Archive | March, 2013

Kidney fracture with active extravasation…

March 31, 2013

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This patient came in shortly after a high speed motor-vehicle collision.  Here is the patient’s CT abdomen with IV contrast:

Kidney fx 3Kidney Fx 2Kidney fx 1

This is an interesting CT as it demonstrates “active extravasation” of IV contrast.  The patient has a large left kidney fracture.  You can see a hematoma surrounding the area where you would expect the kidney.  In that hematoma there is a mix of low attenuation material and high attenuation material.  Both of these represent blood; the high attenuation is contrast material that leaking into the hematoma (some of the high attenuation includes perfusing kidney fragments but most of it is extravasating contrast).  The low attenuation is blood that collected before IV contrast administration.

Practically speaking, this means that there is active bleeding into this hematoma.  This is BAD and represents a large amount of bleeding that needs to be stopped.  The patient was actually relatively stable and was taken to interventional radiology where the offending lesion was embolized.

Author:  Russell Jones, MD

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Lunate dislocation

March 28, 2013

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This is an image provided by one of our UC Davis resident physicians:

Lunate dislocation

Great example of a lunate dislocation!

The key portion of the film above is the half-moon shaped bone (Lunate) which is dislocated in the palmar direction and has a “spilled teacup” appearance (it is rotated from its normal position with the concave portion of the bone facing the distal fingers).

Lunate dislocation

The AP view on this patient is also interesting.  It shows a “Piece of pie” sign, also frequently found with lunate dislocation.  This is an abnormal triangular hyperdensity seen in the lunate on the AP projection (can also be seen in perilunate dislocation).

Lunate dislocation 2

The distinguishing feature of this radiograph to differentiate between perilunate and lunate dislocation is the alignment on the lateral projection.  The capitate and distal radius are still aligned, the lunate is dislocated.  In a perilunate dislocation the lunate will not have a “spilled teacup” rotation and the capitate will be dorsally displaced off the alignment of the distal radius.  An example of a perilunate dislocation:

PL Dislocation 2

Tip:  on lateral wrist xrays, always draw a line through the distal radius, lunate, and capitate.  It should look like an apple sitting in a teacup on a saucer.

Author:  Russell Jones, M.D.

Image Contributor:  Dane Stevenson, M.D.

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Rare cause of intracranial hemorrhage…

March 25, 2013

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This gentleman presented to the ED with headache that began several days prior.  He has a history of disseminated coccidioidomycosis:

IVH Coccidio 1

Disseminated Coccidioidomycosis  (DC) is rarely associated with intracerebral hemorrhage.  Not something we will see everyday!

Here is a brief discussion from the American Journal of Neuroradiology about two cases of fatal intracerebral hemorrhage from DC:

Coccidiomycosis ICH

Some highlights:

    • Coccidioides immitus resides in the topsoil of the Southwestern United States.  There are 60-80,000 new cases of coccidioidomycosis every year with disseminated disease occuring in less than 1% of the population.
    • Vasculitis may occur and usually causes ischemic CNS events but can lead to hemorrhage as well
    • Two case reports are discussed.  A 74-year-old male on chemotherapy for Waldenstrom’s macroglobinemia who had blood culture positive Coccidioidomycosis and developed signs of aphasia, confusion.  He ended up having a CT showing large parenchymal and subarachnoid hemorrhage  with a distal left middle cerebral artery aneurysm.  Second case was a 33-year-old male with a history of coccidioidal meningitis diagnosed a year earlier.  He came in with worsening headache and MR showed enlarging prepontine lesion with subtle enhancement.  He died suddenly and on autopsy had subarachnoid hemorrhage.  Numerus necrotic spherules of Coccidioides immitis were found in perivascular spaces and his basilar artery had full-thickness granulomatous changes with necrosis through the vascular wall.

Author:  Russell Jones, M.D.

References:

1.  Erly WK, Labadie E, Williams PL, Lee DM, Carmody RF, Seeger JF.  Disseminated Coccidioidomycocsis Complicated by Vasculitis:  A Cause of Fatal Subarachnoid Hemorrhage in Two Cases.  Am J Neuroradiol 20: 1605-1608, October 1999.

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WWWTP #6 Answer…

March 21, 2013

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This chest xray was posted several days ago:

RML PNA, high ETT 1

What’s wrong with this picture?

1.  There is an endotracheal tube in the upper trachea, it needs to be advanced!

The other finding on this xray is a right middle lobe pneumonia.  At first this may appear to be a pleural effusion due to the relatively linear appearance to the upper edge of the infiltrate.  However this is a supine film and the diaphragm can be easily seen on the right side.  Effusions, unless loculated, will layer posteriorly in a supine film and the entire lung space will look more radio opaque than the opposing lung.  The fact that the diaphragm can be seen indicates the infiltrate doesn’t come into contact with the diaphragm (see prior post describing “silhouette” phenomena).  Thus, this is a right middle lobe infiltrate.

Author:  Russell Jones, M.D.

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WWWTP #6? (What’s Wrong With This Picture?)

March 18, 2013

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What is wrong with this picture?

RML PNA, high ETT 1

 

Stay tuned for the answer.

Author:  Russell Jones, MD

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Osteochondroma

March 15, 2013

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This person presented to the ED with pain in the legs after an acute trauma.  Here are his tibia/fibula views:

Osteochondroma 2Osteochondroma 1

There is no fracture or dislocation.  However, on the proximal fibula you can see a mass…what is that?

This is an example of an osteochondroma.  Osteochondromas are benign tumors of the growth plate that account for roughly 10-15% of all bone tumors.  They are a common incidental finding and occur mostly on the lower extremity.  Less frequently they can be seen on an upper extremity, and uncommonly on the spine.  Osteochondromas very rarely (<1%) transform to malignant lesions.

A great summary of osteochondromas can be found at Radiopaedia.org.  Their plain film appearance is described as:

“An osteochondroma can be either sessile or pedunculated, and is seen in the metaphyseal region typically projecting away from the epiphysis. There is often associated broadening of the metaphysis from which it arises. The cartilage cap is variable in appearance. It may be thin and difficult to identify, or thick with rings and arcs calcification and irregular subchondral bone.

New cortical irregularity or continued growth after skeletal maturity has been reached, as well as frankly aggressive features (e.g. bony destruction, large soft tissue component, metastases) are all worrying for malignant transformation.”

Author:  Russell Jones, M.D.

References

1.  Niknejad MT, Gaillard F, et al.  Osteochondroma.  http://radiopaedia.org/articles/osteochondroma

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Imaging for acetabular fractures…

March 10, 2013

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This gentleman was in a trauma and sustained an acetabular fracture.  Here is a standard AP pelvis, “Judet” view, CT with bone windows, and a CT 3-dimensional reconstruction image.  On the plain films you can see contrast in the bladder, this is residual from a urogram looking for bladder injury (no injury identified):

Acetabular fx 1Acetabular fx Jud 1

Acetabular fx 3 Acetabular fx 2

There are several ways to image acetabular fractures:

1.  Standard AP pelvis films:  this is a good screening imaging modality

2.  “Judet” films:  xray images that can further delineate the extent, type of acetabular fracture.  wikiRadiography Judet Views

3.  CT pelvis with 3-dimensional reconstruction.  This is the “cadillac” of imaging that orthopedic surgeons get the most pre-operative information from.  Judet Views have largely been replaced by this imaging modality as it offers much more information for the surgeon.  On a PACS radiology system the images can be rotated, flipped to see the extent of the injury as if you were holding the pelvis in your hand.  Its pretty awesome.

Keep in mind that fractures of the acetabulum can be occult.  If you obtain plain films that look normal and the patient cannot bear weight, consider CT imaging for a better look.  MRI can also be of value much like an occult femoral neck fracture.

Here is a free, extensive discussion of imaging acetabular fractures (including a discussion about types of acetabular fractures) available online from Radiographics:

Acetabular Fractures

Author:  Russell Jones, M.D.

References

1.  Judet Views.  http://www.wikiradiography.com/page/Judet+Views

2.  Potok PS, Hopper KD, Umlauf MJ.  Fractures of the Acetabulum:  Imaging, Classification, and Understanding.  Radiographics. 1995 Jan; 15(1), 7-23.

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Another person gets jumped…

March 6, 2013

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…and another head bleed!

SDH with midline shift 2SDH with midline shift 1

This is a subdural hematoma with “midline shift.”  I posted late last year on the difference between subdural and epidural blood characteristics.  See GSW Head for the prior post. 

This is a good example of midline shift.  As you can see above the falx (linear hyperattenuated structure at midline) is bowing away from the subdural hematoma.  It is also compressing the ventricles (seen best on the second image).  What does this mean?  It means the subdural is taking up enough space in the closed intracranial vault to put pressure on the brain.  We don’t like pressure on the brain!  This can cause herniation.  Herniation is bad for one’s health.  Call Neurosurgery or get them to a hospital with neurosurgery capability STAT.

Author:  Russell Jones, MD

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Pediatric aspiration chest xray

March 2, 2013

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This a chest xray one of my colleagues sent me.  He is a 21 month old male who possibly aspirated part of an apple:

Aspiration 1

The interesting portion of this radiograph is the overall hyperinflation of the right lung when compared to the left.  With this clinical history, asymmetric hyperinflation is highly concerning for aspirated foreign body.  The foreign body acts as a “ball-valve,” trapping air on exhalation and therefore causing a hyperinflated lung.  It can, but often doesn’t lead to pneumothorax. 

In this case the asymmetry was visible on upright radiograph and the diagnosis of retained foreign body was made.  The child had a bronchoscopy and an apple fragment was pulled out of his right mainstem bronchus. 

Other imaging tricks in aspiration include decubitus films and expiratory films. 

1.  Expiratory films:  have the patient expire and take a plain upright radiograph.  This may accentuate the asymmetry if the ball-valve effect is causing air trapping.

2.  Decubitus films:  When laying on one’s side the dependent lung should be asymmetrically smaller than the opposing lung.  If one of the lungs stays symmetric while in the dependent position, this can be a sign of air trapping.  It is recommended to obtain films in both decubitus positions (left and right).

Also consider CT imaging as a final imaging modality.  However, the definitive study is bronchoscopy if your suspicion is high. 

Author:  Russell Jones, MD

Image Contributor:  Kendra Grether-Jones, MD

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