Lateral hindfoot impingement MRI Ankle

MRI ANKLE

MRI coronal STIR section of ankle joint shows degenerative subchondral bone marrow oedema involving articular surface of lateral malleolus of fibula, lateral process of talus and calcaneum, loss of joint space, degenerative sub chondral cystic geodes in the lateral process of talus at subtalar joint without joint effusion.

The bone marrow edema in calcaneum is confined to the subjacent articulating surface and characteristically not present all along the cortex around the margins of the sinus tarsi on sagittal STIR. Possibility of lateral hindfoot impingement suggested.

If bone marrow edema in calcaneum is present all along the cortex around the margins of the sinus tarsi, this would not be characteristic and would instead suggest the different diagnosis, that of sinus tarsi syndrome.

There is associated diffuse thickening of anterior talo fibular ligament.

Osseous findings of lateral hindfoot impingement include degenerative changes like subchondral sclerosis, subcortical bone marrow edema at specific locations at the talus, calcaneus and or fibula, sub chondral cystic geodes in advanced cases.

The incidence of calcaneofibular impingement is somewhat lower than talocalcaneal impingement, with calcaneofibular impingement present almost exclusively in individuals shows changes of talocalcaneal impingement, suggesting that the talocalcaneal osseous changes occur before the calcaneofibular changes.

Dural ectasia spine MRI

 

Sagittal MR images of spine showing multiple contiguous widening of CSF space posterior to the cord in thoracolumbar region, associated posterior scalloping of the vertebral bodies, widening of caliber of the bony spinal canal, hypo plastic posterior elements. 

Axial T2 images, STIR coronal images showing multiple lateral meningoceles in thoracolumbar region with enlarged neural foramen.

Spinal cord displaced anteriorly, flattened, compressed against anterior confines of anterior bony spinal canal.

Imaging diagnosis: dural ectasia.

Dural ectasia is widening of the dural sac, associated with herniation of nerve root sleeves out of foramina. Scalloping of the posterior vertebral body, thinning of cortex of pedicles and laminae, widening of neural foramina expected to prolonged pressure effect from the dural sac containing CSF.

Dural ectasia is very well-known with  Marfan syndrome however can also be associated with other inherited connective tissue disorders, including Ehlers-Danlos syndrome and Loeys-Dietz syndrome, type 1 neurofibromatosis, ankylosing spondylitis, Lehman syndrome.

Dural ectasia can also be associated with trauma, scoliosis.

May be asymptomatic, may present with back pain, headaches, radicular pain, leg weakness or urinary incontinence.

Little finger FDP tendon, A2 pulley injury

 MRI LITTLE FINGER

SAGITTAL T2 5TH FINGER

SAGITTAL T2 5TH FINGER

AXIAL T2 A2 PULLEY AT MID PORTION OF PROXIMAL PHALYNX 5TH FINGER

This MRI study of litter finger shows: 

Full-thickness flexor digitorum profundus, FDP tendon tear, Zone II injury. 

There is associated retraction of the proximal end, spring coiled, the torn end of proximal stump is at the level of metacarpo phalangeal joint, with a gap of 36 mm. Length of the distal stump measuring approximately 20 mm from its insertion on to the base of distal phalanx. Quality of both torn ends of the tendon is good, sharp without abnormal fraying or degeneration.

Associated A2 pulley injury at the level of midportion of proximal phalanx with approximately 4 mm bowstringing of FDS. 

A3 pulley intact. 

No associated bony avulsion.

No associated joint subluxation.

No associated volar plate injury.

No associated collateral ligaments tear.

Graefe Usher syndrome MRI

MRI brain shows:

Thinning of bony calvarium with inner table scalloping, cerebral cortical atrophy marked in bilateral frontal and temporal lobes with sub dural hygroma iso intense to Csf.

Diffuse cerebellar atrophy with widening of CSF space in posterior fossa overlying bilateral cerebral convexity, CP angle cisterns isointense to CSF.

Bilateral symmetric widening of bilateral internal auditory canal, Meckel's cave.

Widened empty sella.

Associated bilateral optic nerve atrophy, increased prominence of sub arachnoid spaces around bilateral optic nerves.

Imaging diagnosis: Graefe-Usher syndrome.

Usher syndrome is characterized by partial or total hearing loss, vision loss that worsens over time. The hearing loss is sensorineural, caused by abnormalities of the inner ear. 

A rare, congenital, autosomal recessive disorder characterized by retinitis pigmentosa and sensorineural hearing loss, first described by Von Graefe in 1858.

Mazabraud's syndrome

A young patient presented with mild left thigh pain with swelling.

MRI with Xray correlation shows:

1. Mixed signal intensity lobulated lesion involving metadiaphysis of left proximal femur, part of adjacent epiphysis. Lesion is slightly expansile with groundglass matrix in the region of metaphysis on x-ray. No periosteal reaction on x-ray as well as MRI. No obvious pathological fracture. No abnormal adjacent bone marrow oedema on STIR.

Imaging wise possible diagnosis: Fibrous dysplasia.

2. Multiple T2 hyperintense lobulated space-occupying lesions involving muscles of left adductor compartment. The largest lesion measuring approximately 76 mm x 40 mm at a distance of 20 cm from greater trochanter on medial aspect of femur at 7 o’clock position on axial section.

Imaging wise possible diagnosis: intramuscular myxomas.

Intramuscular myxomas + left femoral fibrous dysplasia = Mazabraud's syndrome.

AVN collapse prediction by Modified Kerboul method

MRI study of hip joints shows:

Avascular necrosis involving bilateral capital femoral epiphysis.

Modified Kerboul method is used for prediction of collapse in femoral head osteonecrosis by volumetric analysis on MRI. 

HOW IS IT CALCULATED ?

The arc of the femoral surface involved by necrosis measured by angles on midcoronal  (A) and midsagittal image (B) and then modified Kerboul angle (A+B) calculated by the sum of the two angles for both the joints.
Right side the angle is (129+169) =298, grade 3 lesion.

Left side the angle is (100+146) =246, grade 3 lesion. 

GRADING

On the basis of combined angle, hips are classified into four categories: 

Grade 1 (<200 degrees), 

Grade 2 (200 degrees to 249 degrees), 

Grade 3 (250 degrees to 299 degrees), and 

Grade 4 (>/=300 degrees).

BACKGROUND 

The hypothesis is that the combined necrotic angle measurement from magnetic resonance imaging scans predicts the subsequent risk of collapse in hips with femoral head necrosis.

With use of the modified method of Kerboul et al., Angle calculated by sum of the arc of the femoral surface involved by necrosis on a midcoronal as well as a midsagittal magnetic resonance image calculated on MRI, rather than on an anteroposterior and a lateral radiograph is far more accurate than on X-ray. 

Physeal bony bar MRI

History of trauma 5 years ago. Operated with nailing for fracture of distal end of radius. 

Now presented with swelling and pain in the region of ulnar styloid process. 

MRI WRIST

  

Protocol:

 

Multi planner multi echo MRI study has been performed. Sequences planned are sagittal, Coronal and Axial FSE T1W images, sagittal, Coronal and Axial FSE T2W images, sagittal, Coronal STIR images.

 

This MRI study of wrist joint with x-ray correlation shows:

Clinical marker on skin.

Under growth of distal end of radius relative to ulna due to bony physeal bar, leading to positive ulnar variance of measuring approximately 15 mm, partial distal radio ulnar subluxation, leading to increased prominence of ulnar styloid process.

Abnormal abrupt angulation of flexor carpi ulnaris tendon over the prominent ulnar styloid process leading to changes of tendinosis owing to ongoing friction in the flexor carpi ulnaris tendon against prominent ulnar styloid process.

The bony physeal bar is involving midportion of growth plate of distal radius. Total width of growth plate measuring approximately 32 mm on coronal with bony physeal bar measuring approximately 11 mm in width in the region of linear track with low signal intensity foci of previous intra medullary nailing for distal end of radius. Physeal bar is involving nearly 30% of the total growth plate. Radial one third and ulnar one third of the growth plate intact.

There is 11° radial tilt on coronal and 23° dorsal tilt on sagittal of distal articular surface of radius.

V-shaped” groove involving distal articular surface of radius, proximal partial herniation of proximal carpal row in the distal radial groove.

Dorsal tilt of lunate bone measuring approximately 40° with dorsal shift of capitate axis.

No signs of lunate avascular necrosis.

 

Impression:

 

Bony physeal bar involving distal radius.

Extramedullary focal fat - fluid level, a specific sign of osteomyelitis

 A 14 yo male with pain in calcaneum since 1months. 

MRI foot for calcaneum with CT correlation shows:

Heterogeneous signal abnormality diffusely involving calcaneum with multiple low signal intensity foci diffusely scattered in calcaneum on T1-weighted images which are hyperintense on STIR. Rest of the intervening calcaneum medulla shows faint high signal on STIR.

No obvious density abnormality on CT. No obvious sclerotic or lytic lesion. No obvious cortical destruction or sclerosis.

There is a focal lentiform shaped parosteal collection measuring approximately 26 mm in height and 6 mm in thickness medially at 2 o’clock position and 4 mm in thickness laterally on plantar aspect at 7 o’clock position on axial section. 

There is fat – fluid level within this collection, focal fat in the supernatant portion of this collection which is hyperintense on T1-weighted images with complete signal suppression on STIR, this portion follows classical fat density on CT. 

There is an associated diffuse oedema involving muscles of plantar aspect of foot especially quadratus plantae muscle, medial as well as lateral teno synovitis.

This finding suggestive of extramedullary focal fat - fluid level which is a pathognomonic sign of acute to subacute osteomyelitis.

Findings were discussed with the referring physician before finalizing the report, who added that there is elevation of inflammatory markers in lab reports and the suspicion of osteomyelitis clinically as well, with a feedback of significant improvement clinically after IV antibiotics. 

Take home note is during MSK MRI interpretation, a bone marrow signal abnormality with an associated focal periosteal extra medullary fat – fluid level, osteomyelitis should be in the list of your differential diagnosis.

References: 

1. Extra-osseous fat fluid level: a specific sign for osteomyelitis. Kumar J, Bandhu S, Kumar A, Alam S. Skeletal Radiol. 2007 Jun;36 Suppl 1:S101-4. doi: 10.1007/s00256-006-0194-1. Epub 2006 Sep 19.

2. Intramedullary and extramedullary fat globules on magnetic resonance imaging as a diagnostic sign for osteomyelitis. Davies AM, Hughes DE, Grimer RJ. Eur Radiol. 2005 Oct;15(10):2194-9. doi: 10.1007/s00330-005-2771-4. Epub 2005 Apr 29.

Rice bodies in subdeltoid bursa MRI

This MRI shoulder joint shows fluid distended sub deltoid bursa with numerous typical rice bodies.

Differentials given are rheumatoid arthritis and tuberculosis.

Suggested CBC, ESR, C-reactive protein, RA, anti-CCP in view of RA and joint fluid aspiration for culture and sensitivity in view of Tubercular Arthritis.

Rice body effusion or rice bodies in joint effusion or bursa represents an uncommon, nonspecific, inflammatory process, where multiple small loose intra-articular bodies resembling polished grains of white rice. 

They are typically seen with Rheumatoid arthritis, Tuberculosis. However it is also known to occur with juvenile arthritis, seronegative arthritis, osteoarthritis, septic joint, trauma and chronic bursitis.

They are almost of same size, hypointense on T1 as well as T2 weighted images without enhancement on post contrast, the shape is very typical with tapering ends resembling rice grains.

They should be differentiated from synovial chondromatosis where loose bodies are relatively larger in size, round to ovoid in shape and impart slightly high signal on T2-weighted images.

Elbow Neuropathic Arthropathy MRI

A middle aged male with unilateral left elbow pain, deformity, progressive swelling, restricted movement.

This MRI elbow joint shows:

Joint effusion, osteolysis involving proximal end of radius as well as ulna, articulating surface of capitulum as well as trochlea. Marked synovial thickening with frond like projections. 

Considering unilateral involvement possibility of infectious aetiology like Tubercular arthritis was one possibility would have been dealt with joint fluid aspiration for culture and sensitivity.

However, MRI CERVICAL SPINE screening was done with suspicion of neuropathic arthropathy which surprisingly revealed cervical cord syrinx.

Here is MRI CERVICAL SPINE of same patient which shows moderate cervical cord syrinx supporting neuropathic arthropathy.

So take home note is it is worthy to suspect and rule out conditions like this whenever applicable and possible as it considerably changes the line of management.