Ultrasound Prioritization

Last updated on June 29, 2023

Logo of BC Guidelines

Effective Date: May 30th, 2018.

Recommendations and Topics

Scope

This guideline summarizes suggested wait times for common indications where ultrasound is the recommended first imaging test.  The purpose is to inform primary care practitioners of how referrals are prioritized by radiologists, radiology departments and community imaging clinics across the province.  This guideline is an adaptation of the British Columbia Radiological Society (BCRS) Ultrasound Prioritization Guidelines (2016).  Management of the listed clinical problems is beyond the scope of this guideline. However, in some cases, notes and alternative tests are provided for additional clinical context.  Primary care practitioners are encouraged to consult a radiologist if they have any concerns or questions regarding which is the appropriate imaging test to choose for a particular problem.

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Background

The BCRS Ultrasound Prioritization Guidelines (2016) were developed to provide imaging departments with a consistent, provincial approach to prioritizing commonly ordered ultrasound tests according to suggested maximum wait times.  The Guidelines were developed by consensus and are based on best BC expert opinion with representation of radiologists from across the province.  Several considerations apply:

  • These are guidelines, and as such, are designed to apply in general terms.  They are not intended to replace clinical judgement or physician-to-physician discussion.
  • Prioritization levels were selected to match other similar guidelines for CT and MRI and are typically assigned by radiologists rather than referring physicians.
  • These guidelines should not be applied rigidly to each case, as varying clinical factors may shift a particular indication from one priority level to another.
  • Access to ultrasound and the ability to respond to emergent/urgent ultrasound requests will depend on local availability.
  • The clinical topics included in this guideline represent broad examples, and do not encompass all possible scenarios or all requirements for ultrasound examinations.
  • These guidelines do not apply to inpatients or emergency room patients.

Priority Level Definitions

The priority levels defined below (Table 1) are in alignment with the Canadian Association of Radiologist's national designation Five Point Classification System1.

Table 1: Priority Level Definitions

Priority Level

Clinical Example

Maximum Suggested 

Wait Time

P1

An examination immediately necessary to diagnose and/or treat life-threatening disease. Such an examination will need to be done either stat or not later than the day of the request.

Immediately to 24 hours

P2

An examination indicated within one week of a request to resolve a clinical management imperative.

Maximum 7 calendar days

P3

An examination indicated to investigate symptoms of potential importance.

Maximum 30 calendar days

P4

An examination indicated for long-range management or for prevention.

Maximum 60 calendar days

P5

Timed follow-up exam or specified procedure date recommended by radiologist and/or clinician.

 

Source: Adapted from the Canadian Association of Radiologists National Maximum Wait Time Access Targets for Medical Imaging.

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Prioritization of Potential Diagnoses

The following potential diagnoses, where ultrasound is the recommended first test, are grouped according to system and then further subdivided into priority levels.  For each system an overview table is presented followed by a more detailed table outlining additional notes and alternative tests where appropriate.  Refer to Appendix A: Ultrasound Prioritization Guideline Summary for a one page summary of all potential diagnoses and prioritizations.  Referring practitioners may consider noting the priority directly on the requisition.

Abdomen and Pelvis

Abdomen and Pelvis: Overview

 P1

P2

P3

P4

P5

Immediately to 24 hours

Max 7 calendar days

Max 30 calendar days

Max 60 calendar days

Specified date

      

 

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Abdomen and Pelvis: Notes and Alternative Tests

Priority Level

Potential Diagnosis

Notes and Alternative Tests

P1

Acute abdominal pain (e.g., appendicitis, cholecystitis,)

  • Choice of first-line test will depend on likely origin of pain and suspected clinical diagnosis, for example:
    • If acute pancreatitis, suggest CT
    • If bowel ischemia, suggest CT
    • If ultrasound is equivocal for appendicitis, consider CT or MRI
  • CT is not recommended for the evaluation of suspected appendicitis in children until after ultrasound has been considered as an option (Choosing Wisely Radiology recommendation)

Acute post-transplant assessment

  • CT for liver transplant if ultrasound inconclusive

Splenic rupture

  • CT is typically ordered as first-line imaging for trauma
  • In pediatric and pregnant population, consider ultrasound as first-line 

Septic renal colic/focal pyelonephritis

  • In pediatric, young female and pregnant population consider ultrasound as first-line
  • CT KUB (kidney/urinary/bladder) can be first-line for renal colic

Acute painful hernia (obstruction, strangulation, or ischemia suspected)

  • If concern for bowel obstruction, consider plain film prior to ultrasound 
  • If ultrasound is inconclusive, CT can be used

Intra-abdominal abscess

 

Painful jaundice

 

Testicular torsion/epididymitis

 

Testicular rupture

  • Associated with an episode of preceding scrotal trauma

Priapism

  • Typically referred by urology or emergency department to elucidate cause

P2

Acute painful hernia (obstruction, strangulation or ischemia not suspected)

  • If ultrasound is inconclusive, CT can be used
  • For acute painless hernia, ultrasound is not recommended

Painless jaundice

  • CT is recommended for characterization if a mass is seen on ultrasound in the liver or pancreas

Pancreatitis, complications

  • To assess for fluid collections and to identify any underlying causes such as gallstones and/or common bile duct stones

Painless hematuria

  • Includes microscopic and macroscopic hematuria
  • Negative ultrasound still requires follow-up (consider CT)

Renal colic

  • Ultrasound is first-line imaging test in pediatric patients and pregnant women
  • Consider CT KUB (kidney/urinary/bladder) as first-line test in adults

Acute renal failure

  • To rule out obstructive uropathy

New testicular mass

 

New painless abdominal or pelvic mass

  • CT is often considered first-line in this situation except in pediatrics
  • In rural and remote areas where CT may  not be available, ultrasound is the first choice modality

P3

Acute painless hernia/chronic hernia

  • Generally no imaging is required, ultrasound may be ordered if diagnosis is in doubt

Extra-testicular mass

  • For example, to differentiate hydrocele, varicocele, epididymal cyst

Cholelithiasis

 

New pulsatile abdominal mass

  • Suspect previously undiagnosed abdominal aortic aneurysm (AAA)

Renal stone burden                 

  • May be supplemented with CT KUB (kidney/urinary/bladder) or KUB radiograph as needed

P4

Chronic abdominal pain/bloating

  • If associated symptoms suggest potential malignancy, consider P3

Abnormal liver function tests/ known chronic liver disease

  • Includes non-alcoholic fatty liver disease (NALFLD) or other causes of chronic hepatitis
  • Includes screening for hepatocellular carcinoma (HCC) in patients with known Hep B/C or other risk factors
  • Interval follow-up may be recommended based on hepatology guidelines2

Pre-transplant work-up

  • As indicated by pre-transplant orders
  • Urgency may be dictated by anticipated surgery date
Scrotal or pelvic ultrasound as part of workup for varicocele embolization/ uterine artery embolization
  • Typically referred by specialists prior to procedure
Peyronie’s disease
  • Typically referred by specialists

P5

Known abdominal aortic aneurysm /endovascular abdominal aortic aneurysm repair follow-up

  • CT can be an alternative imaging test or if ultrasound is technically challenging
  • Timed follow-up, usually done yearly or per advice of vascular surgeon

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Pediatrics

Pediatrics: Overview

P1

P2

P3

P4

Immediately to 24 hours

Max 7 calendar days

Max 30 calendar days

Max 60 calendar days

  • Pyloric stenosis
  • Intussusception
  • Clinically suspicious intra-abdominal/ pelvic mass

 

Pediatrics:  Notes and Alternative Tests

Priority Level

Potential Diagnosis

Notes and Alternative Tests

P1

Pyloric stenosis

 

Intussusception

 

Clinically suspicious

intra-abdominal/pelvic

mass

 

P2

Increasing head circumference (hydrocephalus)

  • Providing the fontanelles are still open

Biliary atresia as the cause of neonatal jaundice

  • When jaundice is refractory or severe
  • Usually requested by pediatrician

P3

Follow-up antenatal hydronephrosis

  • Refer to Associated Documents - BC Children’s Hospital Antenatal Hydronephrosis Imaging Guideline

P4

Developmental dysplasia of the hip (DDH)

  • P4 provided that requisition is sent in at birth, exam should be completed by 4-6 weeks
  • If requisition is sent later, DDH may become a P2 or P3 exam so that exam is completed by 4-6 weeks

Spine ultrasound (prior to 5 months of age)

  • Typically for dysraphism or cord tethering

Urinary tract infection (UTI)

  • For recurrent UTIs, to rule out or confirm bladder problems

Chronic liver disease

  • Or for cystic fibrosis liver evaluation

Renal anomaly

 

 

Obstetrics and Gynecology

Obstetrics and Gynecology: Overview

P1

P2

P3

P4

Immediately to 24 hours

Max 7 calendar days

Max 30 calendar days

Max 60 calendar days

Obstetrics and Gynecology: Notes and Alternative Tests

Priority Level

Potential Diagnosis

Notes and Alternative Tests

P1

Ectopic pregnancy

  • Indicated if clinically suspect pregnant, positive beta human chorionic gonadotropin (BHCG), or pain and/or bleeding regardless of BHCG level

Threatened abortion

 

Embryonic/fetal demise3

 

Placental abruption

 

Vasa/vena previa

 

Pre-term labour to determine cervical length

  • Endovaginal ultrasound to be used if a transabdominal scan is inconclusive

Acute pelvic pain of suspected gynecological cause (e.g., query ruptured cyst, pelvic inflammatory disease, ovarian torsion)

  • MRI can be used in selected cases if ultrasound is inconclusive and if locally available

P2

Medical abortion

  • To confirm intra-uterine pregnancy and gestational age prior to medical abortion4

Polyhydramnios

 

Oligohydramnios

 

Follow-up of oligohydramnios

  • AFI (amniotic fluid index)/fluid volume unless otherwise specified i.e. patient has regularly scheduled checks for AFI

Intrauterine growth restriction (IUGR)

  • Consider P5 as necessary

Post-dates fluid assessment

  • Consider P5 as necessary

Intrauterine device (IUD) localization with pain

 

P3

Post-menopausal bleeding

  • Negative ultrasound should not interfere with further investigation to exclude malignancy

Follow up possible fetal abnormality from routine detail scan

  • Generally as suggested by perinatal specialist

 

High-risk pregnancy

  • Follow-up amniotic fluid is P3 unless otherwise specified by radiologist and/or clinician (i.e. P2)

Pelvic mass

  • Masses detected on pelvic exam include causes such as ovarian cysts and fibroids
  • If symptomatic consider higher priority

Intrauterine device (IUD) localization

  • If without symptoms or bleeding

P4

Dysfunctional uterine bleeding e.g., fibroids, adenomyosis

 

Follow-up placental location

  • If follow-up recommended, not indicated before 32 weeks. If the ultrasound is performed earlier (28-32 weeks) and placenta is found to be low lying, the ultrasound should be repeated at 32 weeks given the significant rate of growth between 28 and 32 weeks.  

Adnexal cyst follow-up (unless otherwise specified)

  • Interval follow-up may be recommended based on the Society of Radiologists in Ultrasound guidelines5

Fetal detail exam (unless otherwise specified)

 

 

 Musculoskeletal/Extremity Overview

P1

P2

P3

P4

P5

Immediately to 24 hours

Max 7 calendar days

Max 30

calendar days

Max 60 calendar days

Specified time

Musculoskeletal/Extremity

Musculoskeletal/Extremity:  Notes and Alternative Tests

Priority Level

Potential Diagnosis

Notes and Alternative Tests

P1

Deep vein thrombosis

  • Correlate with D dimer if available

Septic arthritis/toxic synovitis

  • If effusion present, may prompt fine needle aspiration

Abscess

  • To confirm presence of fluid and exclude solid mass

P2

Acute tendon tears

  • Typically achilles or biceps require emergent surgery or management
  • Except rotator cuff tears which typically are not surgical
  • Unless specified under P4

P3

New palpable neck/thyroid mass

New palpable extremity mass

  • To determine if the mass is cystic or solid
  • If suspicious features on clinical exam or sonograph, CT or MRI may be recommended

Acute rotator cuff tear

  • As part of orthopedic referral or pre-surgical
  • MRI is an alternative test usually suggested by a radiologist if ultrasound is inconclusive, or ordered by a surgeon

P4

Synovitis/arthropathy follow-up

  • Typically ordered by rheumatologists for patients on biologics for inflammatory arthritis

Tendinopathy, chronic shoulder pain, non-operative rotator cuff tear

 

Bursitis

 

Chronic palpable mass

  • E.g., differentiate lipoma, sebaceous cyst, or other

Multi nodular goiter

  • Follow-up studies can be used to confirm stability

Carpal tunnel syndrome or other neuropathy

  • May be useful if other diagnostic tests are equivocal
  • Usually requires specialist referral

Baker’s Cyst

  • To confirm diagnosis and exclude alternate etiology

P5

Follow-up of soft tissue mass

  • To confirm stability

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General

 General: Overview

P1

P2

P3

P4

P5

Immediately to 24 hours

Max 7 calendar days

Max 30 calendar days

Max 60 calendar days

Specified time

  • Abscess

 

 

 

General:  Notes and Alternative Tests

Priority Level

Potential Diagnosis

Notes and Alternative Tests

P1

Abscess

 

P2

Cancer staging or metastatic workup

  • CT is often the preferred modality

New suspicious palpable mass

  • E.g., new breast or lymph node mass

P5

Follow-up of breast mass

  • To confirm stability. For additional guidance refer to BI-RADS6.

 

 

Vascular

Vascular: Overview

P1

P2

P3

P4

P5

Immediately to 24 hours

Max 7 calendar days

Max 30 calendar days

Max 60 calendar days

Specified time

 

 

  • Follow-up of prior carotid surgery or stenting

 

Vascular: Notes and Alternative Tests

Priority Level

Potential Diagnosis

Notes and Alternative Tests

P2

Carotid ultrasound with acute stroke/transient ischemic attack symptoms

  • CT head and computed tomography angiography (CTA) is obligatory for acute stroke assessment but carotid ultrasound is a useful supplementary test
  • Carotid ultrasound may be used to clarify the degree of stenosis if a large amount of calcified plaque is present on  CTA limiting assessment or if a bruit has been heard

P4

Carotid doppler screening

  • For patients with high risk factors or bruit

P5

Follow-up of prior carotid surgery or stenting

 

Resources

  • Canadian Association of Radiology Diagnostic Imaging Referral Guidelines (2012)

www.car.ca/en/standards-guidelines/guidelines.aspx

  • American College of Radiology Appropriateness Criteria

www.acr.org/Quality-Safety/Appropriateness-Criteria

  • Society of Radiologists in Ultrasound 

www.sru.org

  • Choosing Wisely Radiology Recommendations:

Radiology: choosingwiselycanada.org/radiology/

Endocrinology and Metabolism: choosingwiselycanada.org/endocrinology-and-metabolism/

Appendices

Associated Documents

The following documents accompany this guideline

BC Children’s Hospital Antenatal Hydronephrosis Imaging Guideline:

References

  1. Canadian Association of Radiologists National Maximum Wait Time Access Targets for Medical Imaging (MRI and CT).
  2. Heimbach J, Kulik LM, Finn R, et al. AASLD guidelines for the treatment of hepatocellular carcinoma. Hepatology. 2017; Jan 28. [Epub ahead of print].
  3. Doubilet PM, Benson CB, Bourne T, et al. Diagnostic Criteria for Nonviable Pregnancy Early in the First Trimester. N Engl J Med. 2013;369:1443-1451.
  4. Cotescu D, Guilbert E, Benadin J et al. Medical Abortion. J Obstet Gynaecol Can 2016;38(4):366-389.
  5. Levine D, Brown D, Andreotti RF et al. Management of Asymptomatic Ovarian and Other Adnexal Cysts Imaged at US: Society of Radiologists in Ultrasound Consensus Conference Statement. Ultrasound Quarterly. 2010;26(3):121-131.
  6. Mendelson EB, Böhm-Vélez M, Berg WA, et al. ACR BI-RADS® Ultrasound. In: ACR BI-RADS® Atlas, Breast Imaging Reporting and Data System. Reston, VA, American College of Radiology; 2013.

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This guideline is based on expert BC clinical practice current as of the Effective Date. This guideline was developed by the Guidelines and Protocols Advisory Committee based on the British Columbia Radiological Society Ultrasound Prioritization Guidelines (2016), and approved by the Medical Services Commission.

The principles of the Guidelines and Protocols Advisory Committee are to:

  • encourage appropriate responses to common medical situations
  • recommend actions that are sufficient and efficient, neither excessive nor deficient
  • permit exceptions when justified by clinical circumstances.
Contact Information
Guidelines and Protocols Advisory Committee
PO Box 9642 STN PROV GOVT
Victoria BC V8W 9P1
E-mail: hlth.guidelines@gov.bc.ca
Web site: www.BCGuidelines.ca

 

Disclaimer The Clinical Practice Guidelines (the "Guidelines") have been developed by the Guidelines and Protocols Advisory Committee on behalf of the Medical Services Commission. The Guidelines are intended to give an understanding of a clinical problem and outline one or more preferred approaches to the investigation and management of the problem. The Guidelines are not intended as a substitute for the advice or professional judgment of a health care professional, nor are they intended to be the only approach to the management of clinical problems.  We cannot respond to patients or patient advocates requesting advice on issues related to medical conditions. If you need medical advice, please contact a health care professional.

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