2-17-10 Quiz Case Answer: Erosive Osteoarthritis

Most frequently occurs in postmenopausal females. Predilection to involve DIP and PIP joints of the hands. May be mistaken for rheumatoid and psoriatic arthritis.

Radiographic features:

• Severe degenerative changes with osteophytes and subchondral sclerosis at the DIP and PIP joints of the fingers, and the CMC and IP joints of the thumb


• Central erosions due to destruction of articular cartilage are seen with relative sparing of the joint margins produce "seagull" or "gull-wing" sign associated with this arthrosis. Seen at the 4th DIP joint in this example.

"Quiz" case

This case has a "classic" appearance. What's your Dx?

Imaging quizzes

Here are a couple of links to recent NEJM issues that you might find a challenge.
http://image-challenge.nejm.org/?ci=01142010
http://image-challenge.nejm.org/?ci=12242009#12172009

Ankle and Foot links

I just finished preparing a presentation for the podiatrists at DMC Surg Hospital. These links will take to journal articles I found mast useful.


http://radiographics.rsna.org/content/21/6/1425.long

http://radiology.rsna.org/cgi/content/long/184/2/507

http://radiology.rsna.org/cgi/content/long/184/2/499

http://radiographics.rsna.org/cgi/content/long/11/3/415

http://radiographics.rsna.org/content/19/5/1143.full?sid=bc018e98-d433-4d5a-b04d-ab2c6b1bccc4b04d-ab2c6b1bccc4

http://radiographics.rsna.org/content/24/2/343.full?sid=bc018e98-d433-4d5a-b04d-ab2c6b1bccc4b04d-ab2c6b1bccc4

http://radiology.rsnajnls.org/cgi/content/full/218/1/278

http://radiographics.rsnajnls.org/cgi/content/figsonly/27/6/1723

http://radiology.rsnajnls.org/cgi/reprint/171/3/755.pdf

http://radiographics.rsna.org/content/18/6/1481.abstract

Answer to "What would you do?"

I think there are two options. 1) Ultrasound and 2) a pneumoarthrogram with room air. Ultrasound's major drawback is limited assessment of a labral tear. A pneumoarthrogram is capable of delineating rotator cuff pathology, long head biceps tendinopathy, and labral pathology. I elected to do a pneumoarthrogram.

The top image is a paracoronal reformatted CT. The lower image is a conventional radiograph. Both are post injection of 10 cc room air. Both images reveal air in the SA-SD bursa,

Dx: Full thickness rotator cuff tear

What would you do?

Today a patient presented for CT arthrography of his shoulder. He had a truly severe contrast reaction previously and would not permit any injection of contrast. MR is not an option, as he has a cardiac pacemaker. His referring MD wants the labrum and capsular attachments assessed in addition to the usual request to assess for a rotator cuff tear. How would you proceed?

I'll show you how I approached this situation in a few days. Please share your thoughts now.

Femoroacetabular Impingement Assessment

Femoroacetabular impingement (You've heard the terms cam and pincer) is a "hot topic" in hip MR. In reviewing a case last week, Dr. Luo helped me find this link to an informative powerpoint review from the Univ of FL that has some great diagrams on how to determine alpha and lateral center edge angles.http://houndnotes.com/Documents/Femoroacetabular%20Impingement.ppt#256,1,Femoroacetabular Impingement

Medial Patellar Dislocation

http://www.springerlink.com/content/r23348472032m820/fulltext.pdf?page=1

This link takes you to a recent case report from Skeletal Radiology. Back in 1991 I coauthored the case report first describing this entity and associated it with prior lateral release reconstructive surgery for patellar instability. The medial dislocation in this recent report occurred in a patient with no prior surgery. Trochlear dysplasia now appears to be the most important predisposing factor in this rare disorder. The current report nicely demonstrates the roles MR and US played in making the diagnosis.

NEJM Image Quiz

Try this link out as a "instant unknown".http://image-challenge.nejm.org/?ssource=rthome#12252008

Bone Sarcoid

Bone involvement by sarcoid most commonly involves the extremities. Dr. Suwan gave me this interesting case.

A 32 yr old African American female with history of breast cancer and pulmonary sarcoidosis. Staging work-up included a bone scan.

Bone scan images showing multiple foci of increased radioactivity in the skull.
Given the history of breast cancer, the lesions were called metastasis.

CT Shows osteolytic lesions in the skull, thought to be metastasis.


Contrast enhanced MR images demonstrating multiple enhancing skull lesions.


These skull lesions were stable on 6 months follow up CT and bone scan. A direct biopsy was performed revealing non-caseating granulomas consistent with sarcoidosis. No evidence of metastasis.

Thank you, Dr. Suwan

Here is a concise link from the Univ of Washington about bone sarcoid you may find helpful. http://uwmsk.org/residentprojects/sarcoid.html

Images of Conditions That May Be Associated with "Noisy Hips" Part 3

Trochanteric Bursitis
Left Hip

MyPacs.net Case 1758632

Images of Conditions That May Be Associated with "Noisy Hips" Part 2

Loose Body

Radiographics 2oo2 22,1223-1246

Images of Conditions That May Be Associated with "Noisy Hips"

Iliopsoas Bursitis

Axial

Sagittal

The Clicking or Snapping Hip - "Coxa Saltans"

I had heard of "coxa vara", "coxa valga", and "coxa magna" - but when I received a request with the history of "coxa saltans" I was stumped. So what is "coxa saltans".

Check this link http://www.sportsinjurybulletin.com/archive/clicking-hip.html

Here is a video link demonstrating an "external snapping hip" http://www.youtube.com/watch?v=S9ZEHlLilTM

I am familiar with the "snapping hip". "Coxa saltans" is a term that I had not encountered before. I have performed sonography on snapping IT bands (external snapping) and ilioposas tendons (internal snapping), but am unable upload the clips. Ask me to pull them up sometime at the office.

Knee MRI Oblique Views

I have resisted "dumping" a coronal oblique sequence from my standard protocol. I feel that techs can perform this sequence more reliably than the sagittal oblique. Here is an article that reports either oblique plane is effective in increasing diagnostic accuracy of ACL injury. I'm going to stick with the coronal oblique. (Which oblique plane is more helpful in diadnosing ACL tear? Clin Radiol 2009:64(March):291-297)