In December 1895, Germanphysicist Wilhelm Roentgendiscovered these mysteriousrays: X-rays, with X standingfor unknown. In recognition ofhis discovery, Roentgen in1901 became the first Nobellaureate in physics.
They are an electromagnetic radiation emitted by charged particles interactions Photons which can penetrate through matter They have no mass or charge They travel at the speed of light
Enables radiologists tovisualize X-ray imagesin real time on atelevision monitor. Inmost instances theprocedure wouldinvolve theadministration of someform of contrast agentto outline the region ofinterest
A mammographymachine is an X-raymachine dedicated tobreast images.Compared withconventional X-raytechniques,mammograms areobtained with muchlower energy X-rays ofaround 20,000 volts.
It is a diagnostic procedurethat produces X-ray picturesof blood vessels. A catheter isinserted in the vessel to injectcontrast fluid into the lumenof the blood vessel, whichthen becomes visible on X-ray images.
First Angiogram(1896, Hankel):Mercury was injected in a post Digital Subtraction Angiographymortem hand (Mistretta, 1980s)
Angiogram of The 3-D Angiogram ofCoronary Arteries The Brain Arteries
The technique of CTscanning was developedin 1973 by Hounsfield. Athin fan beam of X-raysgenerated by aconventional X-ray tubepasses through a singleslice of a patientthrough to a bank of X-ray detectors.
The number of slices (images) a CT scanner can acquire per revolution of the x-ray tube depends on the number of rows of detectors. Spiral CT units today may be referred to as multislice or multidetector CT scanners.The current number of slices acquired per revolution in most scanners is 32-64 slices.These multislice scanners can produce slices that are submillimeter in thickness and can acquire these images in less than a second. Decreasing the slice thickness produces an increasein the spatial resolution and the ability to visualize smaller structures accurately.
Multiple plane visualization Minute details, within slices 3d reconstruction
More apt in soft tissue pathology diagnosis. images that provide information that is either T1-weighted, proton densityweighted, T2- weighted, T2∗-weighted, or IR:inversion recovery.
joint effusion (arrow). osteomyelitis of the middle phalanx (low signal).
T2-weighted image of same knee with increased signal characteristic of a tear.
Proton density– weighted sagittal image of the knee demonstrating an anterior cruciate ligament tear. Small joint effusion and small popliteal cyst.
T2∗-weighted coronal image of the knee: Small joint effusion andsmall popliteal cyst.
short-tau IR (STIR) and fluid attenuated IR (FLAIR) are used to null the signal coming from a specific tissue such as fat or cerebrospinal fluid (CSF), respectively.Nulling the signal from a specific tissue allows the surrounding tissue with similar signal characteristics to be visible.A STIR pulse sequence, commonly used in musculoskeletal imaging, is used to null the signal from fat. This allows better visibility of free fluid and partial or complete tears.This may be used in combination with a T2-weighted sequence (Figure 1–14) to better visualize pathology that may be difficult to see because of similar high (bright) signals. When imaging the brain or spinal cord, FLAIR images may be used to null the signal from the CSF, allowing improved visibility of the surrounding periventriclar area of the brain.
STIR pulse sequence demonstrating osteomyelitis (high signal) of the middle phalanx of The same index finger.
T2∗-weighted sagittal image of the same knee with fat suppression. Small joint effusion and small popliteal cyst.
Different tissues in our body absorb X-rays at different extents: Bone- high absorption (white) Tissue- somewhere in the middle absorption (grey) Air- low absorption (black)
The initial assessment of any xray is the same:Film Specifics:Name of PatientAge & Date of BirthLocation of PatientDate TakenFilm Number (if applicable)Film Technical factors:Type of projection (Supine is standard)Markings of any special techniques used
A = Anatomic appearance, Alignment, Asymmetry B = Bone Density C = Cartilage (joint, disk spaces), Contours D = Distribution, Density, Deformity E = Erosions S = Soft tissues
Trace the unbroken outline of each vertebrae (including Odontoid on C2). The vertebral bodies should line up with a gentle arch (normalcervical lordosis) using the anteriorand posterior marginal lines on the lateral view. Each body should be rectangular in shape and roughly equal in size although somevariability is allowed (overall height of C4 and C5 may be slightly less than C3 and C6) . The anterior height should roughly equal posterior height (posterior may normally be slightly greater, up to 3mm).
Trace the unbroken outline of each vertebrae (including Odontoid on C2). The vertebral bodies should line up with a gentle arch (normal cervical lordosis) using the anterior and posterior marginal lines on the lateral view. Each body should be rectangular in shape and roughly equal in size although some variability is allowed (overall height of C4 and C5 may be slightly less than C3 and C6) . The anterior height should roughly equal posterior height (posterior may normally be slightly greater, up to 3mm)
Disc spaces should be roughly equal in height at anterior and posterior margins. Disc spaces should be symmetric. Disc space height should also be approximately equal at all levels. In older patients, degenative diseases may lead to spurring and loss of disc height.
Preverteral soft tissue swelling is important in trauma because it is usually due to hematoma formation secondary to occult fractures. Unfortunately, it is extremely variable and nonspecific. Maximum allowable thickness of preverteral spaces is as follows: Nasopharyngeal space (C1) - 10 mm (adult) Retropharyngeal space (C2-C4) - 5-7 mm Retrotracheal space (C5-C7) - 14 mm (children), 22 mm (adults).Soft tissue swelling in symptomatic patients should be considered an indication for further radiographic evaluation. If the space between the lower anterior border of C3 and the pharyngeal air shadow is > 7 mm, one should suspect retropharyngeal swelling (e.g. hemorrhage). This is often a useful indirect sign of a C2 fracture. Space between lower cervical vertebrae and trachea should be < 1 vertebral body.
Some fractures can be very subtle, and soft tissue swelling may be the only sign of fracture. In this case, the lateral view shows only slight soft tissue swelling anterior to C2, and no obvious fracture is seen. On the subsequent CT, a type III dens fracture (fracture of the dens and extends into the body of C2) is demostracted.
Alignment on the A-P view should be evaluated using the edges of the vertebral bodies and articular pillars. The height of the cervical vertebral bodies should be approximately equal on the AP view. The height of each joint space should be roughly equal at all levels. Spinous process should be in midline and in good alignment. If one of the spinous process is displaced to one side, a facet dislocation should be suspected.
Osteophytes Disc space narrowing Loss of cervical lordosis Uncovertebral joint hypertrophy Apophyseal joint osteoarthritis Decreased vertebral canal diameter
Preferred imaging modality to address suspicion of associated ligamentous injury and the assessment of the status of nearby neural tissues
1. Vertebral body.2. Intervertebral disc.3. Posterior body edge adjacent to disc space (site of potential osteophyte formation).4. Posterior disc margin (site of potential disc prolapse).5. Posterior longitudinal ligament (site of potential ossification and cord compression).(6) Cerebrospinal fluid in front of cord. (7) Spinal cord.(8) Ligamentum flavum (site of potential hypertrophy and cord compression)
Axial cervical spine anatomy. (1) Anterior vertebral body endplate. (2) Uncus (constituting one side ofuncovertebral joint). (3) Vertebral artery within foramen transversarium. (4) Lower facet. (5) Medial aspect of facet joint. (6) Lamina. (7) Site of attachment ligamentum flavum. (8) Spinous process.
major disruption of the C4–5 segment in this 23-year-old man. Increased signal intensity is evident in the intradiskal space along with injury to the posterior longitudinal ligament. Edema within the spinal cord is evident spanning multiple levels around the injury.
A sagittal section T2- weighted MRI of the cervical spine in a 21-year- old man. Note the signal change present within the spinal cord approximating the C3–4 levels, which is consistent with edema and a spinal cord contusion. This individual was particularly susceptible to injury because of congenital stenosis.
The outstanding feature of this sagittal section T2-weighted MR image is the increased signal intensity consistent with edema from soft tissue injury. The presence of such findings warrants particular caution to examine scrupulously for the presence of fractures.
T1-weighted MRI revealing basilar invagination. Observe the protrusion of the odontoid process into the foramen magnum and the resulting displacement of the brainstem.
In this sagittal slice of a T2-weighted MRI of the cervical spine in a 44-year- old man, changes typical of the age are evident including the decreased signal intensity of the cervical intervertebral disks, bulging disks (without herniation), and osteophytic lipping at the disk and vertebral body margins.
In this sagittal section T2-weighted MRI, herniation of the C5–6 disk is evident.
In this axial T2- weighted MR image, the effect of displacing the spinal cord and cervical nerve root is visible.
A sagittal view T2- weighted MRI revealing advanced degenerative change resulting in central spinal canal stenosis. Note the absence of signal from the cerebrospinal fluid in the areas of osteophytic growth and disk bulging.
Although this image is somewhat degraded by motion artifact, involvement of the vertebral body of C4 with findings consistent with osteomyelitis is readily apparent. Images degraded from patient motion are frequently a challenge for the physician undertaking interpretation.
In this sagittal section T2-weighted MRI, diffuse metastatic disease is seen in multiple cervical vertebrae as highlighted by the increased signal intensity.
This T2-weighted MRI with contrast shows areas of altered signal within the spinal cord consistent with plaque lesions typical of multiple sclerosis. The plaques are not contrast enhanced, suggesting the image was not captured during a flare of the disease.
Same 4 lines are present in normal alignment Rectangular bodies Gradual increase in disc height With caudal progression in the lumbar spine, the interpedicular distance increases