July Case #1: Flank Pain

80 y/o WF presents to the ED with left flank pain for 1 day.  Her pain has been constant and she denies dysuria, frequency or hematuria.  Denies N/V/D.
PMHx: HTN
PSHx: pacemaker
All: NKDA
SocHx: occ ETOH, denies tob or  drugs

PE: BP 132/64, P 70, R 16, T 98.0, Pox 99% (RA)
GEN:  WNWD, WF, NAD
CHEST: CTA B, non labored
CV: RRR, no M/R/G
ABD: soft, NTND, +BS
GU: L CVAT

Bedside US is performed:

 

What is the diagnosis?
What is the color doppler artifact noted and how does it occur?

Special thanks to Guest Presenter: Dr. Sarah Bogle!

Critical Point #2: The Incomplete Scan

Once again, we are going to look at some ultrasound images critically for technique. Hitting upon the QA questions I gave you in last month's post, we'll begin with: Are these images adequate? The most common reason to have inadequate scans is that images are left out of a protocol or set that gets grouped together to make a diagnosis.

This week we are going to discuss the Renal protocol. As you may recall, a Renal protocol should include the following images at minimum:
1. Right kidney longitudinal
2. Right kidney transverse
3. Left kidney longitudinal
4. Left kidney transverse
5. Bladder (long or transverse)

In recent months I have noticed a trend that people believe that the RUQ or LUQ view may count as the longitudinal kidney view. At times, it may, but most of the times it does not. Case in point, what is wrong with the image below?


Well, although it does give us a nice view of Morrison's pouch and the diaphragm, which are essential to the FAST exam, it does not give us a complete view of the kidney. The good news is that it does include the renal collecting system as evidenced by the hyperechoic center portion of the kidney, but it does not allow us to interrogate the inferior pole of the kidney. What if the patient has a large cyst or tumor on the inferior pole of the kidney which may account for their pain? You must interrogate the entire organ in order to make a clinical decision and diagnosis.

So, you ask "How can I get around that pesky rib that is shadowing out the inferior pole of the kidney?" Here are a couple of suggestions:
1. Slide your probe down 1 rib space. This will take the focus off the kidney-liver/ spleen-kidney junction and focus on the kidney. Many times this will allow complete visualization of the kidney.
2. Sliding the probe more anteriorly, keeping the kidney in focus will often time allow you a complete picture of the kidney.
3. If that rib shadow is getting in the way no matter what, you may need to take several pictures to fully interrogate the kidney. So if you cannot get away from the rib shadow, work around it. I will often take a picture of the rib shadow bisecting the kidney, indicating to the reviewer that the rib space is tight:

This allows me to take a longitudinal measurement since both superior and inferior poles are visible.
Now I look at each pole separately. I slide my probe above the pesky rib and angle up downward to the patient's feet. This allows complete visualization of the superior and mid kidney, while blocking out the inferior pole with rib shadow.


I then slide down over that rib toward the patient's feet and angle up toward the patient's head. This image now focuses on the mid and inferior pole of the kidney.


I realize that this seems time consuming but it can be done pretty quickly as this clip illustrates:

Right Kidney Longitudinal View from UF-Jax Emergency Medicine on Vimeo.

Once the longitudinal view has been obtained, turn your probe counterclockwise 90 degree's to the patient's right to obtain the transverse view of the kidney. This seems to be easier to document since it is much easier to get between ribs in the transverse plane. Although you only need to submit 1 picture, please remember to fan through the entire organ in the transverse plane and take a representative picture. Therefore, if you have a cyst or a stone visible, take a picture of that area and denote which portion of the kidney you have in the image (superior, inferior, mid).
For the last portion of the renal exam, head to the pelvic region to scan the bladder. Remember to angle your probe to the patient's feet in order to locate the bladder. I usually begin a transverse view and then turn into a longitudinal plane. A representative picture of the bladder in either plane is acceptable.


That now completes your basic Renal Scan Protocol!

January Case #2: Flank Pain- Discussion

This patient has a staghorn calculus. After the bedside US was performed, the patient underwent a CT scan which confirmed the diagnosis and noted dilated collecting system and thinning of the cortex on the affected kidney. It also demonstrated hypertrophy of the contralateral kidney with mild hydronephrosis.

Urology was consulted and the patient was admitted to the Hospitalist service. She had a nuclear medicine renal scan which showed her renal function to be 79% on the left and only 21% on the right. She then underwent a right nephrectomy 8 days later. Her urine culture grew out Klebsiella.

Renal Calculi

Renal calculi, in general, affect around 10% of the population. Stones are usually comprised of calcium or uric acid. They are most commonly found in one of three areas: the UPJ (uretero-pelvic junction), the UVJ (uretero-vesicular junction) and the point at which the ureter crosses the pelvic brim. The appear on ultrasound as a hyperechoic crescent shape, usually associated with acoustic shadowing. You may also see the twinkle sign with renal stones (http://rad.usuhs.edu/medpix/kiosk_image.html?mode=case_viewer&imid=38513&pt_id=11272&quiz=&th=&table=card&showall=#pic). This sign is a color Doppler artifact that appears as a combination of red and blue Doppler signals distal to a stone. Small stones may not create an acoustic shadow, but by placing color Doppler on the kidney in a patient suspected to have renal colic, a stone may be identified by noting a twinkle sign.

Renal stones may cause complete or partial blockage of the ureter, resulting in hydroureter and hydronephrosis. A dilation of the ureter and renal collecting system may be present, evidenced by anechoic dilation of these structures. The ureters can be assessed by looking for ureteral jets in the bladder. Looking at the bladder in the transverse plane, scan through until the posterior wall appears flat horizontally. Using color Doppler, ureteral jets appear as red colored flame. If a jet is identified, it is reassuring that the ureter is at least partially patent.
A staghorn calculus is a stone that fills the renal pelvis branching into the calyxes, causing their dilation. They are most often composed of struvite (magnesium ammonium phosphate) and/or calcium carbonate apatite. These stones are often called 'infected stones' since they are usually associated with urinary tract infections with urea splitting organisms. These stones result in obstruction, either by obstructing the collecting system or the ureter. If left untreated, staghorn calculi can cause a kidney function to deteriorate causing end-stage kidney disease. As these stones are likely infected, they pose a risk of progression to sepsis. Thus, most patients require definitive surgical treatment.
On ultrasound, they may appear as various shapes depending on the scan plane, multiple curvilinear structures that outline the renal pelvis. They may or may not have distal shadowing. You may see hydronephrosis and a dilated kidney.

January Case #2: Flank Pain

30 y/o AAF with c/o right flank and back pain for 2 days. +F/C, N/V. Pt c/o thick, discolored urine. She denies vaginal D/C or bleeding or diarrhea. Decreased PO intake.

PMHx: hypothyroidism, kidney stones, UTIs in past
PSHx: none
Meds: synthroid
FHx: none
Social Hx: denies tobacco or drugs, occasional ETOH
Allergies: NKDA

PE:
VS: BP 108/66, P 120, R 18, T 98.6, POx 96% (RA)
GEN: thin AAF, NAD
HEENT: MMM , OP clear
CV: tachycardic, RR, no M/R/G, 2+ pulses B
CHEST: CTA B
ABD: soft, mild RUQ TTP, moderate suprapubic TTP, no guarding or rebound, +BS, +R CVAT

Bedside US is used to asses her urinary tract:












What is the diagnosis?

Thanks to Kristin McKee for submitting this case!

November Case #4 Discussion

The longitudinal and transverse images of the bladder indicate a foreign body. In this case, the ruptured end of a suprapubic catheter. In the transverse view you see the end of the tubing, but in the longitudinal view you can make out the balloon still inflated.

Urology was consulted and a new suprapubic catheter was placed. The old one was later removed with cystoscopy and the end was noted to have been cut cleanly off.

This case illustrates an important point: You must always image any three dimensional structure in two planes. In this case it helped to identify that the suprapubic catheter was not only still in the patient's bladder, but that the balloon was still at least partially inflated.

November Case #4

50 y/o WM presents from his ALF for suprapubic catheter replacement. He states that "it just fell out." He has brought the remains of the previous catheter and you notice that it appears to be missing the distal portion of the catheter. Before you replace the catheter, you quickly ultrasound his bladder.

What do these images tell you?





Thanks to A.J. Wheeles for submitting these images!

November Case #1: Discussion

The initial images illustrate a multicystic kidney which is grossly enlarged. There appears to be flow through the ureter as demonstrated by color flow in the transverse bladder view.

The differential for this patient should include:
1. hydronephrosis
2. renal cysts
3. polycystic kidney disease
4. tuberous sclerosis

To aid us in this differentiation, we took a quick scan through his liver and found the following:


The above pictures illustrate multiple cysts on the liver. This, along with the findings of bilateral multicystic kidneys and bilateral urine flow demonstrated by bladder jets, supports the diagnosis of Polycystic Kidney Disease.

Polycystic Kidney Disease

• Autosomal dominant form found in adults.
• Kidneys appear enlarged bilaterally due to multiple cysts of varying sizes.
• In advanced stages, cysts may destroy renal tissue and cause renal failure and hypertension.
  
• Cysts may be visualized as early as the 2nd decade of life
• Associated with cysts in the liver, pancreas and spleen and arterial aneurysms, especially berry aneurysms in 20% of cases
  

November Case #1

A 62 y/o man presents to the ED with complaints of right flank pain which began several hours prior. The pain is localized, constant and non-radiating. He denies dysuria, hematuria or urinary frequency or urgency. He denies CP, SOB, F/C, N/V, or any other complaints.

PMHx: HTN, DM, "kidney problem"
PSHx: none
Family Hx: unknown
Social Hx: lives alone, denies alcohol, tobacco and drugs

PE:
Gen: WNWD, WM, NAD
Chest: CTA B, nonlabored
CV: RRR, no M/R/G/
Abd: soft, NTND, +BS, no CVAT
Ext: no C/C/E

What's your differential diagnosis?



Bedside ultrasound illustrates the following:





What is the differential for this ultrasound exam?

What other structures should you investigate based on this scan?