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.

Steinstrasse CT KUB

This non-contrast CT study of abdomen for KUB of patient with left abdominal pain shows a dense large calculus in Urinary bladder which is in continuity with ribbon like column of multiple calculi in left ureter. 

Retrograde history taking unfurled that the patient had undergone ESWL one month ago.

Imaging diagnosis: Steinstrasse.

Steinstrasse is the German term which means "stone street", used to describe a possible complication of extracorporeal shock wave lithotripsy (ESWL) for urinary tract calculi, wherein a column of stone fragments forms that blocks the ureter.

Steinstrasse usually develops couple of months after ESWL and the most common site is the distal ureter.

The refined extracorporeal shock wave lithotripsy technique has reduced the incidence of steinstrasse from 20% to 6% 2.

Usually, the stone fragments pass spontaneously, but in about 25% of patients, retrograde stenting may be required. SOS more complex interventions such as stone flushing, ureteral dilatation, or long-term ureteral stenting may be required.

Vitamin C deficiency mimicking inflammatory bone disease MRI hip

A 15 years old school goer presented with on and off bilateral hip pain, restricted hip joint movement, associated backache. 

MRI bilateral hip joint shows abnormal bone marrow edema involving bilateral acetabulum and subchondral portion of right sacral ala. Associated mild left hip joint effusion.

Imaging finding were suggestive of either inflammatory bone disease or multifocal osteitis. However the possibility of nutritional cause like Vit C or D deficiency was kept during discussion with the referring physician. Accordingly, getting the lab investigation done, was assured by refereeing doctor.

Patient's CBC, ESR, C-reactive protein was normal, RA factor was negative. Vitamin and mineral status showed normal zinc, folate and vitamin B6 levels. The vitamin C turned out strikingly low at 5 μmol/L (normal range 23–114 μmol/L) and vitamin D 25-OH at 12.2 ng/mL (normal > 30 ng/mL).

Treatment was already initiated by refereeing doctor with ascorbic acid, cholecalciferol, and liquid meal supplements keeping the diagnosis of scurvy on the basis of severely low vitamin C levels. 

The crucial message from this case is considering the nutritional cause for nonspecific bone marrow edema in MSK imaging is mandatory rather than confining our diagnosis between infective, inflammatory and neoplastic etiology all the time as in our case the treatable cause like Vitamin C deficiency was mimicking the inflammatory bone disease. 

Morel-Lavallée lesion MRI

Clinically RTA, run over by tractor.

This MRI study shows a focal well defined lentiform shaped subcutaneous collection on medial aspect of knee joint superficial to the superficial fascia. Collection is clear, hypo intense on T1-weighted images without any septations or loculations. No obvious high signal intensity methaemoglobin staining on T1-weighted images to suggest any frank haematoma.

Morel-Lavallée lesion

These are focal well defined lentiform shaped subcutaneous serous collections commonly encountered during MRI knee joint in the setting of severe trauma. However these lesions are typically described in thigh as a well defined collection overlying the greater trochanter of the femur and the tensor facia lata. 

These are actually localized haemolymphatic collections secondary to closed degloving injuries, where the skin and subcutaneous fatty tissue abruptly separate from the underlying fascia owing to trauma. The potential space thus created superficial to the superficial fascia is filled by serous fluid, some times frank blood. Similar collection secondary to similar biomechanical forces are described in lumbar region and over the scapula as well. 

The accumulated collection usually needs nothing to be done, resolves spontaneously. However may persist longer if it gets organized and encapsulated. The conservative management is with compression bandage. Surgical drainage may be sufficient for larger collection. However, the capsule may need to be resected to prevent recurrence if it is long standing and encapsulated collection with thick organized wall. 

Osteochondrosis of Superior Pole of Patella

Clinically young male patient with athletic background complaining of typical unilateral anterior knee pain. Marked tenderness at the superior pole of patella.

This MRI study of knee joint shows abnormal irregularity, fragmentation with sclerosis involving superior pole of patella. An associated thickening of quadriceps tendon. 

Knee joint effusion.

Imaging findings consistent with osteochondrosis of patella at superior pole.

Osteochondrosis of the superior pole of the patella

Osteochondroses are the heterogeneous group of injuries to the epiphyses and apophyses of children or adolescents, are actually osteonecrosis owing to repetitive microtrauma and avulsion injuries at tendinous insertions. Imaging wise characterized by bone fragmentation and sclerosis.

There are two well-known such syndromes associated with knee joint, one is Osgood-Schlatter disease, an avulsion of the tibial tuberosity and another is Sinding-Larsen-Johansson disease, a chronic avulsion injury involving lower pole of the patella at the insertion of patellar tendon.

The less well described osteochondrosis at the superior pole of patella appears secondary to similar mechanism associated with quadriceps tendon insertion, a rare cause of anterior knee pain in children between 5 and 10 years of age, usually single knee is affected but bilateral cases have also been reported.

Excessive lateral pressure syndrome MRI

This MRI Axial STIR sections of knee show clinical marker on skin on anteromedial aspect of knee joint. There is patellar tilt, articulating surface of patella facing medially, abnormal thickening of lateral patellar retinaculum and patellofemoral ligament. Associated bone marrow oedema involving lateral margin of lateral articulating facet of patella.

Imaging findings consistent with clinical diagnosis of Excessive lateral pressure syndrome.

Lateral Patellar Compression Syndrome

Synonym : Excessive lateral pressure syndrome, ELPS

This is another common cause of anterior knee pain.

The improper tracking of the patella in the trochlear groove generally caused by imbalance between medial and lateral dynamic stabilizers of knee, the tight lateral retinaculum restricting the patellar mobility with excessive lateral tilt of patella causing friction between lateral articulating facet of patella with lateral trochlea of femur.

Typically affects adults, patient presents with pain on compression of the patella, lateral facet tenderness. Condition is aggravated physical activity.

This is mainly a clinical diagnosis. However, lateral tilt of patella on axial sections of MRI or sunrise knee radiographs, patella facing medially without lateral translation should be depicted meticulously which is very commonly overlooked during MRI interpretation. Furthermore, abnormal thickening and shortening of lateral patellar retinaculum and lateral patellofemoral ligament could be appreciated on MRI. Nonetheless, the important ancillary findings on MRI are subchondral bone marrow oedema, cystic geodes involving lateral articulating facet of patella and adjacent lateral femoral trochlea facing the patella. The patellofemoral angle is calculated on axial sections, the medial opening of the angle, that is demonstration of angle more than 8° can support the diagnosis of ELPS.

Treatment is mainly conservative with physiotherapy focusing on quadriceps stretching and strengthening. Operative lateral retinaculum release is reserved for refractory cases. 

Discoid Meniscus

This MRI study of knee joint depicts discoid lateral meniscus.

No obvious associated meniscal tear or para meniscal cyst.

Discoid meniscus

This is a congenital condition and is bilateral in about 50% of the cases. Usually encountered as an incidental finding on MRI examination in about 5% of the cases, typically affecting lateral meniscus. Discoid medial meniscus is very rare.

The pathology behind  this discoid shape is loss of normal orientation of collagen fibres of meniscus.

Frequently this is an asymptomatic condition however the discoid meniscus has propensity for pressure, wear and tear leading early cystic degeneration, meniscal tear and para meniscal cyst formation. In such cases patient may present with knee pain with or without locking. 

MRI is the investigation of choice. 

The width of the body of meniscus, if 15 mm or more on coronal section is diagnostic of discoid meniscus. The body of the lateral meniscus is normally has bowtie configuration on sagittal section and seen only on two consecutive slices. If the meniscal body is seen on three or more consecutive slices while scrolling the sagittal sections, instead of normal bowtie tie should alarm of discoid morphology. 

The observation is usually managed conservatively if patient is not symptomatic. 

Partial or total resection is the option kept in front of patient if accompanied with complications like tear.