EM REMS

A colleague pointed out an interesting CT on a patient with epigastric pain…

This CT shows stranding around the pancreas with fluid tracking in Gerota’s fascial plane.  What is Gerota’s fascia you say?

Gerota’s fascia (otherwise known as “Renal Fascia”) is the layer of connective tissue surrounding the kidneys and suprarenal glands.  Anterior to this fascial compartment is the prerenal space which contains the pancreas, ascending colon, descending colon, and the second-fourth portions of the duodenum.  Any inflammation with these organs can lead to fluid within Gerota’s fascia.  On the CT above this is demonstrated by the fluid stripe anterior to the left kidney on the middle image (sagittal plane)  and superior to the left kidney on the third image (coronal plane).  For an anatomic picture of Gerota’s fascia see the following Wikipedia reference:

Gerota’s Fascia

Author:  Russell Jones, MD

Image Contributor:  Tag Hopkins, MD

References

1.  Renal Fascia. http://en.wikipedia.org/wiki/Renal_fascia.  Accessed: 5/2013

We’ve all had them…the really, really bad GI bleeder.  Thus man came in peri-code.  He was resuscitated with massive-transfusion to somewhat clinically stable.  After NG tube initially showed over a liter of blood return it stopped, couldn’t be lavaged or suctioned, and his abdomen started distending over the course of the next 1/2 hour.  We decided to get a CT scan to evaluate the distension and this is what was found:

The abdominal CT with contrast shows very large varicies extending into the stomach!  His stomach has several fluid densities consistent with hematoma, blood, and an area concerning for active exstravasation.  On the coronal image you can also see some dependent ascites around the liver.  The distal portion of the nasogastric tube is thought to have been obstructed by the large hematoma in his stomach.

The patient ended up improving with octreotide and correcting his INR of 3.5.  He had an esophagogastroduodenoscopy (EGD) which confirmed varicies and several were banded.

WARNING:  CT abdomen is not a usual imaging modality for GI bleeders.  We obtained imaging because the patient had increasing distension and abdominal pain.  We wanted to rule out aortic pathology, mesenteric ischemia, hemorrhagic malignancy, gastric perforation, and other pathology that sometimes can be associated with GI bleeding.  I don’t advocate CT imaging in most GI bleeders.

Author:  Russell Jones, MD

An elderly patient presented with abdominal pain for a week.  The patient had peritoneal signs on exam and thus xray imaging was pursued (see discussion below):

Image 1

Image 2

Image 3

This is an acute abdominal series showing free intraperitoneal air in the right upper quadrant.  Notice that it cannot be determined if the patient has free air on the supine view (Image 1).  This is because the air is layering to the anterior portion of the peritoneal cavity.  In order to reveal air in the peritoneum, one must layer it to one of the sides (Image 2 – patient is laying on their left side and the air flows to the right upper quadrant) or upright (Image 3 – patient is upright and the air layers under the diaphragm, in this case the right side). 

I like the acute abdominal series to look for free air in the setting of a highly concerning exam.  You can also just do an upright chest xray.  They are quick and if free air is found it will likely be a study that will change the patient’s course; surgery will in most cases take the patient to the operating room with just an xray for exploratory laparotomy.  In our case, however, surgery was tied up for a bit and this allowed an extra 1/2 hour ED stay, I pursued non-contrast CT to further identify what was going on:

Image 4

Image 5

This CT shows findings highly concerning for a perforated duodenal ulcer.  In Image 4 you can see the air just above the liver edge anteriorly along with free intraperitoneal fluid layering on the side of the liver and spleen.  She also has an aortic aneurysm.  Image 5 shows an area of free air and stranding near the distal duodenum.  Laparotomy revealed a perforated duodenal ulcer, the aortic aneurysm was incidental. 

Author:  Russell Jones, MD

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

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

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):

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.

I saw a patient the other day with a gluteal/perianal swelling consistent with abscess.  It looked erythematous, swollen, tender and indurated as a usual abscess would be…roughly 10cm extending from the external anal sphincter into the gluteal area.  What made this abscess interesting was that we could feel a small amount of crepitus on exam.  Bedside ultrasound was hindered by what appeared to be air (unfortunately I didn’t save the ultrasound!).  Here is what appeared on CT imaging of her pelvis:

This is a non-contrast CT because the patient’s creatinine was elevated.  However you can see extensive gas formation in the gluteal area.  It extended up near the sacrum and rectum.  The patient was taken to the operating room for debridement with concerns for necritizing fasciitis.  The amount of gas on CT was not anticipated based on physical exam (the patient had only a little bit of crepitus that could have been missed).

Necrotizing fasciitis on imaging shows up as air in the soft tissue.  This can be seen on plain films but the extent is better characterized on CT.

A couple learning points from this case:

1.  Use ultrasound on your abscesses!  You never know what you may find.

2.  Crepitus is bad.  Even a little bit.  Consider a deep, serious infection that could spread rapidly.

3.  If Necritizing Fasciitis is suspected:  obtain early broad spectrum antibiotics, resuscitation, surgical consultation, and CT imaging for characterization.

Author:  Russell Jones, MD

Here is an interesting CT abdomen in a middle-aged patient with 10 days of left lower quadrant pain and fevers:

This patient has an 8cm abscess from perforated diverticulitis.

In the center of the image you can see a large air and fluid filled cavity with surrounding fat stranding.  This is consistent with an intraperitoneal abscess.  In middle-aged and elderly patients diverticulitis is a very common cause of intraabdominal abscess.  Other causes include perforated appendicitis, post-surgical infection, inflammatory bowel disease, surgical site anastomotic leak, perforated peptic ulcer, gangrenous cholecystitis, mesenteric ischemia with perforation, and pancreatic abscess.

Abscesses on CT have several classic features:

1.  Heterogeneous contents including various densities of fluid and debris with gas formation

2.  Rim enhancement with IV contrast due to high blood flow to the structure

3.  Surrounding inflammation seen as fat stranding

Radiology usually likes oral contrast if you suspect an intraabominal abscess because it helps distinguish abscess cavities from surrounding loops of bowel.  If you are studying abscesses in soft tissues or organs such as the liver, oral contrast is unnecessary.

Author:  Russell Jones, MD

Because it can easily end up in abscesses:

Notice the two rim-enhancing lesions with center hypoattenuation consistent with abscesses on both gluteal areas.  He also has stranding surrounding the area of concern.  This CT image is near the distal sacrum of the pelvis.

He admitted to injecting “tar heroin” intramuscularly in his bilateral gluteal areas.  Last injection was over three days ago and he had a fever, leukocytosis.  With the stranding, rim enhancement, and the clinical picture these were considered abscesses rather than simple fluid of the injected heroin.  This patient would be at risk for MRSA (Methicillin-resistant Staph. Aureus) and was covered with IV clindamycin and admitted to the surgical service for further evaluation and possible operating room intervention.

Author:  Russell Jones, M.D.

Imaging Study:  CT Pelvis with IV Contrast