify microstructural changes associated with spinal cord injury, aiding in prognosis and treatment planning. Demyelinating Diseases : DTI helps evaluate white matter integrity in demyelinating diseases such as multiple sclerosis, providing insights into disease progression and treatment response.

25. The panel on the left shows a color-coded representation of diffusion parameters in an axial plane through the level of the  medulla oblongata The panel on the right shows the reconstructed fiber tracts overlaid on a sagittal reference image. The  decussation  of the corticospinal tracts in the medulla is clearly identified

26. FLASH localizer and FA color images of select regions of the spinal cord in representative subjects.  A , Control subject showing consistently high FA throughout the spinal cord.  B , Representative subject with incomplete injury showing slightly lower FA compared with control subjects. Note that the level of the lesion had a particularly low FA value ( arrowhead ).  C , Representative subject with complete injury showing significantly lower FA compared with that of the control subject in  A

27. Clinical Applications of MRI Spine Imaging : MRI spine imaging is utilized in a wide range of clinical scenarios, including: Degenerative Disc Disease : Assessing disc degeneration, herniation, and spinal stenosis. Spinal Tumors : Detecting and characterizing primary and metastatic spinal cord tumors . Spinal Trauma : Evaluating acute spinal cord injuries, fractures, and ligamentous injuries. Inflammatory Disorders : Diagnosing conditions such as transverse myelitis, sarcoidosis, and multiple sclerosis. Vascular Lesions : Identifying arteriovenous malformations, aneurysms, and spinal cord infarctions

28. Comparison of Modalities: Indications   Advantages Disadvantages X-Ray Trauma Intra-operative localization Inexpensive Widely available Quick Portable  Radiation exposure Difficulty in interpretation High rate of false-positive findings   CT Trauma Visualization of bony structures Widely available Quick Less useful at visualizing soft tissue structures Radiation exposure Cost  MRI Pts with "red flags" case Radiculopathy Tumor Myelopathy Visualization of soft tissue structures (e.g. relationship of disc to nerve) No radiation exposure Contraindications: presence of ferromagnetic implants, cardiac pacemakers, intracranial clips, Claustrophobia Not widely available Cost$$$

29. Myelography: Principles and Technique Indications and Contraindications

30. Principles of Myelography: Myelography involves the injection of a radiopaque contrast agent, typically iodinated contrast medium, into the subarachnoid space surrounding the spinal cord. the contrast material diffuses within the cerebrospinal fluid (CSF) and outlines the spinal cord, nerve roots, and meninges on radiographic images.

31. Indications for Myelography Evaluation of Spinal Cord Compression : Myelography is particularly useful in assessing the extent and location of spinal cord compression caused by herniated discs, tumors, or other structural abnormalities. Diagnosis of Nerve Root Pathology : Myelography can identify nerve root entrapment or compression, which may manifest as radiculopathy or sciatica. Detection of Arachnoiditis : Myelography can detect inflammatory changes within the subarachnoid space, such as arachnoiditis, which may result from infection, trauma, or prior spinal surgery.

32. Technique of Myelography: The myelography procedure involves several key steps: Patient Preparation : Patients undergo pre-procedural assessment to evaluate their medical history, allergies, and contraindications to contrast media. Sedation or anesthesia may be administered to alleviate anxiety and discomfort during the procedure. Injection of Contrast Medium : Under fluoroscopic guidance, a fine needle is inserted into the subarachnoid space, typically at the lumbar or cervical level. A radiopaque contrast medium is then injected, allowing visualization of the spinal cord and nerve roots. Image Acquisition : Following contrast injection, serial radiographic images are obtained in multiple projections to visualize the distribution of contrast within the subarachnoid space. Post-procedure Monitoring : After myelography, patients are monitored for any immediate adverse reactions, such as headache, nausea, or allergic reactions. Close observation is essential to detect and manage potential complications promptly.

33. SPINAL CORD SYNDROME CLASSIFICATION: (A) Complete (B) Incomplete

34. Complete cord syndrome CAUSES : Trauma Metastatic carcinoma Multiple sclerosis Spinal epidural hematoma Autoimmune disorder

35. Complete cord syndrome All descending tract from above and ascending tract from below are interrupted Affect motor, sensory and autonomic function

36. Conti.. SENSORY : All sensation are affected Pin prick test is very valuable Sensory segment is usually 2 segments below the level of lesion Segmental paresthesia occur at the level of lesion

37. Conti.. MOTOR : paraplegia due to corticospinal tract involvement First spinal shock – followed by hypertonic hyperreflexia paraplegia Loss of abdominal and cremastric reflexes At the level of lesion LMN sign occurs

38. Conti.. AUTONOMIC Urinary retention and constipation Anhidrosis, trophic skin changes, vasomotor instability below the level of lesion Sexual dysfunction can occur

39. Incomplete cord syndromes Brown Sequard syndrome central cord syndrome Anterior cord syndrome Posterior cord syndrome Conus medullaris syndrome Cauda equina syndrome

40. Brown-Sequard syndrome Hemi-section of the spinal cord Cause:- Extramedullary lesion tumor and penetrating trauma

41. Conti.. Brown-Sequard syndrome Sensory Ipsilateral loss of proprioception due to posterior column involvement Contralateral loss of pain and temperature due to involvement of lateral spinothalamic tract motor Ipsilateral spastic weakness due to descending corticospinal tract involvement LMN sign at the level of lesion

42. CENTRAL CORD SYNDROME CAUSES : Syringomyelia Hyperextension injury of neck Intramedullary tumor

43. SENSORY: Pain and temperature are affected Touch and proprioception are preserved Shawl(= cape like) like distribution of sensory loss Motor : Upper limb weakness > lower limb

44. ANTERIOR CORD SYNDROME CAUSES: Ischemia from anterior spinal artery occlusion acute Disc herniation Hyperflexor injury

45. Conti.. ANTERIOR CORD SYNDROME SENSORY Loss of pain and temperature Preservation of position and vibration MOTOR Sudden onset flaccid and areflexic paraplegia AUTONOMIC Urinary bowel and sexual dysfunction

46. Posterior cord syndrome Causes: Ischemia from posterior spinal artery occlusion symptom : loss of proprioception and vibration sense Pain temp preserved Absensce of motor deficit

47. POSTERIO LATERAL CORD SYNDROME Causes : VIT B12 deficiency AIDS Tabies dorsalis cervical spondylosis HTLV associated myelopathy Features paresthesia in feet Loss of proprioception and vibration of legs Sensory ataxia Positive Rhomberg sign Corticospinal tract involvement: Spasticity, hyperreflexia Babinski sign- positive

48. Conus Medullaris and Cauda equina syndrome The most distal bulbous part of the spinal cord is called the conus medullaris, and its tapering end continues as the filum terminale . Distal to this end of the spinal cord is a collection of nerve roots, which are horsetail-like in appearance and hence called the cauda equina

49. Conti …Conus Medullaris and Cauda equina syndrome ETIOLOGY: Trauma Herniated disc(90% at L4-5, L5-S1) Inflammation and infection spinal stenosis Neoplasm Itrogenic

50. CASE DISCUSSION: A 50 yr old male p/w Rapid onset lower back pain, bilateral lower limb weakness and reduced sensation over the S1-3 dermatomes

51. MRI Sequences for Spine Imaging MRI spine imaging typically employs a combination of different imaging sequences, each tailored to highlight specific anatomical structures and pathological features. Common MRI sequences used in spine imaging include: T1-weighted Imaging : T1-weighted sequences provide excellent anatomical detail and contrast between different tissues. In T1-weighted images, cerebrospinal fluid (CSF) appears dark, while fat and fluid-filled structures, such as the intervertebral discs, appear bright. T1-weighted images are particularly useful for assessing the morphology of the spinal cord, identifying vertebral fractures, and detecting extradural masses. T2-weighted Imaging : T2-weighted sequences are sensitive to changes in water content and are valuable for detecting abnormalities such as edema , inflammation, and cystic lesions. In T2-weighted images, CSF appears bright, while bone and other dense structures appear dark. T2-weighted imaging is essential for evaluating spinal cord pathology, including disc herniation, spinal cord edema , and intramedullary lesions. Fluid-attenuated Inversion Recovery (FLAIR) : FLAIR sequences suppress the signal from CSF, enhancing the visualization of periventricular and peridural lesions. FLAIR imaging is particularly useful for detecting abnormalities adjacent to CSF-filled spaces, such as intradural tumors , arachnoid cysts, and leptomeningeal metastases. Gradient Echo (GRE) Imaging : GRE sequences are sensitive to susceptibility effects and are valuable for detecting hemorrhagic lesions, calcifications, and hemosiderin deposition. GRE imaging is often used to assess spinal cord hemorrhage , cavernous malformations, and hemosiderin-laden lesions associated with previous hemorrhagic events. Diffusion-weighted Imaging (DWI) : DWI sequences assess the diffusion of water molecules within tissues and are sensitive to changes in tissue microstructure. DWI is useful for evaluating acute ischemic changes, demyelination, and cellular proliferation within spinal cord lesions. Apparent Diffusion Coefficient (ADC) maps derived from DWI data provide quantitative information about tissue diffusion characteristics, aiding in lesion characterization and differential diagnosis. Dynamic Contrast-enhanced Imaging : Dynamic contrast-enhanced (DCE) MRI involves the administration of gadolinium-based contrast agents to assess vascular perfusion and blood flow dynamics within spinal cord lesions. DCE-MRI is valuable for evaluating spinal cord tumors , arteriovenous malformations, and vascular lesions, providing information about lesion vascularity and perfusion characteristics.