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OK, we're live now, Dennis. Thank you. Hi, everybody. We're back on our second part of introduction to arthritis. I'm really happy to know that you all are with us today. I noticed that a lot of you signed up. I don't know how many will be attending totally, but we have some good followers today. And I'm very happy with that. I wanted to share with you that I had a great honor given to me last week by the Ukrainian Radiology Society. I was elected an honorary member for my help in raising them 12,000 €21,000 which allowed the organization to do their meeting this year. They didn't have the funding because of the war in Ukraine. So I'm I'm very happy that we could do that. It was Dr Don Resnick lecturing and myself. So we'll go on with this lecture. Introduction to arthritis. Part two. Welcome to part two of introduction to arthritis. In today's lecture, we will discuss several different types of arthritis, provide their target approach diagrams and show you multiple images. Today, we will cover juvenile rheumatoid arthritis, erosive arthritis, septic arthritis, the spondyloarthropathies, reactive arthritis, psoriatic arthritis, and diffuse idiopathic skeletal hyperostosis as well as gout in following lectures which I will be writing, I will cover each disease in detail, even more detail and we'll be doing, we'll be doing cases as well. So today's lecture is a general overview to give you the basics so that you can begin to understand the disease processes. Juvenile rheumatoid arthritis is a polyarthritis seen in the pediatric population with various radiographic findings clinically. the disease starts before the age of 16 years of age. It's usually located in the larger joints. As we see in the diagram and joint changes are distinct from adult rheumatoid arthritis. However, the distribution can be similar. The radiographic findings include erosions that are really late manifestations, periarticular osteopenia, bone edema, periosteal reaction and growth disturbances including epiphyseal overgrowth, early growth, plate closure, muscle contractures and ankylosis changes in the cartilage with cartilage destruction and erosions are late manifestations of this disease. The distribution is noted in the diagram. Changes are commonly seen in the wrist, metacarpophalangeal joints of the fingers, but not the thumb and the proximal interphalangeal joints in the general skeleton, juvenile rheumatoid arthritis can affect the cervical spine, the shoulder, the elbow, the hip and the knee, no manifestations are seen in the foot. Extra, findings include still's disease which is known as systemic juvenile idiopathic arthritis. Systemic means it may affect not only the joints but other parts of the body including the liver, lungs and heart. It's sometimes referred to also as still's disease and can occur any time during childhood but is most commonly starts at about two years of age. Uveitis, tendinitis and bursitis with soft tissue swelling and deformity are seen in this disorder. Juvenile rheumatoid arthritis is a diagnosis by way of exclusion when inflammatory changes do not match other inflammatory diseases. Juvenile rheumatoid arthritis is also known as juvenile idiopathic arthritis. As I said earlier in this image of the hands, we can see typical ankylosis of the carpal bones and marked periarticular osteopenia. In this patient with juvenile rheumatoid arthritis, there are multiple erosions in the carpals and in the base of the metacarpal bones, diffuse joint space narrowing is also noted throughout. Notice that the epiphysis are not closed indicating the patient's young age. Here we see two different patients with juvenile rheumatoid arthritis. In the image labeled A, we see multiple erosions affecting the carpal bones and the metacarpophalangeal joints, collapse of the scaphoid and lunate bone are noted and periarticular osteopenia is noted across the metacarpophalangeal joints. In the image label B, we see an x-ray of an adult with a history of juvenile rheumatoid arthritis. The bones are foreshortened and the bone length is abnormal because of premature growth, plate closure and epiphyseal overgrowth. We also see multiple examples of severe joint malalignment. Periarticular osteopenia is also noted in this patient, juvenile rheumatoid arthritis, as we mentioned can affect larger joints as well. Here we see an image of the shoulder demonstrating large erosions in the humerus, the glenoid and acromion in a patient with juvenile idiopathic arthritis in this radiograph of a child's pelvis erosions and joint space, narrowing of the right hip joint are present. No other findings are appreciated. We now will move on to erosive osteoarthritis. Erosive osteoarthritis is a disorder that most often involves the hands of postmenopausal women. It can begin abruptly with pain, swelling and tenderness. Distal interphalangeal joints are involved most frequently followed by proximal interphalangeal joints. Clinical findings include an inflammatory form of osteoarthritis of the hand which affects the distal interphalangeal joint and proximal interphalangeal joint and the first carpometacarpal joint of the hand most frequently like osteoarthrosis. The combination of osteophyte formation and central erosions which causes a characteristic biconcave articular surface surface is called the gall wing or seagull deformity. It can also look like a pencil and cup deformity but this is less frequent. The radiographic findings include joint space narrowing, sclerosis of bone with productive bone changes and osteophyte formation with possible ankylosis. The cartilage demonstrates subchondral central erosions. This type of arthritis has the same distribution as osteoarthrosis with a preference for the interphalangeal joints, distal interphalangeal joint more than proximal. The extra findings is that this disorder occurs primarily in older postmenopausal women. The soft tissues in this disorder demonstrate rheumatoid arthritis, like proliferative intraarticular synovitis and soft tissue swelling. Noted about the joint. Here, we have the A P radiographs of two different patients in patient. A we see erosive changes at the proximal interphalangeal joints, two through five and at the distal interphalangeal joint three through five. We see typical gullwing deformity in the distal interphalangeal joint of digits. Three demonstrated by the white arrow. And we see ankylosis of the proximal interphalangeal joint of the fourth finger. Demonstrated by the yellow arrow. Ankylosis occurs late in this disease in patient b joint space narrowing with central erosions are noted goal, wing deformities of the proximal interphalangeal joint two through four and distal interphalangeal joint. I as well as carpal metacarpal degenerative changes are noted at the base of the thumb. Additionally, ankylosis of the distal interphalangeal joint three is noted. This is an image demonstrates a ball catcher's view of the hands in a patient with erosive osteoarthrosis. Bilateral extensive damage is noted in the interphalangeal joints. Note the symmetrical distribution and sparing of the metacarpophalangeal joints. Here we see a typical gullwing appearance of the distal interphalangeal joints which is classically seen in erosive arthritis. It has also been reported in psoriatic and more rarely in rheumatoid arthritis, especially with rheumatoid arthritis affected by post rheumatoid osteoarthritis. Now we move on to our next disorder. A disorder that usually affects one joint at a time. Septic arthritis, septic, arthritis demonstrates rapid destruction of one joint with extensive erosions, destructive bony changes and joint effusion. Clinically septic arthritis is usually an acute mono arthritis. It is secondary to bacteremia, local spread of infection or a complication of surgery or secondary infection. It leads to rapid joint destruction and requires prompt aspiration or drainage and also requires treatment with intravenous antibiotics. Since septic arthritis only affects one joint at a time. We don't have a target approach image for this disorder in the joints, we see joint effusion which is sometime which sometimes contains gas thickened synovium and erosions in the bones after a few days, extraarticular osteoporosis may be seen followed by erosion and joint space narrowing. There may be adjacent bone marrow edema that one can see on magnetic resonance imaging. Late state changes in the bones include ankylosing and sclerosis. Cartilage destruction occurs late in the disease. As I stated earlier, the distribution is a mono arthritis. It is most common in the knees and adults and knees and hips in Children, most commonly infants up to 12 months. Remember, however, if you see one joint involved like this, one joint, that looks bizarre. The first thing that you should think of is infection rule that out and then move on. Additional findings may occur in this disease including fever and bacteria in the synovial fluid. The soft tissues demonstrate erythema warmth and swelling as it would in any infection of the skin or soft tissues. Magnetic resonance imaging shows thickening and enhancing synovium without synovial proliferation and micro abscesses. Here we see a severely destructive of of septic arthritis. This image could suggest the possibility of an aggressive malignancy. However, this patient presents with marked soft tissue swelling, erythema and warmth of the tissues. The patient reported that these changes happened rapidly over seven days time. So another aspect of infection is very, very quick presentation. Radiographically, we see enormous soft tissue swelling of the third finger with extensive erosions of the joint and some bony fragmentation along with a permeated malignancy like appearance. Here is a nice example of infectious arthritis as a complication of a fingertip abscess. Findings include soft tissue, swelling, erosions and joint space, narrowing of the distal interphalangeal joint. The subchondral sclerosis and osteophyte formation are caused by secondary osteoarthritis. In this case, this is a radiograph of the pelvis in a patient with tuberculosis arthritis of the left hip joint, not much is seen except subtle joint space narrowing with minimal subchondral sclerosis of the left hip. These radiographic findings are really nonspecific and most likely would be the result of osteoarthritis because of the of the patient's discomfort and the lack of concrete findings. MRI was performed. The pelvic MRI seen in this image of the same patient was surprising because of the multiple abscesses that we see when abscess formation is this extensive and the clinical findings are minimal. Always think of tuberculous arthritis. The organism was found in the joint aspiration and the patient was started on the proper antibiotic course. Spondyloarthritis comprises a group of inflammatory diseases of the peripheral joints and spine with various clinical manifestations. These disorders have some key features in common including joint inflammation, especially the sacroiliac joints, ESIs, especially that of the lumbar spine. The presence of HLA B 27 genetic factor and they are rheumatoid factor negative. When I learned about these disorders, we called them the seronegative spondyloarthropathies. These disorders can further be divided into an axial and peripheral type. Ankylosing spondylitis is the most common axial type and the prototypical type of spondyloarthritis. The most common peripheral type are psoriatic arthritis, reactive arthritis, which used to be called Reiter's Syndrome and enteropathy, arthritis associated with inflammatory bowel diseases. You should remember that inflammatory bowel diseases causes sacroiliac joint inflammation as well. And that should always be in your differential, especially if the sacroiliac joints are affected alone without other signs of arthritis. Let s discuss a bit about the clinical features for spondyloarthritis of the spine as a as a, as a as in the, in the, in the, in the, in the in many signs and symptoms are associated with disorder, inflammatory back pain that has an insidious onset that improves with exercise but not with rest. Is one of them back pain at night is very frequent, morning, back stiffness greater than or equal to 30 minutes. Alternating gluteal pain, arthritis, enthesitis of the Calcaneus uveitis, dactylitis, psoriasis and Crohn's disease or colitis may be associated spondyloarthritis. Demonstrates a good response to non-steroidal anti-inflammatory a medication, a family history of disease and the presence of HLA B 27 antigen and an elevated c reactive protein. The classification criteria for spondyloarthropathies was developed by the assessment of spondyloarthritis International Society. And these include greater than or equal to three months of back pain with an age of onset, less than or equal to 45 years along with sacroiliac sacroiliitis on imaging plus greater than or equal to one clinical feature that we have spoken about in the chart or HLAB 27 positivity and two other clinical features. Now that we've done with the clinical formalities. Let's talk about some diseases. Ankylosing spondylitis is an axial arthropathy that demonstrates early changes at the vertebral body corners, referred to as shiny corners, the presence of Syndey and the presence of sacroiliitis. Syndesmosis are bony bridges that develop in the anterior fibers of the annulus fibrosis of the intervertebral disc. These bony bridges connect one vertebra with its adjacent vertebra. Above and below. Syndesmosis are vertical, syndesmotic are vertical. Please remember that if you see horizontal bone proliferation at the margin of the of the vertebral body, you have to think of osteophytes and other disorders. Clinically. These patients present with significant back pain, morning stiffness and disability. The disease onset is in the 3rd and 4th decade and the prevalence is about 1%. I have seen many examples of this disorder in my career. Ankylosing spondylitis is the prototypical type of seron negative axial spondyloarthropathy that affects the spine and sacroiliac joints, primarily but can affect other joints like the shoulders, hips, ribs, heels, and small joints of the hands and feet. Radiologic findings include shiny sclerotic vertebral body corners, straightening of the anterior vertebral body contour, the development of bamboo spine and the presence of sacroiliitis. We will show you examples of all of these in a moment. Let's first talk about enthesitis. Inflammation of the enthesis is one of the hallmarks of spondyloarthropathy. The early sign of ankylosing spondylitis is edema at the enthesis which is only visible on MRI imaging. As we see demonstrated in the image number three by the white arrow in a later stage sclerosis of the corners of the vertebral bodies will present which can be termed shiny corner and be seen on conventional radiographs and on CT finally, vertical syn desma fites are formed within the anterior fibers of the annulus fibrosis connecting one vertebral body to another. Here we see three different patients with typical features of early stage ankylosing spondylitis. Image number one demonstrates a nice example of shiny corners of the anterior corner of the vertebral bodies where the emphases are located. Also we see squaring of the anterior vertebral bodies, remember they should be a bit concave and if they are squared, something's going on. In patient number two, we clearly see diffuse squaring of the vertebral bodies and shiny corners on this sagittal ct slice. Finally, in image number three, this patient has edema of the enthesis of the vertebral bodies which is visible on the sagittal stir image and indicated by the white arrow. Patient is in the in the, in the, in the in the the the the and progresses Syndey develop these patients images of show syndesmosis in the lumbar spine and ossification of the paraspinal ligaments. Ossification occurs in the fibers of the annulus fibrosis. Therefore, it is vertical extending from the vertebral body below to the vertebral body. Above as we see in these images. This appearance is specific for ankylosing spondylitis. Notice also in the A P view of the spine that the sacroiliac joints are fused because of these findings, the spine loses its flexibility and can easily fracture even after minor trauma. A and lateral views of the lumbosacral spine demonstrate the appearance of the classic bamboo spine. In ankylosing spondylitis, we see fusion of the lumbar spine by vertical Syndey and ossification of the paraspinal ligaments. This is indicated by the Black arrow. A rigid bamboo spine is prone to hyperextension fractures even after minor trauma. Always keep in mind that poss the possibility of occult fractures in patients with ankylosing spondylitis. Here we have similar examples. But in the cervical spine, A P and lateral views of the cervical spine demonstrate straightening of the cervical spine with complete fusion by Syndey noted anteriorly and posteriorly at the vertebral body margins and complete fusion across the apophyseal joints. Notice that the vertebral bodies anteriorly are straightened, indicated by the black arrow another common sign that we see in ankylosing spondylitis is the dagger sign. This is best seen on the A P views of the lumbosacral spine and is caused by fusion of the spinous processes in the midline indicated by the black arrow. Again, notice the bilateral fusion of the sacroiliac joints in this patient. Finally, we come to sacroiliitis, which is an important hallmark of the of the spondyloarthropathies. Pathologically, sacroiliitis starts with inflammation which is visible on the MRI as peripheral periarticular edema with or without the presence of erosion. Patient is exhibits in the in the in the can be visible on both MRI and conventional radiography. Later in the disease, fatty metaplasia is noted on the MRI alongside the a sacroiliac joint. As we see in the right image, the x-ray demonstrates bilateral subchondral sclerosis and erosions of the sacroiliac joint. A T one weighted postcontrast. Mr of the same patient shows an irregular contour of the si joint caused by inflammation in the presence of erosions. There is enhancement in the subchondral bone and bone marrow edema, no joint effusion is present on the study. The the differential diagnosis of sacroiliitis includes osteoarthritis, which is demonstrated by bilateral subchondral sclerosis without erosions of the sacroiliac joint. These changes usually occur in the lower third of the sacroiliac joints which are the articular portion, the lower two thirds, the upper third is a fibrous joint. Therefore, it it acts differently and reacts differently and it many times fuses earlier than the lower portion. In image. Number two, we see osteitis, condensed ans ilia which presents as bilateral triangular shaped regions of sclerosis adjacent to the sacroiliac joints. Here we see later stages of sacroiliitis with complete joint ankylosis and ligamentous anxy losis of the bilateral iliolumbar ligaments, degenerative changes are noted at the bilateral hips and joints, ssss, ankylosing spondylitis can affect the appendicular skeleton as well. The hatchet sign is a circumscribed, somewhat flat erosion of the lateral dorsal aspect of the humeral head causing the humeral head to appear like a hatchet. This deformity is typical for ankylosing spondyloarthritis. The hatchet sign differs from the deformity seen in avascular necrosis where there is progressive collapse of the articular surface of the humeral head. Here we see two different patients on the left early in their disease and then several months later in the follow-up images on the right notice the flattening and complete destruction of the humeral head. This is classically seen in ankylosing spondylitis and a, I'm sorry. This is classically seen in avascular necrosis. Psoriatic arthritis falls in this group as well. The key findings that we see in psoriatic include erosions and bone proliferation predominantly in a distal distribution presenting most often as a typical pathognomonic pattern but sometimes as a confusing subtype which we will talk about in a bit clinically. Psoriatic arthritis is a peripheral type of spondyloarthritis and presents as a peripheral arthritis with or without sacroiliitis and spondylitis. It frequently is preceded by the disease, psoriasis of the skin but can occur without skin disease. In up to 20% of patients. It does not occur early in the disease but rather much later, sometimes as late as 20 years. After initial diagnosis, the hands are most frequently involved following, followed by the feet. Other locations are the spine, sacroiliac joints and less frequently the knee, elbow, ankle and shoulder. Radiographically, psoriatic arthritis demonstrates small bony erosions at the bare areas of the joint. However, distal to these areas are small regions of productive bone called whispering. They are not osteophytes. The disease tends to be asymmet asymmetric. The dis the distribution of psoriatic arthritis is as we see in the diagram, the spine and sacroiliac joints can show axial psoriatic changes in the hands and feet. The distal joints are more commonly affected than the proximal joints. As we see in both images, the tri scapha joint is commonly involved along with the pisiform joint in the feet. Opathy is predominant at the insertion of the achilles. Tendon changes like that in the hand occur at all metatarsophalangeal joints and distal interphalangeal joints. There are five subs subtypes of psoriatic arthritis because of these different patterns. The diagnosis of psoriatic arthritis can be sometimes challenging in the mall and right classification system. The subtypes include distal interphalangeal arthritis of the hands and feet. Asymmetric mono or oligo arthritis, meaning just a few random findings symmetric polyarthritis with a similar appearance to rheumatoid arthritis, spinal column involvement with spondylitis and sacroiliitis and severe arthritis mule. Here we see an example of sausage digits which are a typical appearance of dactylitis with soft tissue swelling and pencil and cup deformity. In a patient with psoriatic arthritis, notice that the metacarpophalangeal joints are not involved in rheumatoid arthritis. They usually are involved and they are involved. Early psoriatic arthritis can be progressive. If we look at image number one, we see marginal erosions indicated by the black arrow and subchondral bone proliferation indicated by the blue A arrow of the interphalangeal joint. This is a classic appearance of psoriatic arthritis. Later in image number two, these changes progress to typical pencil and cup deformity, the distribution the and bone formation make the diagnosis of rheumatoid arthritis unlikely. The marginal erosions in the absence of distal interphalangeal joint involvement in other joints, makes the diagnosis of erosive osteoarthritis unlikely as well. Although pencil and cup changes can look like the goal wing deformity in erosive arthritis. Here we see another example of pencil and cup deformity. In the image on the left, we see pencil and cup deformity of the 1st and 5th toes. In the image on the right acro osteolysis is noted with resorption of the terminal tuft of digits. Two through five erosions are noted at the metatarsophalangeal joint of the 2nd and 5th digit periostitis is another possible finding in psoriatic arthritis in this patient with psoriatic notice the subtle periostitis of the distal phx of the great toe indicated by the black arrow head. Additionally, there are small erosions of the Tufts of digits two and three on the left indicated by the white arrows. Some of the findings in psoriatic arthritis and some of the findings generally in, in the arthri of the hands and feet are very subtle. So you have to look closely and sometimes magnify, I routinely magnify hands and feet when I'm looking at them. First of all, it allows me to see detail better. And second of all, it's easy on the eyes. If you try to look at some radiographs with in in normal, without magnification, you can become very squinty eyed. By the end of the day, I will now move on to discuss the characteristics of reactive arthritis, which for many years was called Reiter's Syndrome and previously was associated with gyne coccal infection and with urethritis, arthritis and conjunctivitis. This is the way I learned it many years ago. It has been found recently that this reactive arthritis is sterile arthritis following soon after an infection in the body, usually in the geno genitourinary tract or enteric in origin. It is caused by a cross-reaction of an antigen reaction to bacteria as well as synovial tissue. Reactive arthritis is classified as a type of seronegative spondyloarthropathy. The clinical, the the the is usually transient following an infection involving one or two large joints. The classic triad consists of arthritis, conjunctivitis, and urethritis and is and cervicitis in women to help you remember the classic triad. There are two mnemonics. Can't see, can't pee and can't climb a tree. And the other one is, can't see, can't pee and I have a sore knee. Again, we have our distribution diagram and as we can see clearly, this is a disease of the foot, particularly the achilles, tendon, insertion, the midfoot and the great toe. Additionally, it can affect the sacroiliac joints, knee and ankle. Findings in the hand are less likely. So for reactive arthritis, you go to the foot for rheumatoid arthritis, you go to the hand finding findings seen later in the disease include ill defined erosions similar to psoriatic arthritis. However, typically in reactive arthritis, these erosions are at the calcaneus bone proliferation is also noted but also jus to articular osteoporosis and opathy may be seen. This disorder demonstrates uniform joint space narrowing with an asymmetric distribution. As we see in the diagram, the extra findings are that this disorder is usually triggered by a preceding infection. Swelling of the soft tissues occurs with the development of most commonly sausage toes. This patient suffered from an episode of campo bacteria, gastroenteritis. After a few weeks, clinical symptoms of arthritis developed in the image on the right. We see erosions at the base of the third proximal phalanx and at the head of the fifth proximal PHX indicated by the white arrow heads whoops. Sorry about that. I went ahead on the left. There is an erosion at the base of the third proximal PHX and lytic changes of the head of the first proximal PHX demonstrated by the yellow arrow heads based on these nonspecific imaging findings alone, it is difficult to diagnose reactive arthritis but because the patient had an enteric infection previously, it makes the diagnosis far more likely. Now we move on to one of my favorite diseases. Diffuse idiopathic skeletal hyperostosis. This is a disease of the axial skeleton that has some small peripheral findings in the past diffuse idiopathic skeletal hyperostosis also called dish was known as for SDS disease. Rez all in San Diego produce the diagnostic criteria, which has become the definitive description of this disorder. Dish is characterized by bony proliferation at tenderness and ligamentous insertions of the spine and pelvis mostly affecting the elderly. Remember it is a painful disorder, diffuse idiopathic skeletal hyperostosis presents as continuous bulky ossification along the anterior aspects of the thoracolumbar vertebra with relative preservation of the disc space. Remember, however, that because this disorder does occur in the elderly, there may already be some disc space narrowing, which has occurred prior to the development of dish because of the common finding of degenerative changes that may be seen at the intervertebral disc in elderly patients. So you don't need to have preserved intervertebral disks uh as they were in youth, these can be relatively preserved, intervertebral discs the key finding in dish are bulky masses of bone that develop anteriorly to the vertebral bodies in the lumbar spine and on the right laterally in the thoracic spine because the pulsating aorta on the left prohibits their development. The definition that must occur. The definition that this disease must occur over four contiguous levels is an arbitrary number because there were three fellows in training at the time that Reznik defined this entity. I know this to be true because I've heard it personally said by him many times using our A CDS mnemonic for the radiograph radiologic findings. The articular component demonstrates no erosions. The bones show calcification or ossification of the anterior longitudinal ligament and paraspinal connective tissues. As we see in the image on the left, these are lumpy and bumpy masses of bone opathy or whispering can be seen in the pelvis at the iliac crest ischial tuberosity and greater trocars. When we speak of the cartilage, the disc space is typically preserved unless there has been previous degenerative disc disease. Then further degeneration of the disc is halted by the fusion caused by the uh the bulky osteophytes. The distribution is throughout the lower thoracic spine and usually there is no involvement of the synovial inferior part of the sacroiliac joint. Although ossification of the ligamentous part of the sacroiliac joint can occur, which is the upper third of that joint. The extra findings are that the spine is prone to severe fracture after minor trauma in this disorder as well. The soft tissue component is that there is increased susceptibility to fractures. This should not be confused with the findings of an spine and ankylosing spondylitis. The bamboo spine, which is the hallmark of this inflammatory disorder. This is clearly seen in the right image, dam labeled bamboo spine. The syn desma Tes are vertical and are in the outer fibers of the annulus fibrosis, as we have said before, dish demonstrates bulky ossification and calcification anterior to the Antero long to ligament and the paraspinal connective tissue over at least four contiguous levels. Again, typically the discs heights are preserved, other causes of ligamentous ossification in the spine are severe osteoarthritis and less likely vitamin A toxicity and fluorosis. Here is the pelvis of another patient with dish opathy of the iliac crest ischial tuberosity and greater trochanter of the femur are clearly visible. The inferior aspect of the sacroiliac joint is normal in dish ossification of the ligaments in the upper part of the sacroiliac joint is present and clearly visualized. The cervical spine can be affected by dish as well. Typically bulky ossification and calcification is present anterior to the vertebral discs, mild atypical narrowing of the facet joints is also noted in this case, but there there is no sign of degenerative disc disease. The sagittal ct of the cervical spine on the left shows classic dish. Here is a nice example of the complications seen in ankylosing spondylitis and sometimes rarely in dish, the spine becomes rigid and then it is prone to fracture. Even after minor trivial trauma. Patient is Exts are often hyperextension injuries. The patient has minor trauma which however resulted in an unstable hyperextension fracture. With neurologic complications. I have finally come to the last disorder that we will discuss today. Gout is a relatively common disorder with very specific findings and is seen in patients who have diabetes and kidney disease gout is an inflammatory arthropathy caused by the deposition of sodium urate crystals in joints and in the periarticular soft tissues and tendons. The first metatarsophalangeal joint is most often affected classically. The diagnosis is made clinically by the level of urate in the blood and is secondarily supported by joint aspiration. Many times, patients are diagnosed with gout before they have changes in their joints. The articular changes in gout present as punched out erosions greater than five millimeters in size with an overhanging edge of new bone. Bone demineralization is normal. Also in this disease, chondrocalcinosis or osteonecrosis can also occur a joint effusion which is the earliest sign and preservation of joint space is seen. The distribution again is like in the diagram. The red circles indicate the common locations and the yellow circles, those locations that are less frequently affected. The extra findings are that gout is more commonly a disease of men and demonstrates hyperuricemia. The soft tissue findings include top five which are eccentric nodular soft tissue swelling due to crystal deposition about the joint many times. These are hyperdense on radiography because of the presence of urate crystals. Also olecranon and prepatellar bursitis may occur. Here we see radiographs which demonstrate findings of gout characteristic radiographic changes in chronic gout typically demonstrate well-defined punched out eccentric erosions with sclerotic margins in a marginal and extraarticular distribution. These erosions have the characteristic overhanging edges and can be referred to as rat bite erosions. An important characteristic of this disorder is that there is preservation of the joint space, hyperdense, periarticular soft tissue swelling because of the presence of underlying toi are noted and are patho mic for this disease. These toi are in the ligamentous structures around the joints and cause pressure erosions into the bone because of their slow growing style of proliferation. Another patient in which we see typical involvement of the first metatarsophalangeal joint with punched out lesions. The soft tissue swelling is representing a tophus. The distribution is not a common finding in gout but in this case, the result of the erosions and ligamentous injury as a as a as a soft tissue density is common in gout. Here we see typical dense soft tissue swelling surrounding the first metatarsophalangeal joints in a bilateral distribution. This is indicated by the Black Arrow. We also see the extraarticular erosions at the medial side of the distal metatarsal joint which have sclerotic margins. They are most notably seen on the right side A A AAA ques that has come into use for the diagnosis of gout is called dual CT. Here we see the same patient with gout showing the urate crystal depositions in green. In this 3d reconstruction, the crystal depositions are color coated green and can be seen surrounding the metatarsophalangeal joints and at the insertion of the right achilles tendon indicated by the yellow arrow. The green pixels in the nail bed of the digits one and five on the left are artifacts caused by thickening in the keratin of the nails. Dual anergy CT is a noninvasive method of urate crystal detection that can make joint aspiration unnecessary. This technique simultaneously scans the subject at two different energy levels because urate crystals show different attenuation at these energy levels. The crystals are easily identified with high accuracy. Here we have another case with typical gouty PFI and juxta-articular erosions on the plane film. The dual CT image on the right shows gouty attenuation in the first metatarsophalangeal joint and second metatarsophalangeal joint as well as interphalangeal joint of the third digit. Dual anergy CT is useful for the diagnosis when findings are not so typical. It is also very useful to show the extent of the disease. In this case, a bone tumor was suspected. These are some findings that could support the diagnosis of an osteosarcoma or chondrosarcoma. However, this was proven to be gout by dual anergy CT. Here we see the corresponding dual anergy CT three dimensional reconstruction of the previous patient. The large mass about the right first metatarsophalangeal joint of the great toe is gouty in nature is is a is AAA ra ra find in gout are punched out lesions with overhanging edges as seen here indicated the arrow. The is the border of the of the of the erosions. The in gout may be sclerotic because of the slow progression of the disorder. This is the final case for us today. It is somewhat difficult. We see small, bilateral erosions of the proximal interphalangeal joints on both sides of the joint. The arrowheads demonstrate these erosions. These erosions are more juxta-articular than is usually seen in gout. However, this is a proven case based on the distribution rheumatoid arthritis and psoriatic arthritis would have been an option as well. However, then the erosions would have been more marginally located in the bare areas of the joint not covered in cartilage. Additionally, the metacarpophalangeal joints are spared making the diagnosis of rheumatoid arthritis even less likely. What I've tried to do in this talk is to share with you the radiographic findings in various arthritis. I hope you have found this helpful. In part three, we will discuss CPPD crystal deposition disease, scleroderma, sle sarcoid, neuropathic arthro arthropathy, hemophilia CRMO and Sao syndrome. After part three, I will present an in-depth lecture on differentiating radiographically, CPPD hydroxyapatite deposition disease and gout from one another. Soon there will be case presentation, discussions of all the arthritic conditions covered in this series. Thanks again for your time and hope to see you next week. Maria. Are you still there? Yes. Um There's no questions in the chat currently. Would you like me to ask people again if they'd like to ask some? That's OK. That, yeah, ask them again if they'd like to ask. Absolutely not. This was not prerecorded. This is recorded now, but I don't prerecord. This is the way I lecture. Uh I take my lecture training from Don Resnick who records. Uh Similarly, is there an age range for juvenile rheumatoid arthritis, childhood, childhood, and early adolescence for juvenile rheumatoid arthritis. How did I raise funds for the Ukraine? I organized an, an a, a paid webinar that was, that was done by Don Resnik. He did eight hours of lecture and he was able to, we were able to register 198 participants with 159 participating in the, in the conference because of this and because our costs were very low, we only have to pay a little honorarium to doctor Renick. We were able to rate I think range raise about €21,500. I'm glad you all. And thank you for your comment on my voice. I really appreciate that. It's something I've worked on most of my life. Chris, this is I, I'm glad that you're attending these lectures. Uh They will continue, I will continue doing them weekly and we will send out uh information regularly as we do. We'll also send out information also to you. But remember until otherwise stated by me, these lectures will continue every Sunday at noon, Chris, I don't know anything about interventional radiology. I'm a plain film radiologist. I'm old fashioned and I don't do any interventional and I only have done a little bit of MS K interventional in my life. So you have to talk to interventionalist about that. Thank you, Samantha. I'm curious to know how many people attended. I can't see a count. Do you know? Yeah, I can tell you. So, um actually the number will be higher than this, but it says like 19 are currently in the talk that doesn't count for people who've left could probably give you the exact figure when I take a look at the stats after the talks ended. Ok. So I'll give that to you in the email as well. Um So yeah, I'll send you the link to the recording and also the number that I have attended. Super. Thank you so much, James Mohammed, Samantha. Thank you for your time. I'm glad you found it useful and we will continue with these Chris. Where are you from? Are you, are you American? Are you European? Because a lot of these people I know where they're from, but I don't know where you're from. Hi, Tomas. Glad you enjoyed it. Tomas. Uh huh. So you're a Cambridge guy. Are you a, are you a resident or you a, the registrar? I have to say he's gonna tell me he's a, he's a, he's gonna tell me he's a, he's a consultant which is perfectly fine. You can address, you can attend to appreciate it. Chris S OS T One registrar. You need these lectures. These are for you guys. These are for you guys. I do them for my guys at King's all the time. And, uh, no, these are for you guys. If your other ST ones want to attend, they can, and if they're interested, I can repeat the lecture for them. I can repeat the whole series. I don't mind doing it. It's easy. Ok, guys, it's time for me to wrap up for the day and you have things to do since it's sunny out in, in London. I'm going for a walk, take care and hope to see you next week.