Tag Archives: xray

Best Of: Finding Rib Fractures On Chest XRay

September 8, 2015 The Trauma Pro Leave a comment

A lot of people have been viewing and requesting this post recently.

Here’s a neat trick for finding hard to see rib fractures on standard chest xrays.

First, this is not for use with CT scans. Although chest CT is the “gold standard” for finding every possible rib fracture present, it should never be used for this. Rib fractures are generally diagnosed clinically, and they are managed clinically. There is little difference in the management principles of 1 vs 7 rib fractures. Pain management and pulmonary toilet are the mainstays, and having an exact count doesn’t matter. That’s why we don’t get rib detail xrays any more. We really don’t care. Would you deny these treatments in someone with focal chest wall pain and tenderness with no fractures seen on imaging studies? No. It’s still a fracture, even if you can’t see it.

So most rib fractures are identified using plain old chest xray. Sometimes they are obvious, as in the image of a flail chest below.

But sometimes, there are only a few and they are hard to distinguish, especially if the are located laterally. Have a look at this image:

There are rib fractures on the left side side on the posterolateral aspects of the 4th and 5th ribs. Unfortunately, these can get lost with all the other ribs, scapula, lung markings, etc.

Here’s the trick. Our eyes follow arches (think McDonald’s) better than all these crazy lines and curves on the standard chest xray. So tip the xray on its side and make those curves into nice arches, then let your eyes follow them naturally:

Much more obvious! In the old days, we could just manually flip the film to either side. Now you have to use the rotate buttons to properly position the digital image.

Final exam: click here to view a large digital image of a nearly normal chest xray. There is one subtle rib fracture. See if you can pick it out with this trick. You’ll have to save it so you can manipulate it with your own jpg viewer.

General

Do You Really Need To Repeat That Xray?

March 27, 2015 The Trauma Pro Leave a comment

It happens all the time. You get that initial chest and/or pelvic xray in the resuscitation room while evaluating a blunt trauma patient. A few minutes later the tech returns with another armful of xray plates to repeat them. Why? The patient was not centered properly and part of the image is clipped.

Do you really need to go through the process of setting up again, moving the xray unit in, watching people run out of the room (if they are not wearing lead, and see my post below about how much radiation they are really exposed to), and shooting another image? The answer to the question lies in what you are looking for. Let’s address the two most common (and really the only necessary) images needed during early resuscitation of blunt trauma.

First, the chest xray. You are really looking for 3 things:

Big air (pneumothorax)
Big blood (hemothorax)
Big mediastinum (hinting at aortic injury)

Look at the clipped xray above. A portion of the left chest wall is off the image. If there were a large pneumothorax on the left, would you be able to see it? What about a large hemothorax? And the mediastinum is fully included, so no problem there. So in this case, no need to repeat immediately.

The same thing goes for the pelvis. You are looking for gross disruption of the pelvic ring, especially posteriorly because this will cause you to intervene in the ED (order blood, consider wrapping the pelvis). So if parts of the edges or top and bottom are clipped, no big deal.

Bottom line: Don’t let the xray tech disrupt the team again by reflexively repeating images that are not technically perfect. See if you can use what you already have. And how do you decide if you need to repeat it later, if at all? Consider the mechanism of injury and the physical exam. Then ask yourself if there is anything you could possibly see that was not imaged the first time that would change your management in any way. If not, you don’t need it. But it certainly will irritate the radiologists!

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General

Chest X-Ray After Chest Tube: Why Do We Do It?

October 30, 2014 The Trauma Pro Leave a comment

More dogma, or is it actually useful? Any time a chest tube (tube thoracostomy) is inserted, we automatically order a chest x-ray. Even the ATLS course recommends obtaining an image after placement. But anything we do “automatically” is grounds for critical analysis to see if there is a valid reason for doing it.

A South African group looked at the utility of this practice retrospectively in 1004 of their patients. They place 1042 tubes. Here are the factoids:

Patients were included if they had at least one chest x-ray obtained after insertion
Patients were grouped as follows: Group A (10%) had the tube inserted on clinical grounds with no pre-insertion x-ray (e.g. tension pneumothorax). Group B (19%) had a chest x-ray before and had ongoing clinical concerns after insertion. Group C (71%) had a chest-xray before and no ongoing concerns.
75% of injuries were penetrating (75% stab, 25% GSW), 25% were blunt
Group A (insertion with pre-x-ray): 9% had post-insertion findings that prompted a management change (kinked, not inserted far enough)
Group B (ongoing clinical concerns): 58% required a management change based on the post-x-ray. 33% were subcutaneous or not inserted far enough (!!)
Group C (no ongoing clinical concerns): 32 of 710 (5%) required a management change, usually because the tube was too deep

The authors concluded that if there are no clinical concerns (tube functioning, no clinical symptoms) after insertion, then a chest x-ray is not necessary.

Bottom line: But I disagree with the authors! Even with no obvious clinical concerns, the tube may not be functioning for a variety of reasons. Hopefully, this fact would then be discovered the next day when another x-ray is obtained. But this delays the usual progression toward removing the tube promptly by at least one day. It increases hospital stay, as well as the likelihood of infection or other hospital-associated complication. A chest x-ray is cheap compared to a day in the hospital, which would potentially happen in 5% of these patients. I recommend that we continue to obtain a simple one-view chest x-ray after tube insertion.

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General

Are Inlet / Outlet Views Obsolete In Pelvic Trauma?

June 4, 2013 The Trauma Pro Leave a comment

Orthopedic surgeons have long found inlet and outlet views (I/O) of the pelvis to be helpful in their management of pelvic fractures. However, for the last decade we’ve seen an inexorable creep in diagnostic imaging from plain xrays to computed techniques. Have the conventional inlet and outlet views lost their luster?

San Francisco General Hospital and UCSF recently published a registry-based study looking at conventional pelvic I/O images and virtual I/O images reconstructed from CT scans. Two years of registry data were reviewed, and included patients had both conventional I/O images and CT imaging. Images were evaluated by two orthopedic traumatologists for their quality.

Sadly, only 20 patients were available for this study, which makes it an interesting pilot at best. The most interesting results were as follows:

Quality of imaging was judged to be equal except when pelvic rotation was present. CT fared better in these cases.
Both inlet and outlet views were judged to be better when reconstructed by CT
Overall, imaging of all portions of the pelvis was about equal in both types of study
The need for repeat studies was identified in nearly half of conventional images, but in only 8% of CT images

Bottom line: CT scanning is slowly becoming the preferred modality for just about any type of trauma imaging. In the 1980’s, head CTs became widespread, followed rapidly by abdominal imaging. Chest CT for definitive diagnosis became commonplace around 2000, and spine imaging by CT has now become the gold standard. Although there are a few throwbacks where conventional imaging has been thought to be better, they are vanishing rapidly. Computing technology can now reconstruct inlet and outlet views of the pelvis, correcting for rotation and angulation in any study of the abdomen/pelvis. And if the reconstructed image is not quite right, the tech can change a few parameters and generate it again and again until the image is perfect.

Orthopedic surgeons should now expect a nicely formatted set of inlet/outlet CT reconstructions in all trauma patients with pelvic fractures.

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