Rare arm fracture…

Elbow GF1 Elbow GF2 Wrist GF 1 Wrist GF2

This patient presented with arm pain after a fall.  The radiographs obtained showed a distal radius fracture along with a radial head fracture (irregularity and bone fragment seen at the radial head).

I haven’t seen this fracture pattern before.  I’m not sure if it can be classified as an Essex-Lopresti fracture (radial head fracture accompanied by dislocation of the radioulnar joint).  In looking at the radiographs I believe the radioulnar joint is still intact.  However, I’m wondering if the clinical principle of the Essex-Lopresti fracture is maintained:  is there a disruption of the interosseous membrane between the radius and ulna.  This disruption can lead to serious long-term disability including pain, loss of pronation, supination and extension range-of-motion (1).

Has someone out there seen this before?  Any pearls of wisdom regarding this fracture pattern?

Author:  Russell Jones, MD

Imaging Contributor:  Joe Barton, MD

 

References

1.  Essex Lopresti Fracture.  Wheelessonline.com.  Accessed 4/2015.


Filed under: Arm XR, Eponyms, Orthopedics, Trauma, XR Tagged: Essex-Lopresti

Student Corner: CT Evaluation of Appendicitis

Appendicitis is commonly encountered in the ER and is the leading cause of surgical emergency in the abdomen. The initial evaluation for a presentation that is concerning for appendicitis often includes history taking and exam, supplemented by labs. The Alvarado Score is a 10 point rating scale that is widely used as a tool to help decide whether or not a patient presenting with abdominal pain requires CT imaging (although it’s overall clinical usefulness is controversial). It is outlined here by MDCalc. According to the rule, a score of greater than 4 warrants CT evaluation and greater than 7 requires immediate surgical consult.  CT scan is a highly sensitive and specific tool in diagnosing appendicitis, however it comes with radiation, cost, and sometimes IV contrast risks.  In the pediatric patient population radiation from CT scans are not as desirable as the long-term consequences have theoretical potential to be deleterious (long discussion…for another post maybe!).

The purpose of this article is to go over characteristics of appendicitis that can be seen on a CT scan. The use of contrast is a long debated point of contention amongst the emergency medicine community and the usual practice varies between institutions. Medscape has a great rundown of the issue here, which notes that the use of contrast may be more beneficial in circumstances where appendicitis is a relatively less likely diagnosis because the contrast better helps characterize other possibilities.  Contrast studies are also more helpful in the patient not expected to have a large amount of intraperitoneal fat.

As usual, it is important to understand the local anatomy when analyzing radiological images of the abdomen. The image below is an example of an axial cut, non-contrast abdominal CT of a patient who came in with abdominal pain concerning for appendicitis. Try to identify the following structures: vertebrae, psoas major, IVC, iliac arteries, small bowel, colon and appendix.

Appy

And below is a labeled version of the same image:

Appendicitis labeled

Key: Blue arrow = bowel gas, ascending colon; Green arrows = small bowel; Purple arrows = L and R Iliac arteries; Yellow arrow = IVC; Red arrow = inflamed appendix

This image contains several signs that indicate that the appendix is inflamed. They include:

  • Diameter greater than 6mm–this usually implies the the appendix has either been twisted or blocked off from the cecum by an appendicolith, which causes inflammation
  • Periappendiceal fat stranding–seen as distinct lines that radiate out from the appendix in the image above, it is caused by inflammation of the appendix causes fluid accumulation around the wall of the appendix which turns the normally hypodense surrounding fat into a hyperdense area; note that the visceral fat around the appendix on the L side of the image looks much different than the visceral fat on the other side of the image
  • Appendiceal wall thickening–normally the wall of the appendix is thin and barely noticeable, but this image shows that the wall is generally thickened and may even be slightly more hyperdense than expected (more below)

Other signs that aid in the diagnosis of appendicitis include:

  • Appendiceal wall enhancement–the wall of the appendix becomes slightly more hyperdense when you compare it to the wall of any other loop of bowel, which is again a product of inflammation; note that this finding is usually more evident on contrast-enhanced CT
  • Abscess–the colon has a large reservoir of commensal bacteria, which can grow and wall off into an abscess if they are trapped in the appendix
  • Appendicolith–a calcified mass that is hyperdense on CT which can be an obstruction between the cecum and the appendix

Overall, CT has a high degree of sensitivity and specificity when used to evaluate the possibility of appendicitis. The clues outlined above, especially when seen together and as a part of a larger clinical picture that fits with appendicitis, are instrumental in confirming the diagnosis.

References:

Ohle R, O’Reilly F, O’Brien KK, Fahey T, Dimitrov BD. The Alvarado score for predicting acute appendicitis: a systematic review.BMC Med. 2011 Dec 28;9:139. doi: 10.1186/1741-7015-9-139. Review. PubMed PMID: 22204638; PubMed Central PMCID: PMC3299622.

Reich B, Zalut T, Weiner SG. An international evaluation of ultrasound vs. computed tomography in the diagnosis of appendicitis.Int J Emerg Med. 2011 Oct 29;4:68. doi: 10.1186/1865-1380-4-68. PubMed PMID: 22035447; PubMed Central PMCID: PMC3215954.


Filed under: Abdomen/Pelvis, Abdomen/Pelvis, CT, Non-Trauma, Student Corner Tagged: Abscess, Alvarado score, appendiceal wall enhacement, appendiceal wall thickening, Appendicitis, Appendix, ct, EM, emergency medicine, periappendiceal fat stranding, student corner

WWWTP #23 (What’s Wrong With This Picture?) Answer

Patient presented with cough, fevers.  This Chest Xray was obtained:

WWWTP 21 1

One finding on this Xray is very concerning.  The Xray showed free air under the diaphragm.

A further diagnostic study was obtained (CT abdomen/pelvis):

WWWTP 21 2 WWWTP 21 3

Turns out this patient has pneumatosis cystoides intestinalis.  He has a history of this disorder and has had a prior laparoscopy showing multiple cystic structures in the intestinal walls.

Findings on imaging:

1.  Chest Xray:  Concern for free air underneath the diaphragm.  He also has a tracheostomy, pacemaker, scoliosis, and a right lower lung infiltrate.

2.  CT abdomen/pelvis:  The coronal imaging shows multiple cystic structures full of free air in the cecal area.  The cross-sectional imaging above shows a large amount of pneumoperitoneum.

Luckily this patient has a history of pneumatosis cystoides intestinalis.  He has had multiple abdominal CT’s showing similar findings.  Clinically he had no abdominal tenderness.  Keep this rare diagnosis in mind for the patient presenting with free air in the abdomen!  Information about pneumatosis cystoides intestinalis:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3235639/

Author:  Russell Jones, MD

Image Contributor:  Mary Bing, MD


Filed under: Abdomen/Pelvis, Chest XR, Non-Trauma, Respiratory, WWWTP, XR Tagged: Pneumonia

WWWTP #23 (What’s Wrong With This Picture?)

Patient presented with cough, fevers.  This Chest Xray was obtained:

WWWTP 21 1

One finding on this Xray is very concerning.  What is it?

A further diagnostic study was obtained (CT abdomen/pelvis):

WWWTP 21 2 WWWTP 21 3

What’s Wrong With This Picture?

Answer to follow.

Author:  Russell Jones, MD

Image Contributor:  Mary Bing, MD


Filed under: WWWTP

Flank Pain…

Flank pain for several days, history of nephrolithiasis:

Flank Pain 1 Flank Pain 2 Flank Pain 3 Flank Pain 4

This patient has marked right hydronephrosis with significant right renal perinephric inflammatory cystic changes extending into the contiguous right psoas musculature and right retroperitoneum. There is perinephric stranding and edema.

The differential in this case includes renal abscess (most likely) with extension into the right psoas and retroperitoneum.  Additional considerations are atypical infection such as tuberculosis, and urothelial malignancy.

The patient ended up having Xanthogranulomatous pyelonephritis.  This is a subacute/chronic pyelonephritis usually incited by a staghorn calculus.  For more information on this entity please see radiopaedia.org:

http://radiopaedia.org/articles/xanthogranulomatous-pyelonephritis

Author:  Russell Jones, MD

References

1.  Knipe H, Gaillard F et al.  Xanthogranulomatous Pyelonephritis.  www.radeopaedia.org.  Accessed 1/2015.


Filed under: Abdomen/Pelvis, CT, Genitourinary, Non-Trauma Tagged: Renal Abscess

WWWTP #22 (What’s Wrong With This Picture?) Answer…

Patient presented short of breath.  Here is his chest xray:

WWWTP #22 PA WWWTP #22 LA

What’s wrong with this picture?

The findings are very subtle.  This patient has multiple lucencies in the bony structures including ribs, clavicles, scapula, and visualized proximal humerus:

WWWTP 22 edited

This patient turned out to have leukemia.  His shortness of breath was actually symptomatic anemia and he had a severe leukocytosis with a WBC nearing 180 K/MM3.

Remember to approach all imaging with a systematic approach so you don’t miss subtle findings like this!

Author:  Russell Jones, MD


Filed under: WWWTP Tagged: Dyspnea