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Patients undergoing recurrent CT exams: assessment of patients with non-malignant diseases, reasons for imaging and imaging appropriateness

An Editorial Comment to this article was published on 30 January 2020



To determine percent of patients without malignancy and ≤ 40 years of age with high cumulative radiation doses through recurrent CT exams and assess imaging appropriateness.


From the cohort of patients who received cumulative effective dose (CED) of ≥ 100 mSv over a 5-year period, a sub-set was identified with non-malignant disease. The top 50 clinical indications leading to multiple CTs were determined. Clinical decision support (CDS) system scores were analyzed using a widely adopted standard of 1–3 (red) as “not usually appropriate,” 4–6 (yellow) “may or may not be appropriate,” and 7–9 (green) “usually appropriate.” Clinicians reviewed patient records to assess compliance with appropriate use criteria (AUC).


9.6% of patients in our series were with non-malignant conditions and 1.4% with age ≤ 40 years. CDS scores (rounded) were 2% red, 38% yellow, 27% green, and 33% unscored CTs. Clinical society guidelines for CT exams, wherever available, were followed in 87.5 to 100% of cases. AUCs were not available for several clinical indications as also referral guidelines for serial CT imaging. More than half of CT exams were unrelated to follow-up of a primary chronic disease.


We are faced with a situation wherein patients in age ≤ 40 years require or are thought to require many CT exams over the course of a few years but the radiation risk creates concern. There is a fair number of conditions for which AUC are not available. Suggested solutions include development of CT scanners with lesser radiation dose and further development of appropriateness criteria.

Key Points

  • We are faced with a situation wherein patients in age group 0–40 years and with non-malignant diagnosis require or are thought to require many CT exams over the course of a few years.

  • More than half of CT exams were unrelated to follow-up of a primary chronic disease.

  • Imaging guidelines and appropriateness use criteria are not available for many conditions. Wherever available, they are for initial work-up and diagnosis and there is a lack of guidance on serial CT imaging.

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American College of Cardiology


American College of Critical Care Medicine


American College of Radiology


Advanced diagnostic imaging services


Appropriateness use criteria


Clinical decision support


Cumulative effective dose


Centers for Medicare & Medicaid Services


Chronic obstructive pulmonary disease


Computed tomography


Effective dose


Infectious Disease Society of America


Institutional Review Board


Magnetic resonance imaging


National Comprehensive Cancer Network


Protecting Access to Medicare Act


Positron emission tomography


Research Patient Data Registry


Society of Nuclear Medicine and Molecular Imaging


  1. Sistrom CL (2009) The appropriateness of imaging: a comprehensive conceptual framework. Radiology 251(3):637–649

    Article  Google Scholar 

  2. American College of Radiology (ACR) (2018) ACR Appropriateness Criteria [Internet] [updated 2019; cited 2019 July 29]. Accessed 7 Nov 2019

  3. The Royal College of Radiologist. iRefer: radiological investigation guidelines tool, RCR, London Accessed 7 Nov 2019

  4. European Society of Radiology. Referral guidelines for imaging. Accessed 7 Nov 2019

  5. Centers for Medicare & Medicaid Services (CMS), Department of Health and Human Services (HHS) (2016) Appropriate Use Criteria Program. Accessed 7 Nov 2019

  6. Rehani MM, Yang K, Melick ER, Heil J, Šalát D, Sensakovic WF, Liu W (2019) Patients undergoing recurrent CT scans: assessing the magnitude. Eur Radiol.

  7. (2007) The 2007 recommendations of the International Commission on Radiological Protection. ICRP Publication 103. Ann ICRP 37(2-4):1–332

  8. United Nations Scientific Committee on the Effects of Atomic Radiation (2018) Sources, effects and risks of ionizing radiation. UNSCEAR 2017 Report [Internet]. New York, NY: UNSCEAR]. Available from: Accessed 7 Nov 2019

  9. National Council of Radiation Protection and Measurements (2018) Implications of recent epidemiologic studies for the linear-non threshold model and radiation protection. NCRP Commentary No. 27 [Internet]. Bethesda, Maryland: NCRP; Accessed 7 Nov 2019

  10. National Research Council (2006) Health risks from exposure to low levels of ionizing radiation: BEIR VII Phase 2 [Internet]. The National Academies Press, Washington.

    Book  Google Scholar 

  11. ACR Select – National Decision Support Company. CareSelect imaging [Internet]. [updated 2019; cited 2019 July 29]. Available from: Accessed 7 Nov 2019

  12. Hendel RC, Lindsay BD, Allen JM et al (2018) ACC Appropriate Use Criteria methodology: 2018 Update: A Report of the American College of Cardiology Appropriate Use Criteria Task Force. J Am Coll Cardiol 71(8):935–948.

  13. National Comprehensive Cancer Network (NCCN). NCCN Imaging Appropriate Use Criteria (NCCN Imaging AUCTM) Accessed 7 Nov 2019

  14. Society of Nuclear Medicine and Molecular Imaging (SNMMI) (2013) SNMMI Appropriate Use Criteria (AUC)

  15. Hiratzka LF, Bakris GL, Beckman JA, et al (2010) 2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM guidelines for the diagnosis and management of patients with thoracic aortic disease: executive summary. A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, American Association for Thoracic Surgery, American College of Radiology, American Stroke Association, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of Thoracic Surgeons, and Society for Vascular Medicine. Catheter Cardiovas Interv 76:E43-86.

  16. Rosenthal DI, Weilburg JB, Schultz T et al (2006) Radiology order entry with decision support: Initial clinical experience. J Am Coll Radiol 3(10):799–806

    Article  Google Scholar 

  17. Erbel R, Aboyans V, Boileau C et al (2014) 2014 ESC Guidelines on the diagnosis and treatment of aortic diseases: document covering acute and chronic aortic diseases of the thoracic and abdominal aorta of the adult. The Task Force for the Diagnosis and Treatment of Aortic Diseases of the European Society of Cardiology (ESC). Eur Heart J 35(41):2873–2926.

    Article  PubMed  Google Scholar 

  18. Sodickson A, Baeyens PF, Andriole KP et al (2009) Recurrent CT, cumulative radiation exposure, and associated radiation-induced cancer risks from CT of adults. Radiology 251(1):175–184.

    Article  PubMed  Google Scholar 

  19. Griffey RT, Sodickson A (2009) Cumulative radiation exposure and cancer risk estimates in emergency department patients undergoing repeat or multiple CT. AJR Am J Roentgenol 192(4):887–892.

    Article  PubMed  Google Scholar 

  20. Desmond AN, O'Regan K, Curran C et al (2008) Crohns disease: factors associated with exposure to high levels of diagnostic radiation. Gut 57(11):1524–1529.

    CAS  Article  PubMed  Google Scholar 

  21. Smith-Bindman R, Wang Y, Yellen-Nelson TR et al (2017) Predictors of CT radiation dose and their effect on patient care: a comprehensive analysis using automated data. Radiology 282(1):182–193.

    Article  PubMed  Google Scholar 

  22. Smith-Bindman R, Moghadassi M, Wilson N et al (2015) Radiation doses in consecutive CT examinations from five university of California medical centers. Radiology. 277(1):134–141.

    Article  PubMed  PubMed Central  Google Scholar 

  23. Brenner DJ, Elliston CD, Hall EJ, Berdon WE (2001) Estimates of the cancer risks from pediatric CT radiation are not merely theoretical: comment on “Point/Counterpoint: In x-ray computed tomography, technique factors should be selected appropriate to patient size. Against the Proposition”. Med Phys 28(11):2387–2388

  24. Guimarães LS, Fidler JL, Fletcher JG et al (2010) Assessment of appropriateness of indications for CT enterography in younger patients. Inflamm Bowel Dis 16(2):226–232.

    Article  PubMed  Google Scholar 

  25. Giannitto C, Campoleoni M, Maccagnoni S et al (2017) Unindicated multiphase CT scans in non-traumatic abdominal emergencies for women of reproductive age: a significant source of unnecessary exposure. Radiol Med 123(3):185–190.

    Article  PubMed  Google Scholar 

  26. Raja AS, Pourjabbar S, Ip IK et al (2018) Impact of a health information technology–enabled appropriate use criterion on utilization of emergency department CT for renal colic. AJR Am J Roentgenol 212(1):142–145.

    Article  PubMed  Google Scholar 

  27. Mills AM, Ip IK, Langlotz CP, Raja AS, Zafar HM, Khorasani R (2018) Clinical decision support increases diagnostic yield of computed tomography for suspected pulmonary embolism. Am J Emerg Med 36(4):540–544.

    Article  PubMed  Google Scholar 

  28. Weilburg JB, Sistrom CL, Rosenthal DI et al (2017) Utilization management of high-cost imaging in an outpatient setting in a large stable patient and provider cohort over 7 years. Radiology 284(3):766–776.

    Article  PubMed  Google Scholar 

  29. Sistrom CL, Dreyer KJ, Dang PP et al (2009) Recommendations for additional imaging in radiology reports: multifactorial analysis of 5.9 million examinations. Radiology. 253(2):453–461.

    Article  PubMed  Google Scholar 

  30. Vartanians VM, Sistrom CL, Weilburg JB, Rosenthal DI, Thrall JH (2010) Increasing the appropriateness of outpatient imaging: effects of a barrier to ordering low-yield examinations. Radiology 255(3):842–849.

    Article  PubMed  Google Scholar 

  31. Moriarity AK, Klochko C, Obrien M, Halabi S (2015) The effect of clinical decision support for advanced inpatient imaging. J Am Coll Radiol 12(4):358–363.

    Article  PubMed  Google Scholar 

  32. Palen TE, Sharpe RE Jr, Shetterly SM, Steiner JF (2019) Randomized clinical trial of a clinical decision support tool for improving the appropriateness scores for ordering imaging studies in primary and specialty care ambulatory clinics. AJR Am J Roentgenol 16:1–6.

    Article  Google Scholar 

  33. Schneider E, Zelenka S, Grooff P, Alexa D, Bullen J, Obuchowski NA (2015) Radiology order decision support: examination-indication appropriateness assessed using 2 electronic systems. J Am Coll Radiol 12(4):349–357.

    Article  PubMed  Google Scholar 

  34. Revel MP, Sanchez O, Couchon S et al (2012) Diagnostic accuracy of magnetic resonance imaging for an acute pulmonary embolism: results of the ‘IRM-EP’ study. J Thromb Haemost 10(5):743–750.

    CAS  Article  PubMed  Google Scholar 

  35. O’Grady NP, Barie PS, Bartlett JG et al (2008) Guidelines for evaluation of new fever in critically ill adult patients: 2008 update from the American College of Critical Care Medicine and the Infectious Diseases Society of America. Crit Care Med 36(4):1330–1349.

    Article  PubMed  Google Scholar 

  36. Shen KR, Bribriesco A, Crabtree T et al (2017) The American Association for Thoracic Surgery consensus guidelines for the management of empyema. J Thorac Cardiovasc Surg 153(6):e129–e146.

    Article  PubMed  Google Scholar 

  37. Ebell MH, Siwek J, Weiss BD et al (2004) Strength of recommendation taxonomy (SORT): a patient-centered approach to grading evidence in the medical literature. Am Fam Physician 69(3):548–556

    PubMed  Google Scholar 

  38. Kocijancic I, Vidmar K, Ivanovi-Herceg Z (2003) Chest sonography versus lateral decubitus radiography in the diagnosis of small pleural effusions. J Clin Ultrasound 31(2):69–74

    Article  Google Scholar 

  39. Kearney S, Davies C, Davies R, Gleeson F (2000) Computed tomography and ultrasound in parapneumonic effusions and empyema. Clin Radiol 55(7):542–547

    CAS  Article  Google Scholar 

  40. Maskell NA, Butland RJ (2003) BTS guidelines for the investigation of a unilateral pleural effusion in adults. Thorax 58(90002):8ii-17.

  41. Mcloud TC, Flower CD (1991) Imaging the pleura: sonography, CT, and MR imaging. AJR Am J Roentgenol 156(6):1145–1153

    CAS  Article  Google Scholar 

  42. Waite RJ, Carbonneau RJ, Balikian JP, Umali CB, Pezzella AT, Nash G (1990) Parietal pleural changes in empyema: appearances at CT. Radiology 175(1):145–150

    CAS  Article  Google Scholar 

  43. Brambilla M, Vassileva J, Kuchcinskac A, Rehani MM (2019) Multinational data on cumulative radiation exposure of patients from recurrent radiological procedures: call for action. Eur Radiol

  44. Rehani MM (2019) Looking for solutions: vision and a call-for-attention for research scientists. Int J Radiat Biol 17:1–4.

    CAS  Article  Google Scholar 

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The authors sincerely acknowledge the subject matter expertise provided by Prof. Fred Mettler, Emeritus Professor, University of New Mexico and of Dr. Bob Liu, MGH for his help in dealing with IRB.


The authors state that this work has not received any funding.

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Correspondence to Madan M. Rehani.

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The scientific guarantor of this publication is Madan Rehani.

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Study subjects or cohorts overlap


This paper is continuation of the study reported in paper Rehani et al DOI: (reference 6). That paper had only radiation dose information and no medical /clinical information. The current paper analyses the clinical information/ diagnoses of patients and assesses imaging appropriateness.


• Retrospective

• Observational

• Performed at one institution

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Rehani, M.M., Melick, E.R., Alvi, R.M. et al. Patients undergoing recurrent CT exams: assessment of patients with non-malignant diseases, reasons for imaging and imaging appropriateness. Eur Radiol 30, 1839–1846 (2020).

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  • Radiology
  • Referral and consultation
  • Radiation protection
  • Patient safety
  • Radiologic technology