RANZCR is a non-profit association that delivers skills, knowledge, and insight to promote the science and practice of the medical specialties of clinical radiology (diagnostic and interventional) and radiation oncology.

Recommendations and resources

1) Don’t request imaging for acute ankle trauma unless indicated by the Ottawa Ankle Rules (localised bone tenderness or inability to weight-bear as defined in the Rules).

Most clinically significant acute ankle injuries can be diagnosed with history, examination, and selective use of plain radiography.

Extensive validation studies have shown that the Ottawa Ankle Rules can be safely applied to adult and paediatric populations.

Selective use of plain radiography in patients with acute ankle injury is useful in identifying patients who have sustained clinically important fracture, dislocation, and osteochondral injuries. However, acute ligamentous injuries involving the anterior talofibular ligament can be diagnosed clinically and treated symptomatically.
When there are persistent symptoms (such as pain and swelling) after an acute injury, which raise suspicion of either instability or other internal derangement, such as osteochondral injury, MRI can be used if the non-urgent (or delayed or elective or similar) weight bearing x-rays show no abnormality.

Recommendation released April 2015, reviewed April 2016.


2) Don’t request duplex compression ultrasound for suspected lower limb deep venous thrombosis in ambulatory outpatients unless the Wells Score (deep venous thrombosis risk assessment score) is greater than 2, OR if less than 2, D dimer assay is positive.

The potential complications of untreated deep venous thrombosis (DVT) include thrombus propagation, pulmonary embolism (PE) and death from PE. A significant but under-appreciated longer-term complication is post-thrombotic syndrome (PTS) and this can occur in up to 40% of patients with proximal DVT, as a result of venous incompetence and hypertension.

Wells et al. (2003) showed that ambulatory outpatients with suspected lower limb DVT and a DVT risk assessment score (Wells Score) of less than 2, can have DVT excluded by a negative result on D dimer assay, obviating the need to perform duplex compression ultrasound. The lower limit of the negative predictive value of the combination of a score.

Recommendation released April 2015, reviewed April 2016.


3) Don’t request any diagnostic testing for suspected pulmonary embolism (PE) unless indicated by Wells Score (or Charlotte Rule) followed by PE Rule-out Criteria (in patients not pregnant). Low risk patients in whom diagnostic testing is indicated should have PE excluded by a negative D dimer, not imaging.

Pulmonary embolism (PE) affects 2-3 per 1000 adults per year. It can be fatal if untreated, more often in hospitalised people than outpatients. The symptoms and signs of PE (chest pain, cough, dyspnoea, and tachycardia) are non specific and so imaging is required to make the diagnosis.

PE is diagnosed by direct (CT pulmonary angiogram) or indirect (ventilation/perfusion or “V/Q” lung scanning) demonstration of the emboli within the pulmonary arterial tree. PE can be excluded in low risk patients by a negative result on whole blood D dimer. Some low risk patients (“Pulmonary Embolism Rule-out Criteria [PERC] negative”) are at such low risk they require no diagnostic testing, including D dimer.
Clinical decision rules (CDRs) are more specific than clinical gestalt in determining which patients are unlikely to have PE, and thus can prevent unnecessary imaging in these groups.

Validated risk assessment strategies are not applicable to pregnant women and D dimer is physiologically elevated early in pregnancy. Ventilation perfusion lung scanning is the test of choice in the presence of a normal chest radiograph in a pregnant woman with suspected PE as the radiation dose to the breast is much lower than for CT pulmonary angiography and the fetal dose is very small and comparable for both imaging tests.

Recommendation released April 2015, reviewed April 2016.


4) Don’t perform imaging for patients with non-specific acute low back pain and no indicators of a serious cause for low back pain.

Low back pain (LBP) is extremely common, being the third most common health complaint seen by Australian general practitioners.
A simple classification places patients into one of three categories:

  • LBP associated with sciatica or spinal canal stenosis
  • Serious spinal pathology (such as cancer, infection, fracture, and cauda equina syndrome) comprises 1% of GP presentations with LBP
  • Non-specific low back pain (90% of presentations)

When evaluating patients with acute LBP, one of the key issues to be addressed is whether or not the patient should be investigated using imaging to confirm or refute the presence of an underlying/associated condition that would change the subsequent medical treatment or investigation of the patient.
Age over 70 years, trauma, corticosteroid therapy, and female gender are risk factors for fracture and previous or current cancer significantly increases the likelihood of cancer related back pain. At least one of fever, systemic symptoms, recent invasive procedure or sepsis, or elevated CRP are seen in most but not all patients with discitis or epidural abscess. New lower limb or bladder motor dysfunction increase the likelihood of cauda equina syndrome in a patient with LBP and are indications for emergency MRI.

Recommendation released April 2015, reviewed April 2016.


5) Don’t request imaging of the cervical spine in trauma patients, unless indicated by a validated clinical decision rule.

Cervical spine imaging of every trauma patient is costly and results in significant radiation exposure to a large number of patients, very few of whom will have a spinal column injury. Clinical decision rules have been developed that identify patients who can safely be managed without imaging. These rules include the Canadian C-Spine rule or Nexus Low Risk Criteria. The Canadian C-Spine Rule provides higher specificity and lower imaging requirements, and should be used if possible.

This is a joint recommendation with The Australasian College for Emergency Medicine (ACEM).

Recommendation released April 2015, reviewed April 2016.


6) Don’t request computed tomography (CT) head scans in patients with a head injury, unless indicated by a validated clinical decision rule.

Most head injuries presenting to emergency departments will be minor and do not require immediate neurosurgical intervention or inpatient care. Mild head injury patients can be risk stratified into ‘low’ or ‘high’ risk groups based on the presence or absence of identified clinical risk factors. Current validated clinical decision rules include the Canadian CT Head Rule (for adults) or the PECARN (Paediatric Emergency Care Applied Research Network) Tool (for children). These rules can safely identify patients who can be discharged home, without CT scanning.

This is a joint recommendation with Australasian College for Emergency Medicine (ACEM).

Recommendation released April 2015, reviewed April 2016.


Supporting evidence

  • Recommendation one

    • Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Worthington JR. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Ann Emerg Med. 1992; 21(4): 384-90.
  • Recommendation two

    • Wells PS, Anderson DR, Rodger M, Forgie M, Kearon C, Dreyer J, et al. Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis. N Engl J Med. 2003; 349(13): 1227-35.
    • Oudega R, Moons KG, Hoes AW. Ruling out deep venous thrombosis in primary care. A simple diagnostic algorithm including D-dimer testing. Thromb Haemost. 2005; 94(1): 200-5.
  • Recommendation three

    • Lucassen W, Geersing GJ, Erkens PM, Reitsma JB, Moons KG, Buller H, et al. Clinical decision rules for excluding pulmonary embolism: A meta-analysis. Ann Intern Med. 2011; 155(7): 448-60.
    • Wells PS, Anderson DR, Rodger M, Ginsberg JS, Kearon C, Gent M, et al. Derivation of a Simple Clinical Model to Categorize Patients Probability of Pulmonary Embolism-Increasing the Models Utility with the SimpliRED D-dimer. Thromb Haemost. 2000; 83(3): 416-20. Stuttgart.
    • Gibson NS, Sohne M, Kruip MJ, Tick LW, Gerdes VE, Bossuyt PM, et al. Further validation and simplification of the Wells clinical decision rule in pulmonary embolism. Thromb Haemost. 2008; 99(1): 229-34.
    • Le Gal G, Righini M, Roy P, Sanchez O, Aujesky D, Bounameaux H, et al. Prediction of pulmonary embolism in the emergency department: The Revised Geneva Score. Ann Intern Med. 2006; 144(3): 165-71.
    • Klok FA, Mos IC, Nijkeuter M, Righini M, Perrier A, Le Gal G, et al. Simplification of the Revised Geneva score for assessing clinical probability of pulmonary embolism. Arch Intern Med. 2008; 168(19): 2131-6.
    • Douma RA, Gibson NS, Gerdes VE, Buller HR, Wells PS, Perrier A, et al. Validity and clinical utility of the Simplified Wells rule for assessing clinical probability for the exclusion of pulmonary embolism. Thromb Haemost. 2009; 101(1): 197-200.
    • Kline JA, Nelson RD, Jackson RE, Courtney DM. Criteria for the safe use of D-dimer testing in emergency department patients with suspected pulmonary embolism: A multicenter US study. Ann Emerg Med. 2002; 39(2): 144-52.
    • Kline JA, Mitchell AM, Kabrhel C, Richman PB, Courtney DM. Clinical criteria to prevent unnecessary diagnostic testing in emergency department patients with suspected pulmonary embolism. J Thromb Haemost. 2004; 2(8): 1247-55.
    • Kline JA, Courtney DM, Kabrhel C, Moore CL, Smithline HA, Plewa MC, et al. Prospective multicenter evaluation of the Pulmonary Embolism Rule-out Criteria. J Thromb Haemost. 2008; 6(5): 772-80.
    • Singh B, Parsaik AK, Agarwal D, Surana A, Mascarenhas SS, Chandra S. Diagnostic accuracy of Pulmonary Embolism Rule-out Criteria: A systematic review and meta-analysis. Ann Emerg Med. 2012; 59(6): 517-20.e4.
    • McLintock C, Brighton T, Chunilal S, Dekker G, McDonnell N, McRae S, et al. Recommendations for the diagnosis and treatment of deep venous thrombosis and pulmonary embolism in pregnancy and the postpartum period. Aust N Z J Obstet Gynaecol. 2012; 52(1): 14-22.
    • Douma RA, Mos IC, Erkens PM, Nizet TAC, Durian MF, Hovens MM, et al. Performance of 4 clinical decision rules in the diagnostic management of acute pulmonary embolism – A prospective cohort study. Ann Intern Med. 2011; 154(11): 709-18.
    • Wolf SJ, McCubbin TR, Nordenholz KE, Naviaux NW, Haukoos JS. Assessment of the Pulmonary Embolism Rule-out Criteria rule for evaluation of suspected pulmonary embolism in the emergency department. Am J Emerg Med. 2008; 26(2): 181-5.
    • Kline JA, Peterson CE, Steuerwald MT. Prospective evaluation of real time use of the Pulmonary Embolism Rule-out Criteria in an academic emergency department. Acad Emerg Med. 2010; 17(9): 1016-9.
    • Penaloza A, Verschuren F, Dambrine S, Zech F, Thys F, Roy P-M. Performance of the Pulmonary Embolism Rule-out Criteria (the PERC rule) combined with low clinical probability in high prevalence population. Thromb Res. 2012; 129(5): e189-93.
  • Recommendation four

    • Henschke N, Maher CG, Refshauge KM, et al. Prognosis in patients with recent onset low back pain in Australian primary care: inception cohort study. BMJ (Clinical Research Ed). 2008; 337: a171.
    • Koes BW, van Tulder M, Lin CW, Macedo LG, McAuley J and Maher C. An updated overview of clinical guidelines for the management of non-specific low back pain in primary care. Eur Spine J. 2010.
    • Henschke N, Maher C, Refshauge K, et al. Prevalence of and screening for serious spinal pathology in patients presenting to primary care settings with acute low back pain. Arthritis Rheum. 2009; 60: 3072-80.
    • Chou R, Qaseem A, Owens DK and Shekelle P. Diagnostic Imaging for Low Back Pain: Advice for High-Value Health Care From the American College of Physicians. Ann Intern Med. 2011; 154: 181-9.
    • Williams CM, Henschke N, Maher CG, et al. Red flags to screen for vertebral fracture in patients presenting with low back pain. Cochrane Database Syst Rev 2013. 2013.
    • Henschke N, Maher CG, Ostelo RW, de Vet HC, Macaskill P and Irwig L. Red flags to screen for malignancy in patients with low-back pain. Cochrane Database Syst Rev 2013. 2013; 2.
    • Henschke N, Maher C and Refshauge K. Screening for malignancy in low back pain patients: a systematic review. Eur Spine J. 2007; 16: 1673-9.
  • Recommendation five

    • Stiell IG, Wells GA, Vandemheen KL, Clement CM, Lesiuk H, De Maio VJ, et al. The Canadian C-Spine Rule for radiography in alert and stable trauma patients. JAMA. 2001; 286(15): 1841-8.
    • Hoffman JR, Wolfson AB, Todd K, Mower WR. Selective cervical spine radiography in blunt trauma: methodology of the National Emergency X-Radiography Utilization Study (NEXUS). Ann Emerg Med. 1998; 32(4): 461-9.
    • Stiell IG, Clement CM, McKnight RD, Brison R, Schull MJ, Rowe BH, et al. The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. 2003; 349(26): 2510-8.
    • Miller P, Coffey F, Reid A-M, Stevenson K. Can emergency nurses use the Canadian cervical spine rule to reduce unnecessary patient immobilisation? Accid Emerg Nurs. 2006; 14(3): 133-40.
    • Vaillancourt C, Stiell IG, Beaudoin T, Maloney J, Anton AR, Bradford P, et al. The out-of-hospital validation of the Canadian C-Spine Rule by paramedics. Ann Emerg Med. 2009; 54(5): 663-71 e1.
    • Hoffman JR, Mower WR, Wolfson AB, Todd KH, Zucker MI. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. National Emergency X-Radiography Utilization Study Group. N Engl J Med. 2000; 343(2): 94-9.
    • Mahler S, Pattani S, Caldito G. Use of a clinical sobriety assessment tool with the NEXUS low-risk cervical spine criteria to reduce cervical spine imaging in blunt trauma patients with acute alcohol or drug use: A pilot study. Ann Emerg Med. 2009; 54: S26-7.
    • Griffith B, Bolton C, Goyal N, Brown ML, Jain R. Screening cervical spine CT in a level I trauma center: Overutilization? AJR Am J Roentgenol. 2011; 197(2): 463-7.
    • Migliore S, Strelkauskas A, Matteucci M. The NEXUS criteria: Inter-rater reliability between residents versus attending physicians in the emergency department. Acad Emerg Med. 2011; 18: S139-40.
    • Rethnam U, Yesupalan R, Gandham G. Does applying the Canadian Cervical Spine rule reduce cervical spine radiography rates in alert patients with blunt trauma to the neck? A retrospective analysis. BMC Med Imaging. 2008; 8: 12.
    • Coffey F, Hewitt S, Stiell I, Howarth N, Miller P, Clement C, et al. Validation of the Canadian C-spine rule in the UK emergency department setting. Emerg Med J. 2011; 28(10): 873-6.
    • Duane TM, Wilson SP, Mayglothling J, Wolfe LG, Aboutanos MB, Whelan JF, et al. Canadian Cervical Spine rule compared with computed tomography: A prospective analysis. J Trauma. 2011; 71(2): 352-7.

    Paediatric specific resources

    • Viccellio P, Simon H, Pressman BD, Shah MN, Mower WR, Hoffman JR. A prospective multicenter study of cervical spine injury in children. Pediatrics. 2001; 108(2): E20.
  • Recommendation six

    • Finkelstein E, Corso P, Miller T, Associates. The Incidence and Economic Burden of Injuries in the United States. New York: Oxford University Press; 2006.
    • Haydel MJ, Preston CA, Mills TJ, Luber S, Blaudeau E, DeBlieux PM. Indications for computed tomography in patients with minor head injury. N Engl J Med. 2000; 343(2): 100-5.
    • Mower W, Hoffman J, Herbert M, Wolfson A, Pollack C, Zucker M, et al. Developing a clinical decision instrument to rule out intracranial injuries in patients with minor head trauma: methodology of the NEXUS II investigation. Ann Emerg Med. 2002; 40(5): 505-14.
    • Mower WR, Hoffman JR, Herbert M, Wolfson AB, Pollack CV, Jr., Zucker MI. Developing a decision instrument to guide computed tomographic imaging of blunt head injury patients. J Trauma. 2005; 59(4): 954-9.
    • Stiell IG, Lesiuk H, Wells G, McKnight R, Brison R, Clement C, et al. The Canadian CT Head Rule Study for patients with minor head injury: Rationale, objectives, and methodology for phase I (derivation). Ann Emerg Med. 2001; 38(2): 160-9.
    • Stiell IG, Wells GA, Vandemheen K, Clement C, Lesiuk H, Laupacis A, et al. The Canadian CT Head Rule for patients with minor head injury. Lancet. 2001; 357(9266): 1391-6.
    • Stiell IG, Lesiuk H, Wells GA, Coyle D, McKnight RD, Brison R, et al. Canadian CT head rule study for patients with minor head injury: methodology for phase II (validation and economic analysis). Annals of emergency medicine. 2001; 38(3): 317-22.
    • Ro Y, Shin S, Holmes J, Song K, Park J, Cho J, et al. Comparison of clinical performance of cranial computed tomography rules in patients with minor head injury: a multicenter prospective study. Academic emergency medicine. 2011; 18(6): 597-604.
    • Bouida W, Marghli S, Souissi S, Ksibi H, Methammem M, Haguiga H, et al. Prediction Value of the Canadian CT Head Rule and the New Orleans Criteria for Positive Head CT Scan and Acute Neurosurgical Procedures in Minor Head Trauma: A Multicenter External Validation Study. Annals of emergency medicine. 2012; 61(5): 521-7.

    Paediatric specific references

    • Kuppermann N, Holmes JF, Dayan PS, Hoyle JD, Jr., Atabaki SM, Holubkov R, et al. Identification of children at very low risk of clinically-important brain injuries after head trauma: a prospective cohort study. Lancet. 2009; 374(9696): 1160-70.
    • Dunning J, Daly JP, Lomas JP, Lecky F, Batchelor J, Mackway-Jones K. Derivation of the children’s head injury algorithm for the prediction of important clinical events decision rule for head injury in children. Arch Dis Child. 2006; 91(11): 885-91.
    • Osmond M, Klassen T, Wells G, Correll R, Jarvis A, Joubert G, et al. CATCH: a clinical decision rule for the use of computed tomography in children with minor head injury. CMAJ. 2010; 182(4): 341-8.

Last reviewed April 2015

How this list was developed

Clinical radiology recommendations 1-6 (April 2015)

A team of five Lead Radiologists were nominated to guide RANZCR’s Choosing Wisely contribution. These Lead Radiologists analysed previous work completed by RANZCR, in particular a series of Education Modules for Appropriate Imaging Referrals.

These modules had been developed from an extensive evidence base and with multiple stakeholder input. Using the evidence from the Education Modules, the Lead Radiologists developed a draft recommendations list, which was then further developed and endorsed by RANZCR’s Quality and Safety Committee, before being circulated to the RANZCR membership for consultation with a request for alternative recommendations. Member feedback was reviewed by the Lead Radiologists prior to ratification of the final recommendations by the Faculty of Clinical Radiology Council. The final six items selected were those that were felt to meet the goals of Choosing Wisely, i.e. those which are frequently requested or which might expose patients to unnecessary radiation.

Due to the fundamental role of diagnostic imaging in supporting diagnosis across the healthcare system, RANZCR worked closely with other Colleges throughout the project via the Advisory Panel. Following identification of two common recommendations with the Australasian College for Emergency Medicine, it was agreed by both Colleges to present these items jointly. Each organisation was approached for- and subsequently granted – approval to adapt these recommendations as part of the Choosing Wisely New Zealand initiative.


Last updated 12/08/2021