SonoTutorial: The FAST Part 1a: The Right Upper Quadrant: Images That Could Fool You

Now the fun starts! The images and clips below will be a great test to see how much of the information from the prior post on how to perform a complete right upper quadrant view of the FAST scan you recall, while keeping it’s limitations in mind. Remember, to be complete and thorough, you must evaluate above the diaphragm, below the diaphragm, around the liver and superior pole of the kidney, and around the left liver edge and inferior pole of the kidney (along the right paracolic gutter) through slow and deliberate full fanning between multiple rib spaces, and adjusting your depth as needed.

The images will appear with a clinical correlation first which may give you a certain level of suspicion. Think about what part of the RUQ scan is missing (as there is very few times when you can get all of the above areas in just one clip or in just one rib space), how would you improve the evaluation (fan more widely or slowly, depth or gain (brightness) adjustment, etc), and what your interpretation of that image would be (positive or negative for free fluid – or is the image just too technically limited to make a statement on it?)- all while thinking of your level of suspicion of injury given the clinical correlate.

These are all real cases:

Case 1: 50 yr old fell from 2nd story onto concrete with c/o abdominal pain, tender in RUQ, HR 100 RR 18 BP 130/86 O2 sat 96%RA

Part missing: inferior pole, left liver edge, paracolic gutter

Improve image by increasing fanning width as it is incomplete; depth is good

Interpretation: no intrathoracic free fluid since has good mirror image artifact and spine shadow stops at diaphragm; no intraperitoneal free fluid at superior pole; other areas not seen and therefore cannot be interpreted

Other things to note: there is an edge shadowing artifact (refraction) that you can see coming off of the superior pole of the kidney that goes to the end of the screen (commonly mistaken for free fluid)

Actual diagnosis: Right rib fractures, renal contusion, Grade 1 liver laceration (the FAST was positive with trace free fluid only seen at left liver edge and paracolic gutter – areas not seen above)

Case 2: 26 yr old assault victim with bat to chest, abdomen, back c/o pain everywhere with tender chest wall anteriorly bilaterally and tender diffusely over abdomen which is soft HR 90 RR 18 BP 132/88 O2 sat 99%RA

Part missing: above diaphragm, inferior pole, paracolic gutter

Improve image: great evaluation of this section of RUQ

Interpretation: no intraperitoneal free fluid at superior pole; other areas not seen and therefore cannot be interpreted

Other: the double line sign is seen that illustrates the renal cortex and perinephric fat

Actual diagnosis: superficial contusions, no thoracic or intra-abdominal injury

Case 3: 46 yr old hit by car, unconscious, left femur deformity, abdomen soft HR 120 RR 14 BP 100/72 O2 sat 94%by BVM

Part missing: above diaphragm, inferior pole, paracolic gutter

Improve image: slight increase in gain (brightness)

Interpretation: free fluid (anechoic black stripe) at interface of liver and superior pole; unable to assess thoracic cavity

Actual diagnosis: small subdural and subarachnoid hemorrhage, Grade 2 Liver laceration, right renal contusion, bowel contusion, multiple rib fractures with bilateral pulmonary contusions (right predominant) with right hemothorax, femur fracture.

Case 4: 70 yr old male (on Coumadin) fall down 5 stairsteps on right flank c/o right flank pain and tender in right upper quadrant and right flank region. HR 98 RR 22 BP 142/96 O2 sat 95%RA

Part missing: right paracolic gutter

Improve image: great evaluation of this section of RUQ

Interpretation: no right intrathoracic free fluid, no intraperitoneal free fluid at superior or inferior poles; paracolic gutter not seen

Other: the longitudinal IVC and hepatic vasculature are also seen with fanning

Actual diagnosis: multiple rib fractures; no intra-abdominal injury

Case 5: 85 yr old restrained front-side passenger in motor vehicle collision at 25 mph c/o abdominal pain, mild tenderness diffusely HR 80 RR 20 BP 138/90 O2 sat 96%RA

Part missing: above diaphragm

Improve image: by increasing fanning as the complete region of this section of the RUQ is not evaluated

Interpretation: no intraperitoneal free fluid at superior or inferior poles although limited due to poor fanning; thoracic cavity not seen

Other: there is a moderately sized renal cyst which is one of the most common incidental findings seen on FAST scans. Let the patient know, place it in their diagnoses, and encourage follow up with their PCP

Actual diagnosis: Right lower rib fractures with small hemothorax (area not seen on above FAST)

Case 6: 24 yr old fall from bleachers at football stadium at 15 ft height c/o lower chest pain and upper abdominal pain, chest tender in left lower ribs, abdomen soft and nontender. HR 100 RR 20 BP 118/64 O2 sat 96%RA

Part missing: needs better evaluation of right paracolic gutter

Improve image: by increasing fanning as the complete region above and below diaphragm  of the RUQ is not truly evaluated. Avoid sliding down rib spaces while you are fanning. Stay in the rib space and slowly and deliberately fan.

Interpretation: free fluid best seen at left liver edge at paracolic gutter. no intrathoracic free fluid seen

Other: free fluid will first develop at the left liver edge in the RUQ at the paracolic gutter – dont forget to look there! – as you may miss a positive FAST if you don’t.

Actual diagnosis: left rib fractures and grade 2 splenic laceration, left renal contusion (by the way – the left upper quadrant of this patient was without free fluid – just goes to show that free fluid will move to the right upper quadrant)

Case 7: 56 yr old homeless man came to ED altered, moans with palpation everywhere. HR 122 RR 20 BP 92/60 O2 sat 98%RA

Part missing: above diaphragm

Improve image:  Avoid sliding down rib spaces while you are fanning. Stay in the rib space and slowly and deliberately fan. As you can see, increasing fanning is key to seeing the pathology above better.

Interpretation: free fluid best seen at left liver edge at paracolic gutter, and only with proper and thorough fanning can be seen at the interface between the liver and superior pole of kidney.

Other: free fluid will first develop at the left liver edge in the RUQ at the paracolic gutter – dont forget to look there! – and don’t forget to fan thoroughly in each section !!  – as you may miss a positive FAST if you don’t.

Actual diagnosis: Splenic laceration

Case 8: 67 yr old restrained driver in motor vehicle collision at 50mph c/o back pain, abdomen is slightly tender in epigastric region, back is slightly tender in right flank. HR 78 RR 18 BP 134/80 O2 sat 99%RA

Part missing: left liver edge, right paracolic gutter

Improve image:  Adjust depth to be more shallow (less deep) to evaluate space between liver and kidney better.

Interpretation: no intrathoracic free fluid as mirror image is seen above diaphragm; no intraperitoneal free fluid with limitation that no hepatic edge and paracolic gutter seen

Other: the vasculature is prominently seen: the IVC and hepatic vessels.

Actual diagnosis: Bowel perforation, grade 1 liver laceration (his paracolic gutter view was positive, but if we only rely on the above, we would have missed the positive FAST – be complete!)

Case 9: 34 yr old hit by car, diaphoretic, altered, abdomen soft with inability to assess tenderness due to patient status. HR 128 RR 26 BP 110/70  O2 sat 95% on NRB

Part missing: superior and inferior pole of kidney, paracolic gutter

Improve image:  increase width of fanning to evaluate the region better (although you can see the pathology without doing it, but you may not be able to assess the extent of it) .

Interpretation: intrathoracic free fluid is seen above diaphragm; intraperitoneal free fluid is seen below the diaphragm (between diaphragm and liver)

Other: the IVC and hepatic vessels are seen in oblique view.

Actual diagnosis: multiple bilateral rib fractures, right and left hemothorax, high-grade splenic laceration, renal contusion

Case 10: 80 yr old male c/o feeling weak. lungs are clear, abdomen slightly distended with no tenderness. HR 90 RR 20 BP 100/72 O2sat 99%RA

Part missing: above and below diaphragm

Improve image: this is a great image of this section of the RUQ

Interpretation: intraperitoneal free fluid around inferior pole of kidney and along paracolic gutter

Other: most free fluid is seen at the inferior pole of kidney interface along the paracolic gutter only with fanning (if this area was not evaluated through thorough fanning or if it were blocked by a rib shadow, it could have been missed)

Actual diagnosis: renal artery aneurysm rupture

Tune in for the next post which will show even more images that could fool you! As you can see with the above clinical correlates, the FAST scan is used in trauma, in unexplained shock, or abdominal pain of unknown etiology – do it, and do it right!