21 y/o male with hx of previous PTX presents to the ED for evaluation of L sided chest pain x 3 days that developed while lifting a heavy box.Read More
Welcome to the Pulse!
Now that we have your attention - let's talk about liver ultrasound. A topic that we do not deal with often in the ER setting, but due to all of those FAST exams and RUQ studies that we do, it's important to be able to recognize when the liver isn't normal!
And now, onto....
The Basics of Liver Ultrasound
The liver is a large solid vascular organ that is best visualized with a curvilinear transducer with a (low) frequency between 2-5 MHz. The patient can be examined in a supine position with normal respirations. The normal liver has a homogenous echogenic appearance. Any heterogenous appearance should be concerning for pathology. Here are a few non-traumatic pathologies to be aware of during your scanning.
- Simple cysts are considered the most common focal liver lesion. They are anechoic with increased through transmission, and a well-defined back wall.
- Complex cysts are identified by internal echoes, a thick wall, septations that are numerous or thick, solid elements, or calcification and are most often due to hemorrhage
- Vascular lesions such as aneurysms, arterioportal fistulas, and portal hepatic vein fistulas can simulate cysts on gray-scale sonography but are easily distinguished with Doppler analysis
- The most common benign liver neoplasm found most commonly in women.. They are classified by multiple, small, blood-filled spaces are separated by fibrous septations and lined by endothelial cells that typically do not bleed or cause symptoms. Therefore, they are usually an incidental finding on ultrasound.
- They are defined by sharp and smooth margins that may be round or slightly lobulated.
- Only 2% of hemangiomas enlarge on follow-up scans and they usually remain stable overtime. If the patient does not have chronic liver disease or risk of malignancy, a homogeneous hyperechoic liver lesion requires no further evaluation.
Focal nodular hyperplasia (FNH):
- A benign tumor of the liver that is composed of Kupffer cells, hepatocytes, and biliary structures. FNH is usually detected as an incidental mass.
- On ultrasound, most FNHs are isoechoic to liver parenchyma
- Unlike hepatic adenomas, they are not related to birth control pills, although birth control pills may promote their growth. They seldom bleed or cause any clinical symptoms, although pain may be encountered when the lesions are large.
- The differential diagnosis of FNH includes fibrolamellar carcinoma, hepatic adenoma, HCC, hemangioma, and vascular metastases.
- Adenomas are rare benign tumors that contain normal (or occasionally slightly abnormal) hepatocytes but few Kupffer cells and virtually no bile ductules. Adenomas occur most commonly in patients taking birth control pills or anabolic steroids.
- Their propensity to bleed makes them surgical lesions despite their benign histology. They also have a low but real risk of malignant degeneration.
- Simple, small uncomplicated adenomas tend to be homogeneous, varied and nonspecific. In most cases additional imaging is necessary to confirm the diagnosis.
- The lungs and liver are the most frequent sites of distant metastatic disease and usually involve both lobes of the liver.
- Liver function tests are unreliable in detecting liver metastases.
- Metastatic lesions have a target appearance with an echogenic or isoechoic center and a hypoechoic halo while thick halos represent proliferating tumor.
- CT and MRI are also helpful in confirming suspected diffuse metastases. In many clinical situations when metastatic disease is suspected biopsy is required for diagnosis.
- HCC is the most common primary malignancy of the liver.
- The growth pattern of HCC is quite variable: it may be solitary, multifocal, or diffuse and infiltrating. A typical pattern of HCC is a large dominant lesion with scattered smaller satellite lesions.
- Most HCCs are hypervascular and variable; however, this is not always evident on Doppler, particularly in deep lesions.
- Any solid mass detected on an initial sonogram in a patient with cirrhosis should be considered malignant until proved otherwise
Middleton WD, Kurtz AB, Hertzberg BS. Ultrasound: The Requisites. 2nd ed. Philadelphia, PA: Elsevier, Inc; 2016.
51 years old male with medical history of Parkinson's disease, s/p fall with injury to the chest. Pt states that he was walking in the street, when he tripped, fell and hit his chest. No LOC. Not on AC. Patient is complaining of pain in his chest, increased stiffness and swelling over R clavicle and R arm, difficulty breathing. Denies any palpitations, sob, cp before falling. Denies headache, n/v, other extremity pain, back pain, neck pain.
Eyes: No visual changes, eye pain or discharge.
ENMT: No hearing changes, pain, discharge or infections. No neck pain or stiffness.
Cardiac: Pain over R distal clavicle and midsternal. No edema.
Respiratory: +SOB. No cough or respiratory distress.
GI: No nausea, vomiting, diarrhea
GU: No dysuria, frequency or burning.
MS: R arm and clavicle pain and swelling. No myalgia, muscle weakness, back pain.
Neuro: No headache or weakness. No LOC.
Skin: No skin rash, abrasion, laceration.
GENERAL: in distress due to pain
HEAD: Atraumatic, Normocephalic
EYES: EOMI, PERRL, conjunctiva and sclera clear
NECK: No Tracheal Deviation. No Mid-line tenderness C-spine. Supple. No JVD.
CHEST/LUNG: R sided chest tenderness. 5 x5 cm hematoma, lungs clear to auscultation bilaterally;
HEART: Regular rate and rhythm; No murmurs, rubs, or gallops
ABDOMEN: Soft, Nontender, Nondistended; Bowel sounds present
EXTREMITIES: 2+ Peripheral Pulses,
NEUROLOGY: non-focal deficits
Labs, Radiology, Cardiology, and Other Results: FAST exam negative
What is most concerning in blunt trauma to the chest as demonstrated by the images above?
What tests/imaging modalities would you perform?
What findings might you see on bedside echo?
What do you see on this lung ultrasound?
How would you manage this patient?
- Cardiac and lung contusion. This patient has a pulmonary hematoma secondary to sternal fracture.
- EKG, ECHO, cardiac enzymes, CXR, and lung ultrasound.
- Wall motion abnormality, usually of the right ventricle. The right heart is most commonly injured due to its position closest to the anterior chest wall.
- You will see B-lines in various lung fields, which in the setting of blunt force trauma would represent pulmonary contusion. You may also see hypoechoic/anechoic sharply demarcated fluid in various lung fields with a swirling pattern, strongly indicative of a hemothorax. Other major pulmonary injuries that should definitely be considered on ultrasound would be pneumothorax, which can be identified by absence of lung sliding, otherwise known as a “barcode sign.”
- Observe all patients with cardiac monitoring, interval assessment of cardiac markers, SpO2 monitoring, chest tube placement as needed, and pulmonary physical therapy.
70 yoF with PMH of CHF, HTN, HLD, DM2 presents to the ED with abdominal bloating and discomfort for 3 weeks. Denies N/V/D, fever, chills, urinary symptoms, bloody stool, CP, SOB. Last seen by PMD 5 years ago.
T 98.8 (R), BP 180/100, HR 97, RR 16, O2 99% RA
EXAM: Head atraumatic, PERRLA, ears clear BL, throat midline. Heart RRR no MRG. Lungs CTAB. Abd with mild periumbilical discomfort. Extremities warm, well perfused.
Images obtained by ultrasound are seen below.
1. What do you see?
2. What are the normal dimensions of the aorta?
3. What are the different views and landmarks needed to identify the aorta by ultrasound?
4. What are the next steps in the management of this patient?
5. Where are 95% of abdominal aortic aneurysms located?
- Saccular abdominal aortic aneurysm
- The aorta should measure less than 3.0 cm in diameter, and iliac arteries should measure less than 1.5 cm in diameter, measured from outer wall to outer wall.
- Proximal aorta: “sea gull” sign which is created by the celiac trunk/axis splitting into the common hepatic artery and splenic artery. The left gastric artery is also part of the celiac axis, but is not visualized during the transabdominal bedside ultrasound scan.
Middle aorta: “mantle clock” sign created by the superior mesenteric artery and the hyperechoic fat surrounding the vessel. The splenic vein runs superior to the SMA and the left renal vein runs inferior to the SMA and superior to the aorta.
Distal aorta: located just proximal to the iliac bifurcation.
- Consult vascular surgery. Medical optimization of blood pressure.
- 95% of abdominal aortic aneurysms are located in the infrarenal portion of the aorta.