The levels of evidence [A-D] supporting the recommendations are defined at the end of the "Major Recommendations" field.
Abdominal Ultrasonography
Patient Preparation
- The patient should not eat for 6 hours and drink for 2 hours before the examination.
- Fasting is necessary when examining the gallbladder because eating causes a contraction of the bladder. In other indications, the effect of eating or drinking is minimal or null.
- In emergency cases, the examination can be performed without preparations.
Upper Abdomen
- Includes the liver, gallbladder, biliary tract, pancreas, spleen, kidneys, aorta, and retroperitoneal space (for details see below)
Ascites
- Clinically suspected ascites can be confirmed. Ascites formation may be due to heart failure, cirrhosis of the liver, nephrotic syndrome or a tumour.
- Scant ascites is most easily detected between the right kidney and liver where it forms a crescent-shaped fluid collection. Look for ascites also in the lower abdomen around the urinary bladder where small amounts of fluid often accumulate.
Abdominal Infections
- Ultrasonography may be helpful in detecting acute infection or peritonitis (free fluid or gas in the abdominal cavity) when the indications for surgery are determined. Peritonitis is difficult to detect because decreased intestinal motility may make the visibility extremely bad.
- When intra-abdominal abscess as a complication of abdominal surgery or appendicitis (Orr, Porter, & Hartman, 1995) [B] is suspected. However, a computed tomography (CT) scan is often required.
- Ultrasonography is not a routine examination in suspected acute appendicitis because of its inaccuracy (even if the inflamed appendix can often be seen) (Orr, Porter, & Hartman, 1999) [B].
Pancreas
- Included in the upper abdominal examination
- Indications
- Suspicion of moderate or severe pancreatitis
- Suspicion of a pancreatic pseudocyst
- Suspicion of pancreatic carcinoma
- Pancreatic ultrasonography is rather insensitive and has many sources of error. Lying a longer time in supine position may cause the intestinal gas to accumulate and shadow the retroperitoneum in an unfavorable manner. It is recommendable to try also other positions (tilting in different directions, sitting) to help in examining the pancreas that may sometimes be difficult to discern.
Liver
- Included in the upper abdominal examination
- All liver diseases: hepatomegaly, cirrhosis, tumours and metastases, cysts and abscesses, biliary obstruction, abdominal trauma, jaundice
- Cirrhosis and fatty change of the liver increase the echo intensity of the liver. The renal cortex provides a good reference point because it normally has similar density to the liver.
- The sensitivity in the diagnosis of cirrhosis is probably poor. The liver may be smaller than usual, with poorly defined borders and uneven echogenicity. Ascites and collateral vessels may be detected in the terminal phase.
Kidneys and Adrenal Glands
- Included in the upper abdominal examination
- Diagnostics of renal tumours, cysts (Kearon et al., 1998), polycystic kidney disease, hydronephrosis and traumas; examination of a silent kidney observed in urography
- Adrenal adenomas can often be diagnosed (but not excluded) by ultrasonography.
- Primary examination in children with urinary tract infection to exclude structural abnormalities
- No preparations are needed.
- In the assessment of recurrent abdominal pain in children the patient should not eat for 6 hours and drink for 2 hours before elective examination.
Spleen
- Included in the upper abdominal examination
- Splenomegaly, ruptured spleen in abdominal trauma. Ultrasonography is not sensitive in detecting ruptures so a suspicion of such requires clinical follow-up even if the finding is normal, repetition of the ultrasonography in unclear cases and ready use of other imaging techniques (computed tomography [CT], magnetic resonance imaging [MRI]).
Gallbladder
- Ultrasonography is a sensitive primary examination in biliary diagnostics: in cholelithiasis and in cholecystitis
- Cancer of the gallbladder cannot be ruled out by ultrasonography.
Urinary Bladder and Prostate
- Investigation of haematuria, diagnosis of urinary retention
- Residual urine after voiding (see pictures 1 & 2 in the original guideline document) (See also the related Finnish Medical Society Duodecim guideline on "Determining the Volume of Residual Urine by Ultrasonography")
- Size of the prostate (see picture 3 & 4 in the original guideline document), prostatic nodules
- Preparations: the patient should have a full bladder during the examination.
- Transrectal ultrasonography of the prostate is a basic examination by urologists in the assessment of prostatic disease.
Pelvic Ultrasonography and Ultrasonography During Pregnancy
- See the related Finnish Medical Society Duodecim guidelines and "Gynaecologic Ultrasound Examination" and "Ultrasound Scanning During Pregnancy."
Ultrasonography of Blood Vessels
Aorta
- Aortic aneurysm and dissection. An aneurysm larger than 3 cm in size warrants follow-up and a size over 5 cm requires consideration of operative treatment.
Vascular Prostheses
- Surgical complications: haematoma, aneurysm or abscess
Compression and Doppler Examination of the Lower Extremities
- Arterial obstruction and occlusion of the lower extremities (Koelemay et al., 1996) [B]
- Deep venous thrombosis of the femoral and popliteal veins (Kearon et al., 1998) [B] (See also the related Finnish Medical Society Duodecim guideline, "Deep Vein Thrombosis."). Ultrasonography is insensitive in the examination of calf veins (Wells et al., 1995) [A].
- The function of superficial veins can be assessed when planning surgery for varicose veins.
Carotid Arteries
- Carotid stenosis, follow-up after endarterectomy
- A stenosis of more than 50% with either measurement or flow criteria is usually considered as haemodynamically significant.
Thoracic Ultrasonography
Pleural and Pericardial Cavity
- Suspected pleural or pericardial effusion
- Echocardiography (by cardiologists)--see related Finnish Medical Society Duodecim guideline on "Echocardiology"
Thyroid and Parathyroid Ultrasonography
- Primary examination of a thyroid nodule
- No preparations are needed.
Soft Tissues and Joints of the Extremities
- Assessment of the need of surgical treatment for muscle and tendon injuries (e.g., rotator cuff, Achilles tendon, patellar tendon)
- Baker's cyst, bursal fluid, peritendinitis
- Diagnosis of synovitis
- Confirmation of the diagnosis of a ganglion
- A limp or hip pain in children (effusion of the hip joint)
Maxillary and Frontal Sinuses
- Diagnosis of sinusitis, follow-up the therapy
- See related Finnish Medical Society Duodecim guideline on "Diagnosis of Sinusitis"
Testis and Epididymis
- Enlarged or painful scrotum (differential diagnosis of testis torsion and epididymitis, varicocoele, hydrocoele, spermatocoele, scrotal hernia, haematoma, or contusion)
- Always when testicular tumour is suspected
- Investigation of male infertility
Ultrasonographically Guided Biopsies and Punctures
- Pleural fluid and ascites
- Evacuation of cysts, haematomas and abscesses
- Detecting and locating synovial fluid facilitates diagnostic aspiration especially from elbow, ankle and wrist joints. If the patient is afraid of the puncture, locating the fluid with ultrasonography usually ensures that the procedure is successful at first attempt.
- Cytological and histological specimens of suspected tumours (e.g. breast, thyroid gland)
Ultrasonographic Examinations by General Practitioners
- Ultrasonography is a dynamic examination that must be interpreted during the examination. The interpretation cannot usually be reliably performed from printouts afterwards.
- A doctor performing ultrasonographic examinations should be trained by a specialist.
- Some ultrasonographic examinations are suitable to be performed by any doctors, and some for non-radiologists with a special training.
- A positive finding is significant (be careful not to harm the patient with false positive findings): a negative finding in ultrasonography performed by an inexperienced examiner should not be used to rule out a treatable disease.
Any Doctor Can Perform the Following Examinations after Local Training
- Determination of the size and position of a fluid cavity before puncture (urinary bladder, pleural space, ascites, abscess, synovial fluid)
- Determination of residual urine volume and size of the prostate (see related Finnish Medical Society Duodecim guideline "Determining the Volume of Residual Urine by Ultrasonography") when planning pharmacotherapy for prosthetic hyperplasia.
A Doctor with Special Training for Ultrasonography Can Perform the Following Examinations
- Search for gallstones and signs of acute cholecystitis (thickened gallbladder wall, positive sonopalpation) in a patient with upper abdominal pain
- Search for hydronephrosis or dilated urinary tract in patient with urinary symptoms
- Diagnosis or exclusion of abdominal aortic aneurysm
- Detection of pericardial effusion
- Detection of ascites or intra-abdominal bleeding (e.g. in a patient with mild, blunt abdominal trauma that does not require referral on the basis of the history or clinical presentation)
- Estimation of the size of the spleen (a length exceeding 10-12 cm can be considered abnormal)
- Detection of a hydrocele
- Differentiation between a fluid collection or abscess from other subcutaneous masses (confirmation by puncture can be performed after ultrasonography)
- Some ultrasonographic examinations during pregnancy (see related Finnish Medical Society Duodecim guideline "Ultrasound Scanning during Pregnancy")
Related Evidence
- Compared with the landmark technique for placement of internal jugular and subclavian central venous catheters, ultrasound guidance significantly increases the probability of success and reduces the number of complications (Randolph et al., 1996) [A].
Definitions:
Levels of Evidence
- Strong research-based evidence. Multiple relevant, high-quality scientific studies with homogenic results.
- Moderate research-based evidence. At least one relevant, high-quality study or multiple adequate studies.
- Limited research-based evidence. At least one adequate scientific study.
- No research-based evidence. Expert panel evaluation of other information.
